,,the ,,analysis ,,of ,,mind ,by ,bertrand ,russell #aiba ,,muirhead ,,library ,,of ,,philosophy ,an admirable statement of the aims of the ,library of ,philosophy was provided by the first editor1 the late ,professor ,j4 ,h4 ,muirhead1 in his description of the original programme printed in ,erdmann's ,history of ,philosophy under the date #ahij4 ,this was slightly modified in subsequent volumes to take the form of the following statement3 ,the ,muirhead ,library of ,philosophy was designed as a contribution to the ,history of ,modern ,philosophy under the heads3 first of ,different ,schools of ,thought--,sensationalist1 ,realist1 ,idealist1 ,intuitivist2 secondly of different ,subjects--,psychology1 ,ethics1 ,aesthetics1 ,political ,philosophy1 ,theology4 ,while much had been done in ,england in tracing the course of evolution in nature1 history1 economics1 morals and religion1 little had been done in tracing the development of thought on these subjects4 ,yet 'the evolution of opinion is part of the whole evolution'4 ,by the co-operation of different writers in carrying out this plan it was hoped that a thoroughness and completeness of treatment1 otherwise unattainable1 might be secured4 ,it was believed also that from writers mainly ,british and ,american fuller consideration of ,english ,philosophy than it had hitherto received might be looked for4 ,in the earlier series of books containing1 among others1 ,bosanquet's ,history of ,aesthetic1 ,pfleiderer's ,rational ,theology since ,kant1 ,albee's ,history of ,english ,utilitarianism1 ,bonar's ,philosophy and ,political ,economy1 ,brett's ,history of ,psychology1 ,ritchie's ,natural ,rights1 these objects were to a large extent effected4 ,in the meantime original work of a high order was being produced both in ,england and ,america by such writers as ,bradley1 ,stout1 ,bertrand ,russell1 ,baldwin1 ,urban1 ,montague1 and others1 and a new interest in foreign works1 ,german1 ,french and ,italian1 which had either become classical or were attracting public attention1 had developed4 ,the scope of the ,library thus became extended into something more international1 and it is entering on the fifth decade of its existence in the hope that it may contribute to that mutual understanding between countries which is so pressing a need of the present time4 ,the need which ,professor ,muirhead stressed is no less pressing to-day1 and few will deny that philosophy has much to do with enabling us to meet it1 although no one1 least of all ,muirhead himself1 would regard that as the sole1 or even the main1 object of philosophy4 ,as ,professor ,muirhead continues to lend the distinction of his name to the ,library of ,philosophy it seemed not inappropriate to allow him to recall us to these aims in his own words4 ,the emphasis on the history of thought also seemed to me very timely2 and the number of important works promised for the ,library in the very near future augur well for the continued fulfilment1 in this and other ways1 of the expectations of the original editor4 ,h4 ,d4 ,lewis ,,preface ,this book has grown out of an attempt to harmonize two different tendencies1 one in psychology1 the other in physics1 with both of which ,i find myself in sympathy1 although at first sight they might seem inconsistent4 ,on the one hand1 many psychologists1 especially those of the behaviourist school1 tend to adopt what is essentially a materialistic position1 as a matter of method if not of metaphysics4 ,they make psychology increasingly dependent on physiology and external observation1 and tend to think of matter as something much more solid and indubitable than mind4 ,meanwhile the physicists1 especially ,einstein and other exponents of the theory of relativity1 have been making matter less and less material4 ,their world consists of events1 from which matter is derived by a logical construction4 ,whoever reads1 for example1 ,professor ,eddington's ,space1 ,time and ,gravitation 7,cambridge ,university ,press1 #aibj71 will see that an old-fashioned materialism can receive no support from modern physics4 ,i think that what has permanent value in the outlook of the behaviourists is the feeling that physics is the most fundamental science at present in existence4 ,but this position cannot be called materialistic1 if1 as seems to be the case1 physics does not assume the existence of matter4 ,the view that seems to me to reconcile the materialistic tendency of psychology with the anti-materialistic tendency of physics is the view of ,william ,james and the ,american new realists1 according to which the stuff of the world is neither mental nor material1 but a neutral stuff1 out of which both are constructed4 ,i have endeavoured in this work to develop this view in some detail as regards the phenomena with which psychology is concerned4 ,my thanks are due to ,professor ,john ,b4 ,watson and to ,dr4 ,t4 ,p4 ,nunn for reading my ,,mss4 at an early stage and helping me with many valuable suggestions2 also to ,mr4 ,a4 ,wohlgemuth for much very useful information as regards important literature4 ,i have also to acknowledge the help of the editor of this ,library of ,philosophy1 ,professor ,muirhead1 for several suggestions by which ,i have profited4 ,the work has been given in the form of lectures both in ,london and ,peking1 and one lecture1 that on ,desire1 has been published in the ,athenaeum4 ,there are a few allusions to ,china in this book1 all of which were written before ,i had been in ,china1 and are not intended to be taken by the reader as geographically accurate4 ,i have used ,china merely as a synonym for a distant country1 when ,i wanted illustrations of unfamiliar things4 ,peking1 ,january #aiba4 ,,contents ,i4 ,recent ,criticisms of ,consciousness ,,ii4 ,instinct and ,habit ,,iii4 ,desire and ,feeling ,,iv4 ,influence of ,past ,history on ,present ,occurrences in ,living ,organisms ,v4 ,psychological and ,physical ,causal ,laws ,,vi4 ,introspection ,,vii4 ,the ,definition of ,perception ,,viii4,sensations and ,images ,,ix4 ,memory ,x4 ,words and ,meaning ,,xi4 ,general ,ideas and ,thought ,,xii4 ,belief ,,xiii4,truth and ,falsehood ,,xiv4 ,emotions and ,will ,,xv4 ,characteristics of ,mental ,phenomena ,,the ,,analysis ,,of ,,mind ,,lecture ,i4 ,,recent ,,criticisms ,,of ,,consciousness ,there are certain occurrences which we are in the habit of calling mental4 ,among these we may take as typical ,,believing and ,,desiring4 ,the exact definition of the word mental will1 ,i hope1 emerge as the lectures proceed2 for the present1 ,i shall mean by it whatever occurrences would commonly be called mental4 ,i wish in these lectures to analyse as fully as ,i can what it is that really takes place when we1 e4g4 believe or desire4 ,in this first lecture ,i shall be concerned to refute a theory which is widely held1 and which ,i formerly held myself3 the theory that the essence of everything mental is a certain quite peculiar something called consciousness1 conceived either as a relation to objects1 or as a pervading quality of psychical phenomena4 ,the reasons which ,i shall give against this theory will be mainly derived from previous authors4 ,there are two sorts of reasons1 which will divide my lecture into two parts3 7#a7 ,direct reasons1 derived from analysis and its difficulties2 7#b7 ,indirect reasons1 derived from observation of animals 7comparative psychology7 and of the insane and hysterical 7psycho-analysis74 ,few things are more firmly established in popular philosophy than the distinction between mind and matter4 ,those who are not professional metaphysicians are willing to confess that they do not know what mind actually is1 or how matter is constituted2 but they remain convinced that there is an impassable gulf between the two1 and that both belong to what actually exists in the world4 ,philosophers1 on the other hand1 have maintained often that matter is a mere fiction imagined by mind1 and sometimes that mind is a mere property of a certain kind of matter4 ,those who maintain that mind is the reality and matter an evil dream are called idealists--a word which has a different meaning in philosophy from that which it bears in ordinary life4 ,those who argue that matter is the reality and mind a mere property of protoplasm are called materialists4 ,they have been rare among philosophers1 but common1 at certain periods1 among men of science4 ,idealists1 materialists1 and ordinary mortals have been in agreement on one point3 that they knew sufficiently what they meant by the words mind and matter to be able to conduct their debate intelligently4 ,yet it was just in this point1 as to which they were at one1 that they seem to me to have been all alike in error4 ,the stuff of which the world of our experience is composed is1 in my belief1 neither mind nor matter1 but something more primitive than either4 ,both mind and matter seem to be composite1 and the stuff of which they are compounded lies in a sense between the two1 in a sense above them both1 like a common ancestor4 ,as regards matter1 ,i have set forth my reasons for this view on former occasions199 and ,i shall not now repeat them4 ,but the question of mind is more difficult1 and it is this question that ,i propose to discuss in these lectures4 ,a great deal of what ,i shall have to say is not original2 indeed1 much recent work1 in various fields1 has tended to show the necessity of such theories as those which ,i shall be advocating4 ,accordingly in this first lecture ,i shall try to give a brief description of the systems of ideas within which our investigation is to be carried on4 99 ,our ,knowledge of the ,external ,world 7,allen ,unwin71 ,chapters ,,iii and ,,iv4 ,also ,mysticism and ,logic1 ,essays ,,vii and ,,viii4 ,if there is one thing that may be said1 in the popular estimation1 to characterize mind1 that one thing is consciousness4 ,we say that we are conscious of what we see and hear1 of what we remember1 and of our own thoughts and feelings4 ,most of us believe that tables and chairs are not conscious4 ,we think that when we sit in a chair1 we are aware of sitting in it1 but it is not aware of being sat in4 ,it cannot for a moment be doubted that we are right in believing that there is ,,some difference between us and the chair in this respect3 so much may be taken as fact1 and as a datum for our inquiry4 ,but as soon as we try to say what exactly the difference is1 we become involved in perplexities4 ,is consciousness ultimate and simple1 something to be merely accepted and contemplated8 ,or is it something complex1 perhaps consisting in our way of behaving in the presence of objects1 or1 alternatively1 in the existence in us of things called ideas1 having a certain relation to objects1 though different from them1 and only symbolically representative of them8 ,such questions are not easy to answer2 but until they are answered we cannot profess to know what we mean by saying that we are possessed of consciousness4 ,before considering modern theories1 let us look first at consciousness from the standpoint of conventional psychology1 since this embodies views which naturally occur when we begin to reflect upon the subject4 ,for this purpose1 let us as a preliminary consider different ways of being conscious4 ,first1 there is the way of ,,perception4 ,we perceive tables and chairs1 horses and dogs1 our friends1 traffic passing in the street--in short1 anything which we recognize through the senses4 ,i leave on one side for the present the question whether pure sensation is to be regarded as a form of consciousness3 what ,i am speaking of now is perception1 where1 according to conventional psychology1 we go beyond the sensation to the thing which it represents4 ,when you hear a donkey bray1 you not only hear a noise1 but realize that it comes from a donkey4 ,when you see a table1 you not only see a coloured surface1 but realize that it is hard4 ,the addition of these elements that go beyond crude sensation is said to constitute perception4 ,we shall have more to say about this at a later stage4 ,for the moment1 ,i am merely concerned to note that perception of objects is one of the most obvious examples of what is called consciousness4 ,we are conscious of anything that we perceive4 ,we may take next the way of ,,memory4 ,if ,i set to work to recall what ,i did this morning1 that is a form of consciousness different from perception1 since it is concerned with the past4 ,there are various problems as to how we can be conscious now of what no longer exists4 ,these will be dealt with incidentally when we come to the analysis of memory4 ,from memory it is an easy step to what are called ideas--not in the ,platonic sense1 but in that of ,locke1 ,berkeley and ,hume1 in which they are opposed to impressions4 ,you may be conscious of a friend either by seeing him or by thinking of him2 and by thought you can be conscious of objects which cannot be seen1 such as the human race1 or physiology4 ,thought in the narrower sense is that form of consciousness which consists in ideas as opposed to impressions or mere memories4 ,we may end our preliminary catalogue with ,,belief1 by which ,i mean that way of being conscious which may be either true or false4 ,we say that a man is conscious of looking a fool1 by which we mean that he believes he looks a fool1 and is not mistaken in this belief4 ,this is a different form of consciousness from any of the earlier ones4 ,it is the form which gives knowledge in the strict sense1 and also error4 ,it is1 at least apparently1 more complex than our previous forms of consciousness2 though we shall find that they are not so separable from it as they might appear to be4 ,besides ways of being conscious there are other things that would ordinarily be called mental1 such as desire and pleasure and pain4 ,these raise problems of their own1 which we shall reach in ,lecture ,,iii4 ,but the hardest problems are those that arise concerning ways of being conscious4 ,these ways1 taken together1 are called the cognitive elements in mind1 and it is these that will occupy us most during the following lectures4 ,there is one element which ,,seems obviously in common among the different ways of being conscious1 and that is1 that they are all directed to ,,objects4 ,we are conscious of something4 ,the consciousness1 it seems1 is one thing1 and that of which we are conscious is another thing4 ,unless we are to acquiesce in the view that we can never be conscious of anything outside our own minds1 we must say that the object of consciousness need not be mental1 though the consciousness must be4 7,i am speaking within the circle of conventional doctrines1 not expressing my own beliefs47 ,this direction towards an object is commonly regarded as typical of every form of cognition1 and sometimes of mental life altogether4 ,we may distinguish two different tendencies in traditional psychology4 ,there are those who take mental phenomena naively1 just as they would physical phenomena4 ,this school of psychologists tends not to emphasize the object4 ,on the other hand1 there are those whose primary interest is in the apparent fact that we have ,,knowledge1 that there is a world surrounding us of which we are aware4 ,these men are interested in the mind because of its relation to the world1 because knowledge1 if it is a fact1 is a very mysterious one4 ,their interest in psychology is naturally centred in the relation of consciousness to its object1 a problem which1 properly1 belongs rather to theory of knowledge4 ,we may take as one of the best and most typical representatives of this school the ,austrian psychologist ,brentano1 whose ,psychology from the ,empirical ,standpoint199 though published in #ahgd1 is still influential and was the starting-point of a great deal of interesting work4 ,he says 7p4 #aae73 99 ,psychologie vom empirischen ,standpunkte1 vol4 i1 #ahgd4 7,the second volume was never published47 ,every psychical phenomenon is characterized by what the scholastics of the ,middle ,ages called the intentional 7also the mental7 inexistence of an object1 and what we1 although with not quite unambiguous expressions1 would call relation to a content1 direction towards an object 7which is not here to be understood as a reality71 or immanent objectivity4 ,each contains something in itself as an object1 though not each in the same way4 ,in presentation something is presented1 in judgment something is acknowledged or rejected1 in love something is loved1 in hatred hated1 in desire desired1 and so on4 ,this intentional inexistence is exclusively peculiar to psychical phenomena4 ,no physical phenomenon shows anything similar4 ,and so we can define psychical phenomena by saying that they are phenomena which intentionally contain an object in themselves4 ,the view here expressed1 that relation to an object is an ultimate irreducible characteristic of mental phenomena1 is one which ,i shall be concerned to combat4 ,like ,brentano1 ,i am interested in psychology1 not so much for its own sake1 as for the light that it may throw on the problem of knowledge4 ,until very lately ,i believed1 as he did1 that mental phenomena have essential reference to objects1 except possibly in the case of pleasure and pain4 ,now ,i no longer believe this1 even in the case of knowledge4 ,i shall try to make my reasons for this rejection clear as we proceed4 ,it must be evident at first glance that the analysis of knowledge is rendered more difficult by the rejection2 but the apparent simplicity of ,brentano's view of knowledge will be found1 if ,i am not mistaken1 incapable of maintaining itself either against an analytic scrutiny or against a host of facts in psycho-analysis and animal psychology4 ,i do not wish to minimize the problems4 ,i will merely observe1 in mitigation of our prospective labours1 that thinking1 however it is to be analysed1 is in itself a delightful occupation1 and that there is no enemy to thinking so deadly as a false simplicity4 ,travelling1 whether in the mental or the physical world1 is a joy1 and it is good to know that1 in the mental world at least1 there are vast countries still very imperfectly explored4 ,the view expressed by ,brentano has been held very generally1 and developed by many writers4 ,among these we may take as an example his ,austrian successor ,meinong499 ,according to him there are three elements involved in the thought of an object4 ,these three he calls the act1 the content and the object4 ,the act is the same in any two cases of the same kind of consciousness2 for instance1 if ,i think of ,smith or think of ,brown1 the act of thinking1 in itself1 is exactly similar on both occasions4 ,but the content of my thought1 the particular event that is happening in my mind1 is different when ,i think of ,smith and when ,i think of ,brown4 ,the content1 ,meinong argues1 must not be confounded with the object1 since the content must exist in my mind at the moment when ,i have the thought1 whereas the object need not do so4 ,the object may be something past or future2 it may be physical1 not mental2 it may be something abstract1 like equality for example2 it may be something imaginary1 like a golden mountain2 or it may even be something self-contradictory1 like a round square4 ,but in all these cases1 so he contends1 the content exists when the thought exists1 and is what distinguishes it1 as an occurrence1 from other thoughts4 99 ,see1 e4g4 his article3 ,ueber ,gegenstande hoherer ,ordnung und deren ,verhaltniss zur inneren ,wahrnehmung1 ,zeitschrift fur ,psychologie and ,physiologie der ,sinnesorgane1 vol4 xxi1 pp4 #ahb-bgb 7#ahii71 especially pp4 #ahe-h4 ,to make this theory concrete1 let us suppose that you are thinking of ,st4 ,paul's4 ,then1 according to ,meinong1 we have to distinguish three elements which are necessarily combined in constituting the one thought4 ,first1 there is the act of thinking1 which would be just the same whatever you were thinking about4 ,then there is what makes the character of the thought as contrasted with other thoughts2 this is the content4 ,and finally there is ,st4 ,paul's1 which is the object of your thought4 ,there must be a difference between the content of a thought and what it is about1 since the thought is here and now1 whereas what it is about may not be2 hence it is clear that the thought is not identical with ,st4 ,paul's4 ,this seems to show that we must distinguish between content and object4 ,but if ,meinong is right1 there can be no thought without an object3 the connection of the two is essential4 ,the object might exist without the thought1 but not the thought without the object3 the three elements of act1 content and object are all required to constitute the one single occurrence called thinking of ,st4 ,paul's4 ,the above analysis of a thought1 though ,i believe it to be mistaken1 is very useful as affording a schema in terms of which other theories can be stated4 ,in the remainder of the present lecture ,i shall state in outline the view which ,i advocate1 and show how various other views out of which mine has grown result from modifications of the threefold analysis into act1 content and object4 ,the first criticism ,i have to make is that the ,,act seems unnecessary and fictitious4 ,the occurrence of the content of a thought constitutes the occurrence of the thought4 ,empirically1 ,i cannot discover anything corresponding to the supposed act2 and theoretically ,i cannot see that it is indispensable4 ,we say3 ,i think so-and-so1 and this word ,i suggests that thinking is the act of a person4 ,meinong's act is the ghost of the subject1 or what once was the full-blooded soul4 ,it is supposed that thoughts cannot just come and go1 but need a person to think them4 ,now1 of course it is true that thoughts can be collected into bundles1 so that one bundle is my thoughts1 another is your thoughts1 and a third is the thoughts of ,mr4 ,jones4 ,but ,i think the person is not an ingredient in the single thought3 he is rather constituted by relations of the thoughts to each other and to the body4 ,this is a large question1 which need not1 in its entirety1 concern us at present4 ,all that ,i am concerned with for the moment is that the grammatical forms ,i think1 you think1 and ,mr4 ,jones thinks1 are misleading if regarded as indicating an analysis of a single thought4 ,it would be better to say it thinks in me1 like it rains here2 or better still1 there is a thought in me4 ,this is simply on the ground that what ,meinong calls the act in thinking is not empirically discoverable1 or logically deducible from what we can observe4 ,the next point of criticism concerns the relation of content and object4 ,the reference of thoughts to objects is not1 ,i believe1 the simple direct essential thing that ,brentano and ,meinong represent it as being4 ,it seems to me to be derivative1 and to consist largely in ,,beliefs3 beliefs that what constitutes the thought is connected with various other elements which together make up the object4 ,you have1 say1 an image of ,st4 ,paul's1 or merely the word ,st4 ,paul's in your head4 ,you believe1 however vaguely and dimly1 that this is connected with what you would see if you went to ,st4 ,paul's1 or what you would feel if you touched its walls2 it is further connected with what other people see and feel1 with services and the ,dean and ,chapter and ,sir ,christopher ,wren4 ,these things are not mere thoughts of yours1 but your thought stands in a relation to them of which you are more or less aware4 ,the awareness of this relation is a further thought1 and constitutes your feeling that the original thought had an object4 ,but in pure imagination you can get very similar thoughts without these accompanying beliefs2 and in this case your thoughts do not have objects or seem to have them4 ,thus in such instances you have content without object4 ,on the other hand1 in seeing or hearing it would be less misleading to say that you have object without content1 since what you see or hear is actually part of the physical world1 though not matter in the sense of physics4 ,thus the whole question of the relation of mental occurrences to objects grows very complicated1 and cannot be settled by regarding reference to objects as of the essence of thoughts4 ,all the above remarks are merely preliminary1 and will be expanded later4 ,speaking in popular and unphilosophical terms1 we may say that the content of a thought is supposed to be something in your head when you think the thought1 while the object is usually something in the outer world4 ,it is held that knowledge of the outer world is constituted by the relation to the object1 while the fact that knowledge is different from what it knows is due to the fact that knowledge comes by way of contents4 ,we can begin to state the difference between realism and idealism in terms of this opposition of contents and objects4 ,speaking quite roughly and approximately1 we may say that idealism tends to suppress the object1 while realism tends to suppress the content4 ,idealism1 accordingly1 says that nothing can be known except thoughts1 and all the reality that we know is mental2 while realism maintains that we know objects directly1 in sensation certainly1 and perhaps also in memory and thought4 ,idealism does not say that nothing can be known beyond the present thought1 but it maintains that the context of vague belief1 which we spoke of in connection with the thought of ,st4 ,paul's1 only takes you to other thoughts1 never to anything radically different from thoughts4 ,the difficulty of this view is in regard to sensation1 where it seems as if we came into direct contact with the outer world4 ,but the ,berkeleian way of meeting this difficulty is so familiar that ,i need not enlarge upon it now4 ,i shall return to it in a later lecture1 and will only observe1 for the present1 that there seem to me no valid grounds for regarding what we see and hear as not part of the physical world4 ,realists1 on the other hand1 as a rule1 suppress the content1 and maintain that a thought consists either of act and object alone1 or of object alone4 ,i have been in the past a realist1 and ,i remain a realist as regards sensation1 but not as regards memory or thought4 ,i will try to explain what seem to me to be the reasons for and against various kinds of realism4 ,modern idealism professes to be by no means confined to the present thought or the present thinker in regard to its knowledge2 indeed1 it contends that the world is so organic1 so dove-tailed1 that from any one portion the whole can be inferred1 as the complete skeleton of an extinct animal can be inferred from one bone4 ,but the logic by which this supposed organic nature of the world is nominally demonstrated appears to realists1 as it does to me1 to be faulty4 ,they argue that1 if we cannot know the physical world directly1 we cannot really know any thing outside our own minds3 the rest of the world may be merely our dream4 ,this is a dreary view1 and they there fore seek ways of escaping from it4 ,accordingly they maintain that in knowledge we are in direct contact with objects1 which may be1 and usually are1 outside our own minds4 ,no doubt they are prompted to this view1 in the first place1 by bias1 namely1 by the desire to think that they can know of the existence of a world outside themselves4 ,but we have to consider1 not what led them to desire the view1 but whether their arguments for it are valid4 ,there are two different kinds of realism1 according as we make a thought consist of act and object1 or of object alone4 ,their difficulties are different1 but neither seems tenable all through4 ,take1 for the sake of definiteness1 the remembering of a past event4 ,the remembering occurs now1 and is therefore necessarily not identical with the past event4 ,so long as we retain the act1 this need cause no difficulty4 ,the act of remembering occurs now1 and has on this view a certain essential relation to the past event which it remembers4 ,there is no ,,logical objection to this theory1 but there is the objection1 which we spoke of earlier1 that the act seems mythical1 and is not to be found by observation4 ,if1 on the other hand1 we try to constitute memory without the act1 we are driven to a content1 since we must have something that happens ,,now1 as opposed to the event which happened in the past4 ,thus1 when we reject the act1 which ,i think we must1 we are driven to a theory of memory which is more akin to idealism4 ,these arguments1 however1 do not apply to sensation4 ,it is especially sensation1 ,i think1 which is considered by those realists who retain only the object499 ,their views1 which are chiefly held in ,america1 are in large measure derived from ,william ,james1 and before going further it will be well to consider the revolutionary doctrine which he advocated4 ,i believe this doctrine contains important new truth1 and what ,i shall have to say will be in a considerable measure inspired by it4 99 ,this is explicitly the case with ,mach's ,analysis of ,sensations1 a book of fundamental importance in the present connection4 7,translation of fifth ,german edition1 ,open ,court ,co41 #aiad4 ,first ,german edition1 #ahhf47 ,william ,james's view was first set forth in an essay called ,does 'consciousness' exist899 ,in this essay he explains how what used to be the soul has gradually been refined down to the transcendental ego1 which1 he says1 attenuates itself to a thoroughly ghostly condition1 being only a name for the fact that the 'content' of experience ,,is ,,known4 ,it loses personal form and activity--these passing over to the content--and becomes a bare ,bewusstheit or ,bewusstsein uberhaupt1 of which in its own right absolutely nothing can be said4 ,i believe 7he continues7 that 'consciousness1' when once it has evaporated to this estate of pure diaphaneity1 is on the point of disappearing altogether4 ,it is the name of a nonentity1 and has no right to a place among first principles4 ,those who still cling to it are clinging to a mere echo1 the faint rumour left behind by the disappearing 'soul' upon the air of philosophy7p4 #b74 99 ,journal of ,philosophy1 ,psychology and ,scientific ,methods1 vol4 i1 #aijd4 ,reprinted in ,essays in ,radical ,empiricism 7,longmans1 ,green ,co41 #aiab71 pp4 #a-ch1 to which references in what follows refer4 ,he explains that this is no sudden change in his opinions4 ,for twenty years past1 he says1 ,i have mistrusted 'consciousness' as an entity2 for seven or eight years past ,i have suggested its non-existence to my students1 and tried to give them its pragmatic equivalent in realities of experience4 ,it seems to me that the hour is ripe for it to be openly and universally discarded7p4 #c74 ,his next concern is to explain away the air of paradox1 for ,james was never wilfully paradoxical4 ,undeniably1 he says1 'thoughts' do exist4 ,i mean only to deny that the word stands for an entity1 but to insist most emphatically that it does stand for a function4 ,there is1 ,i mean1 no aboriginal stuff or quality of being1 contrasted with that of which material objects are made1 out of which our thoughts of them are made2 but there is a function in experience which thoughts perform1 and for the performance of which this quality of being is invoked4 ,that function is ,,knowing7pp4 #c-d74 ,james's view is that the raw material out of which the world is built up is not of two sorts1 one matter and the other mind1 but that it is arranged in different patterns by its inter-relations1 and that some arrangements may be called mental1 while others may be called physical4 ,my thesis is1 he says1 that if we start with the supposition that there is only one primal stuff or material in the world1 a stuff of which everything is composed1 and if we call that stuff 'pure experience1' then knowing can easily be explained as a particular sort of relation towards one another into which portions of pure experience may enter4 ,the relation itself is a part of pure experience2 one of its 'terms' becomes the subject or bearer of the knowledge1 the knower1 the other becomes the object known7p4 #d74 ,after mentioning the duality of subject and object1 which is supposed to constitute consciousness1 he proceeds in italics3 ,,experience1 ,i ,,believe1 ,,has ,,no ,,such ,,inner ,,duplicity2 ,,and ,,the ,,separation ,,of ,,it ,,into ,,consciousness ,,and ,,content ,,comes1 ,,not ,,by ,,way ,,of ,,subtraction1 ,,but ,,by ,,way ,,of ,,addition7p4 #i74 ,he illustrates his meaning by the analogy of paint as it appears in a paint-shop and as it appears in a picture3 in the one case it is just saleable matter1 while in the other it performs a spiritual function4 ,just so1 ,i maintain 7he continues71 does a given undivided portion of experience1 taken in one context of associates1 play the part of a knower1 of a state of mind1 of 'consciousness'2 while in a different context the same undivided bit of experience plays the part of a thing known1 of an objective 'content4' ,in a word1 in one group it figures as a thought1 in another group as a thing7pp4 #i-aj74 ,he does not believe in the supposed immediate certainty of thought4 ,let the case be what it may in others1 he says1 ,i am as confident as ,i am of anything that1 in myself1 the stream of thinking 7which ,i recognize emphatically as a phenomenon7 is only a careless name for what1 when scrutinized1 reveals itself to consist chiefly of the stream of my breathing4 ,the ',i think' which ,kant said must be able to accompany all my objects1 is the ',i breathe' which actually does accompany them7pp4 #cf-cg74 ,the same view of consciousness is set forth in the succeeding essay1 ,a ,world of ,pure ,experience 7ib41 pp4 #ci-ia74 ,the use of the phrase pure experience in both essays points to a lingering influence of idealism4 ,experience1 like consciousness1 must be a product1 not part of the primary stuff of the world4 ,it must be possible1 if ,james is right in his main contentions1 that roughly the same stuff1 differently arranged1 would not give rise to anything that could be called experience4 ,this word has been dropped by the ,american realists1 among whom we may mention specially ,professor ,r4 ,b4 ,perry of ,harvard and ,mr4 ,edwin ,b4 ,holt4 ,the interests of this school are in general philosophy and the philosophy of the sciences1 rather than in psychology2 they have derived a strong impulsion from ,james1 but have more interest than he had in logic and mathematics and the abstract part of philosophy4 ,they speak of neutral entities as the stuff out of which both mind and matter are constructed4 ,thus ,holt says3 ,if the terms and propositions of logic must be substantialized1 they are all strictly of one substance1 for which perhaps the least dangerous name is neutral-stuff4 ,the relation of neutral-stuff to matter and mind we shall have presently to consider at considerable length4 99 99 ,the ,concept of ,consciousness 7,geo4 ,allen ,co41 #aiad71 p4 #eb4 ,my own belief--for which the reasons will appear in subsequent lectures--is that ,james is right in rejecting consciousness as an entity1 and that the ,american realists are partly right1 though not wholly1 in considering that both mind and matter are composed of a neutral-stuff which1 in isolation1 is neither mental nor material4 ,i should admit this view as regards sensations3 what is heard or seen belongs equally to psychology and to physics4 ,but ,i should say that images belong only to the mental world1 while those occurrences 7if any7 which do not form part of any experience belong only to the physical world4 ,there are1 it seems to me1 prima facie different kinds of causal laws1 one belonging to physics and the other to psychology4 ,the law of gravitation1 for example1 is a physical law1 while the law of association is a psychological law4 ,sensations are subject to both kinds of laws1 and are therefore truly neutral in ,holt's sense4 ,but entities subject only to physical laws1 or only to psychological laws1 are not neutral1 and may be called respectively purely material and purely mental4 ,even those1 however1 which are purely mental will not have that intrinsic reference to objects which ,brentano assigns to them and which constitutes the essence of consciousness as ordinarily understood4 ,but it is now time to pass on to other modern tendencies1 also hostile to consciousness4 ,there is a psychological school called ,behaviourists1 of whom the protagonist is ,professor ,john ,b4 ,watson199 formerly of the ,johns ,hopkins ,university4 ,to them also1 on the whole1 belongs ,professor ,john ,dewey1 who1 with ,james and ,dr4 ,schiller1 was one of the three founders of pragmatism4 ,the view of the behaviourists is that nothing can be known except by external observation4 ,they deny altogether that there is a separate source of knowledge called introspection1 by which we can know things about ourselves which we could never observe in others4 ,they do not by any means deny that all sorts of things ,,may go on in our minds3 they only say that such things1 if they occur1 are not susceptible of scientific observation1 and do not therefore concern psychology as a science4 ,psychology as a science1 they say1 is only concerned with ,,behaviour1 i4e4 with what we ,,do2 this alone1 they contend1 can be accurately observed4 ,whether we think meanwhile1 they tell us1 cannot be known2 in their observation of the behaviour of human beings1 they have not so far found any evidence of thought4 ,true1 we talk a great deal1 and imagine that in so doing we are showing that we can think2 but behaviourists say that the talk they have to listen to can be explained without supposing that people think4 ,where you might expect a chapter on thought processes you come instead upon a chapter on ,the ,language ,habit4 ,it is humiliating to find how terribly adequate this hypothesis turns out to be4 99 ,see especially his ,behavior3 an ,introduction to ,comparative ,psychology1 ,new ,york1 #aiad4 ,behaviourism has not1 however1 sprung from observing the folly of men4 ,it is the wisdom of animals that has suggested the view4 ,it has always been a common topic of popular discussion whether animals think4 ,on this topic people are prepared to take sides without having the vaguest idea what they mean by thinking4 ,those who desired to investigate such questions were led to observe the behaviour of animals1 in the hope that their behaviour would throw some light on their mental faculties4 ,at first sight1 it might seem that this is so4 ,people say that a dog knows its name because it comes when it is called1 and that it remembers its master1 because it looks sad in his absence1 but wags its tail and barks when he returns4 ,that the dog behaves in this way is matter of observation1 but that it knows or remembers anything is an inference1 and in fact a very doubtful one4 ,the more such inferences are examined1 the more precarious they are seen to be4 ,hence the study of animal behaviour has been gradually led to abandon all attempt at mental interpretation4 ,and it can hardly be doubted that1 in many cases of complicated behaviour very well adapted to its ends1 there can be no prevision of those ends4 ,the first time a bird builds a nest1 we can hardly suppose it knows that there will be eggs to be laid in it1 or that it will sit on the eggs1 or that they will hatch into young birds4 ,it does what it does at each stage because instinct gives it an impulse to do just that1 not because it foresees and desires the result of its actions499 99 ,an interesting discussion of the question whether instinctive actions1 when first performed1 involve any prevision1 however vague1 will be found in ,lloyd ,morgan's ,instinct and ,experience 7,methuen1 #aiab71 chap4 ii4 ,careful observers of animals1 being anxious to avoid precarious inferences1 have gradually discovered more and more how to give an account of the actions of animals without assuming what we call consciousness4 ,it has seemed to the behaviourists that similar methods can be applied to human behaviour1 without assuming anything not open to external observation4 ,let us give a crude illustration1 too crude for the authors in question1 but capable of affording a rough insight into their meaning4 ,suppose two children in a school1 both of whom are asked ,what is six times nine8 ,one says fifty-four1 the other says fifty-six4 ,the one1 we say1 knows what six times nine is1 the other does not4 ,but all that we can observe is a certain language-habit4 ,the one child has acquired the habit of saying six times nine is fifty-four2 the other has not4 ,there is no more need of thought in this than there is when a horse turns into his accustomed stable2 there are merely more numerous and complicated habits4 ,there is obviously an observable fact called knowing such-and-such a thing2 examinations are experiments for discovering such facts4 ,but all that is observed or discovered is a certain set of habits in the use of words4 ,the thoughts 7if any7 in the mind of the examinee are of no interest to the examiner2 nor has the examiner any reason to suppose even the most successful examinee capable of even the smallest amount of thought4 ,thus what is called knowing1 in the sense in which we can ascertain what other people know1 is a phenomenon exemplified in their physical behaviour1 including spoken and written words4 ,there is no reason--so ,watson argues--to suppose that their knowledge ,,is anything beyond the habits shown in this behaviour3 the inference that other people have something nonphysical called mind or thought is therefore unwarranted4 ,so far1 there is nothing particularly repugnant to our prejudices in the conclusions of the behaviourists4 ,we are all willing to admit that other people are thoughtless4 ,but when it comes to ourselves1 we feel convinced that we can actually perceive our own thinking4 ,cogito1 ergo sum would be regarded by most people as having a true premiss4 ,this1 however1 the behaviourist denies4 ,he maintains that our knowledge of ourselves is no different in kind from our knowledge of other people4 ,we may see ,,more1 because our own body is easier to observe than that of other people2 but we do not see anything radically unlike what we see of others4 ,introspection1 as a separate source of knowledge1 is entirely denied by psychologists of this school4 ,i shall discuss this question at length in a later lecture2 for the present ,i will only observe that it is by no means simple1 and that1 though ,i believe the behaviourists somewhat overstate their case1 yet there is an important element of truth in their contention1 since the things which we can discover by introspection do not seem to differ in any very fundamental way from the things which we discover by external observation4 ,so far1 we have been principally concerned with knowing4 ,but it might well be maintained that desiring is what is really most characteristic of mind4 ,human beings are constantly engaged in achieving some end they feel pleasure in success and pain in failure4 ,in a purely material world1 it may be said1 there would be no opposition of pleasant and unpleasant1 good and bad1 what is desired and what is feared4 ,a man's acts are governed by purposes4 ,he decides1 let us suppose1 to go to a certain place1 whereupon he proceeds to the station1 takes his ticket and enters the train4 ,if the usual route is blocked by an accident1 he goes by some other route4 ,all that he does is determined--or so it seems--by the end he has in view1 by what lies in front of him1 rather than by what lies behind4 ,with dead matter1 this is not the case4 ,a stone at the top of a hill may start rolling1 but it shows no pertinacity in trying to get to the bottom4 ,any ledge or obstacle will stop it1 and it will exhibit no signs of discontent if this happens4 ,it is not attracted by the pleasantness of the valley1 as a sheep or cow might be1 but propelled by the steepness of the hill at the place where it is4 ,in all this we have characteristic differences between the behaviour of animals and the behaviour of matter as studied by physics4 ,desire1 like knowledge1 is1 of course1 in one sense an observable phenomenon4 ,an elephant will eat a bun1 but not a mutton chop2 a duck will go into the water1 but a hen will not4 ,but when we think of our own desires1 most people believe that we can know them by an immediate self-knowledge which does not depend upon observation of our actions4 ,yet if this were the case1 it would be odd that people are so often mistaken as to what they desire4 ,it is matter of common observation that so-and-so does not know his own motives1 or that ,a is envious of ,b and malicious about him1 but quite unconscious of being so4 ,such people are called self-deceivers1 and are supposed to have had to go through some more or less elaborate process of concealing from themselves what would otherwise have been obvious4 ,i believe that this is an entire mistake4 ,i believe that the discovery of our own motives can only be made by the same process by which we discover other people's1 namely1 the process of observing our actions and inferring the desire which could prompt them4 ,a desire is conscious when we have told ourselves that we have it4 ,a hungry man may say to himself3 ,oh1 ,i do want my lunch4 ,then his desire is conscious4 ,but it only differs from an unconscious desire by the presence of appropriate words1 which is by no means a fundamental difference4 ,the belief that a motive is normally conscious makes it easier to be mistaken as to our own motives than as to other people's4 ,when some desire that we should be ashamed of is attributed to us1 we notice that we have never had it consciously1 in the sense of saying to ourselves1 ,i wish that would happen4 ,we therefore look for some other interpretation of our actions1 and regard our friends as very unjust when they refuse to be convinced by our repudiation of what we hold to be a calumny4 ,moral considerations greatly increase the difficulty of clear thinking in this matter4 ,it is commonly argued that people are not to blame for unconscious motives1 but only for conscious ones4 ,in order1 therefore1 to be wholly virtuous it is only necessary to repeat virtuous formulas4 ,we say3 ,i desire to be kind to my friends1 honourable in business1 philanthropic towards the poor1 public-spirited in politics4 ,so long as we refuse to allow ourselves1 even in the watches of the night1 to avow any contrary desires1 we may be bullies at home1 shady in the ,city1 skinflints in paying wages and profiteers in dealing with the public2 yet1 if only conscious motives are to count in moral valuation1 we shall remain model characters4 ,this is an agreeable doctrine1 and it is not surprising that men are un willing to abandon it4 ,but moral considerations are the worst enemies of the scientific spirit and we must dismiss them from our minds if we wish to arrive at truth4 ,i believe--as ,i shall try to prove in a later lecture--that desire1 like force in mechanics1 is of the nature of a convenient fiction for describing shortly certain laws of behaviour4 ,a hungry animal is restless until it finds food2 then it becomes quiescent4 ,the thing which will bring a restless condition to an end is said to be what is desired4 ,but only experience can show what will have this sedative effect1 and it is easy to make mistakes4 ,we feel dissatisfaction1 and think that such and-such a thing would remove it2 but in thinking this1 we are theorizing1 not observing a patent fact4 ,our theorizing is often mistaken1 and when it is mistaken there is a difference between what we think we desire and what in fact will bring satisfaction4 ,this is such a common phenomenon that any theory of desire which fails to account for it must be wrong4 ,what have been called unconscious desires have been brought very much to the fore in recent years by psycho-analysis4 ,psycho-analysis1 as every one knows1 is primarily a method of understanding hysteria and certain forms of insanity992 but it has been found that there is much in the lives of ordinary men and women which bears a humiliating resemblance to the delusions of the insane4 ,the connection of dreams1 irrational beliefs and foolish actions with unconscious wishes has been brought to light1 though with some exaggeration1 by ,freud and ,jung and their followers4 ,as regards the nature of these unconscious wishes1 it seems to me--though as a layman ,i speak with diffidence--that many psycho-analysts are unduly narrow2 no doubt the wishes they emphasize exist1 but others1 e4g4 for honour and power1 are equally operative and equally liable to concealment4 ,this1 however1 does not affect the value of their general theories from the point of view of theoretic psychology1 and it is from this point of view that their results are important for the analysis of mind4 99 ,there is a wide field of unconscious phenomena which does not depend upon psycho-analytic theories4 ,such occurrences as automatic writing lead ,dr4 ,morton ,prince to say3 ,as ,i view this question of the subconscious1 far too much weight is given to the point of awareness or not awareness of our conscious processes4 ,as a matter of fact1 we find entirely identical phenomena1 that is1 identical in every respect but one-that of awareness in which sometimes we are aware of these conscious phenomena and sometimes not7p4 #hg of ,subconscious ,phenomena1 by various authors1 ,rebman74 ,dr4 ,morton ,price conceives that there may be consciousness without awareness4 ,but this is a difficult view1 and one which makes some definition of consciousness imperative4 ,for nay part1 ,i cannot see how to separate consciousness from awareness4 ,what1 ,i think1 is clearly established1 is that a man's actions and beliefs may be wholly dominated by a desire of which he is quite unconscious1 and which he indignantly repudiates when it is suggested to him4 ,such a desire is generally1 in morbid cases1 of a sort which the patient would consider wicked2 if he had to admit that he had the desire1 he would loathe himself4 ,yet it is so strong that it must force an outlet for itself2 hence it becomes necessary to entertain whole systems of false beliefs in order to hide the nature of what is desired4 ,the resulting delusions in very many cases disappear if the hysteric or lunatic can be made to face the facts about himself4 ,the consequence of this is that the treatment of many forms of insanity has grown more psychological and less physiological than it used to be4 ,instead of looking for a physical defect in the brain1 those who treat delusions look for the repressed desire which has found this contorted mode of expression4 ,for those who do not wish to plunge into the somewhat repulsive and often rather wild theories of psychoanalytic pioneers1 it will be worth while to read a little book by ,dr4 ,bernard ,hart on ,the ,psychology of ,insanity499 ,on this question of the mental as opposed to the physiological study of the causes of insanity1 ,dr4 ,hart says3 99 ,cambridge1 #aiab2 #bnd edition1 #aiad4 ,the following references are to the second edition4 ,the psychological conception of insanity is based on the view that mental processes can be directly studied without any reference to the accompanying changes which are presumed to take place in the brain1 and that insanity may therefore be properly attacked from the standpoint of psychology7p4 #i74 ,this illustrates a point which ,i am anxious to make clear from the outset4 ,any attempt to classify modern views1 such as ,i propose to advocate1 from the old standpoint of materialism and idealism1 is only misleading4 ,in certain respects1 the views which ,i shall be setting forth approximate to materialism2 in certain others1 they approximate to its opposite4 ,on this question of the study of delusions1 the practical effect of the modern theories1 as ,dr4 ,hart points out1 is emancipation from the materialist method4 ,on the other hand1 as he also points out 7pp4 #ch-i71 imbecility and dementia still have to be considered physiologically1 as caused by defects in the brain4 ,there is no inconsistency in this ,if1 as we maintain1 mind and matter are neither of them the actual stuff of reality1 but different convenient groupings of an underlying material1 then1 clearly1 the question whether1 in regard to a given phenomenon1 we are to seek a physical or a mental cause1 is merely one to be decided by trial4 ,metaphysicians have argued endlessly as to the interaction of mind and matter4 ,the followers of ,descartes held that mind and matter are so different as to make any action of the one on the other impossible4 ,when ,i will to move my arm1 they said1 it is not my will that operates on my arm1 but ,god1 who1 by ,his omnipotence1 moves my arm whenever ,i want it moved4 ,the modern doctrine of psychophysical parallelism is not appreciably different from this theory of the ,cartesian school4 ,psycho-physical parallelism is the theory that mental and physical events each have causes in their own sphere1 but run on side by side owing to the fact that every state of the brain coexists with a definite state of the mind1 and vice versa4 ,this view of the reciprocal causal independence of mind and matter has no basis except in metaphysical theory499 ,for us1 there is no necessity to make any such assumption1 which is very difficult to harmonize with obvious facts4 ,i receive a letter inviting me to dinner3 the letter is a physical fact1 but my apprehension of its meaning is mental4 ,here we have an effect of matter on mind4 ,in consequence of my apprehension of the meaning of the letter1 ,i go to the right place at the right time2 here we have an effect of mind on matter4 ,i shall try to persuade you1 in the course of these lectures1 that matter is not so material and mind not so mental as is generally supposed4 ,when we are speaking of matter1 it will seem as if we were inclining to idealism2 when we are speaking of mind1 it will seem as if we were inclining to materialism4 ,neither is the truth4 ,our world is to be constructed out of what the ,american realists call neutral entities1 which have neither the hardness and indestructibility of matter1 nor the reference to objects which is supposed to characterize mind4 99 ,it would seem1 however1 that ,dr4 ,hart accepts this theory as #h methodological precept4 ,see his contribution to ,subconscious ,phenomena 7quoted above71 especially pp4 #aba-b4 ,there is1 it is true1 one objection which might be felt1 not indeed to the action of matter on mind1 but to the action of mind on matter4 ,the laws of physics1 it may be urged1 are apparently adequate to explain everything that happens to matter1 even when it is matter in a man's brain4 ,this1 however1 is only a hypothesis1 not an established theory4 ,there is no cogent empirical reason for supposing that the laws determining the motions of living bodies are exactly the same as those that apply to dead matter4 ,sometimes1 of course1 they are clearly the same4 ,when a man falls from a precipice or slips on a piece of orange peel1 his body behaves as if it were devoid of life4 ,these are the occasions that make ,bergson laugh4 ,but when a man's bodily movements are what we call voluntary1 they are1 at any rate prima facie1 very different in their laws from the movements of what is devoid of life4 ,i do not wish to say dogmatically that the difference is irreducible2 ,i think it highly probable that it is not4 ,i say only that the study of the behaviour of living bodies1 in the present state of our knowledge1 is distinct from physics4 ,the study of gases was originally quite distinct from that of rigid bodies1 and would never have advanced to its present state if it had not been independently pursued4 ,nowadays both the gas and the rigid body are manufactured out of a more primitive and universal kind of matter4 ,in like manner1 as a question of methodology1 the laws of living bodies are to be studied1 in the first place1 without any undue haste to subordinate them to the laws of physics4 ,boyle's law and the rest had to be discovered before the kinetic theory of gases became possible4 ,but in psychology we are hardly yet at the stage of ,boyle's law4 ,meanwhile we need not be held up by the bogey of the universal rigid exactness of physics4 ,this is1 as yet1 a mere hypothesis1 to be tested empirically without any preconceptions4 ,it may be true1 or it may not4 ,so far1 that is all we can say4 ,returning from this digression to our main topic1 namely1 the criticism of consciousness1 we observe that ,freud and his followers1 though they have demonstrated beyond dispute the immense importance of unconscious desires in determining our actions and beliefs1 have not attempted the task of telling us what an unconscious desire actually is1 and have thus invested their doctrine with an air of mystery and mythology which forms a large part of its popular attractiveness4 ,they speak always as though it were more normal for a desire to be conscious1 and as though a positive cause had to be assigned for its being unconscious4 ,thus the unconscious becomes a sort of underground prisoner1 living in a dungeon1 breaking in at long intervals upon our daylight respectability with dark groans and maledictions and strange atavistic lusts4 ,the ordinary reader1 almost inevitably1 thinks of this underground person as another consciousness1 prevented by what ,freud calls the censor from making his voice heard in company1 except on rare and dreadful occasions when he shouts so loud that every one hears him and there is a scandal4 ,most of us like the idea that we could be desperately wicked if only we let ourselves go4 ,for this reason1 the ,freudian unconscious has been a consolation to many quiet and well-behaved persons4 ,i do not think the truth is quite so picturesque as this4 ,i believe an unconscious desire is merely a causal law of our behaviour199 namely1 that we remain restlessly active until a certain state of affairs is realized1 when we achieve temporary equilibrium ,if we know beforehand what this state of affairs is1 our desire is conscious2 if not1 unconscious4 ,the unconscious desire is not something actually existing1 but merely a tendency to a certain behaviour2 it has exactly the same status as a force in dynamics4 ,the unconscious desire is in no way mysterious2 it is the natural primitive form of desire1 from which the other has developed through our habit of observing and theorizing 7often wrongly74 ,it is not necessary to suppose1 as ,freud seems to do1 that every unconscious wish was once conscious1 and was then1 in his terminology1 repressed because we disapproved of it4 ,on the contrary1 we shall suppose that1 although ,freudian repression undoubtedly occurs and is important1 it is not the usual reason for unconsciousness of our wishes4 ,the usual reason is merely that wishes are all1 to begin with1 unconscious1 and only become known when they are actively noticed4 ,usually1 from laziness1 people do not notice1 but accept the theory of human nature which they find current1 and attribute to themselves whatever wishes this theory would lead them to expect4 ,we used to be full of virtuous wishes1 but since ,freud our wishes have become1 in the words of the ,prophet ,jeremiah1 deceitful above all things and desperately wicked4 ,both these views1 in most of those who have held them1 are the product of theory rather than observation1 for observation requires effort1 whereas repeating phrases does not4 99 ,cf4 ,hart1 ,the ,psychology of ,insanity1 p4 #ai4 ,the interpretation of unconscious wishes which ,i have been advocating has been set forth briefly by ,professor ,john ,b4 ,watson in an article called ,the ,psychology of ,wish ,fulfilment1 which appeared in ,the ,scientific ,monthly in ,november1 #aiaf4 ,two quotations will serve to show his point of view3 ,the ,freudians 7he says7 have made more or less of a 'metaphysical entity' out of the censor4 ,they suppose that when wishes are repressed they are repressed into the 'unconscious1' and that this mysterious censor stands at the trapdoor lying between the conscious and the unconscious4 ,many of us do not believe in a world of the unconscious 7a few of us even have grave doubts about the usefulness of the term consciousness71 hence we try to explain censorship along ordinary biological lines4 ,we believe that one group of habits can 'down' another group of habits--or instincts4 ,in this case our ordinary system of habits--those which we call expressive of our 'real selves'--inhibit or quench 7keep inactive or partially inactive7 those habits and instinctive tendencies which belong largely in the past7p4 #dhc74 ,again1 after speaking of the frustration of some impulses which is involved in acquiring the habits of a civilized adult1 he continues3 ,it is among these frustrated impulses that ,i would find the biological basis of the unfulfilled wish4 ,such 'wishes' need never have been 'conscious1' and ,,need ,,never ,,have ,,been ,,suppressed ,,into ,,freud',s ,,realm ,,of ,,the ,,unconscious4 ,it may be inferred from this that there is no particular reason for applying the term 'wish' to such tendencies7p4 #dhe74 ,one of the merits of the general analysis of mind which we shall be concerned with in the following lectures is that it removes the atmosphere of mystery from the phenomena brought to light by the psycho-analysts4 ,mystery is delightful1 but unscientific1 since it depends upon ignorance4 ,man has developed out of the animals1 and there is no serious gap between him and the amoeba4 ,something closely analogous to knowledge and desire1 as regards its effects on behaviour1 exists among animals1 even where what we call consciousness is hard to believe in2 something equally analogous exists in ourselves in cases where no trace of consciousness can be found4 ,it is therefore natural to suppose that1 what ever may be the correct definition of consciousness1 consciousness is not the essence of life or mind4 ,in the following lectures1 accordingly1 this term will disappear until we have dealt with words1 when it will re-emerge as mainly a trivial and unimportant outcome of linguistic habits4 ,,lecture ,,ii4 ,,instinct ,,and ,,habit ,in attempting to understand the elements out of which mental phenomena are compounded1 it is of the greatest importance to remember that from the protozoa to man there is nowhere a very wide gap either in structure or in behaviour4 ,from this fact it is a highly probable inference that there is also nowhere a very wide mental gap4 ,it is1 of course1 ,,possible that there may be1 at certain stages in evolution1 elements which are entirely new from the standpoint of analysis1 though in their nascent form they have little influence on behaviour and no very marked correlatives in structure4 ,but the hypothesis of continuity in mental development is clearly preferable if no psychological facts make it impossible4 ,we shall find1 if ,i am not mistaken1 that there are no facts which refute the hypothesis of mental continuity1 and that1 on the other hand1 this hypothesis affords a useful test of suggested theories as to the nature of mind4 ,the hypothesis of mental continuity throughout organic evolution may be used in two different ways4 ,on the one hand1 it may be held that we have more knowledge of our own minds than those of animals1 and that we should use this knowledge to infer the existence of something similar to our own mental processes in animals and even in plants4 ,on the other hand1 it may be held that animals and plants present simpler phenomena1 more easily analysed than those of human minds2 on this ground it may be urged that explanations which are adequate in the case of animals ought not to be lightly rejected in the case of man4 ,the practical effects of these two views are diametrically opposite3 the first leads us to level up animal intelligence with what we believe ourselves to know about our own intelligence1 while the second leads us to attempt a levelling down of our own intelligence to something not too remote from what we can observe in animals4 ,it is therefore important to consider the relative justification of the two ways of applying the principle of continuity4 ,it is clear that the question turns upon another1 namely1 which can we know best1 the psychology of animals or that of human beings8 ,if we can know most about animals1 we shall use this knowledge as a basis for inference about human beings2 if we can know most about human beings1 we shall adopt the opposite procedure4 ,and the question whether we can know most about the psychology of human beings or about that of animals turns upon yet another1 namely3 ,is introspection or external observation the surer method in psychology8 ,this is a question which ,i propose to discuss at length in ,lecture ,,vi2 ,i shall therefore content myself now with a statement of the conclusions to be arrived at4 ,we know a great many things concerning ourselves which we cannot know nearly so directly concerning animals or even other people4 ,we know when we have a toothache1 what we are thinking of1 what dreams we have when we are asleep1 and a host of other occurrences which we only know about others when they tell us of them1 or otherwise make them inferable by their behaviour4 ,thus1 so far as knowledge of detached facts is concerned1 the advantage is on the side of self-knowledge as against external observation4 ,but when we come to the analysis and scientific understanding of the facts1 the advantages on the side of self-knowledge become far less clear4 ,we know1 for example1 that we have desires and beliefs1 but we do not know what constitutes a desire or a belief4 ,the phenomena are so familiar that it is difficult to realize how little we really know about them4 ,we see in animals1 and to a lesser extent in plants1 behaviour more or less similar to that which1 in us1 is prompted by desires and beliefs1 and we find that1 as we descend in the scale of evolution1 behaviour becomes simpler1 more easily reducible to rule1 more scientifically analysable and predictable4 ,and just because we are not misled by familiarity we find it easier to be cautious in interpreting behaviour when we are dealing with phenomena remote from those of our own minds3 ,moreover1 introspection1 as psychoanalysis has demonstrated1 is extraordinarily fallible even in cases where we feel a high degree of certainty4 ,the net result seems to be that1 though self-knowledge has a definite and important contribution to make to psychology1 it is exceedingly misleading unless it is constantly checked and controlled by the test of external observation1 and by the theories which such observation suggests when applied to animal behaviour4 ,on the whole1 therefore1 there is probably more to be learnt about human psychology from animals than about animal psychology from human beings2 but this conclusion is one of degree1 and must not be pressed beyond a point4 ,it is only bodily phenomena that can be directly observed in animals1 or even1 strictly speaking1 in other human beings4 ,we can observe such things as their movements1 their physiological processes1 and the sounds they emit4 ,such things as desires and beliefs1 which seem obvious to introspection1 are not visible directly to external observation4 ,accordingly1 if we begin our study of psychology by external observation1 we must not begin by assuming such things as desires and beliefs1 but only such things as external observation can reveal1 which will be characteristics of the movements and physiological processes of animals4 ,some animals1 for example1 always run away from light and hide themselves in dark places4 ,if you pick up a mossy stone which is lightly embedded in the earth1 you will see a number of small animals scuttling away from the unwonted daylight and seeking again the darkness of which you have deprived them4 ,such animals are sensitive to light1 in the sense that their movements are affected by it2 but it would be rash to infer that they have sensations in any way analogous to our sensations of sight4 ,such inferences1 which go beyond the observable facts1 are to be avoided with the utmost care4 ,it is customary to divide human movements into three classes1 voluntary1 reflex and mechanical4 ,we may illustrate the distinction by a quotation from ,william ,james 7,psychology1 i1 #ab73 ,if ,i hear the conductor calling 'all aboard' as ,i enter the depot1 my heart first stops1 then palpitates1 and my legs respond to the air-waves falling on my tympanum by quickening their movements4 ,if ,i stumble as ,i run1 the sensation of falling provokes a movement of the hands towards the direction of the fall1 the effect of which is to shield the body from too sudden a shock4 ,if a cinder enter my eye1 its lids close forcibly and a copious flow of tears tends to wash it out4 ,these three responses to a sensational stimulus differ1 however1 in many respects4 ,the closure of the eye and the lachrymation are quite involuntary1 and so is the disturbance of the heart4 ,such involuntary responses we know as 'reflex' acts4 ,the motion of the arms to break the shock of falling may also be called reflex1 since it occurs too quickly to be deliberately intended4 ,whether it be instinctive or whether it result from the pedestrian education of childhood may be doubtful2 it is1 at any rate1 less automatic than the previous acts1 for a man might by conscious effort learn to perform it more skilfully1 or even to suppress it altogether4 ,actions of this kind1 with which instinct and volition enter upon equal terms1 have been called 'semi-reflex4' ,the act of running towards the train1 on the other hand1 has no instinctive element about it4 ,it is purely the result of education1 and is preceded by a consciousness of the purpose to be attained and a distinct mandate of the will4 ,it is a 'voluntary act4' ,thus the animal's reflex and voluntary performances shade into each other gradually1 being connected by acts which may often occur automatically1 but may also be modified by conscious intelligence4 ,an outside observer1 unable to perceive the accompanying consciousness1 might be wholly at a loss to discriminate between the automatic acts and those which volition escorted4 ,but if the criterion of mind's existence be the choice of the proper means for the attainment of a supposed end1 all the acts alike seem to be inspired by intelligence1 for ,,appropriateness characterizes them all alike4 ,there is one movement1 among those that ,james mentions at first1 which is not subsequently classified1 namely1 the stumbling4 ,this is the kind of movement which may be called mechanical2 it is evidently of a different kind from either reflex or voluntary movements1 and more akin to the movements of dead matter4 ,we may define a movement of an animal's body as mechanical when it proceeds as if only dead matter were involved4 ,for example1 if you fall over a cliff1 you move under the influence of gravitation1 and your centre of gravity describes just as correct a parabola as if you were already dead4 ,mechanical movements have not the characteristic of appropriateness1 unless by accident1 as when a drunken man falls into a waterbutt and is sobered4 ,but reflex and voluntary movements are not ,,always appropriate1 unless in some very recondite sense4 ,a moth flying into a lamp is not acting sensibly2 no more is a man who is in such a hurry to get his ticket that he cannot remember the name of his destination4 ,appropriateness is a complicated and merely approximate idea1 and for the present we shall do well to dismiss it from our thoughts4 ,as ,james states1 there is no difference1 from the point of view of the outside observer1 between voluntary and reflex movements4 ,the physiologist can discover that both depend upon the nervous system1 and he may find that the movements which we call voluntary depend upon higher centres in the brain than those that are reflex4 ,but he cannot discover anything as to the presence or absence of will or consciousness1 for these things can only be seen from within1 if at all4 ,for the present1 we wish to place ourselves resolutely in the position of outside observers2 we will therefore ignore the distinction between voluntary and reflex movements4 ,we will call the two together vital movements4 ,we may then distinguish vital from mechanical movements by the fact that vital movements depend for their causation upon the special properties of the nervous system1 while mechanical movements depend only upon the properties which animal bodies share with matter in general4 ,there is need for some care if the distinction between mechanical and vital movements is to be made precise4 ,it is quite likely that1 if we knew more about animal bodies1 we could deduce all their movements from the laws of chemistry and physics4 ,it is already fairly easy to see how chemistry reduces to physics1 i4e4 how the differences between different chemical elements can be accounted for by differences of physical structure1 the constituents of the structure being electrons which are exactly alike in all kinds of matter4 ,we only know in part how to reduce physiology to chemistry1 but we know enough to make it likely that the reduction is possible4 ,if we suppose it effected1 what would become of the difference between vital and mechanical movements8 ,some analogies will make the difference clear4 ,a shock to a mass of dynamite produces quite different effects from an equal shock to a mass of steel3 in the one case there is a vast explosion1 while in the other case there is hardly any noticeable disturbance4 ,similarly1 you may sometimes find on a mountain-side a large rock poised so delicately that a touch will set it crashing down into the valley1 while the rocks all round are so firm that only a considerable force can dislodge them ,what is analogous in these two cases is the existence of a great store of energy in unstable equilibrium ready to burst into violent motion by the addition of a very slight disturbance4 ,similarly1 it requires only a very slight expenditure of energy to send a post-card with the words ,all is discovered2 fly6 but the effect in generating kinetic energy is said to be amazing4 ,a human body1 like a mass of dynamite1 contains a store of energy in unstable equilibrium1 ready to be directed in this direction or that by a disturbance which is physically very small1 such as a spoken word4 ,in all such cases the reduction of behaviour to physical laws can only be effected by entering into great minuteness2 so long as we confine ourselves to the observation of comparatively large masses1 the way in which the equilibrium will be upset cannot be determined4 ,physicists distinguish between macroscopic and microscopic equations3 the former determine the visible movements of bodies of ordinary size1 the latter the minute occurrences in the smallest parts4 ,it is only the microscopic equations that are supposed to be the same for all sorts of matter4 ,the macroscopic equations result from a process of averaging out1 and may be different in different cases4 ,so1 in our instance1 the laws of macroscopic phenomena are different for mechanical and vital movements1 though the laws of microscopic phenomena may be the same4 ,we may say1 speaking somewhat roughly1 that a stimulus applied to the nervous system1 like a spark to dynamite1 is able to take advantage of the stored energy in unstable equilibrium1 and thus to produce movements out of proportion to the proximate cause4 ,movements produced in this way are vital movements1 while mechanical movements are those in which the stored energy of a living body is not involved4 ,similarly dynamite may be exploded1 thereby displaying its characteristic properties1 or may 7with due precautions7 be carted about like any other mineral4 ,the explosion is analogous to vital movements1 the carting about to mechanical movements4 ,mechanical movements are of no interest to the psychologist1 and it has only been necessary to define them in order to be able to exclude them4 ,when a psychologist studies behaviour1 it is only vital movements that concern him4 ,we shall1 therefore1 proceed to ignore mechanical movements1 and study only the properties of the remainder4 ,the next point is to distinguish between movements that are instinctive and movements that are acquired by experience4 ,this distinction also is to some extent one of degree4 ,professor ,lloyd ,morgan gives the following definition of instinctive behaviour3 ,that which is1 on its first occurrence1 independent of prior experience2 which tends to the well-being of the individual and the preservation of the race2 which is similarly performed by all members of the same more or less restricted group of animals2 and which may be subject to subsequent modification under the guidance of experience4 99 99 ,instinct and ,experience 7,methuen1 #aiab7 p4 #e4 ,this definition is framed for the purposes of biology1 and is in some respects unsuited to the needs of psychology4 ,though perhaps unavoidable1 allusion to the same more or less restricted group of animals makes it impossible to judge what is instinctive in the behaviour of an isolated individual4 ,moreover1 the well-being of the individual and the preservation of the race is only a usual characteristic1 not a universal one1 of the sort of movements that1 from our point of view1 are to be called instinctive2 instances of harmful instincts will be given shortly4 ,the essential point of the definition1 from our point of view1 is that an instinctive movement is in dependent of prior experience4 ,we may say that an instinctive movement is a vital movement performed by an animal the first time that it finds itself in a novel situation2 or1 more correctly1 one which it would perform if the situation were novel499 ,the instincts of an animal are different at different periods of its growth1 and this fact may cause changes of behaviour which are not due to learning4 ,the maturing and seasonal fluctuation of the sex-instinct affords a good illustration4 ,when the sex-instinct first matures1 the behaviour of an animal in the presence of a mate is different from its previous behaviour in similar circumstances1 but is not learnt1 since it is just the same if the animal has never previously been in the presence of a mate4 99 ,though this can only be decided by comparison with other members of the species1 and thus exposes us to the need of comparison which we thought an objection to ,professor ,lloyd ,morgan's definition4 ,on the other hand1 a movement is learnt1 or embodies a habit1 if it is due to previous experience of similar situations1 and is not what it would be if the animal had had no such experience4 ,there are various complications which blur the sharpness of this distinction in practice4 ,to begin with1 many instincts mature gradually1 and while they are immature an animal may act in a fumbling manner which is very difficult to distinguish from learning4 ,james 7,psychology1 ii1 #djg7 maintains that children walk by instinct1 and that the awkwardness of their first attempts is only due to the fact that the instinct has not yet ripened4 ,he hopes that some scientific widower1 left alone with his offspring at the critical moment1 may ere long test this suggestion on the living subject4 ,however this may be1 he quotes evidence to show that birds do not ,,learn to fly1 but fly by instinct when they reach the appropriate age 7ib41 p4 #djf74 ,in the second place1 instinct often gives only a rough outline of the sort of thing to do1 in which case learning is necessary in order to acquire certainty and precision in action4 ,in the third place1 even in the clearest cases of acquired habit1 such as speaking1 some instinct is required to set in motion the process of learning4 ,in the case of speaking1 the chief instinct involved is commonly supposed to be that of imitation1 but this may be questioned4 7,see ,thorndike's ,animal ,intelligence1 p4 #bec ff47 ,in spite of these qualifications1 the broad distinction between instinct and habit is undeniable4 ,to take extreme cases1 every animal at birth can take food by instinct1 before it has had opportunity to learn2 on the other hand1 no one can ride a bicycle by instinct1 though1 after learning1 the necessary movements become just as automatic as if they were instinctive4 ,the process of learning1 which consists in the acquisition of habits1 has been much studied in various animals499 ,for example3 you put a hungry animal1 say a cat1 in a cage which has a door that can be opened by lifting a latch2 outside the cage you put food4 ,the cat at first dashes all round the cage1 making frantic efforts to force a way out4 ,at last1 by accident1 the latch is lifted and the cat pounces on the food4 ,next day you repeat the experiment1 and you find that the cat gets out much more quickly than the first time1 although it still makes some random movements4 ,the third day it gets out still more quickly1 and before long it goes straight to the latch and lifts it at once4 ,or you make a model of the ,hampton ,court maze1 and put a rat in the middle1 assaulted by the smell of food on the outside4 ,the rat starts running down the passages1 and is constantly stopped by blind alleys1 but at last1 by persistent attempts1 it gets out4 ,you repeat this experiment day after day2 you measure the time taken by the rat in reaching the food2 you find that the time rapidly diminishes1 and that after a while the rat ceases to make any wrong turnings4 ,it is by essentially similar processes that we learn speaking1 writing1 mathematics1 or the government of an empire4 99 ,the scientific study of this subject may almost be said to begin with ,thorndike's ,animal ,intelligence 7,macmillan1 #aiaa74 ,professor ,watson 7,behavior1 pp4 #bfb-c7 has an ingenious theory as to the way in which habit arises out of random movements4 ,i think there is a reason why his theory cannot be regarded as alone sufficient1 but it seems not unlikely that it is partly correct4 ,suppose1 for the sake of simplicity1 that there are just ten random movements which may be made by the animal--say1 ten paths down which it may go--and that only one of these leads to food1 or whatever else represents success in the case in question4 ,then the successful movement always occurs during the animal's attempts1 whereas each of the others1 on the average1 occurs in only half the attempts4 ,thus the tendency to repeat a previous performance 7which is easily explicable without the intervention of consciousness7 leads to a greater emphasis on the successful movement than on any other1 and in time causes it alone to be performed4 ,the objection to this view1 if taken as the sole explanation1 is that on improvement ought to set in till after the ,,second trial1 whereas experiment shows that already at the second attempt the animal does better than the first time4 ,something further is1 therefore1 required to account for the genesis of habit from random movements2 but ,i see no reason to suppose that what is further required involves consciousness4 ,mr4 ,thorndike 7op4 cit41 p4 #bdd7 formulates two provisional laws of acquired behaviour or learning1 as follows3 ,the ,law of ,effect is that3 ,of several responses made to the same situation1 those which are accompanied or closely followed by satisfaction to the animal will1 other things being equal1 be more firmly connected with the situation1 so that1 when it recurs1 they will be more likely to recur2 those which are accompanied or closely followed by discomfort to the animal will1 other things being equal1 have their connections with that situation weakened1 so that1 when it recurs1 they will be less likely to occur4 ,the greater the satisfaction or discomfort1 the greater the strengthening or weakening of the bond4 ,the ,law of ,exercise is that3 ,any response to a situation will1 other things being equal1 be more strongly connected with the situation in proportion to the number of times it has been connected with that situation and to the average vigour and duration of the connections4 ,with the explanation to be presently given of the meaning of satisfaction and discomfort1 there seems every reason to accept these two laws4 ,what is true of animals1 as regards instinct and habit1 is equally true of men4 ,but the higher we rise in the evolutionary scale1 broadly speaking1 the greater becomes the power of learning1 and the fewer are the occasions when pure instinct is exhibited unmodified in adult life4 ,this applies with great force to man1 so much so that some have thought instinct less important in the life of man than in that of animals4 ,this1 however1 would be a mistake4 ,learning is only possible when instinct supplies the driving-force4 ,the animals in cages1 which gradually learn to get out1 perform random movements at first1 which are purely instinctive4 ,but for these random movements1 they would never acquire the experience which afterwards enables them to produce the right movement4 7,this is partly questioned by ,hobhouse99--wrongly1 ,i think47 ,similarly1 children learning to talk make all sorts of sounds1 until one day the right sound comes by accident4 ,it is clear that the original making of random sounds1 without which speech would never be learnt1 is instinctive4 ,i think we may say the same of all the habits and aptitudes that we acquire in all of them there has been present throughout some instinctive activity1 prompting at first rather inefficient movements1 but supplying the driving force while more and more effective methods are being acquired4 ,a cat which is hungry smells fish1 and goes to the larder4 ,this is a thoroughly efficient method when there is fish in the larder1 and it is often successfully practised by children4 ,but in later life it is found that merely going to the larder does not cause fish to be there2 after a series of random movements it is found that this result is to be caused by going to the ,city in the morning and coming back in the evening4 ,no one would have guessed a priori that this movement of a middle-aged man's body would cause fish to come out of the sea into his larder1 but experience shows that it does1 and the middle-aged man therefore continues to go to the ,city1 just as the cat in the cage continues to lift the latch when it has once found it4 ,of course1 in actual fact1 human learning is rendered easier1 though psychologically more complex1 through language2 but at bottom language does not alter the essential character of learning1 or of the part played by instinct in promoting learning4 ,language1 however1 is a subject upon which ,i do not wish to speak until a later lecture4 99 ,mind in ,evolution 7,macmillan1 #aiae71 pp4 #bcf-bcg4 ,the popular conception of instinct errs by imagining it to be infallible and preternaturally wise1 as well as incapable of modification4 ,this is a complete delusion4 ,instinct1 as a rule1 is very rough and ready1 able to achieve its result under ordinary circumstances1 but easily misled by anything unusual4 ,chicks follow their mother by instinct1 but when they are quite young they will follow with equal readiness any moving object remotely resembling their mother1 or even a human being 7,james1 ,psychology1 ii1 #cif74 ,bergson1 quoting ,fabre1 has made play with the supposed extraordinary accuracy of the solitary wasp ,ammophila1 which lays its eggs in a caterpillar4 ,on this subject ,i will quote from ,drever's ,instinct in ,man1 p4 #ib3 ,according to ,fabre's observations1 which ,bergson accepts1 the ,ammophila stings its prey ,,exactly and ,,unerringly in ,,each of the nervous centres4 ,the result is that the caterpillar is paralyzed1 but not immediately killed1 the advantage of this being that the larva cannot be injured by any movement of the caterpillar1 upon which the egg is deposited1 and is provided with fresh meat when the time comes4 ,now ,dr4 and ,mrs4 ,peckham have shown that the sting of the wasp is ,,not ,,unerring1 as ,fabre alleges1 that the number of stings is ,,not ,,constant1 that sometimes the caterpillar is ,,not ,,paralyzed1 and sometimes it is ,,killed ,,outright1 and that ,,the ,,different ,,circumstances ,,do ,,not ,,apparently ,,make ,,any ,,difference ,,to ,,the ,,larva1 which is not injured by slight movements of the caterpillar1 nor by consuming food decomposed rather than fresh caterpillar4 ,this illustrates how love of the marvellous may mislead even so careful an observer as ,fabre and so eminent a philosopher as ,bergson4 ,in the same chapter of ,dr4 ,drever's book there are some interesting examples of the mistakes made by instinct4 ,i will quote one as a sample3 ,the larva of the ,lomechusa beetle eats the young of the ants1 in whose nest it is reared4 ,nevertheless1 the ants tend the ,lomechusa larvae with the same care they bestow on their own young4 ,not only so1 but they apparently discover that the methods of feeding1 which suit their own larvae1 would prove fatal to the guests1 and accordingly they change their whole system of nursing 7loc4 cit41 p4 #ajf74 ,semon 7,die ,mneme1 pp4 #bjg-i7 gives a good illustration of an instinct growing wiser through experience4 ,he relates how hunters attract stags by imitating the sounds of other members of their species1 male or female1 but find that the older a stag becomes the more difficult it is to deceive him1 and the more accurate the imitation has to be4 ,the literature of instinct is vast1 and illustrations might be multiplied indefinitely4 ,the main points as regards instinct1 which need to be emphasized as against the popular conceptions of it1 are3 7#a7 ,that instinct requires no prevision of the biological end which it serves2 7#b7 ,that instinct is only adapted to achieve this end in the usual circumstances of the animal in question1 and has no more precision than is necessary for success ,,as ,a ,,rule2 7#c7 ,that processes initiated by instinct often come to be performed better after experience2 7#d7 ,that instinct supplies the impulses to experimental movements which are required for the process of learning2 7#e7 ,that instincts in their nascent stages are easily modifiable1 and capable of being attached to various sorts of objects4 ,all the above characteristics of instinct can be established by purely external observation1 except the fact that instinct does not require prevision4 ,this1 though not strictly capable of being ,,proved by observation1 is irresistibly suggested by the most obvious phenomena4 ,who can believe1 for example1 that a new-born baby is aware of the necessity of food for preserving life8 ,or that insects1 in laying eggs1 are concerned for the preservation of their species8 ,the essence of instinct1 one might say1 is that it provides a mechanism for acting without foresight in a manner which is usually advantageous biologically4 ,it is partly for this reason that it is so important to understand the fundamental position of instinct in prompting both animal and human behaviour4 ,,lecture ,,iii4 ,,desire ,,and ,,feeling ,desire is a subject upon which1 if ,i am not mistaken1 true views can only be arrived at by an almost complete reversal of the ordinary unreflecting opinion4 ,it is natural to regard desire as in its essence an attitude towards something which is imagined1 not actual2 this something is called the ,,end or ,,object of the desire1 and is said to be the ,,purpose of any action resulting from the desire4 ,we think of the content of the desire as being just like the content of a belief1 while the attitude taken up towards the content is different4 ,according to this theory1 when we say3 ,i hope it will rain1 or ,i expect it will rain1 we express1 in the first case1 a desire1 and in the second1 a belief1 with an identical content1 namely1 the image of rain4 ,it would be easy to say that1 just as belief is one kind of feeling in relation to this content1 so desire is another kind4 ,according to this view1 what comes first in desire is something imagined1 with a specific feeling related to it1 namely1 that specific feeling which we call desiring it4 ,the discomfort associated with unsatisfied desire1 and the actions which aim at satisfying desire1 are1 in this view1 both of them effects of the desire4 ,i think it is fair to say that this is a view against which common sense would not rebel2 nevertheless1 ,i believe it to be radically mistaken4 ,it cannot be refuted logically1 but various facts can be adduced which make it gradually less simple and plausible1 until at last it turns out to be easier to abandon it wholly and look at the matter in a totally different way4 ,the first set of facts to be adduced against the common sense view of desire are those studied by psycho-analysis4 ,in all human beings1 but most markedly in those suffering from hysteria and certain forms of insanity1 we find what are called unconscious desires1 which are commonly regarded as showing self-deception4 ,most psycho-analysts pay little attention to the analysis of desire1 being interested in discovering by observation what it is that people desire1 rather than in discovering what actually constitutes desire4 ,i think the strangeness of what they report would be greatly diminished if it were expressed in the language of a behaviourist theory of desire1 rather than in the language of every-day beliefs4 ,the general description of the sort of phenomena that bear on our present question is as follows3 ,a person states that his desires are so-and-so1 and that it is these desires that inspire his actions2 but the outside observer perceives that his actions are such as to realize quite different ends from those which he avows1 and that these different ends are such as he might be expected to desire4 ,generally they are less virtuous than his professed desires1 and are therefore less agreeable to profess than these are4 ,it is accordingly supposed that they really exist as desires for ends1 but in a subconscious part of the mind1 which the patient refuses to admit into consciousness for fear of having to think ill of himself4 ,there are no doubt many cases to which such a supposition is applicable without obvious artificiality4 ,but the deeper the ,freudians delve into the underground regions of instinct1 the further they travel from anything resembling conscious desire1 and the less possible it becomes to believe that only positive self-deception conceals from us that we really wish for things which are abhorrent to our explicit life4 ,in the cases in question we have a conflict between the outside observer and the patient's consciousness4 ,the whole tendency of psycho-analysis is to trust the outside observer rather than the testimony of introspection4 ,i believe this tendency to be entirely right1 but to demand a re-statement of what constitutes desire1 exhibiting it as a causal law of our actions1 not as something actually existing in our minds4 ,but let us first get a clearer statement of the essential characteristic of the phenomena4 ,a person1 we find1 states that he desires a certain end ,a1 and that he is acting with a view to achieving it4 ,we observe1 however1 that his actions are such as are likely to achieve a quite different end ,b1 and that ,b is the sort of end that often seems to be aimed at by animals and savages1 though civilized people are supposed to have discarded it4 ,we sometimes find also a whole set of false beliefs1 of such a kind as to persuade the patient that his actions are really a means to ,a1 when in fact they are a means to ,b4 ,for example1 we have an impulse to inflict pain upon those whom we hate2 we therefore believe that they are wicked1 and that punishment will reform them4 ,this belief enables us to act upon the impulse to inflict pain1 while believing that we are acting upon the desire to lead sinners to repentance4 ,it is for this reason that the criminal law has been in all ages more severe than it would have been if the impulse to ameliorate the criminal had been what really inspired it4 ,it seems simple to explain such a state of affairs as due to self-deception1 but this explanation is often mythical4 ,most people1 in thinking about punishment1 have had no more need to hide their vindictive impulses from themselves than they have had to hide the exponential theorem4 ,our impulses are not patent to a casual observation1 but are only to be discovered by a scientific study of our actions1 in the course of which we must regard ourselves as objectively as we should the motions of the planets or the chemical reactions of a new element4 ,the study of animals reinforces this conclusion1 and is in many ways the best preparation for the analysis of desire4 ,in animals we are not troubled by the disturbing influence of ethical considerations4 ,in dealing with human beings1 we are perpetually distracted by being told that such-and-such a view is gloomy or cynical or pessimistic3 ages of human conceit have built up such a vast myth as to our wisdom and virtue that any intrusion of the mere scientific desire to know the facts is instantly resented by those who cling to comfortable illusions4 ,but no one cares whether animals are virtuous or not1 and no one is under the delusion that they are rational4 ,moreover1 we do not expect them to be so conscious1 and are prepared to admit that their instincts prompt useful actions without any prevision of the ends which they achieve4 ,for all these reasons1 there is much in the analysis of mind which is more easily discovered by the study of animals than by the observation of human beings4 ,we all think that1 by watching the behaviour of animals1 we can discover more or less what they desire4 ,if this is the case--and ,i fully agree that it is--desire must be capable of being exhibited in actions1 for it is only the actions of animals that we can observe4 ,they ,,may have minds in which all sorts of things take place1 but we can know nothing about their minds except by means of inferences from their actions2 and the more such inferences are examined1 the more dubious they appear4 ,it would seem1 therefore1 that actions alone must be the test of the desires of animals4 ,from this it is an easy step to the conclusion that an animal's desire is nothing but a characteristic of a certain series of actions1 namely1 those which would be commonly regarded as inspired by the desire in question4 ,and when it has been shown that this view affords a satisfactory account of animal desires1 it is not difficult to see that the same explanation is applicable to the desires of human beings4 ,we judge easily from the behaviour of an animal of a familiar kind whether it is hungry or thirsty1 or pleased or displeased1 or inquisitive or terrified4 ,the verification of our judgment1 so far as verification is possible1 must be derived from the immediately succeeding actions of the animal4 ,most people would say that they infer first something about the animal's state of mind--whether it is hungry or thirsty and so on--and thence derive their expectations as to its subsequent conduct4 ,but this detour through the animal's supposed mind is wholly unnecessary4 ,we can say simply3 ,the animal's behaviour during the last minute has had those characteristics which distinguish what is called hunger1 and it is likely that its actions during the next minute will be similar in this respect1 unless it finds food1 or is interrupted by a stronger impulse1 such as fear4 ,an animal which is hungry is restless1 it goes to the places where food is often to be found1 it sniffs with its nose or peers with its eyes or otherwise increases the sensitiveness of its sense-organs2 as soon as it is near enough to food for its sense-organs to be affected1 it goes to it with all speed and proceeds to eat2 after which1 if the quantity of food has been sufficient1 its whole demeanour changes it may very likely lie down and go to sleep4 ,these things and others like them are observable phenomena distinguishing a hungry animal from one which is not hungry4 ,the characteristic mark by which we recognize a series of actions which display hunger is not the animal's mental state1 which we cannot observe1 but something in its bodily behaviour2 it is this observable trait in the bodily behaviour that ,i am proposing to call hunger1 not some possibly mythical and certainly unknowable ingredient of the animal's mind4 ,generalizing what occurs in the case of hunger1 we may say that what we call a desire in an animal is always displayed in a cycle of actions having certain fairly well marked characteristics4 ,there is first a state of activity1 consisting1 with qualifications to be mentioned presently1 of movements likely to have a certain result2 these movements1 unless interrupted1 continue until the result is achieved1 after which there is usually a period of comparative quiescence4 ,a cycle of actions of this sort has marks by which it is broadly distinguished from the motions of dead matter4 ,the most notable of these marks are--7#a7 the appropriateness of the actions for the realization of a certain result2 7#b7 the continuance of action until that result has been achieved4 ,neither of these can be pressed beyond a point4 ,either may be 7a7 to some extent present in dead matter1 and 7b7 to a considerable extent absent in animals1 while vegetable are intermediate1 and display only a much fainter form of the behaviour which leads us to attribute desire to animals4 7a7 ,one might say rivers desire the sea water1 roughly speaking1 remains in restless motion until it reaches either the sea or a place from which it cannot issue without going uphill1 and therefore we might say that this is what it wishes while it is flowing4 ,we do not say so1 because we can account for the behaviour of water by the laws of physics2 and if we knew more about animals1 we might equally cease to attribute desires to them1 since we might find physical and chemical reactions sufficient to account for their behaviour4 7b7 ,many of the movements of animals do not exhibit the characteristics of the cycles which seem to embody desire4 ,there are first of all the movements which are mechanical1 such as slipping and falling1 where ordinary physical forces operate upon the animal's body almost as if it were dead matter4 ,an animal which falls over a cliff may make a number of desperate struggles while it is in the air1 but its centre of gravity will move exactly as it would if the animal were dead4 ,in this case1 if the animal is killed at the end of the fall1 we have1 at first sight1 just the characteristics of a cycle of actions embodying desire1 namely1 restless movement until the ground is reached1 and then quiescence4 ,nevertheless1 we feel no temptation to say that the animal desired what occurred1 partly because of the obviously mechanical nature of the whole occurrence1 partly because1 when an animal survives a fall1 it tends not to repeat the experience4 ,there may be other reasons also1 but of them ,i do not wish to speak yet4 ,besides mechanical movements1 there are interrupted movements1 as when a bird1 on its way to eat your best peas1 is frightened away by the boy whom you are employing for that purpose4 ,if interruptions are frequent and completion of cycles rare1 the characteristics by which cycles are observed may become so blurred as to be almost unrecognizable4 ,the result of these various considerations is that the differences between animals and dead matter1 when we confine ourselves to external unscientific observation of integral behaviour1 are a matter of degree and not very precise4 ,it is for this reason that it has always been possible for fanciful people to maintain that even stocks and stones have some vague kind of soul4 ,the evidence that animals have souls is so very shaky that1 if it is assumed to be conclusive1 one might just as well go a step further and extend the argument by analogy to all matter4 ,nevertheless1 in spite of vagueness and doubtful cases1 the existence of cycles in the behaviour of animals is a broad characteristic by which they are prima facie distinguished from ordinary matter2 and ,i think it is this characteristic which leads us to attribute desires to animals1 since it makes their behaviour resemble what we do when 7as we say7 we are acting from desire4 ,i shall adopt the following definitions for describing the behaviour of animals3 ,a behaviour-cycle is a series of voluntary or reflex movements of an animal1 tending to cause a certain result1 and continuing until that result is caused1 unless they are interrupted by death1 accident1 or some new behaviour-cycle4 7,here accident may be defined as the intervention of purely physical laws causing mechanical movements47 ,the purpose of a behaviour-cycle is the result which brings it to an end1 normally by a condition of temporary quiescence-provided there is no interruption4 ,an animal is said to desire the purpose of a behaviour cycle while the behaviour-cycle is in progress4 ,i believe these definitions to be adequate also to human purposes and desires1 but for the present ,i am only occupied with animals and with what can be learnt by external observation4 ,i am very anxious that no ideas should be attached to the words purpose and desire beyond those involved in the above definitions4 ,we have not so far considered what is the nature of the initial stimulus to a behaviour-cycle4 ,yet it is here that the usual view of desire seems on the strongest ground4 ,the hungry animal goes on making movements until it gets food2 it seems natural1 therefore1 to suppose that the idea of food is present throughout the process1 and that the thought of the end to be achieved sets the whole process in motion4 ,such a view1 however1 is obviously untenable in many cases1 especially where instinct is concerned4 ,take1 for example1 reproduction and the rearing of the young4 ,birds mate1 build a nest1 lay eggs in it1 sit on the eggs1 feed the young birds1 and care for them until they are fully grown4 ,it is totally impossible to suppose that this series of actions1 which constitutes one behaviour-cycle1 is inspired by any prevision of the end1 at any rate the first time it is performed499 ,we must suppose that the stimulus to the performance of each act is an impulsion from behind1 not an attraction from the future4 ,the bird does what it does1 at each stage1 because it has an impulse to that particular action1 not because it perceives that the whole cycle of actions will contribute to the preservation of the species4 ,the same considerations apply to other instincts4 ,a hungry animal feels restless1 and is led by instinctive impulses to perform the movements which give it nourishment2 but the act of seeking food is not sufficient evidence from which to conclude that the animal has the thought of food in its mind4 99 ,for evidence as to birds' nests1 cf4 ,semon1 ,die ,mneme1 pp4 #bji1 #baj4 ,coming now to human beings1 and to what we know about our own actions1 it seems clear that what1 with us1 sets a behaviour-cycle in motion is some sensation of the sort which we call disagreeable4 ,take the case of hunger3 we have first an uncomfortable feeling inside1 producing a disinclination to sit still1 a sensitiveness to savoury smells1 and an attraction towards any food that there may be in our neighbourhood4 ,at any moment during this process we may become aware that we are hungry1 in the sense of saying to ourselves1 ,i am hungry2 but we may have been acting with reference to food for some time before this moment4 ,while we are talking or reading1 we may eat in complete unconsciousness2 but we perform the actions of eating just as we should if we were conscious1 and they cease when our hunger is appeased4 ,what we call consciousness seems to be a mere spectator of the process2 even when it issues orders1 they are usually1 like those of a wise parent1 just such as would have been obeyed even if they had not been given4 ,this view may seem at first exaggerated1 but the more our so-called volitions and their causes are examined1 the more it is forced upon us4 ,the part played by words in all this is complicated1 and a potent source of confusions2 ,i shall return to it later4 ,for the present1 ,i am still concerned with primitive desire1 as it exists in man1 but in the form in which man shows his affinity to his animal ancestors4 ,conscious desire is made up partly of what is essential to desire1 partly of beliefs as to what we want4 ,it is important to be clear as to the part which does not consist of beliefs4 ,the primitive non-cognitive element in desire seems to be a push1 not a pull1 an impulsion away from the actual1 rather than an attraction towards the ideal4 ,certain sensations and other mental occurrences have a property which we call discomfort2 these cause such bodily movements as are likely to lead to their cessation4 ,when the discomfort ceases1 or even when it appreciably diminishes1 we have sensations possessing a property which we call ,,pleasure4 ,pleasurable sensations either stimulate no action at all1 or at most stimulate such action as is likely to prolong them4 ,i shall return shortly to the consideration of what discomfort and pleasure are in themselves2 for the present1 it is their connection with action and desire that concerns us4 ,abandoning momentarily the standpoint of behaviourism1 we may presume that hungry animals experience sensations involving discomfort1 and stimulating such movements as seem likely to bring them to the food which is outside the cages4 ,when they have reached the food and eaten it1 their discomfort ceases and their sensations become pleasurable4 ,it ,,seems1 mistakenly1 as if the animals had had this situation in mind throughout1 when in fact they have been continually pushed by discomfort4 ,and when an animal is reflective1 like some men1 it comes to think that it had the final situation in mind throughout2 sometimes it comes to know what situation will bring satisfaction1 so that in fact the discomfort does bring the thought of what will allay it4 ,nevertheless the sensation involving discomfort remains the prime mover4 ,this brings us to the question of the nature of discomfort and pleasure4 ,since ,kant it has been customary to recognize three great divisions of mental phenomena1 which are typified by knowledge1 desire and feeling1 where feeling is used to mean pleasure and discomfort4 ,of course1 knowledge is too definite a word3 the states of mind concerned are grouped together as cognitive1 and are to embrace not only beliefs1 but perceptions1 doubts1 and the understanding of concepts4 ,desire1 also1 is narrower than what is intended3 for example1 ,,will is to be included in this category1 and in fact every thing that involves any kind of striving1 or conation as it is technically called4 ,i do not myself believe that there is any value in this threefold division of the contents of mind4 ,i believe that sensations 7including images7 supply all the stuff of the mind1 and that everything else can be analysed into groups of sensations related in various ways1 or characteristics of sensations or of groups of sensations4 ,as regards belief1 ,i shall give grounds for this view in later lectures4 ,as regards desires1 ,i have given some grounds in this lecture4 ,for the present1 it is pleasure and discomfort that concern us4 ,there are broadly three theories that might be held in regard to them4 ,we may regard them as separate existing items in those who experience them1 or we may regard them as intrinsic qualities of sensations and other mental occurrences1 or we may regard them as mere names for the causal characteristics of the occurrences which are uncomfortable or pleasant4 ,the first of these theories1 namely1 that which regards discomfort and pleasure as actual contents in those who experience them1 has1 ,i think1 nothing conclusive to be said in its favour499 ,it is suggested chiefly by an ambiguity in the word pain1 which has misled many people1 including ,berkeley1 whom it supplied with one of his arguments for subjective idealism4 ,we may use pain as the opposite of pleasure1 and painful as the opposite of pleasant1 or we may use pain to mean a certain sort of sensation1 on a level with the sensations of heat and cold and touch4 ,the latter use of the word has prevailed in psychological literature1 and it is now no longer used as the opposite of pleasure4 ,dr4 ,h4 ,head1 in a recent publication1 has stated this distinction as follows39999 99 ,various arguments in its favour are advanced by ,a4 ,wohlgemuth1 ,on the feelings and their neural correlate1 with an examination of the nature of pain1 ,british ,journal of ,psychology1 viii1 #d4 7#aiag74 ,but as these arguments are largely a reductio ad absurdum of other theories1 among which that which ,i am advocating is not included1 ,i cannot regard them as establishing their contention4 9999 ,sensation and the ,cerebral ,cortex1 ,brain1 vol4 xli1 part ii 7,september1 #aiah71 p4 #ij4 ,cf4 also ,wohlgemuth1 loc4 cit4 pp4 #dcg1 #dej4 ,it is necessary at the outset to distinguish clearly between 'discomfort' and 'pain4' ,pain is a distinct sensory quality equivalent to heat and cold1 and its intensity can be roughly graded according to the force expended in stimulation4 ,discomfort1 on the other hand1 is that feeling-tone which is directly opposed to pleasure4 ,it may accompany sensations not in themselves essentially painful2 as for instance that produced by tickling the sole of the foot4 ,the reaction produced by repeated pricking contains both these elements2 for it evokes that sensory quality known as pain1 accompanied by a disagreeable feeling-tone1 which we have called discomfort4 ,on the other hand1 excessive pressure1 except when applied directly over some nerve-trunk1 tends to excite more discomfort than pain4 ,the confusion between discomfort and pain has made people regard discomfort as a more substantial thing than it is1 and this in turn has reacted upon the view taken of pleasure1 since discomfort and pleasure are evidently on a level in this respect4 ,as soon as discomfort is clearly distinguished from the sensation of pain1 it becomes more natural to regard discomfort and pleasure as properties of mental occurrences than to regard them as separate mental occurrences on their own account4 ,i shall therefore dismiss the view that they are separate mental occurrences1 and regard them as properties of such experiences as would be called respectively uncomfortable and pleasant4 ,it remains to be examined whether they are actual qualities of such occurrences1 or are merely differences as to causal properties4 ,i do not myself see any way of deciding this question2 either view seems equally capable of accounting for the facts4 ,if this is true1 it is safer to avoid the assumption that there are such intrinsic qualities of mental occurrences as are in question1 and to assume only the causal differences which are undeniable4 ,without condemning the intrinsic theory1 we can define discomfort and pleasure as consisting in causal properties1 and say only what will hold on either of the two theories4 ,following this course1 we shall say3 ,discomfort is a property of a sensation or other mental occurrence1 consisting in the fact that the occurrence in question stimulates voluntary or reflex movements tending to produce some more or less definite change involving the cessation of the occurrence4 ,pleasure is a property of a sensation or other mental occurrence1 consisting in the fact that the occurrence in question either does not stimulate any voluntary or reflex movement1 or1 if it does1 stimulates only such as tend to prolong the occurrence in question499 99 ,cf4 ,thorndike1 op4 cit41 p4 #bdc4 ,conscious desire1 which we have now to consider1 consists of desire in the sense hitherto discussed1 together with a true belief as to its purpose1 i4e4 as to the state of affairs that will bring quiescence with cessation of the discomfort4 ,if our theory of desire is correct1 a belief as to its purpose may very well be erroneous1 since only experience can show what causes a discomfort to cease4 ,when the experience needed is common and simple1 as in the case of hunger1 a mistake is not very probable4 ,but in other cases--e4g4 erotic desire in those who have had little or no experience of its satisfaction--mistakes are to be expected1 and do in fact very often occur4 ,the practice of inhibiting impulses1 which is to a great extent necessary to civilized life1 makes mistakes easier1 by preventing experience of the actions to which a desire would otherwise lead1 and by often causing the inhibited impulses themselves to be unnoticed or quickly forgotten4 ,the perfectly natural mistakes which thus arise constitute a large proportion of what is1 mistakenly in part1 called self-deception1 and attributed by ,freud to the censor4 ,but there is a further point which needs emphasizing1 namely1 that a belief that something is desired has often a tendency to cause the very desire that is believed in4 ,it is this fact that makes the effect of consciousness on desire so complicated4 ,when we believe that we desire a certain state of affairs1 that often tends to cause a real desire for it4 ,this is due partly to the influence of words upon our emotions1 in rhetoric for example1 and partly to the general fact that discomfort normally belongs to the belief that we desire such-and-such a thing that we do not possess4 ,thus what was originally a false opinion as to the object of a desire acquires a certain truth3 the false opinion generates a secondary subsidiary desire1 which nevertheless becomes real4 ,let us take an illustration4 ,suppose you have been jilted in a way which wounds your vanity4 ,your natural impulsive desire will be of the sort expressed in ,donne's poem3 ,when by thy scorn1 ,o ,murderess1 ,i am dead1 in which he explains how he will haunt the poor lady as a ghost1 and prevent her from enjoying a moment's peace4 ,but two things stand in the way of your expressing yourself so naturally3 on the one hand1 your vanity1 which will not acknowledge how hard you are hit2 on the other hand1 your conviction that you are a civilized and humane person1 who could not possibly indulge so crude a desire as revenge4 ,you will therefore experience a restlessness which will at first seem quite aimless1 but will finally resolve itself in a conscious desire to change your profession1 or go round the world1 or conceal your identity and live in ,putney1 like ,arnold ,bennett's hero4 ,although the prime cause of this desire is a false judgment as to your previous unconscious desire1 yet the new conscious desire has its own derivative genuineness1 and may influence your actions to the extent of sending you round the world4 ,the initial mistake1 however1 will have effects of two kinds4 ,first1 in uncontrolled moments1 under the influence of sleepiness or drink or delirium1 you will say things calculated to injure the faithless deceiver4 ,secondly1 you will find travel disappointing1 and the ,east less fascinating than you had hoped--unless1 some day1 you hear that the wicked one has in turn been jilted4 ,if this happens1 you will believe that you feel sincere sympathy1 but you will suddenly be much more delighted than before with the beauties of tropical islands or the wonders of ,chinese art4 ,a secondary desire1 derived from a false judgment as to a primary desire1 has its own power of influencing action1 and is therefore a real desire according to our definition4 ,but it has not the same power as a primary desire of bringing thorough satisfaction when it is realized2 so long as the primary desire remains unsatisfied1 restlessness continues in spite of the secondary desire's success4 ,hence arises a belief in the vanity of human wishes3 the vain wishes are those that are secondary1 but mistaken beliefs prevent us from realizing that they are secondary4 ,what may1 with some propriety1 be called self-deception arises through the operation of desires for beliefs4 ,we desire many things which it is not in our power to achieve3 that we should be universally popular and admired1 that our work should be the wonder of the age1 and that the universe should be so ordered as to bring ultimate happiness to all1 though not to our enemies until they have repented and been purified by suffering4 ,such desires are too large to be achieved through our own efforts4 ,but it is found that a considerable portion of the satisfaction which these things would bring us if they were realized is to be achieved by the much easier operation of believing that they are or will be realized4 ,this desire for beliefs1 as opposed to desire for the actual facts1 is a particular case of secondary desire1 and1 like all secondary desire its satisfaction does not lead to a complete cessation of the initial discomfort4 ,nevertheless1 desire for beliefs1 as opposed to desire for facts1 is exceedingly potent both individually and socially4 ,according to the form of belief desired1 it is called vanity1 optimism1 or religion4 ,those who have sufficient power usually imprison or put to death any one who tries to shake their faith in their own excellence or in that of the universe2 it is for this reason that seditious libel and blasphemy have always been1 and still are1 criminal offences4 ,it is very largely through desires for beliefs that the primitive nature of desire has become so hidden1 and that the part played by consciousness has been so confusing and so exaggerated4 ,we may now summarize our analysis of desire and feeling4 ,a mental occurrence of any kind--sensation1 image1 belief1 or emotion--may be a cause of a series of actions1 continuing1 unless interrupted1 until some more or less definite state of affairs is realized4 ,such a series of actions we call a behaviour-cycle4 ,the degree of definiteness may vary greatly3 hunger requires only food in general1 whereas the sight of a particular piece of food raises a desire which requires the eating of that piece of food4 ,the property of causing such a cycle of occurrences is called discomfort2 the property of the mental occurrences in which the cycle ends is called pleasure4 ,the actions constituting the cycle must not be purely mechanical1 i4e4 they must be bodily movements in whose causation the special properties of nervous tissue are involved4 ,the cycle ends in a condition of quiescence1 or of such action as tends only to preserve the status quo4 ,the state of affairs in which this condition of quiescence is achieved is called the purpose of the cycle1 and the initial mental occurrence involving discomfort is called a desire for the state of affairs that brings quiescence4 ,a desire is called conscious when it is accompanied by a true belief as to the state of affairs that will bring quiescence2 otherwise it is called unconscious4 ,all primitive desire is unconscious1 and in human beings beliefs as to the purposes of desires are often mistaken4 ,these mistaken beliefs generate secondary desires1 which cause various interesting complications in the psychology of human desire1 without fundamentally altering the character which it shares with animal desire4 ,,lecture ,,iv4 ,,influence ,,of ,,past ,,history ,,on ,,present ,,occurrences ,,in ,,living ,,organisms ,in this lecture we shall be concerned with a very general characteristic which broadly1 though not absolutely1 distinguishes the behaviour of living organisms from that of dead matter4 ,the characteristic in question is this3 ,the response of an organism to a given stimulus is very often dependent upon the past history of the organism1 and not merely upon the stimulus and the ,,hitherto ,,discoverable present state of the organism4 ,this characteristic is embodied in the saying a burnt child fears the fire4 ,the burn may have left no visible traces1 yet it modifies the reaction of the child in the presence of fire4 ,it is customary to assume that1 in such cases1 the past operates by modifying the structure of the brain1 not directly4 ,i have no wish to suggest that this hypothesis is false2 ,i wish only to point out that it is a hypothesis4 ,at the end of the present lecture ,i shall examine the grounds in its favour4 ,if we confine ourselves to facts which have been actually observed1 we must say that past occurrences1 in addition to the present stimulus and the present ascertainable condition of the organism1 enter into the causation of the response4 ,the characteristic is not wholly confined to living organisms4 ,for example1 magnetized steel looks just like steel which has not been magnetized1 but its behaviour is in some ways different4 ,in the case of dead matter1 however1 such phenomena are less frequent and important than in the case of living organisms1 and it is far less difficult to invent satisfactory hypotheses as to the microscopic changes of structure which mediate between the past occurrence and the present changed response4 ,in the case of living organisms1 practically everything that is distinctive both of their physical and of their mental behaviour is bound up with this persistent influence of the past4 ,further1 speaking broadly1 the change in response is usually of a kind that is biologically advantageous to the organism4 ,following a suggestion derived from ,semon 7,die ,mneme1 ,leipzig1 #aijd2 #bnd edition1 #aijh1 ,english translation1 ,allen ,unwin1 #aiba2 ,die mnemischen ,empfindungen1 ,leipzig1 #aiji71 we will give the name of mnemic phenomena to those responses of an organism which1 so far as hitherto observed facts are concerned1 can only be brought under causal laws by including past occurrences in the history of the organism as part of the causes of the present response4 ,i do not mean merely--what would always be the case--that past occurrences are part of a ,,chain of causes leading to the present event4 ,i mean that1 in attempting to state the ,,proximate cause of the present event1 some past event or events must be included1 unless we take refuge in hypothetical modifications of brain structure4 ,for example3 you smell peat-smoke1 and you recall some occasion when you smelt it before4 ,the cause of your recollection1 so far as hitherto observable phenomena are concerned1 consists both of the peat smoke 7present stimulus7 and of the former occasion 7past experience74 ,the same stimulus will not produce the same recollection in another man who did not share your former experience1 although the former experience left no ,,observable traces in the structure of the brain4 ,according to the maxim same cause1 same effect1 we cannot therefore regard the peat-smoke alone as the cause of your recollection1 since it does not have the same effect in other cases4 ,the cause of your recollection must be both the peat-smoke and the past occurrence4 ,accordingly your recollection is an instance of what we are calling mnemic phenomena4 ,before going further1 it will be well to give illustrations of different classes of mnemic phenomena4 7a7 ,,acquired ,,habits4--,in ,lecture ,,ii we saw how animals can learn by experience how to get out of cages or mazes1 or perform other actions which are useful to them but not provided for by their instincts alone4 ,a cat which is put into a cage of which it has had experience behaves differently from the way in which it behaved at first4 ,we can easily invent hypotheses1 which are quite likely to be true1 as to connections in the brain caused by past experience1 and themselves causing the different response4 ,but the observable fact is that the stimulus of being in the cage produces differing results with repetition1 and that the ascertainable cause of the cat's behaviour is not merely the cage and its own ascertainable organization1 but also its past history in regard to the cage4 ,from our present point of view1 the matter is independent of the question whether the cat's behaviour is due to some mental fact called knowledge1 or displays a merely bodily habit4 ,our habitual knowledge is not always in our minds1 but is called up by the appropriate stimuli4 ,if we are asked ,what is the capital of ,france8 we answer ,paris1 because of past experience2 the past experience is as essential as the present question in the causation of our response4 ,thus all our habitual knowledge consists of acquired habits1 and comes under the head of mnemic phenomena4 7b7 ,,images4--,i shall have much to say about images in a later lecture2 for the present ,i am merely concerned with them in so far as they are copies of past sensations4 ,when you hear ,new ,york spoken of1 some image probably comes into your mind1 either of the place itself 7if you have been there71 or of some picture of it 7if you have not74 ,the image is due to your past experience1 as well as to the present stimulus of the words ,new ,york4 ,similarly1 the images you have in dreams are all dependent upon your past experience1 as well as upon the present stimulus to dreaming4 ,it is generally believed that all images1 in their simpler parts1 are copies of sensations2 if so1 their mnemic character is evident4 ,this is important1 not only on its own account1 but also because1 as we shall see later1 images play an essential part in what is called thinking4 7c7 ,,association4--,the broad fact of association1 on the mental side1 is that when we experience something which we have experienced before1 it tends to call up the context of the former experience4 ,the smell of peat-smoke recalling a former scene is an instance which we discussed a moment ago4 ,this is obviously a mnemic phenomenon4 ,there is also a more purely physical association1 which is indistinguishable from physical habit4 ,this is the kind studied by ,mr4 ,thorndike in animals1 where a certain stimulus is associated with a certain act4 ,this is the sort which is taught to soldiers in drilling1 for example4 ,in such a case there need not be anything mental1 but merely a habit of the body4 ,there is no essential distinction between association and habit1 and the observations which we made concerning habit as a mnemic phenomenon are equally applicable to association4 7d7 ,,non-,,sensational ,,elements ,,in ,,perception4--,when we perceive any object of a familiar kind1 much of what appears subjectively to be immediately given is really derived from past experience4 ,when we see an object1 say a penny1 we seem to be aware of its real shape we have the impression of something circular1 not of something elliptical4 ,in learning to draw1 it is necessary to acquire the art of representing things according to the sensation1 not according to the perception4 ,and the visual appearance is filled out with feeling of what the object would be like to touch1 and so on4 ,this filling out and supplying of the real shape and so on consists of the most usual correlates of the sensational core in our perception4 ,it may happen that1 in the particular case1 the real correlates are unusual2 for example1 if what we are seeing is a carpet made to look like tiles4 ,if so1 the non-sensational part of our perception will be illusory1 i4e4 it will supply qualities which the object in question does not in fact have4 ,but as a rule objects do have the qualities added by perception1 which is to be expected1 since experience of what is usual is the cause of the addition4 ,if our experience had been different1 we should not fill out sensation in the same way1 except in so far as the filling out is instinctive1 not acquired4 ,it would seem that1 in man1 all that makes up space perception1 including the correlation of sight and touch and so on1 is almost entirely acquired4 ,in that case there is a large mnemic element in all the common perceptions by means of which we handle common objects4 ,and1 to take another kind of instance1 imagine what our astonishment would be if we were to hear a cat bark or a dog mew4 ,this emotion would be dependent upon past experience1 and would therefore be a mnemic phenomenon according to the definition4 7e7 ,,memory ,,as ,,knowledge4--,the kind of memory of which ,i am now speaking is definite knowledge of some past event in one's own experience4 ,from time to time we remember things that have happened to us1 because something in the present reminds us of them4 ,exactly the same present fact would not call up the same memory if our past experience had been different4 ,thus our remembering is caused by-- 7#a7 ,the present stimulus1 7#b7 ,the past occurrence4 ,it is therefore a mnemic phenomenon according to our definition4 ,a definition of mnemic phenomena which did not include memory would1 of course1 be a bad one4 ,the point of the definition is not that it includes memory1 but that it includes it as one of a class of phenomena which embrace all that is characteristic in the subject matter of psychology4 7f7 ,,experience4--,the word experience is often used very vaguely4 ,james1 as we saw1 uses it to cover the whole primal stuff of the world1 but this usage seems objection able1 since1 in a purely physical world1 things would happen without there being any experience4 ,it is only mnemic phenomena that embody experience4 ,we may say that an animal experiences an occurrence when this occurrence modifies the animal's subsequent behaviour1 i4e4 when it is the mnemic portion of the cause of future occurrences in the animal's life4 ,the burnt child that fears the fire has experienced the fire1 whereas a stick that has been thrown on and taken off again has not experienced anything1 since it offers no more resistance than before to being thrown on4 ,the essence of experience is the modification of behaviour produced by what is experienced4 ,we might1 in fact1 define one chain of experience1 or one biography1 as a series of occurrences linked by mnemic causation4 ,i think it is this characteristic1 more than any other1 that distinguishes sciences dealing with living organisms from physics4 ,the best writer on mnemic phenomena known to me is ,richard ,semon1 the fundamental part of whose theory ,i shall endeavour to summarize before going further3 ,when an organism1 either animal or plant1 is subjected to a stimulus1 producing in it some state of excitement1 the removal of the stimulus allows it to return to a condition of equilibrium4 ,but the new state of equilibrium is different from the old1 as may be seen by the changed capacity for reaction4 ,the state of equilibrium before the stimulus may be called the primary indifference-state2 that after the cessation of the stimulus1 the secondary indifference-state4 ,we define the engraphic effect of a stimulus as the effect in making a difference between the primary and secondary indifference-states1 and this difference itself we define as the engram due to the stimulus4 ,mnemic phenomena are defined as those due to engrams2 in animals1 they are specially associated with the nervous system1 but not exclusively1 even in man4 ,when two stimuli occur together1 one of them1 occurring afterwards1 may call out the reaction for the other also4 ,we call this an ekphoric influence1 and stimuli having this character are called ekphoric stimuli4 ,in such a case we call the engrams of the two stimuli associated4 ,all simultaneously generated engrams are associated2 there is also association of successively aroused engrams1 though this is reducible to simultaneous association4 ,in fact1 it is not an isolated stimulus that leaves an engram1 but the totality of the stimuli at any moment2 consequently any portion of this totality tends1 if it recurs1 to arouse the whole reaction which was aroused before4 ,semon holds that engrams can be inherited1 and that an animal's innate habits may be due to the experience of its ancestors2 on this subject he refers to ,samuel ,butler4 ,semon formulates two mnemic principles4 ,the first1 or ,law of ,engraphy1 is as follows3 ,all simultaneous excitements in an organism form a connected simultaneous excitement-complex1 which as such works engraphically1 i4e4 leaves behind a connected engram-complex1 which in so far forms a whole 7,die mnemischen ,empfindungen1 p4 #adf74 ,the second mnemic principle1 or ,law of ,ekphory1 is as follows3 ,the partial return of the energetic situation which formerly worked engraphically operates ekphorically on a simultaneous engram-complex 7ib41 p4 #agc74 ,these two laws together represent in part a hypothesis 7the engram71 and in part an observable fact4 ,the observable fact is that1 when a certain complex of stimuli has originally caused a certain complex of reactions1 the recurrence of part of the stimuli tends to cause the recurrence of the whole of the reactions4 ,semon's applications of his fundamental ideas in various directions are interesting and ingenious4 ,some of them will concern us later1 but for the present it is the fundamental character of mnemic phenomena that is in question4 ,concerning the nature of an engram1 ,semon confesses that at present it is impossible to say more than that it must consist in some material alteration in the body of the organism 7,die mnemischen ,empfindungen1 p4 #cgf74 ,it is1 in fact1 hypothetical1 invoked for theoretical uses1 and not an outcome of direct observation4 ,no doubt physiology1 especially the disturbances of memory through lesions in the brain1 affords grounds for this hypothesis2 nevertheless it does remain a hypothesis1 the validity of which will be discussed at the end of this lecture4 ,i am inclined to think that1 in the present state of physiology1 the introduction of the engram does not serve to simplify the account of mnemic phenomena4 ,we can1 ,i think1 formulate the known laws of such phenomena in terms1 wholly1 of observable facts1 by recognizing provisionally what we may call mnemic causation4 ,by this ,i mean that kind of causation of which ,i spoke at the beginning of this lecture1 that kind1 namely1 in which the proximate cause consists not merely of a present event1 but of this together with a past event4 ,i do not wish to urge that this form of causation is ultimate1 but that1 in the present state of our knowledge1 it affords a simplification1 and enables us to state laws of behaviour in less hypothetical terms than we should otherwise have to employ4 ,the clearest instance of what ,i mean is recollection of a past event4 ,what we observe is that certain present stimuli lead us to recollect certain occurrences1 but that at times when we are not recollecting them1 there is nothing discoverable in our minds that could be called memory of them4 ,memories1 as mental facts1 arise from time to time1 but do not1 so far as we can see1 exist in any shape while they are latent4 ,in fact1 when we say that they are latent1 we mean merely that they will exist under certain circumstances4 ,if1 then1 there is to be some standing difference between the person who can remember a certain fact and the person who cannot1 that standing difference must be1 not in anything mental1 but in the brain4 ,it is quite probable that there is such a difference in the brain1 but its nature is unknown and it remains hypothetical4 ,everything that has1 so far1 been made matter of observation as regards this question can be put together in the statement3 ,when a certain complex of sensations has occurred to a man1 the recurrence of part of the complex tends to arouse the recollection of the whole4 ,in like manner1 we can collect all mnemic phenomena in living organisms under a single law1 which contains what is hitherto verifiable in ,semon's two laws4 ,this single law is3 ,,if ,a ,,complex ,,stimulus ,a ,,has ,,caused ,a ,,complex ,,reaction ,b ,,in ,,an ,,organism1 ,,the ,,occurrence ,,of ,a ,,part ,,of ,a ,,on ,a ,,future ,,occasion ,,tends ,,to ,,cause ,,the ,,whole ,,reaction ,b4 ,this law would need to be supplemented by some account of the influence of frequency1 and so on2 but it seems to contain the essential characteristic of mnemic phenomena1 without admixture of anything hypothetical4 ,whenever the effect resulting from a stimulus to an organism differs according to the past history of the organism1 without our being able actually to detect any relevant difference in its present structure1 we will speak of mnemic causation1 provided we can discover laws embodying the influence of the past4 ,in ordinary physical causation1 as it appears to common sense1 we have approximate uniformities of sequence1 such as lightning is followed by thunder1 drunkenness is followed by headache1 and so on4 ,none of these sequences are theoretically invariable1 since something may intervene to disturb them4 ,in order to obtain invariable physical laws1 we have to proceed to differential equations1 showing the direction of change at each moment1 not the integral change after a finite interval1 however short4 ,but for the purposes of daily life many sequences are to all in tents and purposes invariable4 ,with the behaviour of human beings1 however1 this is by no means the case4 ,if you say to an ,englishman1 ,you have a smut on your nose1 he will proceed to remove it1 but there will be no such effect if you say the same thing to a ,frenchman who knows no ,english4 ,the effect of words upon the hearer is a mnemic phenomena1 since it depends upon the past experience which gave him understanding of the words4 ,if there are to be purely psychological causal laws1 taking no account of the brain and the rest of the body1 they will have to be of the form1 not ,x now causes ,y now1 but-- ,a1 ,b1 ,c1444 in the past1 together with ,x now1 cause ,y now4 ,for it cannot be successfully maintained that our understanding of a word1 for example1 is an actual existent content of the mind at times when we are not thinking of the word4 ,it is merely what may be called a disposition1 i4e4 it is capable of being aroused whenever we hear the word or happen to think of it4 ,a disposition is not something actual1 but merely the mnemic portion of a mnemic causal law4 ,in such a law as ,a1 ,b1 ,c1444 in the past1 together with ,x now1 cause ,y now1 we will call ,a1 ,b1 ,c1444 the mnemic cause1 ,x the occasion or stimulus1 and ,y the reaction4 ,all cases in which experience influences behaviour are instances of mnemic causation4 ,believers in psycho-physical parallelism hold that psychology can theoretically be freed entirely from all dependence on physiology or physics4 ,that is to say1 they believe that every psychical event has a psychical cause and a physical concomitant4 ,if there is to be parallelism1 it is easy to prove by mathematical logic that the causation in physical and psychical matters must be of the same sort1 and it is impossible that mnemic causation should exist in psychology but not in physics4 ,but if psychology is to be independent of physiology1 and if physiology can be reduced to physics1 it would seem that mnemic causation is essential in psychology4 ,otherwise we shall be compelled to believe that all our knowledge1 all our store of images and memories1 all our mental habits1 are at all times existing in some latent mental form1 and are not merely aroused by the stimuli which lead to their display4 ,this is a very difficult hypothesis4 ,it seems to me that if1 as a matter of method rather than metaphysics1 we desire to obtain as much independence for psychology as is practically feasible1 we shall do better to accept mnemic causation in psychology protem1 and therefore reject parallelism1 since there is no good ground for admitting mnemic causation in physics4 ,it is perhaps worth while to observe that mnemic causation is what led ,bergson to deny that there is causation at all in the psychical sphere4 ,he points out1 very truly1 that the same stimulus1 repeated1 does not have the same consequences1 and he argues that this is contrary to the maxim1 same cause1 same effect4 ,it is only necessary1 however1 to take account of past occurrences and include them with the cause1 in order to re-establish the maxim1 and the possibility of psychological causal laws4 ,the metaphysical conception of a cause lingers in our manner of viewing causal laws3 we want to be able to ,,feel a connection between cause and effect1 and to be able to imagine the cause as operating4 ,this makes us unwilling to regard causal laws as ,,merely observed uniformities of sequence2 yet that is all that science has to offer4 ,to ask why such-and-such a kind of sequence occurs is either to ask a meaningless question1 or to demand some more general kind of sequence which includes the one in question4 ,the widest empirical laws of sequence known at any time can only be explained in the sense of being subsumed by later discoveries under wider laws2 but these wider laws1 until they in turn are subsumed1 will remain brute facts1 resting solely upon observation1 not upon some supposed inherent rationality4 ,there is therefore no a priori objection to a causal law in which part of the cause has ceased to exist4 ,to argue against such a law on the ground that what is past cannot operate now1 is to introduce the old metaphysical notion of cause1 for which science can find no place4 ,the only reason that could be validly alleged against mnemic causation would be that1 in fact1 all the phenomena can be explained without it4 ,they are explained without it by ,semon's engram1 or by any theory which regards the results of experience as embodied in modifications of the brain and nerves4 ,but they are not explained1 unless with extreme artificiality1 by any theory which regards the latent effects of experience as psychical rather than physical4 ,those who desire to make psychology as far as possible independent of physiology would do well1 it seems to me1 if they adopted mnemic causation4 ,for my part1 however1 ,i have no such desire1 and ,i shall therefore endeavour to state the grounds which occur to me in favour of some such view as that of the engram4 ,one of the first points to be urged is that mnemic phenomena are just as much to be found in physiology as in psychology4 ,they are even to be found in plants1 as ,sir ,francis ,darwin pointed out 7cf4 ,semon1 ,die ,mneme1 #bnd edition1 p4 #bh n474 ,habit is a characteristic of the body at least as much as of the mind4 ,we should1 therefore1 be compelled to allow the intrusion of mnemic causation1 if admitted at all1 into non-psychological regions1 which ought1 one feels1 to be subject only to causation of the ordinary physical sort4 ,the fact is that a great deal of what1 at first sight1 distinguishes psychology from physics is found1 on examination1 to be common to psychology and physiology2 this whole question of the influence of experience is a case in point4 ,now it is possible1 of course1 to take the view advocated by ,professor ,j4 ,s4 ,haldane1 who contends that physiology is not theoretically reducible to physics and chemistry499 ,but the weight of opinion among physiologists appears to be against him on this point2 and we ought certainly to require very strong evidence before admitting any such breach of continuity as between living and dead matter4 ,the argument from the existence of mnemic phenomena in physiology must therefore be allowed a certain weight against the hypothesis that mnemic causation is ultimate4 99 ,see his ,the ,new ,physiology and ,other ,addresses1 ,griffin1 #aiai1 also the symposium1 ,are ,physical1 ,biological and ,psychological ,categories ,irreducible8 in ,life and ,finite ,individuality1 edited for the ,aristotelian ,society1 with an ,introduction4 ,by ,h4 ,wildon ,carr1 ,williams ,norgate1 #aiah4 ,the argument from the connection of brain-lesions with loss of memory is not so strong as it looks1 though it has also1 some weight4 ,what we know is that memory1 and mnemic phenomena generally1 can be disturbed or destroyed by changes in the brain4 ,this certainly proves that the brain plays an essential part in the causation of memory1 but does not prove that a certain state of the brain is1 by itself1 a sufficient condition for the existence of memory4 ,yet it is this last that has to be proved4 ,the theory of the engram1 or any similar theory1 has to maintain that1 given a body and brain in a suitable state1 a man will have a certain memory1 without the need of any further conditions4 ,what is known1 however1 is only that he will not have memories if his body and brain are not in a suitable state4 ,that is to say1 the appropriate state of body and brain is proved to be necessary for memory1 but not to be sufficient4 ,so far1 therefore1 as our definite knowledge goes1 memory may require for its causation a past occurrence as well as a certain present state of the brain4 ,in order to prove conclusively that mnemic phenomena arise whenever certain physiological conditions are fulfilled1 we ought to be able actually to see differences between the brain of a man who speaks ,english and that of a man who speaks ,french1 between the brain of a man who has seen ,new ,york and can recall it1 and that of a man who has never seen that city4 ,it may be that the time will come when this will be possible1 but at present we are very far removed from it4 ,at present1 there is1 so far as ,i am aware1 no good evidence that every difference between the knowledge possessed by ,a and that possessed by ,b is paralleled by some difference in their brains4 ,we may believe that this is the case1 but if we do1 our belief is based upon analogies and general scientific maxims1 not upon any foundation of detailed observation4 ,i am myself inclined1 as a working hypothesis1 to adopt the belief in question1 and to hold that past experience only affects present behaviour through modifications of physiological structure4 ,but the evidence seems not quite conclusive1 so that ,i do not think we ought to forget the other hypothesis1 or to reject entirely the possibility that mnemic causation may be the ultimate explanation of mnemic phenomena4 ,i say this1 not because ,i think it ,,likely that mnemic causation is ultimate1 but merely because ,i think it ,,possible1 and because it often turns out important to the progress of science to remember hypotheses which have previously seemed improbable4 ,,lecture ,v4 ,,psychological ,,and ,,physical ,,causal ,,laws ,the traditional conception of cause and effect is one which modern science shows to be fundamentally erroneous1 and requiring to be replaced by a quite different notion1 that of ,,laws ,,of ,,change4 ,in the traditional conception1 a particular event ,a caused a particular event ,b1 and by this it was implied that1 given any event ,b1 some earlier event ,a could be discovered which had a relation to it1 such that-- 7#a7 ,whenever ,a occurred1 it was followed by ,b2 7#b7 ,in this sequence1 there was something necessary1 not a mere de facto occurrence of ,a first and then ,b4 ,the second point is illustrated by the old discussion as to whether it can be said that day causes night1 on the ground that day is always followed by night4 ,the orthodox answer was that day could not be called the cause of night1 because it would not be followed by night if the earth's rotation were to cease1 or rather to grow so slow that one complete rotation would take a year4 ,a cause1 it was held1 must be such that under no conceivable circumstances could it fail to be followed by its effect4 ,as a matter of fact1 such sequences as were sought by believers in the traditional form of causation have not so far been found in nature4 ,everything in nature is apparently in a state of continuous change199 so that what we call one event turns out to be really a process4 ,if this event is to cause another event1 the two will have to be contiguous in time2 for if there is any interval between them1 something may happen during that interval to prevent the expected effect4 ,cause and effect1 therefore1 will have to be temporally contiguous processes4 ,it is difficult to believe1 at any rate where physical laws are concerned1 that the earlier part of the process which is the cause can make any difference to the effect1 so long as the later part of the process which is the cause remains unchanged4 ,suppose1 for example1 that a man dies of arsenic poisoning1 we say that his taking arsenic was the cause of death4 ,but clearly the process by which he acquired the arsenic is irrelevant3 everything that happened before he swallowed it may be ignored1 since it cannot alter the effect except in so far as it alters his condition at the moment of taking the dose4 ,but we may go further3 swallowing arsenic is not really the proximate cause of death1 since a man might be shot through the head immediately after taking the dose1 and then it would not be of arsenic that he would die4 ,the arsenic produces certain physiological changes1 which take a finite time before they end in death4 ,the earlier parts of these changes can be ruled out in the same way as we can rule out the process by which the arsenic was acquired4 ,proceeding in this way1 we can shorten the process which we are calling the cause more and more4 ,similarly we shall have to shorten the effect4 ,it may happen that immediately after the man's death his body is blown to pieces by a bomb4 ,we cannot say what will happen after the man's death1 through merely knowing that he has died as the result of arsenic poisoning4 ,thus1 if we are to take the cause as one event and the effect as another1 both must be shortened indefinitely4 ,the result is that we merely have1 as the embodiment of our causal law1 a certain direction of change at each moment4 ,hence we are brought to differential equations as embodying causal laws4 ,a physical law does not say ,a will be followed by ,b1 but tells us what acceleration a particle will have under given circumstances1 i4e4 it tells us how the particle's motion is changing at each moment1 not where the particle will be at some future moment4 99 ,the theory of quanta suggests that the continuity is only apparent4 ,if so1 we shall be able theoretically to reach events which are not processes4 ,but in what is directly observable there is still apparent continuity1 which justifies the above remarks for the prevent4 ,laws embodied in differential equations may possibly be exact1 but cannot be known to be so4 ,all that we can know empirically is approximate and liable to exceptions2 the exact laws that are assumed in physics are known to be somewhere near the truth1 but are not known to be true just as they stand4 ,the laws that we actually know empirically have the form of the traditional causal laws1 except that they are not to be regarded as universal or necessary4 ,taking arsenic is followed by death is a good empirical generalization2 it may have exceptions1 but they will be rare4 ,as against the professedly exact laws of physics1 such empirical generalizations have the advantage that they deal with observable phenomena4 ,we cannot observe infinitesimals1 whether in time or space2 we do not even know whether time and space are infinitely divisible4 ,therefore rough empirical generalizations have a definite place in science1 in spite of not being exact of universal4 ,they are the data for more exact laws1 and the grounds for believing that they are ,,usually true are stronger than the grounds for believing that the more exact laws are ,,always true4 ,science starts1 therefore1 from generalizations of the form1 ,a is usually followed by ,b4 ,this is the nearest approach that can be made to a causal law of the traditional sort4 ,it may happen in any particular instance that ,a is ,,always followed by ,b1 but we cannot know this1 since we cannot foresee all the perfectly possible circumstances that might make the sequence fail1 or know that none of them will actually occur4 ,if1 however1 we know of a very large number of cases in which ,a is followed by ,b1 and few or none in which the sequence fails1 we shall in ,,practice be justified in saying ,a causes ,b1 provided we do not attach to the notion of cause any of the metaphysical superstitions that have gathered about the word4 ,there is another point1 besides lack of universality and necessity1 which it is important to realize as regards causes in the above sense1 and that is the lack of uniqueness4 ,it is generally assumed that1 given any event1 there is some one phenomenon which is ,,the cause of the event in question4 ,this seems to be a mere mistake4 ,cause1 in the only sense in which it can be practically applied1 means nearly invariable antecedent4 ,we cannot in practice obtain an antecedent which is ,,quite invariable1 for this would require us to take account of the whole universe1 since something not taken account of may prevent the expected effect4 ,we cannot distinguish1 among nearly invariable antecedents1 one as ,,the cause1 and the others as merely its concomitants3 the attempt to do this depends upon a notion of cause which is derived from will1 and will 7as we shall see later7 is not at all the sort of thing that it is generally supposed to be1 nor is there any reason to think that in the physical world there is anything even remotely analogous to what will is supposed to be4 ,if we could find one antecedent1 and only one1 that was ,,quite invariable1 we could call that one ,,the cause without introducing any notion derived from mistaken ideas about will4 ,but in fact we cannot find any antecedent that we know to be quite invariable1 and we can find many that are nearly so4 ,for example1 men leave a factory for dinner when the hooter sounds at twelve o'clock4 ,you may say the hooter is ,,the cause of their leaving4 ,but innumerable other hooters in other factories1 which also always sound at twelve o'clock1 have just as good a right to be called the cause4 ,thus every event has many nearly invariable antecedents1 and therefore many antecedents which may be called its cause4 ,the laws of traditional physics1 in the form in which they deal with movements of matter or electricity1 have an apparent simplicity which somewhat conceals the empirical character of what they assert4 ,a piece of matter1 as it is known empirically1 is not a single existing thing1 but a system of existing things4 ,when several people simultaneously see the same table1 they all see something different2 therefore the table1 which they are supposed all to see1 must be either a hypothesis or a construction4 ,the table is to be neutral as between different observers3 it does not favour the aspect seen by one man at the expense of that seen by another4 ,it was natural1 though to my mind mistaken1 to regard the real table as the common cause of all the appearances which the table presents 7as we say7 to different observers4 ,but why should we suppose that there is some one common cause of all these appearances8 ,as we have just seen1 the notion of cause is not so reliable as to allow us to infer the existence of something that1 by its very nature1 can never be observed4 ,instead of looking for an impartial source1 we can secure neutrality by the equal representation of all parties4 ,instead of supposing that there is some unknown cause1 the real table1 behind the different sensations of those who are said to be looking at the table1 we may take the whole set of these sensations 7together possibly with certain other particulars7 as actually ,,being the table4 ,that is to say1 the table which is neutral as between different observers 7actual and possible7 is the set of all those particulars which would naturally be called aspects of the table from different points of view4 7,this is a first approximation1 modified later47 ,it may be said3 ,if there is no single existent which is the source of all these aspects1 how are they collected together8 ,the answer is simple3 ,just as they would be if there were such a single existent4 ,the supposed real table underlying its appearances is1 in any case1 not itself perceived1 but inferred1 and the question whether such-and-such a particular is an aspect of this table is only to be settled by the connection of the particular in question with the one or more particulars by which the table is defined4 ,that is to say1 even if we assume a real table1 the particulars which are its aspects have to be collected together by their relations to each other1 not to it1 since it is merely inferred from them4 ,we have only1 therefore1 to notice how they are collected together1 and we can then keep the collection without assuming any real table as distinct from the collection4 ,when different people see what they call the same table1 they see things which are not exactly the same1 owing to difference of point of view1 but which are sufficiently alike to be described in the same words1 so long as no great accuracy or minuteness is sought4 ,these closely similar particulars are collected together by their similarity primarily and1 more correctly1 by the fact that they are related to each other approximately according to the laws of perspective and of reflection and diffraction of light4 ,i suggest1 as a first approximation1 that these particulars1 together with such correlated others as are unperceived1 jointly ,,are the table2 and that a similar definition applies to all physical objects499 99,see ,our ,knowledge of the ,external ,world 7,allen ,unwin71 chaps4 iii and iv4 ,in order to eliminate the reference to our perceptions1 which introduces an irrelevant psychological suggestion1 ,i will take a different illustration1 namely1 stellar photography4 ,a photographic plate exposed on a clear night reproduces the appearance of the portion of the sky concerned1 with more or fewer stars according to the power of the telescope that is being used4 ,each separate star which is photographed produces its separate effect on the plate1 just as it would upon ourselves if we were looking at the sky4 ,if we assume1 as science normally does1 the continuity of physical processes1 we are forced to conclude that1 at the place where the plate is1 and at all places between it and a star which it photographs1 ,,something is happening which is specially connected with that star4 ,in the days when the aether was less in doubt1 we should have said that what was happening was a certain kind of transverse vibration in the aether4 ,but it is not necessary or desirable to be so explicit3 all that we need say is that ,,something happens which is specially connected with the star in question4 ,it must be something specially connected with that star1 since that star produces its own special effect upon the plate4 ,whatever it is must be the end of a process which starts from the star and radiates outwards1 partly on general grounds of continuity1 partly to account for the fact that light is transmitted with a certain definite velocity4 ,we thus arrive at the conclusion that1 if a certain star is visible at a certain place1 or could be photographed by a sufficiently sensitive plate at that place1 something is happening there which is specially connected with that star4 ,therefore in every place at all times a vast multitude of things must be happening1 namely1 at least one for every physical object which can be seen or photographed from that place4 ,we can classify such happenings on either of two principles3 7#a7 ,we can collect together all the happenings in one place1 as is done by photography so far as light is concerned2 7#b7 ,we can collect together all the happenings1 in different places1 which are connected in the way that common sense regards as being due to their emanating from one object4 ,thus1 to return to the stars1 we can collect together either-- 7#a7 ,all the appearances of different stars in a given place1 or1 7#b7 ,all the appearances of a given star in different places4 ,but when ,i speak of appearances1 ,i do so only for brevity3 ,i do not mean anything that must appear to somebody1 but only that happening1 whatever it may be1 which is connected1 at the place in question1 with a given physical object--according to the old orthodox theory1 it would be a transverse vibration in the aether4 ,like the different appearances of the table to a number of simultaneous observers1 the different particulars that belong to one physical object are to be collected together by continuity and inherent laws of correlation1 not by their supposed causal connection with an unknown assumed existent called a piece of matter1 which would be a mere unnecessary metaphysical thing in itself4 ,a piece of matter1 according to the definition that ,i propose1 is1 as a first approximation199 the collection of all those correlated particulars which would normally be regarded as its appearances or effects in different places4 ,some further elaborations are desirable1 but we can ignore them for the present4 ,i shall return to them at the end of this lecture4 99,the exact definition of a piece of matter as a construction will be given later4 ,according to the view that ,i am suggesting1 a physical object or piece of matter is the collection of all those correlated particulars which would be regarded by common sense as its effects or appearances in different places4 ,on the other hand1 all the happenings in a given place represent what common sense would regard as the appearances of a number of different objects as viewed from that place4 ,all the happenings in one place may be regarded as the view of the world from that place4 ,i shall call the view of the world from a given place a perspective4 ,a photograph represents a perspective4 ,on the other hand1 if photographs of the stars were taken in all points throughout space1 and in all such photographs a certain star1 say ,sirius1 were picked out whenever it appeared1 all the different appearances of ,sirius1 taken together1 would represent ,sirius4 ,for the understanding of the difference between psychology and physics it is vital to understand these two ways of classifying particulars1 namely3 7#a7 ,according to the place where they occur2 7#b7 ,according to the system of correlated particulars in different places to which they belong1 such system being defined as a physical object4 ,given a system of particulars which is a physical object1 ,i shall define that one of the system which is in a given place 7if any7 as the appearance of that object in that place4 ,when the appearance of an object in a given place changes1 it is found that one or other of two things occurs4 ,the two possibilities may be illustrated by an example4 ,you are in a room with a man1 whom you see3 you may cease to see him either by shutting your eyes or by his going out of the room4 ,in the first case1 his appearance to other people remains unchanged2 in the second1 his appearance changes from all places4 ,in the first case1 you say that it is not he who has changed1 but your eyes2 in the second1 you say that he has changed4 ,generalizing1 we distinguish-- 7#a7 ,cases in which only certain appearances of the object change1 while others1 and especially appearances from places very near to the object1 do not change2 7#b7 ,cases where all1 or almost all1 the appearances of the object undergo a connected change4 ,in the first case1 the change is attributed to the medium between the object and the place2 in the second1 it is attributed to the object itself499 99 ,the application of this distinction to motion raises complications due to relativity1 but we may ignore these for our present purposes4 ,it is the frequency of the latter kind of change1 and the comparatively simple nature of the laws governing the simultaneous alterations of appearances in such cases1 that have made it possible to treat a physical object as one thing1 and to overlook the fact that it is a system of particulars4 ,when a number of people at a theatre watch an actor1 the changes in their several perspectives are so similar and so closely correlated that all are popularly regarded as identical with each other and with the changes of the actor himself4 ,so long as all the changes in the appearances of a body are thus correlated there is no pressing prima facie need to break up the system of appearances1 or to realize that the body in question is not really one thing but a set of correlated particulars4 ,it is especially and primarily such changes that physics deals with1 i4e4 it deals primarily with processes in which the unity of a physical object need not be broken up because all its appearances change simultaneously according to the same law--or1 if not all1 at any rate all from places sufficiently near to the object1 with in creasing accuracy as we approach the object4 ,the changes in appearances of an object which are due to changes in the intervening medium will not affect1 or will affect only very slightly1 the appearances from places close to the object4 ,if the appearances from sufficiently neighbouring places are either wholly un changed1 or changed to a diminishing extent which has zero for its limit1 it is usually found that the changes can be accounted for by changes in objects which are between the object in question and the places from which its appearance has changed appreciably4 ,thus physics is able to reduce the laws of most changes with which it deals to changes in physical objects1 and to state most of its fundamental laws in terms of matter4 ,it is only in those cases in which the unity of the system of appearances constituting a piece of matter has to be broken up1 that the statement of what is happening cannot be made exclusively in terms of matter4 ,the whole of psychology1 we shall find1 is included among such cases2 hence their importance for our purposes4 ,we can now begin to understand one of the fundamental differences between physics and psychology4 ,physics treats as a unit the whole system of appearances of a piece of matter1 whereas psychology is interested in certain of these appearances themselves4 ,confining ourselves for the moment to the psychology of perceptions1 we observe that perceptions are certain of the appearances of physical objects4 ,from the point of view that we have been hitherto adopting1 we might define them as the appearances of objects at places from which sense-organs and the suitable parts of the nervous system form part of the intervening medium4 ,just as a photographic plate receives a different impression of a cluster of stars when a telescope is part of the intervening medium1 so a brain receives a different impression when an eye and an optic nerve are part of the intervening medium4 ,an impression due to this sort of intervening medium is called a perception1 and is interesting to psychology on its own account1 not merely as one of the set of correlated particulars which is the physical object of which 7as we say7 we are having a perception4 ,we spoke earlier of two ways of classifying particulars4 ,one way collects together the appearances commonly regarded as a given object from different places2 this is1 broadly speaking1 the way of physics1 leading to the construction of physical objects as sets of such appearances4 ,the other way collects together the appearances of different objects from a given place1 the result being what we call a perspective4 ,in the particular case where the place concerned is a human brain1 the perspective belonging to the place consists of all the perceptions of a certain man at a given time4 ,thus classification by perspectives is relevant to psychology1 and is essential in defining what we mean by one mind4 ,i do not wish to suggest that the way in which ,i have been defining perceptions is the only possible way1 or even the best way4 ,it is the way that arose naturally out of our present topic4 ,but when we approach psychology from a more introspective standpoint1 we have to distinguish sensations and perceptions1 if possible1 from other mental occurrences1 if any4 ,we have also to consider the psychological effects of sensations1 as opposed to their physical causes and correlates4 ,these problems are quite distinct from those with which we have been concerned in the present lecture1 and ,i shall not deal with them until a later stage4 ,it is clear that psychology is concerned essentially with actual particulars1 not merely with systems of particulars4 ,in this it differs from physics1 which1 broadly speaking1 is concerned with the cases in which all the particulars which make up one physical object can be treated as a single causal unit1 or rather the particulars which are sufficiently near to the object of which they are appearances can be so treated4 ,the laws which physics seeks can1 broadly speaking1 be stated by treating such systems of particulars as causal units4 ,the laws which psychology seeks cannot be so stated1 since the particulars themselves are what interests the psychologist4 ,this is one of the fundamental differences between physics and psychology2 and to make it clear has been the main purpose of this lecture4 ,i will conclude with an attempt to give a more precise definition of a piece of matter4 ,the appearances of a piece of matter from different places change partly according to intrinsic laws 7the laws of perspective1 in the case of visual shape71 partly according to the nature of the intervening medium--fog1 blue spectacles1 telescopes1 microscopes1 sense-organs1 etc4 ,as we approach nearer to the object1 the effect of the intervening medium grows less4 ,in a generalized sense1 all the intrinsic laws of change of appearance may be called laws of perspective4 ,given any appearance of an object1 we can construct hypothetically a certain system of appearances to which the appearance in question would belong if the laws of perspective alone were concerned4 ,if we construct this hypothetical system for each appearance of the object in turn1 the system corresponding to a given appearance x will be independent of any distortion due to the medium beyond x1 and will only embody such distortion as is due to the medium between x and the object4 ,thus1 as the appearance by which our hypothetical system is defined is moved nearer and nearer to the object1 the hypothetical system of appearances defined by its means embodies less and less of the effect of the medium4 ,the different sets of appearances resulting from moving x nearer and nearer to the object will approach to a limiting set1 and this limiting set will be that system of appearances which the object would present if the laws of perspective alone were operative and the medium exercised no distorting effect4 ,this limiting set of appearances may be defined1 for purposes of physics1 as the piece of matter concerned4 ,,lecture ,,vi4 ,,introspection ,one of the main purposes of these lectures is to give grounds for the belief that the distinction between mind and matter is not so fundamental as is commonly supposed4 ,in the preceding lecture ,i dealt in outline with the physical side of this problem4 ,i attempted to show that what we call a material object is not itself a substance1 but is a system of particulars analogous in their nature to sensations1 and in fact often including actual sensations among their number4 ,in this way the stuff of which physical objects are composed is brought into relation with the stuff of which part1 at least1 of our mental life is composed4 ,there is1 however1 a converse task which is equally necessary for our thesis1 and that is1 to show that the stuff of our mental life is devoid of many qualities which it is commonly supposed to have1 and is not possessed of any attributes which make it incapable of forming part of the world of matter4 ,in the present lecture ,i shall begin the arguments for this view4 ,corresponding to the supposed duality of matter and mind1 there are1 in orthodox psychology1 two ways of knowing what exists4 ,one of these1 the way of sensation and external perception1 is supposed to furnish data for our knowledge of matter1 the other1 called introspection1 is supposed to furnish data for knowledge of our mental processes4 ,to common sense1 this distinction seems clear and easy4 ,when you see a friend coming along the street1 you acquire knowledge of an external1 physical fact2 when you realize that you are glad to meet him1 you acquire knowledge of a mental fact4 ,your dreams and memories and thoughts1 of which you are often conscious1 are mental facts1 and the process by which you become aware of them ,,seems to be different from sensation4 ,kant calls it the inner sense2 sometimes it is spoken of as consciousness of self2 but its commonest name in modern ,english psychology is introspection4 ,it is this supposed method of acquiring knowledge of our mental processes that ,i wish to analyse and examine in this lecture4 ,i will state at the outset the view which ,i shall aim at establishing4 ,i believe that the stuff of our mental life1 as opposed to its relations and structure1 consists wholly of sensations and images4 ,sensations are connected with matter in the way that ,i tried to explain in ,lecture ,v1 i4e4 each is a member of a system which is a certain physical object4 ,images1 though they ,,usually have certain characteristics1 especially lack of vividness1 that distinguish them from sensations1 are not ,,invariably so distinguished1 and cannot therefore be defined by these characteristics4 ,images1 as opposed to sensations1 can only be defined by their different causation3 they are caused by association with a sensation1 not by a stimulus external to the nervous system--or perhaps one should say external to the brain1 where the higher animals are concerned4 ,the occurrence of a sensation or image does not in itself constitute knowledge but any sensation or image may come to be known if the conditions are suitable4 ,when a sensation--like the hearing of a clap of thunder--is normally correlated with closely similar sensations in our neighbours1 we regard it as giving knowledge of the external world1 since we regard the whole set of similar sensations as due to a common external cause4 ,but images and bodily sensations are not so correlated4 ,bodily sensations can be brought into a correlation by physiology1 and thus take their place ultimately among sources of knowledge of the physical world4 ,but images cannot be made to fit in with the simultaneous sensations and images of others4 ,apart from their hypothetical causes in the brain1 they have a causal connection with physical objects1 through the fact that they are copies of past sensations2 but the physical objects with which they are thus connected are in the past1 not in the present4 ,these images remain private in a sense in which sensations are not4 ,a sensation ,,seems to give us knowledge of a present physical object1 while an image does not1 except when it amounts to a hallucination1 and in this case the seeming is deceptive4 ,thus the whole context of the two occurrences is different4 ,but in themselves they do not differ profoundly1 and there is no reason to invoke two different ways of knowing for the one and for the other4 ,consequently introspection as a separate kind of knowledge disappears4 ,the criticism of introspection has been in the main the work of ,american psychologists4 ,i will begin by summarizing an article which seems to me to afford a good specimen of their arguments1 namely1 ,the ,case against ,introspection1 by ,knight ,dunlap 7,psychological ,review1 vol xix1 ,no4 #e1 pp4 #djd-dac1 ,september1 #aiab74 ,after a few historical quotations1 he comes to two modern defenders of introspection1 ,stout and ,james4 ,he quotes from ,stout such statements as the following3 ,psychical states as such become objects only when we attend to them in an introspective way4 ,otherwise they are not themselves objects1 but only constituents of the process by which objects are recognized 7,manual1 #bnd edition1 p4 #acd4 ,the word recognized in ,dunlap's quotation should be cognized47 ,the object itself can never be identified with the present modification of the individual's consciousness by which it is cognized 7ib4 p4 #fj74 ,this is to be true even when we are thinking about modifications of our own consciousness2 such modifications are to be always at least partially distinct from the conscious experience in which we think of them4 ,at this point ,i wish to interrupt the account of ,knight ,dunlap's article in order to make some observations on my own account with reference to the above quotations from ,stout4 ,in the first place1 the conception of psychical states seems to me one which demands analysis of a somewhat destructive character4 ,this analysis ,i shall give in later lectures as regards cognition2 ,i have already given it as regards desire4 ,in the second place1 the conception of objects depends upon a certain view as to cognition which ,i believe to be wholly mistaken1 namely1 the view which ,i discussed in my first lecture in connection with ,brentano4 ,in this view a single cognitive occurrence contains both content and object1 the content being essentially mental1 while the object is physical except in introspection and abstract thought4 ,i have already criticized this view1 and will not dwell upon it now1 beyond saying that the process by which objects are cognized appears to be a very slippery phrase4 ,when we see a table1 as common sense would say1 the table as a physical object is not the object 7in the psychological sense7 of our perception4 ,our perception is made up of sensations1 images and beliefs1 but the supposed object is something inferential1 externally related1 not logically bound up with what is occurring in us4 ,this question of the nature of the object also affects the view we take of self-consciousness4 ,obviously1 a conscious experience is different from a physical object2 therefore it is natural to assume that a thought or perception whose object is a conscious experience must be different from a thought or perception whose object is a physical object4 ,but if the relation to the object is inferential and external1 as ,i maintain1 the difference between two thoughts may bear very little relation to the difference between their objects4 ,and to speak of the present modification of the individual's consciousness by which an object is cognized is to suggest that the cognition of objects is a far more direct process1 far more intimately bound up with the objects1 than ,i believe it to be4 ,all these points will be amplified when we come to the analysis of knowledge1 but it is necessary briefly to state them now in order to suggest the atmosphere in which our analysis of introspection is to be carried on4 ,another point in which ,stout's remarks seem to me to suggest what ,i regard as mistakes is his use of consciousness4 ,there is a view which is prevalent among psychologists1 to the effect that one can speak of a conscious experience in a curious dual sense1 meaning1 on the one hand1 an experience which is conscious of something1 and1 on the other hand1 an experience which has some intrinsic nature characteristic of what is called consciousness4 ,that is to say1 a conscious experience is characterized on the one hand by relation to its object and on the other hand by being composed of a certain peculiar stuff1 the stuff of consciousness4 ,and in many authors there is yet a third confusion3 a conscious experience1 in this third sense1 is an experience of which we are conscious4 ,all these1 it seems to me1 need to be clearly separated4 ,to say that one occurrence is conscious of another is1 to my mind1 to assert an external and rather remote relation between them4 ,i might illustrate it by the relation of uncle and nephew a man becomes an uncle through no effort of his own1 merely through an occurrence elsewhere4 ,similarly1 when you are said to be conscious of a table1 the question whether this is really the case cannot be decided by examining only your state of mind3 it is necessary also to ascertain whether your sensation is having those correlates which past experience causes you to assume1 or whether the table happens1 in this case1 to be a mirage4 ,and1 as ,i explained in my first lecture1 ,i do not believe that there is any stuff of consciousness1 so that there is no intrinsic character by which a conscious experience could be distinguished from any other4 ,after these preliminaries1 we can return to ,knight ,dunlap's article4 ,his criticism of ,stout turns on the difficulty of giving any empirical meaning to such notions as the mind or the subject2 he quotes from ,stout the sentence3 ,the most important drawback is that the mind1 in watching its own workings1 must necessarily have its attention divided between two objects1 and he concludes3 ,without question1 ,stout is bringing in here illicitly the concept of a single observer1 and his introspection does not provide for the observation of this observer2 for the process observed and the observer are distinct 7p4 #djg74 ,the objections to any theory which brings in the single observer were considered in ,lecture ,i1 and were acknowledged to be cogent4 ,in so far1 therefore1 as ,stout's theory of introspection rests upon this assumption1 we are compelled to reject it4 ,but it is perfectly possible to believe in introspection without supposing that there is a single observer4 ,william ,james's theory of introspection1 which ,dunlap next examines1 does not assume a single observer4 ,it changed after the publication of his ,psychology1 in consequence of his abandoning the dualism of thought and things4 ,dunlap summarizes his theory as follows3 ,the essential points in ,james's scheme of consciousness are ,,subject1 ,,object1 and a ,,knowing of the object by the subject4 ,the difference between ,james's scheme and other schemes involving the same terms is that ,james considers subject and object to be the same thing1 but at different times ,in order to satisfy this requirement ,james supposes a realm of existence which he at first called 'states of consciousness' or 'thoughts1' and later1 'pure experience1' the latter term including both the 'thoughts' and the 'knowing4' ,this scheme1 with all its magnificent artificiality1 ,james held on to until the end1 simply dropping the term consciousness and the dualism between the thought and an external reality7p4 #dji74 ,he adds3 ,all that ,james's system really amounts to is the acknowledgment that a succession of things are known1 and that they are known by something4 ,this is all any one can claim1 except for the fact that the things are known together1 and that the knower for the different items is one and the same 7ib474 ,in this statement1 to my mind1 ,dunlap concedes far more than ,james did in his later theory4 ,i see no reason to suppose that the knower for different items is one and the same1 and ,i am convinced that this proposition could not possibly be ascertained except by introspection of the sort that ,dunlap rejects4 ,the first of these points must wait until we come to the analysis of belief3 the second must be considered now4 ,dunlap's view is that there is a dualism of subject and object1 but that the subject can never become object1 and therefore there is no awareness of an awareness4 ,he says in discussing the view that introspection reveals the occurrence of knowledge3 ,there can be no denial of the existence of the thing 7knowing7 which is alleged to be known or observed in this sort of 'introspection4' ,the allegation that the knowing is observed is that which may be denied4 ,knowing there certainly is2 known1 the knowing certainly is not7p4 #daj74 ,and again3 ,i am never aware of an awareness 7ib474 ,and on the next page3 ,it may sound paradoxical to say that one cannot observe the process 7or relation7 of observation1 and yet may be certain that there is such a process3 but there is really no inconsistency in the saying4 ,how do ,i know that there is awareness8 ,by being aware of something4 ,there is no meaning in the term 'awareness' which is not expressed in the statement ',i am aware of a colour 7or what-not74' ,but the paradox cannot be so lightly disposed of4 ,the statement ,i am aware of a colour is assumed by ,knight ,dunlap to be known to be true1 but he does not explain how it comes to be known4 ,the argument against him is not conclusive1 since he may be able to show some valid way of inferring our awareness4 ,but he does not suggest any such way4 ,there is nothing odd in the hypothesis of beings which are aware of objects1 but not of their own awareness2 it is1 indeed1 highly probable that young children and the higher animals are such beings4 ,but such beings cannot make the statement ,i am aware of a colour1 which ,,we can make4 ,we have1 therefore1 some knowledge which they lack4 ,it is necessary to ,knight ,dunlap's position to maintain that this additional knowledge is purely inferential1 but he makes no attempt to show how the inference is possible4 ,it may1 of course1 be possible1 but ,i cannot see how4 ,to my mind the fact 7which he admits7 that we know there is awareness1 is ,,all ,,but decisive against his theory1 and in favour of the view that we can be aware of an awareness4 ,dunlap asserts 7to return to ,james7 that the real ground for ,james's original belief in introspection was his belief in two sorts of objects1 namely1 thoughts and things4 ,he suggests that it was a mere inconsistency on ,james's part to adhere to introspection after abandoning the dualism of thoughts and things4 ,i do not wholly agree with this view1 but it is difficult to disentangle the difference as to introspection from the difference as to the nature of knowing4 ,dunlap suggests 7p4 #daa7 that what is called introspection really consists of awareness of images1 visceral sensations1 and so on4 ,this view1 in essence1 seems to me sound4 ,but then ,i hold that knowing itself consists of such constituents suitably related1 and that in being aware of them we are sometimes being aware of instances of knowing4 ,for this reason1 much as ,i agree with his view as to what are the objects of which there is awareness1 ,i cannot wholly agree with his conclusion as to the impossibility of introspection4 ,the behaviourists have challenged introspection even more vigorously than ,knight ,dunlap1 and have gone so far as to deny the existence of images4 ,but ,i think that they have confused various things which are very commonly confused1 and that it is necessary to make several distinctions before we can arrive at what is true and what false in the criticism of introspection4 ,i wish to distinguish three distinct questions1 any one of which may be meant when we ask whether introspection is a source of knowledge4 ,the three questions are as follows3 7#a7 ,can we observe anything about ourselves which we cannot observe about other people1 or is everything we can observe ,,public1 in the sense that another could also observe it if suitably placed8 7#b7 ,does everything that we can observe obey the laws of physics and form part of the physical world1 or can we observe certain things that lie outside physics8 7#c7 ,can we observe anything which differs in its intrinsic nature from the constituents of the physical world1 or is everything that we can observe composed of elements intrinsically similar to the constituents of what is called matter8 ,any one of these three questions may be used to define introspection4 ,i should favour introspection in the sense of the first question1 i4e4 ,i think that some of the things we observe cannot1 even theoretically1 be observed by any one else4 ,the second question1 tentatively and for the present1 ,i should answer in favour of introspection2 ,i think that images1 in the actual condition of science1 cannot be brought under the causal laws of physics1 though perhaps ultimately they may be4 ,the third question ,i should answer adversely to introspection ,i think that observation shows us nothing that is not composed of sensations and images1 and that images differ from sensations in their causal laws1 not intrinsically4 ,i shall deal with the three questions successively4 7#a7 ,,publicity ,,or ,,privacy ,,of ,,what ,,is ,,observed4 ,confining ourselves1 for the moment1 to sensations1 we find that there are different degrees of publicity attaching to different sorts of sensations4 ,if you feel a toothache when the other people in the room do not1 you are in no way surprised2 but if you hear a clap of thunder when they do not1 you begin to be alarmed as to your mental condition4 ,sight and hearing are the most public of the senses2 smell only a trifle less so2 touch1 again1 a trifle less1 since two people can only touch the same spot successively1 not simultaneously4 ,taste has a sort of semi-publicity1 since people seem to experience similar taste-sensations when they eat similar foods2 but the publicity is incomplete1 since two people cannot eat actually the same piece of food4 ,but when we pass on to bodily sensations--headache1 toothache1 hunger1 thirst1 the feeling of fatigue1 and so on--we get quite away from publicity1 into a region where other people can tell us what they feel1 but we cannot directly observe their feeling4 ,as a natural result of this state of affairs1 it has come to be thought that the public senses give us knowledge of the outer world1 while the private senses only give us knowledge as to our own bodies4 ,as regards privacy1 all images1 of whatever sort1 belong with the sensations which only give knowledge of our own bodies1 i4e4 each is only observable by one observer4 ,this is the reason why images of sight and hearing are more obviously different from sensations of sight and hearing than images of bodily sensations are from bodily sensations2 and that is why the argument in favour of images is more conclusive in such cases as sight and hearing than in such cases as inner speech4 ,the whole distinction of privacy and publicity1 however1 so long as we confine ourselves to sensations1 is one of degree1 not of kind4 ,no two people1 there is good empirical reason to think1 ever have exactly similar sensations related to the same physical object at the same moment2 on the other hand1 even the most private sensation has correlations which would theoretically enable another observer to infer it4 ,that no sensation is ever completely public1 results from differences of point of view4 ,two people looking at the same table do not get the same sensation1 because of perspective and the way the light falls4 ,they get only correlated sensations4 ,two people listening to the same sound do not hear exactly the same thing1 because one is nearer to the source of the sound than the other1 one has better hearing than the other1 and so on4 ,thus publicity in sensations consists1 not in having ,,precisely similar sensations1 but in having more or less similar sensations correlated according to ascertainable laws4 ,the sensations which strike us as public are those where the correlated sensations are very similar and the correlations are very easy to discover4 ,but even the most private sensations have correlations with things that others can observe4 ,the dentist does not observe your ache1 but he can see the cavity which causes it1 and could guess that you are suffering even if you did not tell him4 ,this fact1 however1 cannot be used1 as ,watson would apparently wish1 to extrude from science observations which are private to one observer1 since it is by means of many such observations that correlations are established1 e4g4 between toothaches and cavities4 ,privacy1 therefore does not by itself make a datum unamenable to scientific treatment4 ,on this point1 the argument against introspection must be rejected4 7#b7 ,,does ,,everything ,,observable ,,obey ,,the ,,laws ,,of ,,physics8 ,we come now to the second ground of objection to introspection1 namely1 that its data do not obey the laws of physics4 ,this1 though less emphasized1 is1 ,i think1 an objection which is really more strongly felt than the objection of privacy4 ,and we obtain a definition of introspection more in harmony with usage if we define it as observation of data not subject to physical laws than if we define it by means of privacy4 ,no one would regard a man as introspective because he was conscious of having a stomach ache4 ,opponents of introspection do not mean to deny the obvious fact that we can observe bodily sensations which others cannot observe4 ,for example1 ,knight ,dunlap contends that images are really muscular contractions199 and evidently regards our awareness of muscular contractions as not coming under the head of introspection4 ,i think it will be found that the essential characteristic of introspective data1 in the sense which now concerns us1 has to do with ,,localization3 either they are not localized at all1 or they are localized1 like visual images1 in a place already physically occupied by something which would be inconsistent with them if they were regarded as part of the physical world4 ,if you have a visual image of your friend sitting in a chair which in fact is empty1 you cannot locate the image in your body1 because it is visual1 nor 7as a physical phenomenon7 in the chair1 because the chair1 as a physical object1 is empty4 ,thus it seems to follow that the physical world does not include all that we are aware of1 and that images1 which are introspective data1 have to be regarded1 for the present1 as not obeying the laws of physics2 this is1 ,i think1 one of the chief reasons why an attempt is made to reject them4 ,i shall try to show in ,lecture ,,viii that the purely empirical reasons for accepting images are overwhelming4 ,but we cannot be nearly so certain that they will not ultimately be brought under the laws of physics4 ,even if this should happen1 however1 they would still be distinguishable from sensations by their proximate causal laws1 as gases remain distinguishable from solids4 99 ,psychological ,review1 #aiaf1 ,thought-,content and ,feeling1 p4 #ei4 ,see also ib41 #aiab1 ,the ,nature of ,perceived ,relations1 where he says3 ',introspection1' divested of its mythological suggestion of the observing of consciousness1 is really the observation of bodily sensations 7sensibles7 and feelings 7feelables77p4 #dbg n474 7#c7 ,,can ,,we ,,observe ,,anything ,,intrinsically ,,different ,,from ,,sensations8 ,we come now to our third question concerning introspection4 ,it is commonly thought that by looking within we can observe all sorts of things that are radically different from the constituents of the physical world1 e4g4 thoughts1 beliefs1 desires1 pleasures1 pains and emotions4 ,the difference between mind and matter is increased partly by emphasizing these supposed introspective data1 partly by the supposition that matter is composed of atoms or electrons or whatever units physics may at the moment prefer4 ,as against this latter supposition1 ,i contend that the ultimate constituents of matter are not atoms or electrons1 but sensations1 and other things similar to sensations as regards extent and duration4 ,as against the view that introspection reveals a mental world radically different from sensations1 ,i propose to argue that thoughts1 beliefs1 desires1 pleasures1 pains and emotions are all built up out of sensations and images alone1 and that there is reason to think that images do not differ from sensations in their intrinsic character4 ,we thus effect a mutual rapprochement of mind and matter1 and reduce the ultimate data of introspection 7in our second sense7 to images alone4 ,on this third view of the meaning of introspection1 therefore1 our decision is wholly against it4 ,there remain two points to be considered concerning introspection4 ,the first is as to how far it is trustworthy2 the second is as to whether1 even granting that it reveals no radically different ,,stuff from that revealed by what might be called external perception1 it may not reveal different ,,relations1 and thus acquire almost as much importance as is traditionally assigned to it4 ,to begin with the trustworthiness of introspection4 ,it is common among certain schools to regard the knowledge of our own mental processes as incomparably more certain than our knowledge of the external world2 this view is to be found in the ,british philosophy which descends from ,hume1 and is present1 somewhat veiled1 in ,kant and his followers4 ,there seems no reason whatever to accept this view4 ,our spontaneous1 unsophisticated beliefs1 whether as to ourselves or as to the outer world1 are always extremely rash and very liable to error4 ,the acquisition of caution is equally necessary and equally difficult in both directions4 ,not only are we often un aware of entertaining a belief or desire which exists in us2 we are often actually mistaken4 ,the fallibility of introspection as regards what we desire is made evident by psycho-analysis2 its fallibility as to what we know is easily demonstrated4 ,an autobiography1 when confronted by a careful editor with documentary evidence1 is usually found to be full of obviously inadvertent errors4 ,any of us confronted by a forgotten letter written some years ago will be astonished to find how much more foolish our opinions were than we had remembered them as being4 ,and as to the analysis of our mental operations--believing1 desiring1 willing1 or what not--introspection unaided gives very little help3 it is necessary to construct hypotheses and test them by their consequences1 just as we do in physical science4 ,introspection1 therefore1 though it is one among our sources of knowledge1 is not1 in isolation1 in any degree more trustworthy than external perception4 ,i come now to our second question3 ,does introspection give us materials for the knowledge of relations other than those arrived at by reflecting upon external perception8 ,it might be contended that the essence of what is mental consists of relations1 such as knowing for example1 and that our knowledge concerning these essentially mental relations is entirely derived from introspection4 ,if knowing were an unanalysable relation1 this view would be incontrovertible1 since clearly no such relation forms part of the subject matter of physics4 ,but it would seem that knowing is really various relations1 all of them complex4 ,therefore1 until they have been analysed1 our present question must remain unanswered ,i shall return to it at the end of the present course of lectures4 ,,lecture ,,vii4 ,,the ,,definition ,,of ,,perception ,in ,lecture ,v we found reason to think that the ultimate constituents99 of the world do not have the characteristics of either mind or matter as ordinarily understood3 they are not solid persistent objects moving through space1 nor are they fragments of consciousness4 ,but we found two ways of grouping particulars1 one into things or pieces of matter1 the other into series of perspectives1 each series being what may be called a biography4 ,before we can define either sensations or images1 it is necessary to consider this twofold classification in somewhat greater detail1 and to derive from it a definition of perception4 ,it should be said that1 in so far as the classification assumes the whole world of physics 7including its unperceived portions71 it contains hypothetical elements4 ,but we will not linger on the grounds for admitting these1 which belong to the philosophy of physics rather than of psychology4 99 ,when ,i speak of ultimate constituents1 ,i do not mean necessarily such as are theoretically incapable of analysis1 but only such as1 at present1 we can see no means of analysing4 ,i speak of such constituents as particulars1 or as ,,relative particulars when ,i wish to emphasize the fact that they may be themselves complex4 ,the physical classification of particulars collects together all those that are aspects of one thing4 ,given any one particular1 it is found often 7we do not say always7 that there are a number of other particulars differing from this one in gradually increasing degrees4 ,those 7or some of those7 that differ from it only very slightly will be found to differ approximately according to certain laws which may be called1 in a generalized sense1 the laws of perspective2 they include the ordinary laws of perspective as a special case4 ,this approximation grows more and more nearly exact as the difference grows less2 in technical language1 the laws of perspective account for the differences to the first order of small quantities1 and other laws are only required to account for second-order differences4 ,that is to say1 as the difference diminishes1 the part of the difference which is not according to the laws of perspective diminishes much more rapidly1 and bears to the total difference a ratio which tends towards zero as both are made smaller and smaller4 ,by this means we can theoretically collect together a number of particulars which may be defined as the aspects or appearances of one thing at one time4 ,if the laws of perspective were sufficiently known1 the connection between different aspects would be expressed in differential equations4 ,this gives us1 so far1 only those particulars which constitute one thing at one time4 ,this set of particulars may be called a momentary thing4 ,to define that series of momentary things that constitute the successive states of one thing is a problem involving the laws of dynamics4 ,these give the laws governing the changes of aspects from one time to a slightly later time1 with the same sort of differential approximation to exactness as we obtained for spatially neighbouring aspects through the laws of perspective4 ,thus a momentary thing is a set of particulars1 while a thing 7which may be identified with the whole history of the thing7 is a series of such sets of particulars4 ,the particulars in one set are collected together by the laws of perspective2 the successive sets are collected together by the laws of dynamics4 ,this is the view of the world which is appropriate to traditional physics4 ,the definition of a momentary thing involves problems concerning time1 since the particulars constituting a momentary thing will not be all simultaneous1 but will travel outward from the thing with the velocity of light 7in case the thing is in vacuo74 ,there are complications connected with relativity1 but for our present purpose they are not vital1 and ,i shall ignore them4 ,instead of first collecting together all the particulars constituting a momentary thing1 and then forming the series of successive sets1 we might have first collected together a series of successive aspects related by the laws of dynamics1 and then have formed the set of such series related by the laws of perspective4 ,to illustrate by the case of an actor on the stage3 our first plan was to collect together all the aspects which he presents to different spectators at one time1 and then to form the series of such sets4 ,our second plan is first to collect together all the aspects which he presents successively to a given spectator1 and then to do the same thing for the other spectators1 thus forming a set of series instead of a series of sets4 ,the first plan tells us what he does2 the second the impressions he produces4 ,this second way of classifying particulars is one which obviously has more relevance to psychology than the other4 ,it is partly by this second method of classification that we obtain definitions of one experience or biography or person4 ,this method of classification is also essential to the definition of sensations and images1 as ,i shall endeavour to prove later on4 ,but we must first amplify the definition of perspectives and biographies4 ,in our illustration of the actor1 we spoke1 for the moment1 as though each spectator's mind were wholly occupied by the one actor4 ,if this were the case1 it might be possible to define the biography of one spectator as a series of successive aspects of the actor related according to the laws of dynamics4 ,but in fact this is not the case4 ,we are at all times during our waking life receiving a variety of impressions1 which are aspects of a variety of things4 ,we have to consider what binds together two simultaneous sensations in one person1 or1 more generally1 any two occurrences which forte part of one experience4 ,we might say1 adhering to the standpoint of physics1 that two aspects of different things belong to the same perspective when they are in the same place4 ,but this would not really help us1 since a place has not yet been defined4 ,can we define what is meant by saying that two aspects are in the same place1 without introducing anything beyond the laws of perspective and dynamics8 ,i do not feel sure whether it is possible to frame such a definition or not2 accordingly ,i shall not assume that it is possible1 but shall seek other characteristics by which a perspective or biography may be defined4 ,when 7for example7 we see one man and hear another speaking at the same time1 what we see and what we hear have a relation which we can perceive1 which makes the two together form1 in some sense1 one experience4 ,it is when this relation exists that two occurrences become associated4 ,semon's engram is formed by all that we experience at one time4 ,he speaks of two parts of this total as having the relation of ,nebeneinander 7,m4 #aah2 ,m4,e4 #cc ff471 which is reminiscent of ,herbart's ,zusammen4 ,i think the relation may be called simply simultaneity4 ,it might be said that at any moment all sorts of things that are not part of my experience are happening in the world1 and that therefore the relation we are seeking to define cannot be merely simultaneity4 ,this1 however1 would be an error--the sort of error that the theory of relativity avoids4 ,there is not one universal time1 except by an elaborate construction2 there are only local times1 each of which may be taken to be the time within one biography4 ,accordingly1 if ,i am 7say7 hearing a sound1 the only occurrences that are1 in any simple sense1 simultaneous with my sensation are events in my private world1 i4e4 in my biography4 ,we may therefore define the perspective to which the sensation in question belongs as the set of particulars that are simultaneous with this sensation4 ,and similarly we may define the biography to which the sensation belongs as the set of particulars that are earlier or later than1 or simultaneous with1 the given sensation4 ,moreover1 the very same definitions can be applied to particulars which are not sensations4 ,they are actually required for the theory of relativity1 if we are to give a philosophical explanation of what is meant by local time in that theory ,the relations of simultaneity and succession are known to us in our own experience2 they may be analysable1 but that does not affect their suitability for defining perspectives and biographies4 ,such time-relations as can be constructed between events in different biographies are of a different kind3 they are not experienced1 and are merely logical1 being designed to afford convenient ways of stating the correlations between different biographies4 ,it is not only by time-relations that the parts of one biography are collected together in the case of living beings4 ,in this case there are the mnemic phenomena which constitute the unity of one experience1 and transform mere occurrences into experiences4 ,i have already dwelt upon the importance of mnemic phenomena for psychology1 and shall not enlarge upon them now1 beyond observing that they are what transforms a biography 7in our technical sense7 into a life4 ,it is they that give the continuity of a person or a mind4 ,but there is no reason to suppose that mnemic phenomena are associated with biographies except in the case of animals and plants4 ,our two-fold classification of particulars gives rise to the dualism of body and biography in regard to everything in the universe1 and not only in regard to living things4 ,this arises as follows4 ,every particular of the sort considered by physics is a member of two groups 7#a7 ,the group of particulars constituting the other aspects of the same physical object2 7#b7 ,the group of particulars that have direct time-relations to the given particular4 ,each of these is associated with a place4 ,when ,i look at a star1 my sensation is 7#a7 ,a member of the group of particulars which is the star1 and which is associated with the place where the star is2 7#b7 ,a member of the group of particulars which is my biography1 and which is associated with the place where ,i am499 99,i have explained elsewhere the manner in which space is constructed on this theory1 and in which the position of a perspective is brought into relation with the position of a physical object 7,our ,knowledge of the ,external ,world1 ,lecture ,,iii1 pp4 #ij1 #ia74 ,the result is that every particular of the kind relevant to physics is associated with ,,two places2 e4g4 my sensation of the star is associated with the place where ,i am and with the place where the star is4 ,this dualism has nothing to do with any mind that ,i may be supposed to possess2 it exists in exactly the same sense if ,i am replaced by a photographic plate4 ,we may call the two places the active and passive places respectively499 ,thus in the case of a perception or photograph of a star1 the active place is the place where the star is1 while the passive place is the place where the percipient or photographic plate is4 99 ,i use these as mere names2 ,i do not want to introduce any notion of activity4 ,we can thus1 without departing from physics1 collect together all the particulars actively at a given place1 or all the particulars passively at a given place4 ,in our own case1 the one group is our body 7or our brain71 while the other is our mind1 in so far as it consists of perceptions4 ,in the case of the photographic plate1 the first group is the plate as dealt with by physics1 the second the aspect of the heavens which it photographs4 7,for the sake of schematic simplicity1 ,i am ignoring various complications connected with time1 which require some tedious but perfectly feasible elaborations47 ,thus what may be called subjectivity in the point of view is not a distinctive peculiarity of mind3 it is present just as much in the photographic plate4 ,and the photographic plate has its biography as well as its matter4 ,but this biography is an affair of physics1 and has none of the peculiar characteristics by which mental phenomena are distinguished1 with the sole exception of subjectivity4 ,adhering1 for the moment1 to the standpoint of physics1 we may define a perception of an object as the appearance of the object from a place where there is a brain 7or1 in lower animals1 some suitable nervous structure71 with sense-organs and nerves forming part of the intervening medium4 ,such appearances of objects are distinguished from appearances in other places by certain peculiarities1 namely3 7#a7 ,they give rise to mnemic phenomena2 7#b7 ,they are themselves affected by mnemic phenomena4 ,that is to say1 they may be remembered and associated or influence our habits1 or give rise to images1 etc41 and they are themselves different from what they would have been if our past experience had been different--for example1 the effect of a spoken sentence upon the hearer depends upon whether the hearer knows the language or not1 which is a question of past experience4 ,it is these two characteristics1 both connected with mnemic phenomena1 that distinguish perceptions from the appearances of objects in places where there is no living being4 ,theoretically1 though often not practically1 we can1 in our perception of an object1 separate the part which is due to past experience from the part which proceeds without mnemic influences out of the character of the object4 ,we may define as sensation that part which proceeds in this way1 while the remainder1 which is a mnemic phenomenon1 will have to be added to the sensation to make up what is called the perception4 ,according to this definition1 the sensation is a theoretical core in the actual experience2 the actual experience is the perception4 ,it is obvious that there are grave difficulties in carrying out these definitions1 but we will not linger over them4 ,we have to pass1 as soon as we can1 from the physical standpoint1 which we have been hitherto adopting1 to the standpoint of psychology1 in which we make more use of introspection in the first of the three senses discussed in the preceding lecture4 ,but before making the transition1 there are two points which must be made clear4 ,first3 ,everything outside my own personal biography is outside my experience2 therefore if anything can be known by me outside my biography1 it can only be known in one of two ways3 7#a7 ,by inference from things within my biography1 or 7#b7 ,by some a priori principle independent of experience4 ,i do not myself believe that anything approaching certainty is to be attained by either of these methods1 and therefore whatever lies outside my personal biography must be regarded1 theoretically1 as hypothesis4 ,the theoretical argument for adopting the hypothesis is that it simplifies the statement of the laws according to which events happen in our experience4 ,but there is no very good ground for supposing that a simple law is more likely to be true than a complicated law1 though there is good ground for assuming a simple law in scientific practice1 as a working hypothesis1 if it explains the facts as well as another which is less simple4 ,belief in the existence of things outside my own biography exists antecedently to evidence1 and can only be destroyed1 if at all1 by a long course of philosophic doubt4 ,for purposes of science1 it is justified practically by the simplification which it introduces into the laws of physics4 ,but from the standpoint of theoretical logic it must be regarded as a prejudice1 not as a well-grounded theory4 ,with this proviso1 ,i propose to continue yielding to the prejudice4 ,the second point concerns the relating of our point of view to that which regards sensations as caused by stimuli external to the nervous system 7or at least to the brain71 and distinguishes images as centrally excited1 i4e4 due to causes in the brain which cannot be traced back to anything affecting the sense-organs4 ,it is clear that1 if our analysis of physical objects has been valid1 this way of defining sensations needs reinterpretation4 ,it is also clear that we must be able to find such a new interpretation if our theory is to be admissible4 ,to make the matter clear1 we will take the simplest possible illustration4 ,consider a certain star1 and suppose for the moment that its size is negligible4 ,that is to say1 we will regard it as1 for practical purposes1 a luminous point4 ,let us further suppose that it exists only for a very brief time1 say a second4 ,then1 according to physics1 what happens is that a spherical wave of light travels outward from the star through space1 just as1 when you drop a stone into a stagnant pond1 ripples travel outward from the place where the stone hit the water4 ,the wave of light travels with a certain very nearly constant velocity1 roughly #cjj1jjj kilometres per second4 ,this velocity may be ascertained by sending a flash of light to a mirror1 and observing how long it takes before the reflected flash reaches you1 just as the velocity of sound may be ascertained by means of an echo4 ,what it is that happens when a wave of light reaches a given place we cannot tell1 except in the sole case when the place in question is a brain connected with an eye which is turned in the right direction4 ,in this one very special case we know what happens3 we have the sensation called seeing the star4 ,in all other cases1 though we know 7more or less hypothetically7 some of the correlations and abstract properties of the appearance of the star1 we do not know the appearance itself4 ,now you may1 for the sake of illustration1 compare the different appearances of the star to the conjugation of a ,greek verb1 except that the number of its parts is really infinite1 and not only apparently so to the despairing schoolboy4 ,in vacuo1 the parts are regular1 and can be derived from the 7imaginary7 root according to the laws of grammar1 i4e4 of perspective4 ,the star being situated in empty space1 it may be defined1 for purposes of physics1 as consisting of all those appearances which it presents in vacuo1 together with those which1 according to the laws of perspective1 it would present elsewhere if its appearances elsewhere were regular4 ,this is merely the adaptation of the definition of matter which ,i gave in an earlier lecture4 ,the appearance of a star at a certain place1 if it is regular1 does not require any cause or explanation beyond the existence of the star4 ,every regular appearance is an actual member of the system which is the star1 and its causation is entirely internal to that system4 ,we may express this by saying that a regular appearance is due to the star alone1 and is actually part of the star1 in the sense in which a man is part of the human race4 ,but presently the light of the star reaches our atmosphere4 ,it begins to be refracted1 and dimmed by mist1 and its velocity is slightly diminished4 ,at last it reaches a human eye1 where a complicated process takes place1 ending in a sensation which gives us our grounds for believing in all that has gone before4 ,now1 the irregular appearances of the star are not1 strictly speaking1 members of the system which is the star1 according to our definition of matter4 ,the irregular appearances1 however1 are not merely irregular3 they proceed according to laws which can be stated in terms of the matter through which the light has passed on its way4 ,the sources of an irregular appearance are therefore twofold3 7#a7 ,the object which is appearing irregularly2 #b7 ,the intervening medium4 ,it should be observed that1 while the conception of a regular appearance is perfectly precise1 the conception of an irregular appearance is one capable of any degree of vagueness4 ,when the distorting influence of the medium is sufficiently great1 the resulting particular can no longer be regarded as an appearance of an object1 but must be treated on its own account4 ,this happens especially when the particular in question cannot be traced back to one object1 but is a blend of two or more4 ,this case is normal in perception3 we see as one what the microscope or telescope reveals to be many different objects4 ,the notion of perception is therefore not a precise one3 we perceive things more or less1 but always with a very considerable amount of vagueness and confusion4 ,in considering irregular appearances1 there are certain very natural mistakes which must be avoided4 ,in order that a particular may count as an irregular appearance of a certain object1 it is not necessary that it should bear any resemblance to the regular appearances as regard its intrinsic qualities4 ,all that is necessary is that it should be derivable from the regular appearances by the laws which express the distorting influence of the medium4 ,when it is so derivable1 the particular in question may be regarded as caused by the regular appearances1 and therefore by the object itself1 together with the modifications resulting from the medium4 ,in other cases1 the particular in question may1 in the same sense1 be regarded as caused by several objects together with the medium2 in this case1 it may be called a confused appearance of several objects4 ,if it happens to be in a brain1 it may be called a confused perception of these objects4 ,all actual perception is confused to a greater or less extent4 ,we can now interpret in terms of our theory the distinction between those mental occurrences which are said to have an external stimulus1 and those which are said to be centrally excited1 i4e4 to have no stimulus external to the brain4 ,when a mental occurrence can be regarded as an appearance of an object external to the brain1 however irregular1 or even as a confused appearance of several such objects1 then we may regard it as having for its stimulus the object or objects in question1 or their appearances at the sense-organ concerned4 ,when1 on the other hand1 a mental occurrence has not sufficient connection with objects external to the brain to be regarded as an appearance of such objects1 then its physical causation 7if any7 will have to be sought in the brain4 ,in the former case it can be called a perception2 in the latter it cannot be so called4 ,but the distinction is one of degree1 not of kind4 ,until this is realized1 no satisfactory theory of perception1 sensation1 or imagination is possible4 ,,lecture ,,viii4 ,,sensations ,,and ,,images ,the dualism of mind and matter1 if we have been right so far1 cannot be allowed as metaphysically valid4 ,nevertheless1 we seem to find a certain dualism1 perhaps not ultimate1 within the world as we observe it4 ,the dualism is not primarily as to the stuff of the world1 but as to causal laws4 ,on this subject we may again quote ,william ,james4 ,he points out that when1 as we say1 we merely imagine things1 there are no such effects as would ensue if the things were what we call real4 ,he takes the case of imagining a fire4 ,i make for myself an experience of blazing fire2 ,i place it near my body2 but it does not warm me in the least4 ,i lay a stick upon it and the stick either burns or remains green1 as ,i please4 ,i call up water1 and pour it on the fire1 and absolutely no difference ensues4 ,i account for all such facts by calling this whole train of experiences unreal1 a mental train4 ,mental fire is what won't burn real sticks2 mental water is what won't necessarily 7though of course it may7 put out even a mental fire4444 ,with 'real' objects1 on the contrary1 consequences always accrue2 and thus the real experiences get sifted from the mental ones1 the things from our thoughts of them1 fanciful or true1 and precipitated together as the stable part of the whole experience--chaos1 under the name of the physical world499 99 ,essays in ,radical ,empiricism1 pp4 #cb-c4 ,in this passage ,james speaks1 by mere inadvertence1 as though the phenomena which he is describing as mental had ,,no effects4 ,this is1 of course1 not the case3 they have their effects1 just as much as physical phenomena do1 but their effects follow different laws4 ,for example1 dreams1 as ,freud has shown1 are just as much subject to laws as are the motions of the planets4 ,but the laws are different3 in a dream you may be transported from one place to another in a moment1 or one person may turn into another under your eyes4 ,such differences compel you to distinguish the world of dreams from the physical world4 ,if the two sorts of causal laws could be sharply distinguished1 we could call an occurrence physical when it obeys causal laws appropriate to the physical world1 and mental when it obeys causal laws appropriate to the mental world4 ,since the mental world and the physical world interact1 there would be a boundary between the two3 there would be events which would have physical causes and mental effects1 while there would be others which would have mental causes and physical effects4 ,those that have physical causes and mental effects we should define as sensations4 ,those that have mental causes and physical effects might perhaps be identified with what we call voluntary movements2 but they do not concern us at present4 ,these definitions would have all the precision that could be desired if the distinction between physical and psychological causation were clear and sharp4 ,as a matter of fact1 however1 this distinction is1 as yet1 by no means sharp4 ,it is possible that1 with fuller knowledge1 it will be found to be no more ultimate than the distinction between the laws of gases and the laws of rigid bodies4 ,it also suffers from the fact that an event may be an effect of several causes according to several causal laws we cannot1 in general1 point to anything unique as ,,the cause of such-and-such an event4 ,and finally it is by no means certain that the peculiar causal laws which govern mental events are not really physiological4 ,the law of habit1 which is one of the most distinctive1 may be fully explicable in terms of the peculiarities of nervous tissue1 and these peculiarities1 in turn1 may be explicable by the laws of physics4 ,it seems1 therefore1 that we are driven to a different kind of definition4 ,it is for this reason that it was necessary to develop the definition of perception4 ,with this definition1 we can define a sensation as the non-mnemic elements in a perception4 ,when1 following our definition1 we try to decide what elements in our experience are of the nature of sensations1 we find more difficulty than might have been expected4 ,prima facie1 everything is sensation that comes to us through the senses3 the sights we see1 the sounds we hear1 the smells we smell1 and so on2 also such things as headache or the feeling of muscular strain4 ,but in actual fact so much interpretation1 so much of habitual correlation1 is mixed with all such experiences1 that the core of pure sensation is only to be extracted by careful investigation4 ,to take a simple illustration3 if you go to the theatre in your own country1 you seem to hear equally well in the stalls or the dress circle2 in either case you think you miss nothing4 ,but if you go in a foreign country where you have a fair knowledge of the language1 you will seem to have grown partially deaf1 and you will find it necessary to be much nearer the stage than you would need to be in your own country4 ,the reason is that1 in hearing our own language spoken1 we quickly and unconsciously fill out what we really hear with inferences to what the man must be saying1 and we never realize that we have not heard the words we have merely inferred4 ,in a foreign language1 these inferences are more difficult1 and we are more dependent upon actual sensation4 ,if we found ourselves in a foreign world1 where tables looked like cushions and cushions like tables1 we should similarly discover how much of what we think we see is really inference4 ,every fairly familiar sensation is to us a sign of the things that usually go with it1 and many of these things will seem to form part of the sensation4 ,i remember in the early days of motor-cars being with a friend when a tyre burst with a loud report4 ,he thought it was a pistol1 and supported his opinion by maintaining that he had seen the flash4 ,but of course there had been no flash4 ,nowadays no one sees a flash when a tyre bursts4 ,in order1 therefore1 to arrive at what really is sensation in an occurrence which1 at first sight1 seems to contain nothing else1 we have to pare away all that is due to habit or expectation or interpretation4 ,this is a matter for the psychologist1 and by no means an easy matter4 ,for our purposes1 it is not important to determine what exactly is the sensational core in any case2 it is only important to notice that there certainly is a sensational core1 since habit1 expectation and interpretation are diversely aroused on diverse occasions1 and the diversity is clearly due to differences in what is presented to the senses4 ,when you open your newspaper in the morning1 the actual sensations of seeing the print form a very minute part of what goes on in you1 but they are the starting-point of all the rest1 and it is through them that the newspaper is a means of information or mis-information4 ,thus1 although it may be difficult to determine what exactly is sensation in any given experience1 it is clear that there is sensation1 unless1 like ,leibniz1 we deny all action of the outer world upon us4 ,sensations are obviously the source of our knowledge of the world1 including our own body4 ,it might seem natural to regard a sensation as itself a cognition1 and until lately ,i did so regard it4 ,when1 say1 ,i see a person ,i know coming towards me in the street1 it ,,seems as though the mere seeing were knowledge4 ,it is of course undeniable that knowledge comes ,,through the seeing1 but ,i think it is a mistake to regard the mere seeing itself as knowledge4 ,if we are so to regard it1 we must distinguish the seeing from what is seen3 we must say that1 when we see a patch of colour of a certain shape1 the patch of colour is one thing and our seeing of it is another4 ,this view1 however1 demands the admission of the subject1 or act1 in the sense discussed in our first lecture4 ,if there is a subject1 it can have a relation to the patch of colour1 namely1 the sort of relation which we might call awareness4 ,in that case the sensation1 as a mental event1 will consist of awareness of the colour1 while the colour itself will remain wholly physical1 and may be called the sense-datum1 to distinguish it from the sensation4 ,the subject1 however1 appears to be a logical fiction1 like mathematical points and instants4 ,it is introduced1 not because observation reveals it1 but because it is linguistically convenient and apparently demanded by grammar4 ,nominal entities of this sort may or may not exist1 but there is no good ground for assuming that they do4 ,the functions that they appear to perform can always be performed by classes or series or other logical constructions1 consisting of less dubious entities4 ,if we are to avoid a perfectly gratuitous assumption1 we must dispense with the subject as one of the actual ingredients of the world4 ,but when we do this1 the possibility of distinguishing the sensation from the sense-datum vanishes2 at least ,i see no way of preserving the distinction4 ,accordingly the sensation that we have when we see a patch of colour simply is that patch of colour1 an actual constituent of the physical world1 and part of what physics is concerned with4 ,a patch of colour is certainly not knowledge1 and therefore we cannot say that pure sensation is cognitive4 ,through its psychological effects1 it is the cause of cognitions1 partly by being itself a sign of things that are correlated with it1 as e4g4 sensations of sight and touch are correlated1 and partly by giving rise to images and memories after the sensation is faded4 ,but in itself the pure sensation is not cognitive4 ,in the first lecture we considered the view of ,brentano1 that we may define psychical phenomena by saying that they are phenomena which intentionally contain an object4 ,we saw reasons to reject this view in general2 we are now concerned to show that it must be rejected in the particular case of sensations4 ,the kind of argument which formerly made me accept ,brentano's view in this case was exceedingly simple4 ,when ,i see a patch of colour1 it seemed to me that the colour is not psychical1 but physical1 while my seeing is not physical1 but psychical4 ,hence ,i concluded that the colour is something other than my seeing of the colour4 ,this argument1 to me historically1 was directed against idealism3 the emphatic part of it was the assertion that the colour is physical1 not psychical4 ,i shall not trouble you now with the grounds for holding as against ,berkeley that the patch of colour is physical2 ,i have set them forth before1 and ,i see no reason to modify them4 ,but it does not follow that the patch of colour is not also psychical1 unless we assume that the physical and the psychical cannot overlap1 which ,i no longer consider a valid assumption4 ,if we admit--as ,i think we should--that the patch of colour may be both physical and psychical1 the reason for distinguishing the sense-datum from the sensation disappears1 and we may say that the patch of colour and our sensation in seeing it are identical4 ,this is the view of ,william ,james1 ,professor ,dewey1 and the ,american realists4 ,perceptions1 says ,professor ,dewey1 are not per se cases of knowledge1 but simply natural events with no more knowledge status than 7say7 a shower4 ,let them the realists try the experiment of conceiving perceptions as pure natural events1 not cases of awareness or apprehension1 and they will be surprised to see how little they miss499 ,i think he is right in this1 except in supposing that the realists will be surprised4 ,many of them already hold the view he is advocating1 and others are very sympathetic to it4 ,at any rate1 it is the view which ,i shall adopt in these lectures4 99 ,dewey1 ,essays in ,experimental ,logic1 pp4 #bec1 #bfb4 ,the stuff of the world1 so far as we have experience of it1 consists1 on the view that ,i am advocating1 of innumerable transient particulars such as occur in seeing1 hearing1 etc41 together with images more or less resembling these1 of which ,i shall speak shortly4 ,if physics is true1 there are1 besides the particulars that we experience1 others1 probably equally 7or almost equally7 transient1 which make up that part of the material world that does not come into the sort of contact with a living body that is required to turn it into a sensation4 ,but this topic belongs to the philosophy of physics1 and need not concern us in our present inquiry4 ,sensations are what is common to the mental and physical worlds2 they may be defined as the intersection of mind and matter4 ,this is by no means a new view2 it is advocated1 not only by the ,american authors ,i have mentioned1 but by ,mach in his ,analysis of ,sensations1 which was published in #ahhf4 ,the essence of sensation1 according to the view ,i am advocating1 is its independence of past experience4 ,it is a core in our actual experiences1 never existing in isolation except possibly in very young infants4 ,it is not itself knowledge1 but it supplies the data for our knowledge of the physical world1 including our own bodies4 ,there are some who believe that our mental life is built up out of sensations alone4 ,this may be true2 but in any case ,i think the only ingredients required in addition to sensations are images4 ,what images are1 and how they are to be defined1 we have now to inquire4 ,the distinction between images and sensations might seem at first sight by no means difficult4 ,when we shut our eyes and call up pictures of familiar scenes1 we usually have no difficulty1 so long as we remain awake1 in discriminating between what we are imagining and what is really seen4 ,if we imagine some piece of music that we know1 we can go through it in our mind from beginning to end without any discoverable tendency to suppose that we are really hearing it4 ,but although such cases are so clear that no confusion seems possible1 there are many others that are far more difficult1 and the definition of images is by no means an easy problem4 ,to begin with3 we do not always know whether what we are experiencing is a sensation or an image4 ,the things we see in dreams when our eyes are shut must count as images1 yet while we are dreaming they seem like sensations4 ,hallucinations often begin as persistent images1 and only gradually acquire that influence over belief that makes the patient regard them as sensations4 ,when we are listening for a faint sound--the striking of a distant clock1 or a horse's hoofs on the road--we think we hear it many times before we really do1 because expectation brings us the image1 and we mistake it for sensation4 ,the distinction between images and sensations is1 therefore1 by no means always obvious to inspection499 99 ,on the distinction between images and sensation1 cf4 ,semon1 ,die mnemischen ,empfindungen1 pp4 #ai-bj4 ,we may consider three different ways in which it has been sought to distinguish images from sensations1 namely3 7#a7 ,by the less degree of vividness in images2 7#b7 ,by our absence of belief in their physical reality2 7#c7 ,by the fact that their causes and effects are different from those of sensations4 ,i believe the third of these to be the only universally applicable criterion4 ,the other two are applicable in very many cases1 but cannot be used for purposes of definition because they are liable to exceptions4 ,nevertheless1 they both deserve to be carefully considered4 7#a7 ,hume1 who gives the names impressions and ideas to what may1 for present purposes1 be identified with our sensations and images1 speaks of impressions as those perceptions which enter with most force and violence while he defines ideas as the faint images of these 7i4e4 of impressions7 in thinking and reasoning4 ,his immediately following observations1 however1 show the inadequacy of his criteria of force and faintness4 ,he says3 ,i believe it will not be very necessary to employ many words in explaining this distinction4 ,every one of himself will readily perceive the difference betwixt feeling and thinking4 ,the common degrees of these are easily distinguished1 though it is not impossible but in particular instances they may very nearly approach to each other4 ,thus in sleep1 in a fever1 in madness1 or in any very violent emotions of soul1 our ideas may approach to our impressions2 as1 on the other hand1 it sometimes happens1 that our impressions are so faint and low that we cannot distinguish them from our ideas4 ,but notwithstanding this near resemblance in a few instances1 they are in general so very different1 that no one can make a scruple to rank them under distinct heads1 and assign to each a peculiar name to mark the difference 7,treatise of ,human ,nature1 ,part ,i1 ,section ,i74 ,i think ,hume is right in holding that they should be ranked under distinct heads1 with a peculiar name for each4 ,but by his own confession in the above passage1 his criterion for distinguishing them is not always adequate4 ,a definition is not sound if it only applies in cases where the difference is glaring3 the essential purpose of a definition is to provide a mark which is applicable even in marginal cases--except1 of course1 when we are dealing with a conception1 like1 e4g4 baldness1 which is one of degree and has no sharp boundaries4 ,but so far we have seen no reason to think that the difference between sensations and images is only one of degree4 ,professor ,stout1 in his ,manual of ,psychology1 after discussing various ways of distinguishing sensations and images1 arrives at a view which is a modification of ,hume's4 ,he says 7,i quote from the second edition73 ,our conclusion is that at bottom the distinction between image and percept1 as respectively faint and vivid states1 is based on a difference of quality4 ,the percept has an aggressiveness which does not belong to the image4 ,it strikes the mind with varying degrees of force or liveliness according to the varying intensity of the stimulus4 ,this degree of force or liveliness is part of what we ordinarily mean by the intensity of a sensation4 ,but this constituent of the intensity of sensations is absent in mental imagery7p4 #dai74 ,this view allows for the fact that sensations may reach any degree of faintness--e4g4 in the case of a just visible star or a just audible sound--without becoming images1 and that therefore mere faintness cannot be the characteristic mark of images4 ,after explaining the sudden shock of a flash of lightning or a steam-whistle1 ,stout says that no mere image ever does strike the mind in this manner7p4 #dag74 ,but ,i believe that this criterion fails in very much the same instances as those in which ,hume's criterion fails in its original form4 ,macbeth speaks of-- that suggestion ,whose horrid image doth unfix my hair ,and make my seated heart knock at my ribs ,against the use of nature4 ,the whistle of a steam-engine could hardly have a stronger effect than this4 ,a very intense emotion will often bring with it--especially where some future action or some undecided issue is involved--powerful compelling images which may determine the whole course of life1 sweeping aside all contrary solicitations to the will by their capacity for exclusively possessing the mind4 ,and in all cases where images1 originally recognized as such1 gradually pass into hallucinations1 there must be just that force or liveliness which is supposed to be always absent from images4 ,the cases of dreams and fever-delirium are as hard to adjust to ,professor ,stout's modified criterion as to ,hume's4 ,i conclude therefore that the test of liveliness1 however applicable in ordinary instances1 cannot be used to define the differences between sensations and images4 7#b7 ,we might attempt to distinguish images from sensations by our absence of belief in the physical reality of images4 ,when we are aware that what we are experiencing is an image1 we do not give it the kind of belief that we should give to a sensation3 we do not think that it has the same power of producing knowledge of the external world4 ,images are imaginary2 in ,,some sense they are unreal4 ,but this difference is hard to analyse or state correctly4 ,what we call the unreality of images requires interpretation it cannot mean what would be expressed by saying there's no such thing4 ,images are just as truly part of the actual world as sensations are4 ,all that we really mean by calling an image unreal is that it does not have the concomitants which it would have if it were a sensation4 ,when we call up a visual image of a chair1 we do not attempt to sit in it1 because we know that1 like ,macbeth's dagger1 it is not sensible to feeling as to sight--i4e4 it does not have the correlations with tactile sensations which it would have if it were a visual sensation and not merely a visual image4 ,but this means that the so-called unreality of images consists merely in their not obeying the laws of physics1 and thus brings us back to the causal distinction between images and sensations4 ,this view is confirmed by the fact that we only feel images to be unreal when we already know them to be images4 ,images cannot be defined by the ,,feeling of unreality1 because when we falsely believe an image to be a sensation1 as in the case of dreams1 it ,,feels just as real as if it were a sensation4 ,our feeling of unreality results from our having already realized that we are dealing with an image1 and cannot therefore be the definition of what we mean by an image4 ,as soon as an image begins to deceive us as to its status1 it also deceives us as to its correlations1 which are what we mean by its reality4 7#c7 ,this brings us to the third mode of distinguishing images from sensations1 namely1 by their causes and effects4 ,i believe this to be the only valid ground of distinction4 ,james1 in the passage about the mental fire which won't burn real sticks1 distinguishes images by their effects1 but ,i think the more reliable distinction is by their causes4 ,professor ,stout 7loc4 cit41 p4 #abg7 says3 ,one characteristic mark of what we agree in calling sensation is its mode of production4 ,it is caused by what we call a ,,stimulus4 ,a stimulus is always some condition external to the nervous system itself and operating upon it4 ,i think that this is the correct view1 and that the distinction between images and sensations can only be made by taking account of their causation4 ,sensations come through sense-organs1 while images do not4 ,we cannot have visual sensations in the dark1 or with our eyes shut1 but we can very well have visual images under these circumstances4 ,accordingly images have been defined as centrally excited sensations1 i4e4 sensations which have their physiological cause in the brain only1 not also in the sense-organs and the nerves that run from the sense-organs to the brain4 ,i think the phrase centrally excited sensations assumes more than is necessary1 since it takes it for granted that an image must have a proximate physiological cause4 ,this is probably true1 but it is an hypothesis1 and for our purposes an unnecessary one4 ,it would seem to fit better with what we can immediately observe if we were to say that an image is occasioned1 through association1 by a sensation or another image1 in other words that it has a mnemic cause--which does not prevent it from also having a physical cause4 ,and ,i think it will be found that the causation of an image always proceeds according to mnemic laws1 i4e4 that it is governed by habit and past experience4 ,if you listen to a man playing the pianola without looking at him1 you will have images of his hands on the keys as if he were playing the piano2 if you suddenly look at him while you are absorbed in the music1 you will experience a shock of surprise when you notice that his hands are not touching the notes4 ,your image of his hands is due to the many times that you have heard similar sounds and at the same time seen the player's hands on the piano4 ,when habit and past experience play this part1 we are in the region of mnemic as opposed to ordinary physical causation4 ,and ,i think that1 if we could regard as ultimately valid the difference between physical and mnemic causation1 we could distinguish images from sensations as having mnemic causes1 though they may also have physical causes4 ,sensations1 on the other hand1 will only have physical causes4 ,however this may be1 the practically effective distinction between sensations and images is that in the causation of sensations1 but not of images1 the stimulation of nerves carrying an effect into the brain1 usually from the surface of the body1 plays an essential part4 ,and this accounts for the fact that images and sensations cannot always be distinguished by their intrinsic nature4 ,images also differ from sensations as regards their effects4 ,sensations1 as a rule1 have both physical and mental effects4 ,as you watch the train you meant to catch leaving the station1 there are both the successive positions of the train 7physical effects7 and the successive waves of fury and disappointment 7mental effects74 ,images1 on the contrary1 though they ,,may produce bodily movements1 do so according to mnemic laws1 not according to the laws of physics4 ,all their effects1 of whatever nature1 follow mnemic laws4 ,but this difference is less suitable for definition than the difference as to causes4 ,professor ,watson1 as a logical carrying-out of his behaviourist theory1 denies altogether that there are any observable phenomena such as images are supposed to be4 ,he replaces them all by faint sensations1 and especially by pronunciation of words sotto voce4 ,when we think of a table 7say71 as opposed to seeing it1 what happens1 according to him1 is usually that we are making small movements of the throat and tongue such as would lead to our uttering the word table if they were more pronounced4 ,i shall consider his view again in connection with words2 for the present ,i am only concerned to combat his denial of images4 ,this denial is set forth both in his book on ,behavior and in an article called ,image and ,affection in ,behavior in the ,journal of ,philosophy1 ,psychology and ,scientific ,methods1 vol4 x 7,july1 #aiac74 ,it seems to me that in this matter he has been betrayed into denying plain facts in the interests of a theory1 namely1 the supposed impossibility of introspection4 ,i dealt with the theory in ,lecture ,,vi2 for the present ,i wish to reinforce the view that the facts are undeniable4 ,images are of various sorts1 according to the nature of the sensations which they copy4 ,images of bodily movements1 such as we have when we imagine moving an arm or1 on a smaller scale1 pronouncing a word1 might possibly be explained away on ,professor ,watson's lines1 as really consisting in small incipient movements such as1 if magnified and prolonged1 would be the movements we are said to be imagining4 ,whether this is the case or not might even be decided experimentally4 ,if there were a delicate instrument for recording small movements in the mouth and throat1 we might place such an instrument in a person's mouth and then tell him to recite a poem to himself1 as far as possible only in imagination4 ,i should not be at all surprised if it were found that actual small movements take place while he is mentally saying over the verses4 ,the point is important1 because what is called thought consists mainly 7though ,i think not wholly7 of inner speech4 ,if ,professor ,watson is right as regards inner speech1 this whole region is transferred from imagination to sensation4 ,but since the question is capable of experimental decision1 it would be gratuitous rashness to offer an opinion while that decision is lacking4 ,but visual and auditory images are much more difficult to deal with in this way1 because they lack the connection with physical events in the outer world which belongs to visual and auditory sensations4 ,suppose1 for example1 that ,i am sitting in my room1 in which there is an empty arm-chair4 ,i shut my eyes1 and call up a visual image of a friend sitting in the arm-chair4 ,if ,i thrust my image into the world of physics1 it contradicts all the usual physical laws4 ,my friend reached the chair without coming in at the door in the usual way2 subsequent inquiry will show that he was somewhere else at the moment4 ,if regarded as a sensation1 my image has all the marks of the supernatural4 ,my image1 therefore1 is regarded as an event in me1 not as having that position in the orderly happenings of the public world that belongs to sensations4 ,by saying that it is an event in me1 we leave it possible that it may be ,,physiologically caused3 its privacy may be only due to its connection with my body4 ,but in any case it is not a public event1 like an actual person walking in at the door and sitting down in my chair4 ,and it cannot1 like inner speech1 be regarded as a ,,small sensation1 since it occupies just as large an area in my visual field as the actual sensation would do4 ,professor ,watson says3 ,i should throw out imagery altogether and attempt to show that all natural thought goes on in terms of sensori-motor processes in the larynx4 ,this view seems to me flatly to contradict experience4 ,if you try to persuade any uneducated person that she cannot call up a visual picture of a friend sitting in a chair1 but can only use words describing what such an occurrence would be like1 she will conclude that you are mad4 7,this statement is based upon experiment47 ,galton1 as every one knows1 investigated visual imagery1 and found that education tends to kill it3 the ,fellows of the ,royal ,society turned out to have much less of it than their wives4 ,i see no reason to doubt his conclusion that the habit of abstract pursuits makes learned men much inferior to the average in power of visualizing1 and much more exclusively occupied with words in their thinking4 ,and ,professor ,watson is a very learned man4 ,i shall henceforth assume that the existence of images is admitted1 and that they are to be distinguished from sensations by their causes1 as well as1 in a lesser degree1 by their effects4 ,in their intrinsic nature1 though they often differ from sensations by being more dim or vague or faint1 yet they do not always or universally differ from sensations in any way that can be used for defining them4 ,their privacy need form no bar to the scientific study of them1 any more than the privacy of bodily sensations does4 ,bodily sensations are admitted by even the most severe critics of introspection1 although1 like images1 they can only be observed by one observer4 ,it must be admitted1 however1 that the laws of the appearance and disappearance of images are little known and difficult to discover1 because we are not assisted1 as in the case of sensations1 by our knowledge of the physical world4 ,there remains one very important point concerning images1 which will occupy us much hereafter1 and that is1 their resemblance to previous sensations4 ,they are said to be copies of sensations1 always as regards the simple qualities that enter into them1 though not always as regards the manner in which these are put together4 ,it is generally believed that we cannot imagine a shade of colour that we have never seen1 or a sound that we have never heard4 ,on this subject ,hume is the classic4 ,he says1 in the definitions already quoted3 ,those perceptions1 which enter with most force and violence1 we may name ,,impressions2 and under this name ,i comprehend all our sensations1 passions and emotions1 as they make their first appearance in the soul4 ,by ,,ideas ,i mean the faint images of these in thinking and reasoning4 ,he next explains the difference between simple and complex ideas1 and explains that a complex idea may occur without any similar complex impression4 ,but as regards simple ideas1 he states that every simple idea has a simple impression1 which resembles it1 and every simple impression a correspondent idea4 ,he goes on to enunciate the general principle that all our simple ideas in their first appearance are derived from simple impressions1 which are correspondent to them1 and which they exactly represent 7,treatise of ,human ,nature1 ,part ,i1 ,section ,i74 ,it is this fact1 that images resemble antecedent sensations1 which enables us to call them images of this or that4 ,for the understanding of memory1 and of knowledge generally1 the recognizable resemblance of images and sensations is of fundamental importance4 ,there are difficulties in establishing ,hume's principles1 and doubts as to whether it is exactly true4 ,indeed1 he himself signalized an exception immediately after stating his maxim4 ,nevertheless1 it is impossible to doubt that in the main simple images are copies of similar simple sensations which have occurred earlier1 and that the same is true of complex images in all cases of memory as opposed to mere imagination4 ,our power of acting with reference to what is sensibly absent is largely due to this characteristic of images1 although1 as education advances1 images tend to be more and more replaced by words4 ,we shall have much to say in the next two lectures on the subject of images as copies of sensations4 ,what has been said now is merely by way of reminder that this is their most notable characteristic4 ,i am by no means confident that the distinction between images and sensations is ultimately valid1 and ,i should be glad to be convinced that images can be reduced to sensations of a peculiar kind4 ,i think it is clear1 however1 that1 at any rate in the case of auditory and visual images1 they do differ from ordinary auditory and visual sensations1 and therefore form a recognizable class of occurrences1 even if it should prove that they can be regarded as a sub-class of sensations4 ,this is all that is necessary to validate the use of images to be made in the sequel4 ,,lecture ,,ix4 ,,memory ,memory1 which we are to consider to-day1 introduces us to knowledge in one of its forms4 ,the analysis of knowledge will occupy us until the end of the thirteenth lecture1 and is the most difficult part of our whole enterprise4 ,i do not myself believe that the analysis of knowledge can be effected entirely by means of purely external observation1 such as behaviourists employ4 ,i shall discuss this question in later lectures4 ,in the present lecture ,i shall attempt the analysis of memory-knowledge1 both as an introduction to the problem of knowledge in general1 and because memory1 in some form1 is presupposed in almost all other knowledge4 ,sensation1 we decided1 is not a form of knowledge4 ,it might1 however1 have been expected that we should begin our discussion of knowledge with ,,perception1 i4e4 with that integral experience of things in the environment1 out of which sensation is extracted by psychological analysis4 ,what is called perception differs from sensation by the fact that the sensational ingredients bring up habitual associates--images and expectations of their usual correlates--all of which are subjectively indistinguishable from the sensation4 ,the ,,fact of past experience is essential in producing this filling-out of sensation1 but not the ,,recollection of past experience4 ,the non-sensational elements in perception can be wholly explained as the result of habit1 produced by frequent correlations4 ,perception1 according to our definition in ,lecture ,,vii1 is no more a form of knowledge than sensation is1 except in so far as it involves expectations4 ,the purely psychological problems which it raises are not very difficult1 though they have sometimes been rendered artificially obscure by unwillingness to admit the fallibility of the non-sensational elements of perception4 ,on the other hand1 memory raises many difficult and very important problems1 which it is necessary to consider at the first possible moment4 ,one reason for treating memory at this early stage is that it seems to be involved in the fact that images are recognized as copies of past sensible experience4 ,in the preceding lecture ,i alluded to ,hume's principle that all our simple ideas in their first appearance are derived from simple impressions1 which are correspondent to them1 and which they exactly represent4 ,whether or not this principle is liable to exceptions1 everyone would agree that is has a broad measure of truth1 though the word exactly might seem an overstatement1 and it might seem more correct to say that ideas ,,approximately represent impressions4 ,such modifications of ,hume's principle1 however1 do not affect the problem which ,i wish to present for your consideration1 namely3 ,why do we believe that images are1 sometimes or always1 approximately or exactly1 copies of sensations8 ,what sort of evidence is there8 ,and what sort of evidence is logically possible8 ,the difficulty of this question arises through the fact that the sensation which an image is supposed to copy is in the past when the image exists1 and can therefore only be known by memory1 while1 on the other hand1 memory of past sensations seems only possible by means of present images4 ,how1 then1 are we to find any way of comparing the present image and the past sensation8 ,the problem is just as acute if we say that images differ from their prototypes as if we say that they resemble them2 it is the very possibility of comparison that is hard to understand499 ,we think we can know that they are alike or different1 but we cannot bring them together in one experience and compare them4 ,to deal with this problem1 we must have a theory of memory4 ,in this way the whole status of images as copies is bound up with the analysis of memory4 99 ,how1 for example1 can we obtain such knowledge as the following3 ,if we look at1 say1 a red nose and perceive it1 and after a little while ekphore1 its memory-image1 we note immediately how unlike1 in its likeness1 this memory-image is to the original perception 7,a4 ,wohlgemuth1 ,on the ,feelings and their ,neural ,correlate with an ,examination of the ,nature of ,pain1 ,journal of ,psychology1 vol4 viii1 part iv1 ,june1 #aiag74 ,in investigating memory-beliefs1 there are certain points which must be borne in mind4 ,in the first place1 everything constituting a memory-belief is happening now1 not in that past time to which the belief is said to refer4 ,it is not logically necessary to the existence of a memory-belief that the event remembered should have occurred1 or even that the past should have existed at all4 ,there is no logical impossibility in the hypothesis that the world sprang into being five minutes ago1 exactly as it then was1 with a population that remembered a wholly unreal past4 ,there is no logically necessary connection between events at different times2 therefore nothing that is happening now or will happen in the future can disprove the hypothesis that the world began five minutes ago4 ,hence the occurrences which are ,,called knowledge of the past are logically independent of the past2 they are wholly analysable into present contents1 which might1 theoretically1 be just what they are even if no past had existed4 ,i am not suggesting that the non-existence of the past should be entertained as a serious hypothesis4 ,like all sceptical hypotheses1 it is logically tenable1 but uninteresting4 ,all that ,i am doing is to use its logical tenability as a help in the analysis of what occurs when we remember4 ,in the second place1 images without beliefs are insufficient to constitute memory2 and habits are still more insufficient4 ,the behaviourist1 who attempts to make psychology a record of behaviour1 has to trust his memory in making the record4 ,habit is a concept involving the occurrence of similar events at different times2 if the behaviourist feels confident that there is such a phenomenon as habit1 that can only be because he trusts his memory1 when it assures him that there have been other times4 ,and the same applies to images4 ,if we are to know as it is supposed we do--that images are copies1 accurate or inaccurate1 of past events1 something more than the mere occurrence of images must go to constitute this knowledge4 ,for their mere occurrence1 by itself1 would not suggest any connection with anything that had happened before4 ,can we constitute memory out of images together with suitable beliefs8 ,we may take it that memory-images1 when they occur in true memory1 are 7a7 known to be copies1 7b7 sometimes known to be imperfect copies 7cf4 footnote on previous page74 ,how is it possible to know that a memory-image is an imperfect copy1 without having a more accurate copy by which to replace it8 ,this would ,,seem to suggest that we have a way of knowing the past which is independent of images1 by means of which we can criticize image-memories4 ,but ,i do not think such an inference is warranted4 ,what results1 formally1 from our knowledge of the past through images of which we recognize the inaccuracy1 is that such images must have two characteristics by which we can arrange them in two series1 of which one corresponds to the more or less remote period in the past to which they refer1 and the other to our greater or less confidence in their accuracy4 ,we will take the second of these points first4 ,our confidence or lack of confidence in the accuracy of a memory-image must1 in fundamental cases1 be based upon a characteristic of the image itself1 since we cannot evoke the past bodily and compare it with the present image4 ,it might be suggested that vagueness is the required characteristic1 but ,i do not think this is the case4 ,we sometimes have images that are by no means peculiarly vague1 which yet we do not trust--for example1 under the influence of fatigue we may see a friend's face vividly and clearly1 but horribly distorted4 ,in such a case we distrust our image in spite of its being unusually clear4 ,i think the characteristic by which we distinguish the images we trust is the feeling of ,,familiarity that accompanies them4 ,some images1 like some sensations1 feel very familiar1 while others feel strange4 ,familiarity is a feeling capable of degrees4 ,in an image of a well-known face1 for example1 some parts may feel more familiar than others2 when this happens1 we have more belief in the accuracy of the familiar parts than in that of the unfamiliar parts4 ,i think it is by this means that we become critical of images1 not by some imageless memory with which we compare them4 ,i shall return to the consideration of familiarity shortly4 ,i come now to the other characteristic which memory-images must have in order to account for our knowledge of the past4 ,they must have some characteristic which makes us regard them as referring to more or less remote portions of the past4 ,that is to say if we suppose that ,a is the event remembered1 ,b the remembering1 and t the interval of time between ,a and ,b1 there must be some characteristic of ,b which is capable of degrees1 and which1 in accurately dated memories1 varies as t varies4 ,it may increase as t increases1 or diminish as t increases4 ,the question which of these occurs is not of any importance for the theoretic serviceability of the characteristic in question4 ,in actual fact1 there are doubtless various factors that concur in giving us the feeling of greater or less remoteness in some remembered event4 ,there may be a specific feeling which could be called the feeling of pastness1 especially where immediate memory is concerned4 ,but apart from this1 there are other marks4 ,one of these is context4 ,a recent memory has1 usually1 more context than a more distant one4 ,when a remembered event has a remembered context1 this may occur in two ways1 either 7a7 by successive images in the same order as their prototypes1 or 7b7 by remembering a whole process simultaneously1 in the same way in which a present process may be apprehended1 through akoluthic sensations which1 by fading1 acquire the mark of just-pastness in an increasing degree as they fade1 and are thus placed in a series while all sensibly present4 ,it will be context in this second sense1 more specially1 that will give us a sense of the nearness or remoteness of a remembered event4 ,there is1 of course1 a difference between knowing the temporal relation of a remembered event to the present1 and knowing the time-order of two remembered events4 ,very often our knowledge of the temporal relation of a remembered event to the present is inferred from its temporal relations to other remembered events4 ,it would seem that only rather recent events can be placed at all accurately by means of feelings giving their temporal relation to the present1 but it is clear that such feelings must play an essential part in the process of dating remembered events4 ,we may say1 then1 that images are regarded by us as more or less accurate copies of past occurrences because they come to us with two sorts of feelings3 7#a7 ,those that may be called feelings of familiarity2 7#b7 those that may be collected together as feelings giving a sense of pastness4 ,the first lead us to trust our memories1 the second to assign places to them in the time-order4 ,we have now to analyse the memory-belief1 as opposed to the characteristics of images which lead us to base memory-beliefs upon them4 ,if we had retained the subject or act in knowledge1 the whole problem of memory would have been comparatively simple4 ,we could then have said that remembering is a direct relation between the present act or subject and the past occurrence remembered3 the act of remembering is present1 though its object is past4 ,but the rejection of the subject renders some more complicated theory necessary4 ,remembering has to be a present occurrence in some way resembling1 or related to1 what is remembered4 ,and it is difficult to find any ground1 except a pragmatic one1 for supposing that memory is not sheer delusion1 if1 as seems to be the case1 there is not1 apart from memory1 any way of ascertaining that there really was a past occurrence having the required relation to our present remembering4 ,what1 if we followed ,meinong's terminology1 we should call the object in memory1 i4e4 the past event which we are said to be remembering1 is unpleasantly remote from the content1 i4e4 the present mental occurrence in remembering4 ,there is an awkward gulf between the two1 which raises difficulties for the theory of knowledge4 ,but we must not falsify observation to avoid theoretical difficulties4 ,for the present1 therefore1 let us forget these problems1 and try to discover what actually occurs in memory4 ,some points may be taken as fixed1 and such as any theory of memory must arrive at4 ,in this case1 as in most others1 what may be taken as certain in advance is rather vague4 ,the study of any topic is like the continued observation of an object which is approaching us along a road3 what is certain to begin with is the quite vague knowledge that there is ,,some object on the road4 ,if you attempt to be less vague1 and to assert that the object is an elephant1 or a man1 or a mad dog1 you run a risk of error2 but the purpose of continued observation is to enable you to arrive at such more precise knowledge4 ,in like manner1 in the study of memory1 the certainties with which you begin are very vague1 and the more precise propositions at which you try to arrive are less certain than the hazy data from which you set out4 ,nevertheless1 in spite of the risk of error1 precision is the goal at which we must aim4 ,the first of our vague but indubitable data is that there is knowledge of the past4 ,we do not yet know with any precision what we mean by knowledge1 and we must admit that in any given instance our memory may be at fault4 ,nevertheless1 whatever a sceptic might urge in theory1 we cannot practically doubt that we got up this morning1 that we did various things yesterday1 that a great war has been taking place1 and so on4 ,how far our knowledge of the past is due to memory1 and how far to other sources1 is of course a matter to be investigated1 but there can be no doubt that memory forms an indispensable part of our knowledge of the past4 ,the second datum is that we certainly have more capacity for knowing the past than for knowing the future4 ,we know some things about the future1 for example what eclipses there will be2 but this knowledge is a matter of elaborate calculation and inference1 whereas some of our knowledge of the past comes to us without effort1 in the same sort of immediate way in which we acquire knowledge of occurrences in our present environment4 ,we might provisionally1 though perhaps not quite correctly1 define memory as that way of knowing about the past which has no analogue in our knowledge of the future2 such a definition would at least serve to mark the problem with which we are concerned1 though some expectations may deserve to rank with memory as regards immediacy4 ,a third point1 perhaps not quite so certain as our previous two1 is that the truth of memory cannot be wholly practical1 as pragmatists wish all truth to be4 ,it seems clear that some of the things ,i remember are trivial and without any visible importance for the future1 but that my memory is true 7or false7 in virtue of a past event1 not in virtue of any future consequences of my belief4 ,the definition of truth as the correspondence between beliefs and facts seems peculiarly evident in the case of memory1 as against not only the pragmatist definition but also the idealist definition by means of coherence4 ,these considerations1 however1 are taking us away from psychology1 to which we must now return4 ,it is important not to confuse the two forms of memory which ,bergson distinguishes in the second chapter of his ,matter and ,memory1 namely the sort that consists of habit1 and the sort that consists of independent recollection4 ,he gives the instance of learning a lesson by heart3 when ,i know it by heart ,i am said to remember it1 but this merely means that ,i have acquired certain habits2 on the other hand1 my recollection of 7say7 the second time ,i read the lesson while ,i was learning it is the recollection of a unique event1 which occurred only once4 ,the recollection of a unique event cannot1 so ,bergson contends1 be wholly constituted by habit1 and is in fact something radically different from the memory which is habit4 ,the recollection alone is true memory4 ,this distinction is vital to the understanding of memory4 ,but it is not so easy to carry out in practice as it is to draw in theory4 ,habit is a very intrusive feature of our mental life1 and is often present where at first sight it seems not to be4 ,there is1 for example1 a habit of remembering a unique event4 ,when we have once described the event1 the words we have used easily become habitual4 ,we may even have used words to describe it to ourselves while it was happening2 in that case1 the habit of these words may fulfil the function of ,bergson's true memory1 while in reality it is nothing but habit-memory4 ,a gramophone1 by the help of suitable records1 might relate to us the incidents of its past2 and people are not so different from gramophones as they like to believe4 ,in spite1 however1 of a difficulty in distinguishing the two forms of memory in practice1 there can be no doubt that both forms exist4 ,i can set to work now to remember things ,i never remembered before1 such as what ,i had to eat for breakfast this morning1 and it can hardly be wholly habit that enables me to do this4 ,it is this sort of occurrence that constitutes the essence of memory ,until we have analysed what happens in such a case as this1 we have not succeeded in understanding memory4 ,the sort of memory with which we are here concerned is the sort which is a form of knowledge4 ,whether knowledge itself is reducible to habit is a question to which ,i shall return in a later lecture2 for the present ,i am only anxious to point out that1 whatever the true analysis of knowledge may be1 knowledge of past occurrences is not proved by behaviour which is due to past experience4 ,the fact that a man can recite a poem does not show that he remembers any previous occasion on which he has recited or read it4 ,similarly1 the performances of animals in getting out of cages or mazes to which they are accustomed do not prove that they remember having been in the same situation before4 ,arguments in favour of 7for example7 memory in plants are only arguments in favour of habit-memory1 not of knowledge-memory4 ,samuel ,butler's arguments in favour of the view that an animal remembers something of the lives of its ancestors99 are1 when examined1 only arguments in favour of habit-memory4 ,semon's two books1 mentioned in an earlier lecture1 do not touch knowledge-memory at all closely4 ,they give laws according to which images of past occurrences come into our minds1 but do not discuss our belief that these images refer to past occurrences1 which is what constitutes knowledge-memory4 ,it is this that is of interest to theory of knowledge4 ,i shall speak of it as true memory1 to distinguish it from mere habit acquired through past experience4 ,before considering true memory1 it will be well to consider two things which are on the way towards memory1 namely the feeling of familiarity and recognition4 99 ,see his ,life and ,habit and ,unconscious ,memory4 ,we often feel that something in our sensible environment is familiar1 without having any definite recollection of previous occasions on which we have seen it4 ,we have this feeling normally in places where we have often been before--at home1 or in well-known streets4 ,most people and animals find it essential to their happiness to spend a good deal of their time in familiar surroundings1 which are especially comforting when any danger threatens4 ,the feeling of familiarity has all sorts of degrees1 down to the stage where we dimly feel that we have seen a person before4 ,it is by no means always reliable2 almost everybody has at some time experienced the well-known illusion that all that is happening now happened before at some time4 ,there are occasions when familiarity does not attach itself to any definite object1 when there is merely a vague feeling that ,,something is familiar4 ,this is illustrated by ,turgenev's ,smoke1 where the hero is long puzzled by a haunting sense that something in his present is recalling something in his past1 and at last traces it to the smell of heliotrope4 ,whenever the sense of familiarity occurs without a definite object1 it leads us to search the environment until we are satisfied that we have found the appropriate object1 which leads us to the judgment3 ,,this is familiar4 ,i think we may regard familiarity as a definite feeling1 capable of existing without an object1 but normally standing in a specific relation to some feature of the environment1 the relation being that which we express in words by saying that the feature in question is familiar4 ,the judgment that what is familiar has been experienced before is a product of reflection1 and is no part of the feeling of familiarity1 such as a horse may be supposed to have when he returns to his stable4 ,thus no knowledge as to the past is to be derived from the feeling of familiarity alone4 ,a further stage is ,,recognition4 ,this may be taken in two senses1 the first when a thing not merely feels familiar1 but we know it is such-and-such4 ,we recognize our friend ,jones1 we know cats and dogs when we see them1 and so on4 ,here we have a definite influence of past experience1 but not necessarily any actual knowledge of the past4 ,when we see a cat1 we know it is a cat because of previous cats we have seen1 but we do not1 as a rule1 recollect at the moment any particular occasion when we have seen a cat4 ,recognition in this sense does not necessarily involve more than a habit of association3 the kind of object we are seeing at the moment is associated with the word cat1 or with an auditory image of purring1 or whatever other characteristic we may happen to recognize in the cat of the moment4 ,we are1 of course1 in fact able to judge1 when we recognize an object1 that we have seen it before1 but this judgment is something over and above recognition in this first sense1 and may very probably be impossible to animals that nevertheless have the experience of recognition in this first sense of the word4 ,there is1 however1 another sense of the word1 in which we mean by recognition1 not knowing the name of a thing or some other property of it1 but knowing that we have seen it before ,in this sense recognition does involve knowledge about the ,fast4 ,this knowledge is memory in one sense1 though in another it is not4 ,it does not involve a definite memory of a definite past event1 but only the knowledge that something happening now is similar to something that happened before4 ,it differs from the sense of familiarity by being cognitive2 it is a belief or judgment1 which the sense of familiarity is not4 ,i do not wish to undertake the analysis of belief at present1 since it will be the subject of the twelfth lecture2 for the present ,i merely wish to emphasize the fact that recognition1 in our second sense1 consists in a belief1 which we may express approximately in the words3 ,this has existed before4 ,there are1 however1 several points in which such an account of recognition is inadequate4 ,to begin with1 it might seem at first sight more correct to define recognition as ,i have seen this before than as this has existed before4 ,we recognize a thing 7it may be urged7 as having been in our experience before1 whatever that may mean2 we do not recognize it as merely having been in the world before4 ,i am not sure that there is anything substantial in this point4 ,the definition of my experience is difficult2 broadly speaking1 it is everything that is connected with what ,i am experiencing now by certain links1 of which the various forms of memory are among the most important4 ,thus1 if ,i recognize a thing1 the occasion of its previous existence in virtue of which ,i recognize it forms part of my experience by ,,definition3 recognition will be one of the marks by which my experience is singled out from the rest of the world4 ,of course1 the words this has existed before are a very inadequate translation of what actually happens when we form a judgment of recognition1 but that is unavoidable3 words are framed to express a level of thought which is by no means primitive1 and are quite incapable of expressing such an elementary occurrence as recognition4 ,i shall return to what is virtually the same question in connection with true memory1 which raises exactly similar problems4 ,a second point is that1 when we recognize something1 it was not in fact the very same thing1 but only something similar1 that we experienced on a former occasion4 ,suppose the object in question is a friend's face4 ,a person's face is always changing1 and is not exactly the same on any two occasions4 ,common sense treats it as one face with varying expressions2 but the varying expressions actually exist1 each at its proper time1 while the one face is merely a logical construction4 ,we regard two objects as the same1 for common-sense purposes1 when the reaction they call for is practically the same4 ,two visual appearances1 to both of which it is appropriate to say3 ,hullo1 ,jones6 are treated as appearances of one identical object1 namely ,jones4 ,the name ,jones is applicable to both1 and it is only reflection that shows us that many diverse particulars are collected together to form the meaning of the name ,jones4 ,what we see on any one occasion is not the whole series of particulars that make up ,jones1 but only one of them 7or a few in quick succession74 ,on another occasion we see another member of the series1 but it is sufficiently similar to count as the same from the standpoint of common sense4 ,accordingly1 when we judge ,i have seen ,,this before1 we judge falsely if this is taken as applying to the actual constituent of the world that we are seeing at the moment4 ,the word this must be interpreted vaguely so as to include anything sufficiently like what we are seeing at the moment4 ,here1 again1 we shall find a similar point as regards true memory2 and in connection with true memory we will consider the point again4 ,it is sometimes suggested1 by those who favour behaviourist views1 that recognition consists in behaving in the same way when a stimulus is repeated as we behaved on the first occasion when it occurred4 ,this seems to be the exact opposite of the truth4 ,the essence of recognition is in the ,,difference between a repeated stimulus and a new one4 ,on the first occasion there is no recognition2 on the second occasion there is4 ,in fact1 recognition is another instance of the peculiarity of causal laws in psychology1 namely1 that the causal unit is not a single event1 but two or more events ,habit is the great instance of this1 but recognition is another4 ,a stimulus occurring once has a certain effect2 occurring twice1 it has the further effect of recognition4 ,thus the phenomenon of recognition has as its cause the two occasions when the stimulus has occurred2 either alone is insufficient4 ,this complexity of causes in psychology might be connected with ,bergson's arguments against repetition in the mental world4 ,it does not prove that there are no causal laws in psychology1 as ,bergson suggests2 but it does prove that the causal laws of psychology are ,prima facie very different from those of physics4 ,on the possibility of explaining away the difference as due to the peculiarities of nervous tissue ,i have spoken before1 but this possibility must not be forgotten if we are tempted to draw unwarranted metaphysical deductions4 ,true memory1 which we must now endeavour to understand1 consists of knowledge of past events1 but not of all such knowledge4 ,some knowledge of past events1 for example what we learn through reading history1 is on a par with the knowledge we can acquire concerning the future3 it is obtained by inference1 not 7so to speak7 spontaneously4 ,there is a similar distinction in our knowledge of the present3 some of it is obtained through the senses1 some in more indirect ways4 ,i know that there are at this moment a number of people in the streets of ,new ,york1 but ,i do not know this in the immediate way in which ,i know of the people whom ,i see by looking out of my window4 ,it is not easy to state precisely wherein the difference between these two sorts of knowledge consists1 but it is easy to feel the difference4 ,for the moment1 ,i shall not stop to analyse it1 but shall content myself with saying that1 in this respect1 memory resembles the knowledge derived from the senses4 ,it is immediate1 not inferred1 not abstract2 it differs from perception mainly by being referred to the past4 ,in regard to memory1 as throughout the analysis of knowledge1 there are two very distinct problems1 namely 7#a7 as to the nature of the present occurrence in knowing2 7#b7 as to the relation of this occurrence to what is known4 ,when we remember1 the knowing is now1 while what is known is in the past4 ,our two questions are1 in the case of memory3 7#a7 ,what is the present occurrence when we remember8 7#b7 ,what is the relation of this present occurrence to the past event which is remembered8 ,of these two questions1 only the first concerns the psychologist2 the second belongs to theory of knowledge4 ,at the same time1 if we accept the vague datum with which we began1 to the effect that1 in some sense1 there is knowledge of the past1 we shall have to find1 if we can1 such an account of the present occurrence in remembering as will make it not impossible for remembering to give us knowledge of the past4 ,for the present1 however1 we shall do well to forget the problems concerning theory of knowledge1 and concentrate upon the purely psychological problem of memory4 ,between memory-image and sensation there is an intermediate experience concerning the immediate past4 ,for example1 a sound that we have just heard is present to us in a way which differs both from the sensation while we are hearing the sound and from the memory-image of something heard days or weeks ago4 ,james states that it is this way of apprehending the immediate past that is the ,,original of our experience of pastness1 from whence we get the meaning of the term7,psychology1 i1 p4 #fjd74 ,everyone knows the experience of noticing 7say7 that the clock ,,has ,,been striking1 when we did not notice it while it was striking4 ,and when we hear a remark spoken1 we are conscious of the earlier words while the later ones are being uttered1 and this retention feels different from recollection of something definitely past4 ,a sensation fades gradually1 passing by continuous gradations to the status of an image4 ,this retention of the immediate past in a condition intermediate between sensation and image may be called immediate memory4 ,everything belonging to it is included with sensation in what is called the specious present4 ,the specious present includes elements at all stages on the journey from sensation to image4 ,it is this fact that enables us to apprehend such things as movements1 or the order of the words in a spoken sentence4 ,succession can occur within the specious present1 of which we can distinguish some parts as earlier and others as later4 ,it is to be supposed that the earliest parts are those that have faded most from their original force1 while the latest parts are those that retain their full sensational character4 ,at the beginning of a stimulus we have a sensation2 then a gradual transition2 and at the end an image4 ,sensations while they are fading are called akoluthic sensations499 ,when the process of fading is completed 7which happens very quickly71 we arrive at the image1 which is capable of being revived on subsequent occasions with very little change4 ,true memory1 as opposed to immediate memory1 applies only to events sufficiently distant to have come to an end of the period of fading4 ,such events1 if they are represented by anything present1 can only be represented by images1 not by those intermediate stages1 between sensations and images1 which occur during the period of fading4 99 ,see ,semon1 ,die mnemischen ,empfindungen1 chap4 vi4 ,immediate memory is important both because it provides experience of succession1 and because it bridges the gulf between sensations and the images which are their copies4 ,but it is now time to resume the consideration of true memory4 ,suppose you ask me what ,i ate for breakfast this morning4 ,suppose1 further1 that ,i have not thought about my breakfast in the meantime1 and that ,i did not1 while ,i was eating it1 put into words what it consisted of4 ,in this case my recollection will be true memory1 not habit-memory4 ,the process of remembering will consist of calling up images of my breakfast1 which will come to me with a feeling of belief such as distinguishes memory-images from mere imagination-images4 ,or sometimes words may come without the intermediary of images2 but in this case equally the feeling of belief is essential4 ,let us omit from our consideration1 for the present1 the memories in which words replace images4 ,these are always1 ,i think1 really habit-memories1 the memories that use images being the typical true memories4 ,memory-images and imagination-images do not differ in their intrinsic qualities1 so far as we can discover4 ,they differ by the fact that the images that constitute memories1 unlike those that constitute imagination1 are accompanied by a feeling of belief which may be expressed in the words this happened4 ,the mere occurrence of images1 without this feeling of belief1 constitutes imagination2 it is the element of belief that is the distinctive thing in memory499 99 ,for belief of a specific kind1 cf4 ,dorothy ,wrinch ,on the ,nature of ,memory1 ,mind1 ,january1 #aibj4 ,there are1 if ,i am not mistaken1 at least three different kinds of belief-feeling1 which we may call respectively memory1 expectation and bare assent4 ,in what ,i call bare assent1 there is no time-element in the feeling of belief1 though there may be in the content of what is believed4 ,if ,i believe that ,caesar landed in ,britain in ,b4,c4 #ee1 the time-determination lies1 not in the feeling of belief1 but in what is believed4 ,i do not remember the occurrence1 but have the same feeling towards it as towards the announcement of an eclipse next year4 ,but when ,i have seen a flash of lightning and am waiting for the thunder1 ,i have a belief-feeling analogous to memory1 except that it refers to the future3 ,i have an image of thunder1 combined with a feeling which may be expressed in the words3 this will happen4 ,so1 in memory1 the pastness lies1 not in the content of what is believed1 but in the nature of the belief-feeling4 ,i might have just the same images and expect their realization2 ,i might entertain them without any belief1 as in reading a novel2 or ,i might entertain them together with a time-determination1 and give bare assent1 as in reading history4 ,i shall return to this subject in a later lecture1 when we come to the analysis of belief4 ,for the present1 ,i wish to make it clear that a certain special kind of belief is the distinctive characteristic of memory4 ,the problem as to whether memory can be explained as habit or association requires to be considered afresh in connection with the causes of our remembering something4 ,let us take again the case of my being asked what ,i had for breakfast this morning4 ,in this case the question leads to my setting to work to recollect4 ,it is a little strange that the question should instruct me as to what it is that ,i am to recall4 ,this has to do with understanding words1 which will be the topic of the next lecture2 but something must be said about it now4 ,our understanding of the words breakfast this morning is a habit1 in spite of the fact that on each fresh day they point to a different occasion4 ,this morning does not1 whenever it is used1 mean the same thing1 as ,john or ,st4 ,paul's does2 it means a different period of time on each different day4 ,it follows that the habit which constitutes our understanding of the words this morning is not the habit of associating the words with a fixed object1 but the habit of associating them with something having a fixed time-relation to our present4 ,this morning has1 to-day1 the same time-relation to my present that yesterday morning had yesterday4 ,in order to understand the phrase this morning it is necessary that we should have a way of feeling time-intervals1 and that this feeling should give what is constant in the meaning of the words this morning4 ,this appreciation of time-intervals is1 however1 obviously a product of memory1 not a presupposition of it4 ,it will be better1 therefore1 if we wish to analyse the causation of memory by something not presupposing memory1 to take some other instance than that of a question about this morning4 ,let us take the case of coming into a familiar room where something has been changed--say a new picture hung on the wall4 ,we may at first have only a sense that ,,something is unfamiliar1 but presently we shall remember1 and say that picture was not on the wall before4 ,in order to make the case definite1 we will suppose that we were only in the room on one former occasion4 ,in this case it seems fairly clear what happens4 ,the other objects in the room are associated1 through the former occasion1 with a blank space of wall where now there is a picture4 ,they call up an image of a blank wall1 which clashes with perception of the picture4 ,the image is associated with the belief-feeling which we found to be distinctive of memory1 since it can neither be abolished nor harmonized with perception4 ,if the room had remained unchanged1 we might have had only the feeling of familiarity without the definite remembering2 it is the change that drives us from the present to memory of the past4 ,we may generalize this instance so as to cover the causes of many memories4 ,some present feature of the environment is associated1 through past experiences1 with something now absent2 this absent something comes before us as an image1 and is contrasted with present sensation4 ,in cases of this sort1 habit 7or association7 explains why the present feature of the environment brings up the memory-image1 but it does not explain the memory-belief4 ,perhaps a more complete analysis could explain the memory-belief also on lines of association and habit1 but the causes of beliefs are obscure1 and we cannot investigate them yet4 ,for the present we must content ourselves with the fact that the memory-image can be explained by habit4 ,as regards the memory-belief1 we must1 at least provisionally1 accept ,bergson's view that it cannot be brought under the head of habit1 at any rate when it first occurs1 i4e4 when we remember something we never remembered before4 ,we must now consider somewhat more closely the content of a memory-belief4 ,the memory-belief confers upon the memory-image something which we may call meaning2 it makes us feel that the image points to an object which existed in the past4 ,in order to deal with this topic we must consider the verbal expression of the memory-belief4 ,we might be tempted to put the memory-belief into the words3 ,something like this image occurred4 ,but such words would be very far from an accurate translation of the simplest kind of memory-belief4 ,something like this image is a very complicated conception4 ,in the simplest kind of memory we are not aware of the difference between an image and the sensation which it copies1 which may be called its prototype4 ,when the image is before us1 we judge rather this occurred4 ,the image is not distinguished from the object which existed in the past3 the word this covers both1 and enables us to have a memory-belief which does not introduce the complicated notion something like this4 ,it might be objected that1 if we judge this occurred when in fact this is a present image1 we judge falsely1 and the memory-belief1 so interpreted1 becomes deceptive4 ,this1 however1 would be a mistake1 produced by attempting to give to words a precision which they do not possess when used by unsophisticated people4 ,it is true that the image is not absolutely identical with its prototype1 and if the word this meant the image to the exclusion of everything else1 the judgment this occurred would be false4 ,but identity is a precise conception1 and no word1 in ordinary speech1 stands for anything precise4 ,ordinary speech does not distinguish between identity and close similarity4 ,a word always applies1 not only to one particular1 but to a group of associated particulars1 which are not recognized as multiple in common thought or speech4 ,thus primitive memory1 when it judges that this occurred1 is vague1 but not false4 ,vague identity1 which is really close similarity1 has been a source of many of the confusions by which philosophy has lived4 ,of a vague subject1 such as a this1 which is both an image and its prototype1 contradictory predicates are true simultaneously3 this existed and does not exist1 since it is a thing remembered1 but also this exists and did not exist1 since it is a present image4 ,hence ,bergson's interpenetration of the present by the past1 ,hegelian continuity and identity-in-diversity1 and a host of other notions which are thought to be profound because they are obscure and confused4 ,the contradictions resulting from confounding image and prototype in memory force us to precision4 ,but when we become precise1 our remembering becomes different from that of ordinary life1 and if we forget this we shall go wrong in the analysis of ordinary memory4 ,vagueness and accuracy are important notions1 which it is very necessary to understand4 ,both are a matter of degree4 ,all thinking is vague to some extent1 and complete accuracy is a theoretical ideal not practically attainable4 ,to understand what is meant by accuracy1 it will be well to consider first instruments of measurement1 such as a balance or a thermometer4 ,these are said to be accurate when they give different results for very slightly different stimuli499 ,a clinical thermometer is accurate when it enables us to detect very slight differences in the temperature of the blood4 ,we may say generally that an instrument is accurate in proportion as it reacts differently to very slightly different stimuli4 ,when a small difference of stimulus produces a great difference of reaction1 the instrument is accurate2 in the contrary case it is not4 99 ,this is a necessary but not a sufficient condition4 ,the subject of accuracy and vagueness will be considered again in ,lecture ,,xiii4 ,exactly the same thing applies in defining accuracy of thought or perception4 ,a musician will respond differently to very minute differences in playing which would be quite imperceptible to the ordinary mortal4 ,a negro can see the difference between one negro and another one is his friend1 another his enemy4 ,but to us such different responses are impossible3 we can merely apply the word negro indiscriminately4 ,accuracy of response in regard to any particular kind of stimulus is improved by practice4 ,understanding a language is a case in point4 ,few ,frenchmen can hear any difference between the sounds hall and hole1 which produce quite different impressions upon us4 ,the two statements the hall is full of water and the hole is full of water call for different responses1 and a hearing which cannot distinguish between them is inaccurate or vague in this respect4 ,precision and vagueness in thought1 as in perception1 depend upon the degree of difference between responses to more or less similar stimuli4 ,in the case of thought1 the response does not follow immediately upon the sensational stimulus1 but that makes no difference as regards our present question4 ,thus to revert to memory3 ,a memory is vague when it is appropriate to many different occurrences3 for instance1 ,i met a man is vague1 since any man would verify it4 ,a memory is precise when the occurrences that would verify it are narrowly circumscribed3 for instance1 ,i met ,jones is precise as compared to ,i met a man4 ,a memory is accurate when it is both precise and true1 i4e4 in the above instance1 if it was ,jones ,i met4 ,it is precise even if it is false1 provided some very definite occurrence would have been required to make it true4 ,it follows from what has been said that a vague thought has more likelihood of being true than a precise one4 ,to try and hit an object with a vague thought is like trying to hit the bull's eye with a lump of putty3 when the putty reaches the target1 it flattens out all over it1 and probably covers the bull's eye along with the rest4 ,to try and hit an object with a precise thought is like trying to hit the bull's eye with a bullet4 ,the advantage of the precise thought is that it distinguishes between the bull's eye and the rest of the target4 ,for example1 if the whole target is represented by the fungus family and the bull's eye by mushrooms1 a vague thought which can only hit the target as a whole is not much use from a culinary point of view4 ,and when ,i merely remember that ,i met a man1 my memory may be very inadequate to my practical requirements1 since it may make a great difference whether ,i met ,brown or ,jones4 ,the memory ,i met ,jones is relatively precise4 ,it is accurate if ,i met ,jones1 inaccurate if ,i met ,brown1 but precise in either case as against the mere recollection that ,i met a man4 ,the distinction between accuracy and precision is however1 not fundamental4 ,we may omit precision from out thoughts and confine ourselves to the distinction between accuracy and vagueness4 ,we may then set up the following definitions3 ,an instrument is reliable with respect to a given set of stimuli when to stimuli which are not relevantly different it gives always responses which are not relevantly different4 ,an instrument is a measure of a set of stimuli which are serially ordered when its responses1 in all cases where they are relevantly different1 are arranged in a series in the same order4 ,the degree of accuracy of an instrument which is a reliable measurer is the ratio of the difference of response to the difference of stimulus in cases where the difference of stimulus is small499 ,that is to say1 if a small difference of stimulus produces a great difference of response1 the instrument is very accurate2 in the contrary case1 very inaccurate4 99 ,strictly speaking1 the limit of this1 i4e4 the derivative of the response with respect to the stimulus4 ,a mental response is called vague in proportion to its lack of accuracy1 or rather precision4 ,these definitions will be found useful1 not only in the case of memory1 but in almost all questions concerned with knowledge4 ,it should be observed that vague beliefs1 so far from being necessarily false1 have a better chance of truth than precise ones1 though their truth is less valuable than that of precise beliefs1 since they do not distinguish between occurrences which may differ in important ways4 ,the whole of the above discussion of vagueness and accuracy was occasioned by the attempt to interpret the word this when we judge in verbal memory that this occurred4 ,the word this1 in such a judgment1 is a vague word1 equally applicable to the present memory-image and to the past occurrence which is its prototype4 ,a vague word is not to be identified with a general word1 though in practice the distinction may often be blurred4 ,a word is general when it is understood to be applicable to a number of different objects in virtue of some common property4 ,a word is vague when it is in fact applicable to a number of different objects because1 in virtue of some common property1 they have not appeared1 to the person using the word1 to be distinct4 ,i emphatically do not mean that he has judged them to be identical1 but merely that he has made the same response to them all and has not judged them to be different4 ,we may compare a vague word to a jelly and a general word to a heap of shot4 ,vague words precede judgments of identity and difference2 both general and particular words are subsequent to such judgments4 ,the word this in the primitive memory-belief is a vague word1 not a general word2 it covers both the image and its prototype because the two are not distinguished499 99 ,on the vague and the general cf4 ,ribot3 ,evolution of ,general ,ideas1 ,open ,court ,co41 #ahii1 p4 #cb3 ,the sole permissible formula is this3 ,intelligence progresses from the indefinite to the definite4 ,if 'indefinite' is taken as synonymous with general1 it may be said that the particular does not appear at the outset1 but neither does the general in any exact sense3 the vague would be more appropriate4 ,in other words1 no sooner has the intellect progressed beyond the moment of perception and of its immediate reproduction in memory1 than the generic image makes its appearance1 i4e4 a state intermediate between the particular and the general1 participating in the nature of the one and of the other--a confused simplification4 ,but we have not yet finished our analysis of the memory-belief4 ,the tense in the belief that this occurred is provided by the nature of the belief-feeling involved in memory2 the word this1 as we have seen1 has a vagueness which we have tried to describe4 ,but we must still ask what we mean by occurred4 ,the image is1 in one sense1 occurring now2 and therefore we must find some other sense in which the past event occurred but the image does not occur4 ,there are two distinct questions to be asked3 7#a7 ,what causes us to say that a thing occurs8 7#b7 ,what are we feeling when we say this8 ,as to the first question1 in the crude use of the word1 which is what concerns us1 memory-images would not be said to occur2 they would not be noticed in themselves1 but merely used as signs of the past event4 ,images are merely imaginary2 they have not1 in crude thought1 the sort of reality that belongs to outside bodies4 ,roughly speaking1 real things would be those that can cause sensations1 those that have correlations of the sort that constitute physical objects4 ,a thing is said to be real or to occur when it fits into a context of such correlations4 ,the prototype of our memory-image did fit into a physical context1 while our memory-image does not4 ,this causes us to feel that the prototype was real1 while the image is imaginary4 ,but the answer to our second question1 namely as to what we are feeling when we say a thing occurs or is real1 must be somewhat different4 ,we do not1 unless we are unusually reflective1 think about the presence or absence of correlations3 we merely have different feelings which1 intellectualized1 may be represented as expectations of the presence or absence of correlations4 ,a thing which feels real inspires us with hopes or fears1 expectations or curiosities1 which are wholly absent when a thing feels imaginary4 ,the feeling of reality is a feeling akin to respect3 it belongs ,,primarily to whatever can do things to us without our voluntary co-operation4 ,this feeling of reality1 related to the memory-image1 and referred to the past by the specific kind of belief-feeling that is characteristic of memory1 seems to be what constitutes the act of remembering in its pure form4 ,we may now summarize our analysis of pure memory4 ,memory demands 7a7 an image1 7b7 a belief in past existence4 ,the belief may be expressed in the words this existed4 ,the belief1 like every other1 may be analysed into 7#a7 the believing1 7#b7 what is believed4 ,the believing is a specific feeling or sensation or complex of sensations1 different from expectation or bare assent in a way that makes the belief refer to the past2 the reference to the past lies in the belief-feeling1 not in the content believed4 ,there is a relation between the belief-feeling and the content1 making the belief-feeling refer to the content1 and expressed by saying that the content is what is believed4 ,the content believed may or may not be expressed in words4 ,let us take first the case when it is not4 ,in that case1 if we are merely remembering that something of which we now have an image occurred1 the content consists of 7a7 the image1 7b7 the feeling1 analogous to respect1 which we translate by saying that something is real as opposed to imaginary1 7c7 a relation between the image and the feeling of reality1 of the sort expressed when we say that the feeling refers to the image4 ,this content does not contain in itself any time-determination4 ,the time-determination lies in the nature of the belief feeling1 which is that called remembering or 7better7 recollecting4 ,it is only subsequent reflection upon this reference to the past that makes us realize the distinction between the image and the event recollected4 ,when we have made this distinction1 we can say that the image means the past event4 ,the content expressed in words is best represented by the words the existence of this1 since these words do not involve tense1 which belongs to the belief-feeling1 not to the content4 ,here this is a vague term1 covering the memory-image and anything very like it1 including its prototype4 ,existence expresses the feeling of a reality aroused primarily by whatever can have effects upon us without our voluntary co-operation4 ,the word of in the phrase the existence of this represents the relation which subsists between the feeling of reality and the this4 ,this analysis of memory is probably extremely faulty1 but ,i do not know how to improve it4 ,,note4-,when ,i speak of a ,,feeling of belief1 ,i use the word feeling in a popular sense1 to cover a sensation or an image or a complex of sensations or images or both2 ,i use this word because ,i do not wish to commit myself to any special analysis of the belief-feeling4 ,,lecture ,x4 ,,words ,,and ,,meaning ,the problem with which we shall be concerned in this lecture is the problem of determining what is the relation called meaning4 ,the word ,napoleon1 we say1 means a certain person4 ,in saying this1 we are asserting a relation between the word ,napoleon and the person so designated4 ,it is this relation that we must now investigate4 ,let us first consider what sort of object a word is when considered simply as a physical thing1 apart from its meaning4 ,to begin with1 there are many instances of a word1 namely all the different occasions when it is employed4 ,thus a word is not something unique and particular1 but a set of occurrences4 ,if we confine ourselves to spoken words1 a word has two aspects1 according as we regard it from the point of view of the speaker or from that of the hearer4 ,from the point of view of the speaker1 a single instance of the use of a word consists of a certain set of movements in the throat and mouth1 combined with breath4 ,from the point of view of the hearer1 a single instance of the use of a word consists of a certain series of sounds1 each being approximately represented by a single letter in writing1 though in practice a letter may represent several sounds1 or several letters may represent one sound4 ,the connection between the spoken word and the word as it reaches the hearer is causal4 ,let us confine ourselves to the spoken word1 which is the more important for the analysis of what is called thought4 ,then we may say that a single instance of the spoken word consists of a series of movements1 and the word consists of a whole set of such series1 each member of the set being very similar to each other member4 ,that is to say1 any two instances of the word ,napoleon are very similar1 and each instance consists of a series of movements in the mouth4 ,a single word1 accordingly1 is by no means simple it is a class of similar series of movements 7confining ourselves still to the spoken word74 ,the degree of similarity required cannot be precisely defined3 a man may pronounce the word ,napoleon so badly that it can hardly be determined whether he has really pronounced it or not4 ,the instances of a word shade off into other movements by imperceptible degrees4 ,and exactly analogous observations apply to words heard or written or read4 ,but in what has been said so far we have not even broached the question of the ,,definition of a word1 since meaning is clearly what distinguishes a word from other sets of similar movements1 and meaning remains to be defined4 ,it is natural to think of the meaning of a word as something conventional4 ,this1 however1 is only true with great limitations4 ,a new word can be added to an existing language by a mere convention1 as is done1 for instance1 with new scientific terms4 ,but the basis of a language is not conventional1 either from the point of view of the individual or from that of the community4 ,a child learning to speak is learning habits and associations which are just as much determined by the environment as the habit of expecting dogs to bark and cocks to crow4 ,the community that speaks a language has learnt it1 and modified it by processes almost all of which are not deliberate1 but the results of causes operating according to more or less ascertainable laws4 ,if we trace any ,indo-,european language back far enough1 we arrive hypothetically 7at any rate according to some authorities7 at the stage when language consisted only of the roots out of which subsequent words have grown4 ,how these roots acquired their meanings is not known1 but a conventional origin is clearly just as mythical as the social contract by which ,hobbes and ,rousseau supposed civil government to have been established4 ,we can hardly suppose a parliament of hitherto speechless elders meeting together and agreeing to call a cow a cow and a wolf a wolf4 ,the association of words with their meanings must have grown up by some natural process1 though at present the nature of the process is unknown4 ,spoken and written words are1 of course1 not the only way of conveying meaning4 ,a large part of one of ,wundt's two vast volumes on language in his ,volkerpsychologie is concerned with gesture-language4 ,ants appear to be able to communicate a certain amount of information by means of their antennae4 ,probably writing itself1 which we now regard as merely a way of representing speech1 was originally an independent language1 as it has remained to this day in ,china4 ,writing seems to have consisted originally of pictures1 which gradually became conventionalized1 coming in time to represent syllables1 and finally letters on the telephone principle of ,t for ,tommy4 ,but it would seem that writing nowhere began as an attempt to represent speech it began as a direct pictorial representation of what was to be expressed4 ,the essence of language lies1 not in the use of this or that special means of communication1 but in the employment of fixed associations 7however these may have originated7 in order that something now sensible--a spoken word1 a picture1 a gesture1 or what not--may call up the idea of something else4 ,whenever this is done1 what is now sensible may be called a sign or symbol1 and that of which it is intended to call up the idea may be called its meaning4 ,this is a rough outline of what constitutes meaning4 ,but we must fill in the outline in various ways4 ,and1 since we are concerned with what is called thought1 we must pay more attention than we otherwise should do to the private as opposed to the social use of language4 ,language profoundly affects our thoughts1 and it is this aspect of language that is of most importance to us in our present inquiry4 ,we are almost more concerned with the internal speech that is never uttered than we are with the things said out loud to other people4 ,when we ask what constitutes meaning1 we are not asking what is the meaning of this or that particular word4 ,the word ,napoleon means a certain individual2 but we are asking1 not who is the individual meant1 but what is the relation of the word to the individual which makes the one mean the other4 ,but just as it is useful to realize the nature of a word as part of the physical world1 so it is useful to realize the sort of thing that a word may mean4 ,when we are clear both as to what a word is in its physical aspect1 and as to what sort of thing it can mean1 we are in a better position to discover the relation of the two which is meaning4 ,the things that words mean differ more than words do4 ,there are different sorts of words1 distinguished by the grammarians2 and there are logical distinctions1 which are connected to some extent1 though not so closely as was formerly supposed1 with the grammatical distinctions of parts of speech4 ,it is easy1 however1 to be misled by grammar1 particularly if all the languages we know belong to one family4 ,in some languages1 according to some authorities1 the distinction of parts of speech does not exist2 in many languages it is widely different from that to which we are accustomed in the ,indo-,european languages4 ,these facts have to be borne in mind if we are to avoid giving metaphysical importance to mere accidents of our own speech4 ,in considering what words mean1 it is natural to start with proper names1 and we will again take ,napoleon as our instance4 ,we commonly imagine1 when we use a proper name1 that we mean one definite entity1 the particular individual who was called ,napoleon4 ,but what we know as a person is not simple4 ,there ,,may be a single simple ego which was ,napoleon1 and remained strictly identical from his birth to his death4 ,there is no way of proving that this cannot be the case1 but there is also not the slightest reason to suppose that it is the case4 ,napoleon as he was empirically known consisted of a series of gradually changing appearances3 first a squalling baby1 then a boy1 then a slim and beautiful youth1 then a fat and slothful person very magnificently dressed ,this series of appearances1 and various occurrences having certain kinds of causal connections with them1 constitute ,napoleon as empirically known1 and therefore are ,napoleon in so far as he forms part of the experienced world4 ,napoleon is a complicated series of occurrences1 bound together by causal laws1 not1 like instances of a word1 by similarities4 ,for although a person changes gradually1 and presents similar appearances on two nearly contemporaneous occasions1 it is not these similarities that constitute the person1 as appears from the ,comedy of ,errors for example4 ,thus in the case of a proper name1 while the word is a set of similar series of movements1 what it means is a series of occurrences bound together by causal laws of that special kind that makes the occurrences taken together constitute what we call one person1 or one animal or thing1 in case the name applies to an animal or thing instead of to a person4 ,neither the word nor what it names is one of the ultimate indivisible constituents of the world4 ,in language there is no direct way of designating one of the ultimate brief existents that go to make up the collections we call things or persons4 ,if we want to speak of such existents--which hardly happens except in philosophy--we have to do it by means of some elaborate phrase1 such as the visual sensation which occupied the centre of my field of vision at noon on ,january #a1 #aiai4 ,such ultimate simples ,i call particulars4 ,particulars ,,might have proper names1 and no doubt would have if language had been invented by scientifically trained observers for purposes of philosophy and logic4 ,but as language was invented for practical ends1 particulars have remained one and all without a name4 ,we are not1 in practice1 much concerned with the actual particulars that come into our experience in sensation2 we are concerned rather with whole systems to which the particulars belong and of which they are signs4 ,what we see makes us say ,hullo1 there's ,jones1 and the fact that what we see is a sign of ,jones 7which is the case because it is one of the particulars that make up ,jones7 is more interesting to us than the actual particular itself4 ,hence we give the name ,jones to the whole set of particulars1 but do not trouble to give separate names to the separate particulars that make up the set4 ,passing on from proper names1 we come next to general names1 such as man1 cat1 triangle4 ,a word such as man means a whole class of such collections of particulars as have proper names4 ,the several members of the class are assembled together in virtue of some similarity or common property4 ,all men resemble each other in certain important respects2 hence we want a word which shall be equally applicable to all of them4 ,we only give proper names to the individuals of a species when they differ inter se in practically important respects4 ,in other cases we do not do this4 ,a poker1 for instance1 is just a poker2 we do not call one ,john and another ,peter4 ,there is a large class of words1 such as eating1 walking1 speaking1 which mean a set of similar occurrences4 ,two instances of walking have the same name because they resemble each other1 whereas two instances of ,jones have the same name because they are causally connected4 ,in practice1 however1 it is difficult to make any precise distinction between a word such as walking and a general name such as man4 ,one instance of walking cannot be concentrated into an instant3 it is a process in time1 in which there is a causal connection between the earlier and later parts1 as between the earlier and later parts of ,jones4 ,thus an instance of walking differs from an instance of man solely by the fact that it has a shorter life4 ,there is a notion that an instance of walking1 as compared with ,jones1 is unsubstantial1 but this seems to be a mistake4 ,we think that ,jones walks1 and that there could not be any walking unless there were somebody like ,jones to perform the walking4 ,but it is equally true that there could be no ,jones unless there were something like walking for him to do4 ,the notion that actions are performed by an agent is liable to the same kind of criticism as the notion that thinking needs a subject or ego1 which we rejected in ,lecture ,i4 ,to say that it is ,jones who is walking is merely to say that the walking in question is part of the whole series of occurrences which is ,jones4 ,there is no ,,logical impossibility in walking occurring as an isolated phenomenon1 not forming part of any such series as we call a person4 ,we may therefore class with eating1 walking1 speaking words such as rain1 sunrise1 lightning1 which do not denote what would commonly be called actions4 ,these words illustrate1 incidentally1 how little we can trust to the grammatical distinction of parts of speech1 since the substantive rain and the verb to rain denote precisely the same class of meteorological occurrences4 ,the distinction between the class of objects denoted by such a word and the class of objects denoted by a general name such as man1 vegetable1 or planet1 is that the sort of object which is an instance of 7say7 lightning is much simpler than 7say7 an individual man4 7,i am speaking of lightning as a sensible phenomenon1 not as it is described in physics47 ,the distinction is one of degree1 not of kind4 ,but there is1 from the point of view of ordinary thought1 a great difference between a process which1 like a flash of lightning1 can be wholly comprised within one specious present and a process which1 like the life of a man1 has to be pieced together by observation and memory and the apprehension of causal connections4 ,we may say broadly1 therefore1 that a word of the kind we have been discussing denotes a set of similar occurrences1 each 7as a rule7 much more brief and less complex than a person or thing4 ,words themselves1 as we have seen1 are sets of similar occurrences of this kind4 ,thus there is more logical affinity between a word and what it means in the case of words of our present sort than in any other case4 ,there is no very great difference between such words as we have just been considering and words denoting qualities1 such as white or round4 ,the chief difference is that words of this latter sort do not denote processes1 however brief1 but static features of the world4 ,snow falls1 and is white2 the falling is a process1 the whiteness is not4 ,whether there is a universal1 called whiteness1 or whether white things are to be defined as those having a certain kind of similarity to a standard thing1 say freshly fallen snow1 is a question which need not concern us1 and which ,i believe to be strictly insoluble4 ,for our purposes1 we may take the word white as denoting a certain set of similar particulars or collections of particulars1 the similarity being in respect of a static quality1 not of a process4 ,from the logical point of view1 a very important class of words are those that express relations1 such as in1 above1 before1 greater1 and so on4 ,the meaning of one of these words differs very fundamentally from the meaning of one of any of our previous classes1 being more abstract and logically simpler than any of them4 ,if our business were logic1 we should have to spend much time on these words4 ,but as it is psychology that concerns us1 we will merely note their special character and pass on1 since the logical classification of words is not our main business4 ,we will consider next the question what is implied by saying that a person understands a word1 in the sense in which one understands a word in one's own language1 but not in a language of which one is ignorant4 ,we may say that a person understands a word when 7a7 suitable circumstances make him use it1 7b7 the hearing of it causes suitable behaviour in him4 ,we may call these two active and passive understanding respectively4 ,dogs often have passive understanding of some words1 but not active understanding1 since they cannot use words4 ,it is not necessary1 in order that a man should understand a word1 that he should know what it means1 in the sense of being able to say this word means so-and-so4 ,understanding words does not consist in knowing their dictionary definitions1 or in being able to specify the objects to which they are appropriate4 ,such understanding as this may belong to lexicographers and students1 but not to ordinary mortals in ordinary life4 ,understanding language is more like understanding cricket993 it is a matter of habits1 acquired in oneself and rightly presumed in others4 ,to say that a word has a meaning is not to say that those who use the word correctly have ever thought out what the meaning is3 the use of the word comes first1 and the meaning is to be distilled out of it by observation and analysis4 ,moreover1 the meaning of a word is not absolutely definite3 there is always a greater or less degree of vagueness4 ,the meaning is an area1 like a target3 it may have a bull's eye1 but the outlying parts of the target are still more or less within the meaning1 in a gradually diminishing degree as we travel further from the bull's eye4 ,as language grows more precise1 there is less and less of the target outside the bull's eye1 and the bull's eye itself grows smaller and smaller2 but the bull's eye never shrinks to a point1 and there is always a doubtful region1 however small1 surrounding it49999 99 ,this point of view1 extended to the analysis of thought is urged with great force by ,j4 ,b4 ,watson1 both in his ,behavior1 and in ,psychology from the ,standpoint of a ,behaviorist 7,lippincott4 #aiai71 chap4 ix4 9999 ,on the understanding of words1 a very admirable little book is ,ribot's ,evolution of ,general ,ideas1 ,open ,court ,co41 #ahii4 ,ribot says 7p4 #aca73 ,we learn to understand a concept as we learn to walk1 dance1 fence or play a musical instrument3 it is a habit1 i4e4 an organized memory4 ,general terms cover an organized1 latent knowledge which is the hidden capital without which we should be in a state of bankruptcy1 manipulating false money or paper of no value4 ,general ideas are habits in the intellectual order4 ,a word is used correctly when the average hearer will be affected by it in the way intended4 ,this is a psychological1 not a literary1 definition of correctness4 ,the literary definition would substitute1 for the average hearer1 a person of high education living a long time ago2 the purpose of this definition is to make it difficult to speak or write correctly4 ,the relation of a word to its meaning is of the nature of a causal law governing our use of the word and our actions when we hear it used4 ,there is no more reason why a person who uses a word correctly should be able to tell what it means than there is why a planet which is moving correctly should know ,kepler's laws4 ,to illustrate what is meant by understanding words and sentences1 let us take instances of various situations4 ,suppose you are walking in ,london with an absent-minded friend1 and while crossing a street you say1 ,look out1 there's a motor coming4 ,he will glance round and jump aside without the need of any mental intermediary4 ,there need be no ideas1 but only a stiffening of the muscles1 followed quickly by action4 ,he understands the words1 because he does the right thing4 ,such understanding may be taken to belong to the nerves and brain1 being habits which they have acquired while the language was being learnt4 ,thus understanding in this sense may be reduced to mere physiological causal laws4 ,if you say the same thing to a ,frenchman with a slight knowledge of ,english he will go through some inner speech which may be represented by ,que dit-il8 ,ah1 oui1 une automobile6 ,after this1 the rest follows as with the ,englishman4 ,watson would contend that the inner speech must be incipiently pronounced2 we should argue that it ,,might be merely imaged4 ,but this point is not important in the present connection4 ,if you say the same thing to a child who does not yet know the word motor1 but does know the other words you are using1 you produce a feeling of anxiety and doubt you will have to point and say1 ,there1 that's a motor4 ,after that the child will roughly understand the word motor1 though he may include trains and steam-rollers ,if this is the first time the child has heard the word motor1 he may for a long time continue to recall this scene when he hears the word4 ,so far we have found four ways of understanding words3 7#a7 ,on suitable occasions you use the word properly4 7#b7 ,when you hear it you act appropriately4 7#c7 ,you associate the word with another word 7say in a different language7 which has the appropriate effect on behaviour4 7#d7 ,when the word is being first learnt1 you may associate it with an object1 which is what it means1 or a representative of various objects that it means4 ,in the fourth case1 the word acquires1 through association1 some of the same causal efficacy as the object4 ,the word motor can make you leap aside1 just as the motor can1 but it cannot break your bones4 ,the effects which a word can share with its object are those which proceed according to laws other than the general laws of physics1 i4e4 those which1 according to our terminology1 involve vital movements as opposed to merely mechanical movements4 ,the effects of a word that we understand are always mnemic phenomena in the sense explained in ,lecture ,,iv1 in so far as they are identical with1 or similar to1 the effects which the object itself might have4 ,so far1 all the uses of words that we have considered can be accounted for on the lines of behaviourism4 ,but so far we have only considered what may be called the demonstrative use of language1 to point out some feature in the present environment4 ,this is only one of the ways in which language may be used4 ,there are also its narrative and imaginative uses1 as in history and novels4 ,let us take as an instance the telling of some remembered event4 ,we spoke a moment ago of a child who hears the word motor for the first time when crossing a street along which a motor-car is approaching4 ,on a later occasion1 we will suppose1 the child remembers the incident and relates it to someone else4 ,in this case1 both the active and passive understanding of words is different from what it is when words are used demonstratively4 ,the child is not seeing a motor1 but only remembering one2 the hearer does not look round in expectation of seeing a motor coming1 but understands that a motor came at some earlier time4 ,the whole of this occurrence is much more difficult to account for on behaviourist lines4 ,it is clear that1 in so far as the child is genuinely remembering1 he has a picture of the past occurrence1 and his words are chosen so as to describe the picture2 and in so far as the hearer is genuinely apprehending what is said1 the hearer is acquiring a picture more or less like that of the child4 ,it is true that this process may be telescoped through the operation of the word-habit4 ,the child may not genuinely remember the incident1 but only have the habit of the appropriate words1 as in the case of a poem which we know by heart1 though we cannot remember learning it4 ,and the hearer also may only pay attention to the words1 and not call up any corresponding picture4 ,but it is1 nevertheless1 the possibility of a memory-image in the child and an imagination-image in the hearer that makes the essence of the narrative meaning of the words4 ,in so far as this is absent1 the words are mere counters1 capable of meaning1 but not at the moment possessing it4 ,yet this might perhaps be regarded as something of an overstatement4 ,the words alone1 without the use of images1 may cause appropriate emotions and appropriate behaviour4 ,the words have been used in an environment which produced certain emotions2 by a telescoped process1 the words alone are now capable of producing similar emotions4 ,on these lines it might be sought to show that images are unnecessary4 ,i do not believe1 however1 that we could account on these lines for the entirely different response produced by a narrative and by a description of present facts4 ,images1 as contrasted with sensations1 are the response expected during a narrative2 it is understood that present action is not called for4 ,thus it seems that we must maintain our distinction words used demonstratively describe and are intended to lead to sensations1 while the same words used in narrative describe and are only intended to lead to images4 ,we have thus1 in addition to our four previous ways in which words can mean1 two new ways1 namely the way of memory and the way of imagination4 ,that is to say3 7#e7 ,words may be used to describe or recall a memory-image3 to describe it when it already exists1 or to recall it when the words exist as a habit and are known to be descriptive of some past experience4 7#f7 ,words may be used to describe or create an imagination-image3 to describe it1 for example1 in the case of a poet or novelist1 or to create it in the ordinary case for giving information-though1 in the latter case1 it is intended that the imagination-image1 when created1 shall be accompanied by belief that something of the sort occurred4 ,these two ways of using words1 including their occurrence in inner speech1 may be spoken of together as the use of words in thinking4 ,if we are right1 the use of words in thinking depends1 at least in its origin1 upon images1 and cannot be fully dealt with on behaviourist lines4 ,and this is really the most essential function of words1 namely that1 originally through their connection with images1 they bring us into touch with what is remote in time or space4 ,when they operate without the medium of images1 this seems to be a telescoped process4 ,thus the problem of the meaning of words is brought into connection with the problem of the meaning of images4 ,to understand the function that words perform in what is called thinking1 we must understand both the causes and the effects of their occurrence4 ,the causes of the occurrence of words require somewhat different treatment according as the object designated by the word is sensibly present or absent4 ,when the object is present1 it may itself be taken as the cause of the word1 through association4 ,but when it is absent there is more difficulty in obtaining a behaviourist theory of the occurrence of the word4 ,the language-habit consists not merely in the use of words demonstratively1 but also in their use to express narrative or desire4 ,professor ,watson1 in his account of the acquisition of the language-habit1 pays very little attention to the use of words in narrative and desire4 ,he says 7,behavior1 pp4 #cbi-ccj73 ,the stimulus 7object7 to which the child often responds1 a box1 e4g4 by movements such as opening and closing and putting objects into it1 may serve to illustrate our argument4 ,the nurse1 observing that the child reacts with his hands1 feet1 etc41 to the box1 begins to say 'box' when the child is handed the box1 'open box' when the child opens it1 'close box' when he closes it1 and 'put doll in box' when that act is executed4 ,this is repeated over and over again4 ,in the process of time it comes about that without any other stimulus than that of the box which originally called out the bodily habits1 he begins to say 'box' when he sees it1 'open box' when he opens it1 etc4 ,the visible box now becomes a stimulus capable of releasing either the bodily habits or the word-habit1 i4e4 development has brought about two things3 7#a7 a series of functional connections among arcs which run from visual receptor to muscles of throat1 and 7#b7 a series of already earlier connected arcs which run from the same receptor to the bodily muscles4444 ,the object meets the child's vision4 ,he runs to it and tries to reach it and says 'box4'444 ,finally the word is uttered without the movement of going towards the box being executed4444 ,habits are formed of going to the box when the arms are full of toys4 ,the child has been taught to deposit them there4 ,when his arms are laden with toys and no box is there1 the word-habit arises and he calls 'box'2 it is handed to him1 and he opens it and deposits the toys therein4 ,this roughly marks what we would call the genesis of a true language-habit47pp4 #cbi-ccj7499 99 ,just the same account of language is given in ,professor ,watson's more recent book 7reference above74 ,we need not linger over what is said in the above passage as to the use of the word box in the presence of the box4 ,but as to its use in the absence of the box1 there is only one brief sentence1 namely3 ,when his arms are laden with toys and no box is there1 the word-habit arises and he calls 'box4' ,this is inadequate as it stands1 since the habit has been to use the word when the box is present1 and we have to explain its extension to cases in which the box is absent4 ,having admitted images1 we may say that the word box1 in the absence of the box1 is caused by an image of the box4 ,this may or may not be true--in fact1 it is true in some cases but not in others4 ,even1 however1 if it were true in all cases1 it would only slightly shift our problem3 we should now have to ask what causes an image of the box to arise4 ,we might be inclined to say that desire for the box is the cause4 ,but when this view is investigated1 it is found that it compels us to suppose that the box can be desired without the child's having either an image of the box or the word box4 ,this will require a theory of desire which may be1 and ,i think is1 in the main true1 but which removes desire from among things that actually occur1 and makes it merely a convenient fiction1 like force in mechanics499 ,with such a view1 desire is no longer a true cause1 but merely a short way of describing certain processes4 99 ,see ,lecture ,,iii1 above4 ,in order to explain the occurrence of either the word or the image in the absence of the box1 we have to assume that there is something1 either in the environment or in our own sensations1 which has frequently occurred at about the same time as the word box4 ,one of the laws which distinguish psychology 7or nerve-physiology87 from physics is the law that1 when two things have frequently existed in close temporal contiguity1 either comes in time to cause the other499 ,this is the basis both of habit and of association4 ,thus1 in our case1 the arms full of toys have frequently been followed quickly by the box1 and the box in turn by the word box4 ,the box itself is subject to physical laws1 and does not tend to be caused by the arms full of toys1 however often it may in the past have followed them--always provided that1 in the case in question1 its physical position is such that voluntary movements cannot lead to it4 ,but the word box and the image of the box are subject to the law of habit2 hence it is possible for either to be caused by the arms full of toys4 ,and we may lay it down generally that1 whenever we use a word1 either aloud or in inner speech1 there is some sensation or image 7either of which may be itself a word7 which has frequently occurred at about the same time as the word1 and now1 through habit1 causes the word4 ,it follows that the law of habit is adequate to account for the use of words in the absence of their objects2 moreover1 it would be adequate even without introducing images4 ,although1 therefore1 images seem undeniable1 we cannot derive an additional argument in their favour from the use of words1 which could1 theoretically1 be explained without introducing images4 99,for a more exact statement of this law1 with the limitations suggested by experiment1 see ,a4 ,wohlgemuth1 ,on ,memory and the ,direction of ,associations1 ,british ,journal of ,psychology1 vol4 v1 part iv 7,march1 #aiac74 ,when we understand a word1 there is a reciprocal association between it and the images of what it means4 ,images may cause us to use words which mean them1 and these words1 heard or read1 may in turn cause the appropriate images4 ,thus speech is a means of producing in our hearers the images which are in us4 ,also1 by a telescoped process1 words come in time to produce directly the effects which would have been produced by the images with which they were associated4 ,the general law of telescoped processes is that1 if ,a causes ,b and ,b causes ,c1 it will happen in time that ,a will cause ,c directly1 without the intermediary of ,b4 ,this is a characteristic of psychological and neural causation4 ,in virtue of this law1 the effects of images upon our actions come to be produced by words1 even when the words do not call up appropriate images4 ,the more familiar we are with words1 the more our thinking goes on in words instead of images4 ,we may1 for example1 be able to describe a person's appearance correctly without having at any time had any image of him1 provided1 when we saw him1 we thought of words which fitted him2 the words alone may remain with us as a habit1 and enable us to speak as if we could recall a visual image of the man4 ,in this and other ways the understanding of a word often comes to be quite free from imagery2 but in first learning the use of language it would seem that imagery always plays a very important part4 ,images as well as words may be said to have meaning2 indeed1 the meaning of images seems more primitive than the meaning of words4 ,what we call 7say7 an image of ,st4 ,paul's may be said to mean ,st4 ,paul's4 ,but it is not at all easy to say exactly what constitutes the meaning of an image4 ,a memory-image of a particular occurrence1 when accompanied by a memory-belief1 may be said to mean the occurrence of which it is an image4 ,but most actual images do not have this degree of definiteness4 ,if we call up an image of a dog1 we are very likely to have a vague image1 which is not representative of some one special dog1 but of dogs in general4 ,when we call up an image of a friend's face1 we are not likely to reproduce the expression he had on some one particular occasion1 but rather a compromise expression derived from many occasions4 ,and there is hardly any limit to the vagueness of which images are capable4 ,in such cases1 the meaning of the image1 if defined by relation to the prototype1 is vague3 there is not one definite prototype1 but a number1 none of which is copied exactly499 99 ,cf4 ,semon1 ,mnemische ,empfindungen1 chap4 xvi1 especially pp4 #cja-cjh4 ,there is1 however1 another way of approaching the meaning of images1 namely through their causal efficacy4 ,what is called an image of some definite object1 say ,st4 ,paul's1 has some of the effects which the object would have4 ,this applies especially to the effects that depend upon association4 ,the emotional effects1 also1 are often similar3 images may stimulate desire almost as strongly as do the objects they represent4 ,and conversely desire may cause images993 a hungry man will have images of food1 and so on4 ,in all these ways the causal laws concerning images are connected with the causal laws concerning the objects which the images mean4 ,an image may thus come to fulfil the function of a general idea4 ,the vague image of a dog1 which we spoke of a moment ago1 will have effects which are only connected with dogs in general1 not the more special effects which would be produced by some dogs but not by others4 ,berkeley and ,hume1 in their attack on general ideas1 do not allow for the vagueness of images3 they assume that every image has the definiteness that a physical object would have ,this is not the case1 and a vague image may well have a meaning which is general4 99 ,this phrase is in need of interpretation1 as appears from the analysis of desire4 ,but the reader can easily supply the interpretation for himself4 ,in order to define the meaning of an image1 we have to take account both of its resemblance to one or more prototypes1 and of its causal efficacy4 ,if there were such a thing as a pure imagination-image1 without any prototype whatever1 it would be destitute of meaning4 ,but according to ,hume's principle1 the simple elements in an image1 at least1 are derived from prototypes-except possibly in very rare exceptional cases4 ,often1 in such instances as our image of a friend's face or of a nondescript dog1 an image is not derived from one prototype1 but from many2 when this happens1 the image is vague1 and blurs the features in which the various prototypes differ4 ,to arrive at the meaning of the image in such a case1 we observe that there are certain respects1 notably associations1 in which the effects of images resemble those of their prototypes4 ,if we find1 in a given case1 that our vague image1 say1 of a nondescript dog1 has those associative effects which all dogs would have1 but not those belonging to any special dog or kind of dog1 we may say that our image means dog in general4 ,if it has all the associations appropriate to spaniels but no others1 we shall say it means spaniel2 while if it has all the associations appropriate to one particular dog1 it will mean that dog1 however vague it may be as a picture4 ,the meaning of an image1 according to this analysis1 is constituted by a combination of likeness and associations4 ,it is not a sharp or definite conception1 and in many cases it will be impossible to decide with any certainty what an image means4 ,i think this lies in the nature of things1 and not in defective analysis4 ,we may give somewhat more precision to the above account of the meaning of images1 and extend it to meaning in general4 ,we find sometimes that1 ,,in ,,mnemic ,,causation1 an image or word1 as stimulus1 has the same effect 7or very nearly the same effect7 as would belong to some object1 say1 a certain dog4 ,in that case we say that the image or word means that object4 ,in other cases the mnemic effects are not all those of one object1 but only those shared by objects of a certain kind1 e4g4 by all dogs4 ,in this case the meaning of the image or word is general3 it means the whole kind4 ,generality and particularity are a matter of degree4 ,if two particulars differ sufficiently little1 their mnemic effects will be the same2 therefore no image or word can mean the one as opposed to the other2 this sets a bound to the particularity of meaning4 ,on the other hand1 the mnemic effects of a number of sufficiently dissimilar objects will have nothing discoverable in common2 hence a word which aims at complete generality1 such as entity for example1 will have to be devoid of mnemic effects1 and therefore of meaning4 ,in practice1 this is not the case3 such words have ,,verbal associations1 the learning of which constitutes the study of metaphysics4 ,the meaning of a word1 unlike that of an image1 is wholly constituted by mnemic causal laws1 and not in any degree by likeness 7except in exceptional cases74 ,the word dog bears no resemblance to a dog1 but its effects1 like those of an image of a dog1 resemble the effects of an actual dog in certain respects4 ,it is much easier to say definitely what a word means than what an image means1 since words1 however they originated1 have been framed in later times for the purpose of having meaning1 and men have been engaged for ages in giving increased precision to the meanings of words4 ,but although it is easier to say what a word means than what an image means1 the relation which constitutes meaning is much the same in both cases4 ,a word1 like an image1 has the same associations as its meaning has4 ,in addition to other associations1 it is associated with images of its meaning1 so that the word tends to call up the image and the image tends to call up the word41 ,but this association is not essential to the intelligent use of words4 ,if a word has the right associations with other objects1 we shall be able to use it correctly1 and understand its use by others1 even if it evokes no image4 ,the theoretical understanding of words involves only the power of associating them correctly with other words2 the practical understanding involves associations with other bodily movements4 ,the use of words is1 of course1 primarily social1 for the purpose of suggesting to others ideas which we entertain or at least wish them to entertain4 ,but the aspect of words that specially concerns us is their power of promoting our own thought4 ,almost all higher intellectual activity is a matter of words1 to the nearly total exclusion of everything else4 ,the advantages of words for purposes of thought are so great that ,i should never end if ,i were to enumerate them4 ,but a few of them deserve to be mentioned4 ,in the first place1 there is no difficulty in producing a word1 whereas an image cannot always be brought into existence at will1 and when it comes it often contains much irrelevant detail4 ,in the second place1 much of our thinking is concerned with abstract matters which do not readily lend themselves to imagery1 and are apt to be falsely conceived if we insist upon finding images that may be supposed to represent them4 ,the word is always concrete and sensible1 however abstract its meaning may be1 and thus by the help of words we are able to dwell on abstractions in a way which would otherwise be impossible4 ,in the third place1 two instances of the same word are so similar that neither has associations not capable of being shared by the other4 ,two instances of the word dog are much more alike than 7say7 a pug and a great dane2 hence the word dog makes it much easier to think about dogs in general4 ,when a number of objects have a common property which is important but not obvious1 the invention of a name for the common property helps us to remember it and to think of the whole set of objects that possess it4 ,but it is unnecessary to prolong the catalogue of the uses of language in thought4 ,at the same time1 it is possible to conduct rudimentary thought by means of images1 and it is important1 sometimes1 to check purely verbal thought by reference to what it means4 ,in philosophy especially the tyranny of traditional words is dangerous1 and we have to be on our guard against assuming that grammar is the key to metaphysics1 or that the structure of a sentence corresponds at all accurately with the structure of the fact that it asserts4 ,sayce maintained that all ,european philosophy since ,aristotle has been dominated by the fact that the philosophers spoke ,indo-,european languages1 and therefore supposed the world1 like the sentences they were used to1 necessarily divisible into subjects and predicates4 ,when we come to the consideration of truth and falsehood1 we shall see how necessary it is to avoid assuming too close a parallelism between facts and the sentences which assert them4 ,against such errors1 the only safeguard is to be able1 once in a way1 to discard words for a moment and contemplate facts more directly through images4 ,most serious advances in philosophic thought result from some such comparatively direct contemplation of facts4 ,but the outcome has to be expressed in words if it is to be communicable4 ,those who have a relatively direct vision of facts are often incapable of translating their vision into words1 while those who possess the words have usually lost the vision4 ,it is partly for this reason that the highest philosophical capacity is so rare3 it requires a combination of vision with abstract words which is hard to achieve1 and too quickly lost in the few who have for a moment achieved it4 ,,lecture ,,xi4 ,,general ,,ideas ,,and ,,thought ,it is said to be one of the merits of the human mind that it is capable of framing abstract ideas1 and of conducting nonsensational thought4 ,in this it is supposed to differ from the mind of animals4 ,from ,plato onward the idea has played a great part in the systems of idealizing philosophers4 ,the idea has been1 in their hands1 always something noble and abstract1 the apprehension and use of which by man confers upon him a quite special dignity4 ,the thing we have to consider to-day is this3 seeing that there certainly are words of which the meaning is abstract1 and seeing that we can use these words intelligently1 what must be assumed or inferred1 or what can be discovered by observation1 in the way of mental content to account for the intelligent use of abstract words8 ,taken as a problem in logic1 the answer is1 of course1 that absolutely nothing in the way of abstract mental content is inferable from the mere fact that we can use intelligently words of which the meaning is abstract4 ,it is clear that a sufficiently ingenious person could manufacture a machine moved by olfactory stimuli which1 whenever a dog appeared in its neighbourhood1 would say1 ,there is a dog1 and when a cat appeared would throw stones at it4 ,the act of saying ,there is a dog1 and the act of throwing stones1 would in such a case be equally mechanical4 ,correct speech does not of itself afford any better evidence of mental content than the performance of any other set of biologically useful movements1 such as those of flight or combat4 ,all that is inferable from language is that two instances of a universal1 even when they differ very greatly1 may cause the utterance of two instances of the same word which only differ very slightly4 ,as we saw in the preceding lecture1 the word dog is useful1 partly1 because two instances of this word are much more similar than 7say7 a pug and a great dane4 ,the use of words is thus a method of substituting for two particulars which differ widely1 in spite of being instances of the same universal1 two other particulars which differ very little1 and which are also instances of a universal1 namely the name of the previous universal4 ,thus1 so far as logic is concerned1 we are entirely free to adopt any theory as to general ideas which empirical observation may recommend4 ,berkeley and ,hume made a vigorous onslaught on abstract ideas4 ,they meant by an idea approximately what we should call an image4 ,locke having maintained that he could form an idea of triangle in general1 without deciding what sort of triangle it was to be1 ,berkeley contended that this was impossible4 ,he says3 ,whether others1 have this wonderful faculty of abstracting their ideas1 they best can tell3 for myself1 ,i dare be confident ,i have it not4 ,i find1 indeed1 ,i have indeed a faculty of imagining1 or representing to myself1 the ideas of those particular things ,i have perceived1 and of variously compounding and dividing them4 ,i can imagine a man with two heads1 or the upper parts of a man joined to the body of a horse4 ,i can consider the hand1 the eye1 the nose1 each by itself abstracted or separated from the rest of the body4 ,but1 then1 whatever hand or eye ,i imagine1 it must have some particular shape and colour4 ,likewise the idea of a man that ,i frame to myself must be either of a white1 or a black1 or a tawny1 a straight1 or a crooked1 a tall1 or a low1 or a middle-sized man4 ,i cannot by any effort of thought conceive the abstract idea above described4 ,and it is equally impossible for me to form the abstract idea of motion distinct from the body moving1 and which is neither swift nor slow1 curvilinear nor rectilinear2 and the like may be said of all other abstract general ideas whatsoever4 ,to be plain1 ,i own myself able to abstract in one sense1 as when ,i consider some particular parts of qualities separated from others1 with which1 though they are united in some object1 yet it is possible they may really exist without them4 ,but ,i deny that ,i can abstract from one another1 or conceive separately1 those qualities which it is impossible should exist so separated2 or that ,i can frame a general notion1 by abstracting from particulars in the manner aforesaid--which last are the two proper acceptations of ,,abstraction4 ,and there is ground to think most men will acknowledge themselves to be in my case4 ,the generality of men which are simple and illiterate never pretend to ,,abstract ,,notions4 ,it is said they are difficult and not to be attained without pains and study2 we may therefore reasonably conclude that1 if such there be1 they are confined only to the learned4 ,i proceed to examine what can be alleged in defence of the doctrine of abstraction1 and try if ,i can discover what it is that inclines the men of speculation to embrace an opinion so remote from common sense as that seems to be4 ,there has been a late excellent and deservedly esteemed philosopher who1 no doubt1 has given it very much countenance1 by seeming to think the having abstract general ideas is what puts the widest difference in point of understanding betwixt man and beast4 ',the having of general ideas1' saith he1 'is that which puts a perfect distinction betwixt man and brutes1 and is an excellency which the faculties of brutes do by no means attain unto4 ,for1 it is evident we observe no footsteps in them of making use of general signs for universal ideas2 from which we have reason to imagine that they have not the faculty of abstracting1 or making general ideas1 since they have no use of words or any other general signs4' ,and a little after3 ',therefore1 ,i think1 we may suppose that it is in this that the species of brutes are discriminated from men1 and it is that proper difference wherein they are wholly separated1 and which at last widens to so wide a distance4 ,for1 if they have any ideas at all1 and are not bare machines 7as some would have them71 we cannot deny them to have some reason4 ,it seems as evident to me that they do1 some of them1 in certain instances reason as that they have sense2 but it is only in particular ideas1 just as they receive them from their senses4 ,they are the best of them tied up within those narrow bounds1 and have not 7as ,i think7 the faculty to enlarge them by any kind of abstraction499 7,essay on ,human ,understanding1 ,bk4 ,,ii1 chap4 xi1 paragraphs #aj and #aa47 ,i readily agree with this learned author1 that the faculties of brutes can by no means attain to abstraction4 ,but1 then1 if this be made the distinguishing property of that sort of animals1 ,i fear a great many of those that pass for men must be reckoned into their number4 ,the reason that is here assigned why we have no grounds to think brutes have abstract general ideas is1 that we observe in them no use of words or any other general signs2 which is built on this supposition-that the making use of words implies the having general ideas4 ,from which it follows that men who use language are able to abstract or generalize their ideas4 ,that this is the sense and arguing of the author will further appear by his answering the question he in another place puts3 ',since all things that exist are only particulars1 how come we by general terms8' ,his answer is3 ',words become general by being made the signs of general ideas4' 7,essay on ,human ,understanding1 ,bk4 ,,iii1 chap4 ,,iii1 paragraph #f47 ,but it seems that a word becomes general by being made the sign1 not of an abstract general idea1 but of several particular ideas1 any one of which it indifferently suggests to the mind4 ,for example1 when it is said 'the change of motion is proportional to the impressed force1' or that 'whatever has extension is divisible1' these propositions are to be understood of motion and extension in general2 and nevertheless it will not follow that they suggest to my thoughts an idea of motion without a body moved1 or any determinate direction and velocity1 or that ,i must conceive an abstract general idea of extension1 which is neither line1 surface1 nor solid1 neither great nor small1 black1 white1 nor red1 nor of any other determinate colour4 ,it is only implied that whatever particular motion ,i consider1 whether it be swift or slow1 perpendicular1 horizontal1 or oblique1 or in whatever object1 the axiom concerning it holds equally true4 ,as does the other of every particular extension1 it matters not whether line1 surface1 or solid1 whether of this or that magnitude or figure4 ,by observing how ideas become general1 we may the better judge how words are made so4 ,and here it is to be noted that ,i do not deny absolutely there are general ideas1 but only that there are any ,,abstract general ideas2 for1 in the passages we have quoted wherein there is mention of general ideas1 it is always supposed that they are formed by abstraction1 after the manner set forth in sections #h and #i4 ,now1 if we will annex a meaning to our words1 and speak only of what we can conceive1 ,i believe we shall acknowledge that an idea which1 considered in itself1 is particular1 becomes general by being made to represent or stand for all other particular ideas of the same sort4 ,to make this plain by an example1 suppose a geometrician is demonstrating the method of cutting a line in two equal parts4 ,he draws1 for instance1 a black line of an inch in length3 this1 which in itself is a particular line1 is nevertheless with regard to its signification general1 since1 as it is there used1 it represents all particular lines whatsoever2 so that what is demonstrated of it is demonstrated of all lines1 or1 in other words1 of a line in general4 ,and1 as ,,that ,,particular ,,line becomes general by being made a sign1 so the ,,name 'line1' which taken absolutely is particular1 by being a sign is made general4 ,and as the former owes its generality not to its being the sign of an abstract or general line1 but of all particular right lines that may possibly exist1 so the latter must be thought to derive its generality from the same cause1 namely1 the various particular lines which it indifferently denotes4 99 99 ,introduction to ,a ,treatise concerning the ,principles of ,human ,knowledge1 paragraphs #aj1 #aa1 and #ab4 ,berkeley's view in the above passage1 which is essentially the same as ,hume's1 does not wholly agree with modern psychology1 although it comes nearer to agreement than does the view of those who believe that there are in the mind single contents which can be called abstract ideas4 ,the way in which ,berkeley's view is inadequate is chiefly in the fact that images are as a rule not of one definite prototype1 but of a number of related similar prototypes4 ,on this subject ,semon has written well4 ,in ,die ,mneme1 pp4 #bag ff41 discussing the effect of repeated similar stimuli in producing and modifying our images1 he says3 ,we choose a case of mnemic excitement whose existence we can perceive for ourselves by introspection1 and seek to ekphore the bodily picture of our nearest relation in his absence1 and have thus a pure mnemic excitement before us4 ,at first it may seem to us that a determinate quite concrete picture becomes manifest in us1 but just when we are concerned with a person with whom we are in constant contact1 we shall find that the ekphored picture has something so to speak generalized4 ,it is something like those ,american photographs which seek to display what is general about a type by combining a great number of photographs of different heads over each other on one plate4 ,in our opinion1 the generalizations happen by the homophonic working of different pictures of the same face which we have come across in the most different conditions and situations1 once pale1 once reddened1 once cheerful1 once earnest1 once in this light1 and once in that4 ,as soon as we do not let the whole series of repetitions resound in us uniformly1 but give our attention to one particular moment out of the many444 this particular mnemic stimulus at once overbalances its simultaneously roused predecessors and successors1 and we perceive the face in question with concrete definiteness in that particular situation4 ,a little later he says3 ,the result is--at least in man1 but probably also in the higher animals--the development of a sort of ,,physiological abstraction4 ,mnemic homophony gives us1 without the addition of other processes of thought1 a picture of our friend ,x which is in a certain sense abstract1 not the concrete in any one situation1 but ,x cut loose from any particular point of time4 ,if the circle of ekphored engrams is drawn even more widely1 abstract pictures of a higher order appear3 for instance1 a white man or a negro4 ,in my opinion1 the first form of abstract concepts in general is based upon such abstract pictures4 ,the physiological abstraction which takes place in the above described manner is a predecessor of purely logical abstraction4 ,it is by no means a monopoly of the human race1 but shows itself in various ways also among the more highly organized animals4 ,the same subject is treated in more detail in ,chapter xvi of ,die mnemischen ,empfindungen1 but what is said there adds nothing vital to what is contained in the above quotations4 ,it is necessary1 however1 to distinguish between the vague and the general4 ,so long as we are content with ,semon's composite image1 we ,,may get no farther than the vague4 ,the question whether this image takes us to the general or not depends1 ,i think1 upon the question whether1 in addition to the generalized image1 we have also particular images of some of the instances out of which it is compounded4 ,suppose1 for example1 that on a number of occasions you had seen one negro1 and that you did not know whether this one was the same or different on the different occasions4 ,suppose that in the end you had an abstract memory-image of the different appearances presented by the negro on different occasions1 but no memory-image of any one of the single appearances4 ,in that case your image would be vague4 ,if1 on the other hand1 you have1 in addition to the generalized image1 particular images of the several appearances1 sufficiently clear to be recognized as different1 and as instances of the generalized picture1 you will then not feel the generalized picture to be adequate to any one particular appearance1 and you will be able to make it function as a general idea rather than a vague idea4 ,if this view is correct1 no new general content needs to be added to the generalized image4 ,what needs to be added is particular images compared and contrasted with the generalized image4 ,so far as ,i can judge by introspection1 this does occur in practice4 ,take for example ,semon's instance of a friend's face4 ,unless we make some special effort of recollection1 the face is likely to come before us with an average expression1 very blurred and vague1 but we can at will recall how our friend looked on some special occasion when he was pleased or angry or unhappy1 and this enables us to realize the generalized character of the vague image4 ,there is1 however1 another way of distinguishing between the vague1 the particular and the general1 and this is not by their content1 but by the reaction which they produce4 ,a word1 for example1 may be said to be vague when it is applicable to a number of different individuals1 but to each as individuals2 the name ,smith1 for example1 is vague3 it is always meant to apply to one man1 but there are many men to each of whom it applies499 ,the word man1 on the other hand1 is general4 ,we say1 ,this is ,smith1 but we do not say ,this is man1 but ,this is a man4 ,thus we may say that a word embodies a vague idea when its effects are appropriate to an individual1 but are the same for various similar individuals1 while a word embodies a general idea when its effects are different from those appropriate to individuals4 ,in what this difference consists it is1 however1 not easy to say4 ,i am inclined to think that it consists merely in the knowledge that no one individual is represented1 so that what distinguishes a general idea from a vague idea is merely the presence of a certain accompanying belief4 ,if this view is correct1 a general idea differs from a vague one in a way analogous to that in which a memory-image differs from an imagination-image4 ,there also we found that the difference consists merely of the fact that a memory-image is accompanied by a belief1 in this case as to the past4 99 ,smith would only be a quite satisfactory representation of vague words if we failed to discriminate between different people called ,smith4 ,it should also be said that our images even of quite particular occurrences have always a greater or a less degree of vagueness4 ,that is to say1 the occurrence might have varied within certain limits without causing our image to vary recognizably4 ,to arrive at the general it is necessary that we should be able to contrast it with a number of relatively precise images or words for particular occurrences2 so long as all our images and words are vague1 we cannot arrive at the contrast by which the general is defined4 ,this is the justification for the view which ,i quoted on p4 #ahd from ,ribot 7op4 cit41 p4 #cb71 viz4 that intelligence progresses from the indefinite to the definite1 and that the vague appears earlier than either the particular or the general4 ,i think the view which ,i have been advocating1 to the effect that a general idea is distinguished from a vague one by the presence of a judgment1 is also that intended by ,ribot when he says 7op4 cit41 p4 #ib73 ,the generic image is never1 the concept is always1 a judgment4 ,we know that for logicians 7formerly at any rate7 the concept is the simple and primitive element2 next comes the judgment1 uniting two or several concepts2 then ratiocination1 combining two or several judgments4 ,for the psychologists1 on the contrary1 affirmation is the fundamental act2 the concept is the result of judgment 7explicit or implicit71 of similarities with exclusion of differences4 ,a great deal of work professing to be experimental has been done in recent years on the psychology of thought4 ,a good summary of such work up to the year agog is contained in ,titchener's ,lectures on the ,experimental ,psychology of the ,thought ,processes 7#aiji74 ,three articles in the ,archiv fur die gesammte ,psychologie by ,watt199 ,messer9999 and ,buhler999999 contain a great deal of the material amassed by the methods which ,titchener calls experimental4 99 ,henry ,j4 ,watt1 ,experimentelle ,beitrage zu einer ,theorie des ,denkens1 vol4 iv 7#aije7 pp4 #bhi-dcf4 9999 ,august ,messer1 ,experimentell-psychologische ,untersuchu gen uber das ,denken1 vol4 iii 7#aijf71 pp4 #a-bbd4 999999 ,karl ,buhler1 ,uber ,gedanken1 vol4 ix 7#aijg71 pp4 #big-cfe4 ,for my part ,i am unable to attach as much importance to this work as many psychologists do4 ,the method employed appears to me hardly to fulfil the conditions of scientific experiment4 ,broadly speaking1 what is done is1 that a set of questions are asked of various people1 their answers are recorded1 and likewise their own accounts1 based upon introspection1 of the processes of thought which led them to give those answers4 ,much too much reliance seems to me to be placed upon the correctness of their introspection4 ,on introspection as a method ,i have spoken earlier 7,lecture ,,vi74 ,i am not prepared1 like ,professor ,watson1 to reject it wholly1 but ,i do consider that it is exceedingly fallible and quite peculiarly liable to falsification in accordance with preconceived theory4 ,it is like depending upon the report of a shortsighted person as to whom he sees coming along the road at a moment when he is firmly convinced that ,jones is sure to come4 ,if everybody were shortsighted and obsessed with beliefs as to what was going to be visible1 we might have to make the best of such testimony1 but we should need to correct its errors by taking care to collect the simultaneous evidence of people with the most divergent expectations4 ,there is no evidence that this was done in the experiments in question1 nor indeed that the influence of theory in falsifying the introspection was at all adequately recognized4 ,i feel convinced that if ,professor ,watson had been one of the subjects of the questionnaires1 he would have given answers totally different from those recorded in the articles in question4 ,titchener quotes an opinion of ,wundt on these investigations1 which appears to me thoroughly justified4 ,these experiments1 he says1 are not experiments at all in the sense of a scientific methodology2 they are counterfeit experiments1 that seem methodical simply because they are ordinarily performed in a psychological laboratory1 and involve the co-operation of two persons1 who purport to be experimenter and observer4 ,in reality1 they are as unmethodical as possible2 they possess none of the special features by which we distinguish the introspections of experimental psychology from the casual introspections of everyday life499 ,titchener1 of course1 dissents from this opinion1 but ,i cannot see that his reasons for dissent are adequate4 ,my doubts are only increased by the fact that ,buhler at any rate used trained psychologists as his subjects4 ,a trained psychologist is1 of course1 supposed to have acquired the habit of observation1 but he is at least equally likely to have acquired a habit of seeing what his theories require4 ,we may take ,buhler's ,uber ,gedanken to illustrate the kind of results arrived at by such methods4 ,buhler says 7p4 #cjc73 ,we ask ourselves the general question3 ',,what ,,do ,,we ,,experience ,,when ,,we ,,think8' ,then we do not at all attempt a preliminary determination of the concept 'thought1' but choose for analysis only such processes as everyone would describe as processes of thought4 ,the most important thing in thinking1 he says1 is awareness that444 7,bewusstheit dass71 which he calls a thought4 ,it is1 he says1 thoughts in this sense that are essential to thinking4 ,thinking1 he maintains1 does not need language or sensuous presentations4 ,i assert rather that in principle every object can be thought 7meant7 distinctly1 without any help from sensuous presentation 7,anschauungshilfen74 ,every individual shade of blue colour on the picture that hangs in my room ,i can think with complete distinctness unsensuously 7unanschaulich71 provided it is possible that the object should be given to me in another manner than by the help of sensations4 ,how that is possible we shall see later4 ,what he calls a thought 7,gedanke7 cannot be reduced1 according to him1 to other psychic occurrences4 ,he maintains that thoughts consist for the most part of known rules 7p4 #cdb74 ,it is clearly essential to the interest of this theory that the thought or rule alluded to by ,buhler should not need to be expressed in words1 for if it is expressed in words it is immediately capable of being dealt with on the lines with which the behaviourists have familiarized us4 ,it is clear also that the supposed absence of words rests solely upon the introspective testimony of the persons experimented upon4 ,i cannot think that there is sufficient certainty of their reliability in this negative observation to make us accept a difficult and revolutionary view of thought1 merely because they have failed to observe the presence of words or their equivalent in their thinking4 ,i think it far more likely1 especially in view of the fact that the persons concerned were highly educated1 that we are concerned with telescoped processes1 in which habit has caused a great many intermediate terms to be elided or to be passed over so quickly as to escape observation4 99 ,titchener1 op4 cit41 p4 #gi4 ,i am inclined to think that similar remarks apply to the general idea of imageless thinking1 concerning which there has been much controversy4 ,the advocates of imageless thinking are not contending merely that there can be thinking which is purely verbal2 they are contending that there can be thinking which proceeds neither in words nor in images4 ,my own feeling is that they have rashly assumed the presence of thinking in cases where habit has rendered thinking unnecessary4 ,when ,thorndike experimented with animals in cages1 he found that the associations established were between a sensory stimulus and a bodily movement 7not the idea of it71 without the need of supposing any non-physiological intermediary 7op4 cit41 p4 #ajj ff474 ,the same thing1 it seems to me1 applies to ourselves4 ,a certain sensory situation produces in us a certain bodily movement4 ,sometimes this movement consists in uttering words4 ,prejudice leads us to suppose that between the sensory stimulus and the utterance of the words a process of thought must have intervened1 but there seems no good reason for such a supposition4 ,any habitual action1 such as eating or dressing1 may be performed on the appropriate occasion1 without any need of thought1 and the same seems to be true of a painfully large proportion of our talk4 ,what applies to uttered speech applies of course equally to the internal speech which is not uttered4 ,i remain1 therefore1 entirely unconvinced that there is any such phenomenon as thinking which consists neither of images nor of words1 or that ideas have to be added to sensations and images as part of the material out of which mental phenomena are built4 ,the question of the nature of our consciousness of the universal is much affected by our view as to the general nature of the relation of consciousness to its object4 ,if we adopt the view of ,brentano1 according to which all mental content has essential reference to an object1 it is then natural to suppose that there is some peculiar kind of mental content of which the object is a universal1 as oppose to a particular4 ,according to this view1 a particular cat can be ,p,e,rceived or imagined1 while the universal cat is ,c,o,nceived4 ,but this whole manner of viewing our dealings with universals has to be abandoned when the relation of a mental occurrence to its object is regarded as merely indirect and causal1 which is the view that we have adopted4 ,the mental content is1 of course1 always particular1 and the question as to what it means 7in case it means anything7 is one which cannot be settled by merely examining the intrinsic character of the mental content1 but only by knowing its causal connections in the case of the person concerned4 ,to say that a certain thought means a universal as opposed to either a vague or a particular1 is to say something exceedingly complex4 ,a horse will behave in a certain manner whenever he smells a bear1 even if the smell is derived from a bearskin4 ,that is to say1 any environment containing an instance of the universal smell of a bear produces closely similar behaviour in the horse1 but we do not say that the horse is conscious of this universal4 ,there is equally little reason to regard a man as conscious of the same universal1 because under the same circumstances he can react by saying1 ,i smell a bear4 ,this reaction1 like that of the horse1 is merely closely similar on different occasions where the environment affords instances of the same universal4 ,words of which the logical meaning is universal can therefore be employed correctly1 without anything that could be called consciousness of universals4 ,such consciousness in the only sense in which it can be said to exist is a matter of reflective judgment consisting in the observation of similarities and differences4 ,a universal never appears before the mind as a single object in the sort of way in which something perceived appears4 ,i ,,think a logical argument could be produced to show that universals are part of the structure of the world1 but they are an inferred part1 not a part of our data4 ,what exists in us consists of various factors1 some open to external observation1 others only visible to introspection4 ,the factors open to external observation are primarily habits1 having the peculiarity that very similar reactions are produced by stimuli which are in many respects very different from each other4 ,of this the reaction of the horse to the smell of the bear is an instance1 and so is the reaction of the man who says bear under the same circumstances4 ,the verbal reaction is1 of course1 the most important from the point of view of what may be called knowledge of universals4 ,a man who can always use the word dog when he sees a dog may be said1 in a certain sense1 to know the meaning of the word dog1 and ,,in ,,that ,,sense to have knowledge of the universal dog4 ,but there is1 of course1 a further stage reached by the logician in which he not merely reacts with the word dog1 but sets to work to discover what it is in the environment that causes in him this almost identical reaction on different occasions4 ,this further stage consists in knowledge of similarities and differences3 similarities which are necessary to the applicability of the word dog1 and differences which are compatible with it4 ,our knowledge of these similarities and differences is never exhaustive1 and therefore our knowledge of the meaning of a universal is never complete4 ,in addition to external observable habits 7including the habit of words71 there is also the generic image produced by the superposition1 or1 in ,semon's phrase1 homophony1 of a number of similar perceptions4 ,this image is vague so long as the multiplicity of its prototypes is not recognized1 but becomes universal when it exists alongside of the more specific images of its instances1 and is knowingly contrasted with them4 ,in this case we find again1 as we found when we were discussing words in general in the preceding lecture1 that images are not logically necessary in order to account for observable behaviour1 i4e4 in this case intelligent speech4 ,intelligent speech could exist as a motor habit1 without any accompaniment of images1 and this conclusion applies to words of which the meaning is universal1 just as much as to words of which the meaning is relatively particular4 ,if this conclusion is valid1 it follows that behaviourist psychology1 which eschews introspective data1 is capable of being an independent science1 and of accounting for all that part of the behaviour of other people which is commonly regarded as evidence that they think4 ,it must be admitted that this conclusion considerably weakens the reliance which can be placed upon introspective data4 ,they must be accepted simply on account of the fact that we seem to perceive them1 not on account of their supposed necessity for explaining the data of external observation4 ,this1 at any rate1 is the conclusion to which we are forced1 so long as1 with the behaviourists1 we accept common-sense views of the physical world4 ,but if1 as ,i have urged1 the physical world itself1 as known1 is infected through and through with subjectivity1 if1 as the theory of relativity suggests1 the physical universe contains the diversity of points of view which we have been accustomed to regard as distinctively psychological1 then we are brought back by this different road to the necessity for trusting observations which are in an important sense private4 ,and it is the privacy of introspective data which causes much of the behaviourists' objection to them4 ,this is an example of the difficulty of constructing an adequate philosophy of any one science without taking account of other sciences4 ,the behaviourist philosophy of psychology1 though in many respects admirable from the point of view of method1 appears to me to fail in the last analysis because it is based upon an inadequate philosophy of physics4 ,in spite1 therefore1 of the fact that the evidence for images1 whether generic or particular1 is merely introspective1 ,i cannot admit that images should be rejected1 or that we should minimize their function in our knowledge of what is remote in time or space4 ,,lecture ,,xii4 ,,belief ,belief1 which is our subject to-day1 is the central problem in the analysis of mind4 ,believing seems the most mental thing we do1 the thing most remote from what is done by mere matter4 ,the whole intellectual life consists of beliefs1 and of the passage from one belief to another by what is called reasoning4 ,beliefs give knowledge and error2 they are the vehicles of truth and falsehood4 ,psychology1 theory of knowledge and metaphysics revolve about belief1 and on the view we take of belief our philosophical outlook largely depends4 ,before embarking upon the detailed analysis of belief1 we shall do well to note certain requisites which any theory must fulfil4 7#a7 ,just as words are characterized by meaning1 so beliefs are characterized by truth or falsehood4 ,and just as meaning consists in relation to the object meant1 so truth and falsehood consist in relation to something that lies outside the belief4 ,you may believe that such-and-such a horse will win the ,derby4 ,the time comes1 and your horse wins or does not win2 according to the outcome1 your belief was true or false4 ,you may believe that six times nine is fifty-six2 in this case also there is a fact which makes your belief false4 ,you may believe that ,america was discovered in #adib1 or that it was discovered in #ajff4 ,in the one case your belief is true1 in the other false2 in either case its truth or falsehood depends upon the actions of ,columbus1 not upon anything present or under your control4 ,what makes a belief true or false ,i call a fact4 ,the particular fact that makes a given belief true or false ,i call its objective199 and the relation of the belief to its objective ,i call the reference or the objective reference of the belief4 ,thus1 if ,i believe that ,columbus crossed the ,atlantic in #adib1 the objective of my belief is ,columbus's actual voyage1 and the reference of my belief is the relation between my belief and the voyage--that relation1 namely1 in virtue of which the voyage makes my belief true 7or1 in another case1 false74 ,reference of beliefs differs from meaning of words in various ways1 but especially in the fact that it is of two kinds1 true reference and false reference4 ,the truth or falsehood of a belief does not depend upon anything intrinsic to the belief1 but upon the nature of its relation to its objective4 ,the intrinsic nature of belief can be treated without reference to what makes it true or false4 ,in the remainder of the present lecture ,i shall ignore truth and falsehood1 which will be the subject of ,lecture ,,xiii4 ,it is the intrinsic nature of belief that will concern us to-day4 99 ,this terminology is suggested by ,meinong1 but is not exactly the same as his4 7#b7 ,we must distinguish between believing and what is believed4 ,i may believe that ,columbus crossed the ,atlantic1 that all ,cretans are liars1 that two and two are four1 or that nine times six is fifty-six2 in all these cases the believing is just the same1 and only the contents believed are different4 ,i may remember my breakfast this morning1 my lecture last week1 or my first sight of ,new ,york4 ,in all these cases the feeling of memory-belief is just the same1 and only what is remembered differs4 ,exactly similar remarks apply to expectations4 ,bare assent1 memory and expectation are forms of belief2 all three are different from what is believed1 and each has a constant character which is independent of what is believed4 ,in ,lecture ,i we criticized the analysis of a presentation into act1 content and object4 ,but our analysis of belief contains three very similar elements1 namely the believing1 what is believed and the objective4 ,the objections to the act 7in the case of presentations7 are not valid against the believing in the case of beliefs1 because the believing is an actual experienced feeling1 not something postulated1 like the act4 ,but it is necessary first to complete our preliminary requisites1 and then to examine the content of a belief4 ,after that1 we shall be in a position to return to the question as to what constitutes believing4 7#c7 ,what is believed1 and the believing1 must both consist of present occurrences in the believer1 no matter what may be the objective of the belief4 ,suppose ,i believe1 for example1 that ,caesar crossed the ,rubicon4 ,the objective of my belief is an event which happened long ago1 which ,i never saw and do not remember4 ,this event itself is not in my mind when ,i believe that it happened4 ,it is not correct to say that ,i am believing the actual event2 what ,i am believing is something now in my mind1 something related to the event 7in a way which we shall investigate in ,lecture ,,xiii71 but obviously not to be confounded with the event1 since the event is not occurring now but the believing is4 ,what a man is believing at a given moment is wholly determinate if we know the contents of his mind at that moment2 but ,caesar's crossing of the ,rubicon was an historical physical event1 which is distinct from the present contents of every present mind4 ,what is believed1 however true it may be1 is not the actual fact that makes the belief true1 but a present event related to the fact4 ,this present event1 which is what is believed1 ,i shall call the content of the belief4 ,we have already had occasion to notice the distinction between content and objective in the case of memory-beliefs1 where the content is this occurred and the objective is the past event4 7#d7 ,between content and objective there is sometimes a very wide gulf1 for example in the case of ,caesar crossed the ,rubicon4 ,this gulf may1 when it is first perceived1 give us a feeling that we cannot really know anything about the outer world4 ,all we can know1 it may be said1 is what is now in our thoughts4 ,if ,caesar and the ,rubicon cannot be bodily in our thoughts1 it might seem as though we must remain cut off from knowledge of them4 ,i shall not now deal at length with this feeling1 since it is necessary first to define knowing1 which cannot be done yet4 ,but ,i will say1 as a preliminary answer1 that the feeling assumes an ideal of knowing which ,i believe to be quite mistaken4 ,it assumes1 if it is thought out1 something like the mystic unity of knower and known4 ,these two are often said to be combined into a unity by the fact of cognition2 hence when this unity is plainly absent1 it may seem as if there were no genuine cognition4 ,for my part1 ,i think such theories and feelings wholly mistaken3 ,i believe knowing to be a very external and complicated relation1 incapable of exact definition1 dependent upon causal laws1 and involving no more unity than there is between a signpost and the town to which it points4 ,i shall return to this question on a later occasion2 for the moment these provisional remarks must suffice4 7#e7 ,the objective reference of a belief is connected with the fact that all or some of the constituents of its content have meaning4 ,if ,i say ,caesar conquered ,gaul1 a person who knows the meaning of the three words composing my statement knows as much as can be known about the nature of the objective which would make my statement true4 ,it is clear that the objective reference of a belief is1 in general1 in some way derivative from the meanings of the words or images that occur in its content4 ,there are1 however1 certain complications which must be borne in mind4 ,in the first place1 it might be contended that a memory-image acquires meaning only through the memory-belief1 which would seem1 at least in the case of memory1 to make belief more primitive than the meaning of images4 ,in the second place1 it is a very singular thing that meaning1 which is single1 should generate objective reference1 which is dual1 namely true and false4 ,this is one of the facts which any theory of belief must explain if it is to be satisfactory4 ,it is now time to leave these preliminary requisites1 and attempt the analysis of the contents of beliefs4 ,the first thing to notice about what is believed1 i4e4 about the content of a belief1 is that it is always complex3 ,we believe that a certain thing has a certain property1 or a certain relation to something else1 or that it occurred or will occur 7in the sense discussed at the end of ,lecture ,,ix72 or we may believe that all the members of a certain class have a certain property1 or that a certain property sometimes occurs among the members of a class2 or we may believe that if one thing happens1 another will happen 7for example1 if it rains ,i shall bring my umbrella71 or we may believe that something does not happen1 or did not or will not happen 7for example1 it won't rain72 or that one of two things must happen 7for example1 either you withdraw your accusation1 or ,i shall bring a libel action74 ,the catalogue of the sorts of things we may believe is infinite1 but all of them are complex4 ,language sometimes conceals the complexity of a belief4 ,we say that a person believes in ,god1 and it might seem as if ,god formed the whole content of the belief4 ,but what is really believed is that ,god exists1 which is very far from being simple4 ,similarly1 when a person has a memory-image with a memory-belief1 the belief is this occurred1 in the sense explained in ,lecture ,,ix2 and this occurred is not simple4 ,in like manner all cases where the content of a belief seems simple at first sight will be found1 on examination1 to confirm the view that the content is always complex4 ,the content of a belief involves not merely a plurality of constituents1 but definite relations between them2 it is not determinate when its constituents alone are given4 ,for example1 ,plato preceded ,aristotle and ,aristotle preceded ,plato are both contents which may be believed1 but1 although they consist of exactly the same constituents1 they are different1 and even incompatible4 ,the content of a belief may consist of words only1 or of images only1 or of a mixture of the two1 or of either or both together with one or more sensations4 ,it must contain at least one constituent which is a word or an image1 and it may or may not contain one or more sensations as constituents4 ,some examples will make these various possibilities clear4 ,we may take first recognition1 in either of the forms this is of such-and-such a kind or this has occurred before4 ,in either case1 present sensation is a constituent4 ,for example1 you hear a noise1 and you say to yourself tram4 ,here the noise and the word tram are both constituents of your belief2 there is also a relation between them1 expressed by is in the proposition that is a tram4 ,as soon as your act of recognition is completed by the occurrence of the word tram1 your actions are affected3 you hurry if you want the tram1 or cease to hurry if you want a bus4 ,in this case the content of your belief is a sensation 7the noise7 and a word 7tram7 related in a way which may be called predication4 ,the same noise may bring into your mind the visual image of a tram1 instead of the word tram4 ,in this case your belief consists of a sensation and an image suitable related4 ,beliefs of this class are what are called judgments of perception4 ,as we saw in ,lecture ,,viii1 the images associated with a sensation often come with such spontaneity and force that the unsophisticated do not distinguish them from the sensation2 it is only the psychologist or the skilled observer who is aware of the large mnemic element that is added to sensation to make perception4 ,it may be objected that what is added consists merely of images without belief4 ,this is no doubt sometimes the case1 but is certainly sometimes not the case4 ,that belief always occurs in perception as opposed to sensation it is not necessary for us to maintain2 it is enough for our purposes to note that it sometimes occurs1 and that when it does1 the content of our belief consists of a sensation and an image suitably related4 ,in a ,,pure memory-belief only images occur4 ,but a mixture of words and images is very common in memory4 ,you have an image of the past occurrence1 and you say to yourself3 ,yes1 that's how it was4 ,here the image and the words together make up the content of the belief4 ,and when the remembering of an incident has become a habit1 it may be purely verbal1 and the memory-belief may consist of words alone4 ,the more complicated forms of belief tend to consist only of words4 ,often images of various kinds accompany them1 but they are apt to be irrelevant1 and to form no part of what is actually believed4 ,for example1 in thinking of the ,solar ,system1 you are likely to have vague images of pictures you have seen of the earth surrounded by clouds1 ,saturn and his rings1 the sun during an eclipse1 and so on2 but none of these form part of your belief that the planets revolve round the sun in elliptical orbits4 ,the only images that form an actual part of such beliefs are1 as a rule1 images of words4 ,and images of words1 for the reasons considered in ,lecture ,,viii1 cannot be distinguished with any certainty from sensations1 when1 as is often1 if not usually1 the case1 they are kinaesthetic images of pronouncing the words4 ,it is impossible for a belief to consist of sensations alone1 except when1 as in the case of words1 the sensations have associations which make them signs possessed of meaning4 ,the reason is that objective reference is of the essence of belief1 and objective reference is derived from meaning4 ,when ,i speak of a belief consisting partly of sensations and partly of words1 ,i do not mean to deny that the words1 when they are not mere images1 are sensational1 but that they occur as signs1 not 7so to speak7 in their own right4 ,to revert to the noise of the tram1 when you hear it and say tram1 the noise and the word are both sensations 7if you actually pronounce the word71 but the noise is part of the fact which makes your belief true1 whereas the word is not part of this fact4 ,it is the ,,meaning of the word tram1 not the actual word1 that forms part of the fact which is the objective of your belief4 ,thus the word occurs in the belief as a symbol1 in virtue of its meaning1 whereas the noise enters into both the belief and its objective4 ,it is this that distinguishes the occurrence of words as symbols from the occurrence of sensations in their own right3 the objective contains the sensations that occur in their own right1 but contains only the meanings of the words that occur as symbols4 ,for the sake of simplicity1 we may ignore the cases in which sensations in their own right form part of the content of a belief1 and confine ourselves to images and words4 ,we may also omit the cases in which both images and words occur in the content of a belief4 ,thus we become confined to two cases3 7a7 when the content consists wholly of images1 7b7 when it consists wholly of words4 ,the case of mixed images and words has no special importance1 and its omission will do no harm4 ,let us take in illustration a case of memory4 ,suppose you are thinking of some familiar room4 ,you may call up an image of it1 and in your image the window may be to the left of the door4 ,without any intrusion of words1 you may believe in the correctness of your image4 ,you then have a belief1 consisting wholly of images1 which becomes1 when put into words1 the window is to the left of the door4 ,you may yourself use these words and proceed to believe them4 ,you thus pass from an image-content to the corresponding word-content4 ,the content is different in the two cases1 but its objective reference is the same4 ,this shows the relation of image-beliefs to word-beliefs in a very simple case4 ,in more elaborate cases the relation becomes much less simple4 ,it may be said that even in this very simple case the objective reference of the word-content is not quite the same as that of the image-content1 that images have a wealth of concrete features which are lost when words are substituted1 that the window in the image is not a mere window in the abstract1 but a window of a certain shape and size1 not merely to the left of the door1 but a certain distance to the left1 and so on4 ,in reply1 it may be admitted at once that there is1 as a rule1 a certain amount of truth in the objection4 ,but two points may be urged to minimize its force4 ,first1 images do not1 as a rule1 have that wealth of concrete detail that would make it ,,impossible to express them fully in words4 ,they are vague and fragmentary3 a finite number of words1 though perhaps a large number1 would exhaust at least their ,,significant features4 ,for--and this is our second point--images enter into the content of a belief through the fact that they are capable of meaning1 and their meaning does not1 as a rule1 have as much complexity as they have3 some of their characteristics are usually devoid of meaning4 ,thus it may well be possible to extract in words all that has meaning in an image-content2 in that case the word-content and the image-content will have exactly the same objective reference4 ,the content of a belief1 when expressed in words1 is the same thing 7or very nearly the same thing7 as what in logic is called a proposition4 ,a proposition is a series of words 7or sometimes a single word7 expressing the kind of thing that can be asserted or denied4 ,that all men are mortal1 that ,columbus discovered ,america1 that ,charles ,i died in his bed1 that all philosophers are wise1 are propositions4 ,not any series of words is a proposition1 but only such series of words as have meaning1 or1 in our phraseology1 objective reference4 ,given the meanings of separate words1 and the rules of syntax1 the meaning of a proposition is determinate4 ,this is the reason why we can understand a sentence we never heard before4 ,you probably never heard before the proposition that the inhabitants of the ,andaman ,islands habitually eat stewed hippopotamus for dinner1 but there is no difficulty in understanding the proposition4 ,the question of the relation between the meaning of a sentence and the meanings of the separate words is difficult1 and ,i shall not pursue it now2 ,i brought it up solely as being illustrative of the nature of propositions4 ,we may extend the term proposition so as to cover the image-contents of beliefs consisting of images4 ,thus1 in the case of remembering a room in which the window is to the left of the door1 when we believe the image-content the proposition will consist of the image of the window on the left together with the image of the door on the right4 ,we will distinguish propositions of this kind as image-propositions and propositions in words as word-propositions4 ,we may identify propositions in general with the contents of actual and possible beliefs1 and we may say that it is propositions that are true or false4 ,in logic we are concerned with propositions rather than beliefs1 since logic is not interested in what people do in fact believe1 but only in the conditions which determine the truth or falsehood of possible beliefs4 ,whenever possible1 except when actual beliefs are in question1 it is generally a simplification to deal with propositions4 ,it would seem that image-propositions are more primitive than word-propositions1 and may well ante-date language4 ,there is no reason why memory-images1 accompanied by that very simple belief-feeling which we decided to be the essence of memory1 should not have occurred before language arose2 indeed1 it would be rash to assert positively that memory of this sort does not occur among the higher animals4 ,our more elementary beliefs1 notably those that are added to sensation to make perception1 often remain at the level of images4 ,for example1 most of the visual objects in our neighbourhood rouse tactile images3 we have a different feeling in looking at a sofa from what we have in looking at a block of marble1 and the difference consists chiefly in different stimulation of our tactile imagination4 ,it may be said that the tactile images are merely present1 without any accompanying belief2 but ,i think this view1 though sometimes correct1 derives its plausibility as a general proposition from our thinking of explicit conscious belief only4 ,most of our beliefs1 like most of our wishes1 are unconscious1 in the sense that we have never told ourselves that we have them4 ,such beliefs display themselves when the expectations that they arouse fail in any way4 ,for example1 if someone puts tea 7without milk7 into a glass1 and you drink it under the impression that it is going to be beer2 or if you walk on what appears to be a tiled floor1 and it turns out to be a soft carpet made to look like tiles4 ,the shock of surprise on an occasion of this kind makes us aware of the expectations that habitually enter into our perceptions2 and such expectations must be classed as beliefs1 in spite of the fact that we do not normally take note of them or put them into words4 ,i remember once watching a cock pigeon running over and over again to the edge of a looking-glass to try to wreak vengeance on the particularly obnoxious bird whom he expected to find there1 judging by what he saw in the glass4 ,he must have experienced each time the sort of surprise on finding nothing1 which is calculated to lead in time to the adoption of ,berkeley's theory that objects of sense are only in the mind4 ,his expectation1 though not expressed in words1 deserved1 ,i think1 to be called a belief4 ,i come now to the question what constitutes believing1 as opposed to the content believed4 ,to begin with1 there are various different attitudes that may be taken towards the same content4 ,let us suppose1 for the sake of argument1 that you have a visual image of your breakfast-table4 ,you may expect it while you are dressing in the morning2 remember it as you go to your work2 feel doubt as to its correctness when questioned as to your powers of visualizing2 merely entertain the image1 without connecting it with anything external1 when you are going to sleep2 desire it if you are hungry1 or feel aversion for it if you are ill4 ,suppose1 for the sake of definiteness1 that the content is an egg for breakfast4 ,then you have the following attitudes ,i expect there will be an egg for breakfast2 ,i remember there was an egg for breakfast2 ,was there an egg for breakfast8 ,an egg for breakfast3 well1 what of it8 ,i hope there will be an egg for breakfast2 ,i am afraid there will be an egg for breakfast and it is sure to be bad4 ,i do not suggest that this is a list of all possible attitudes on the subject2 ,i say only that they are different attitudes1 all concerned with the one content an egg for breakfast4 ,these attitudes are not all equally ultimate4 ,those that involve desire and aversion have occupied us in ,lecture ,,iii4 ,for the present1 we are only concerned with such as are cognitive4 ,in speaking of memory1 we distinguished three kinds of belief directed towards the same content1 namely memory1 expectation and bare assent without any time-determination in the belief-feeling4 ,but before developing this view1 we must examine two other theories which might be held concerning belief1 and which1 in some ways1 would be more in harmony with a behaviourist outlook than the theory ,i wish to advocate4 7#a7 ,the first theory to be examined is the view that the differentia of belief consists in its causal efficacy ,i do not wish to make any author responsible for this theory3 ,i wish merely to develop it hypothetically so that we may judge of its tenability4 ,we defined the meaning of an image or word by causal efficacy1 namely by associations3 an image or word acquires meaning1 we said1 through having the same associations as what it means4 ,we propose hypothetically to define belief by a different kind of causal efficacy1 namely efficacy in causing voluntary movements4 7,voluntary movements are defined as those vital movements which are distinguished from reflex movements as involving the higher nervous centres4 ,i do not like to distinguish them by means of such notions as consciousness or will1 because ,i do not think these notions1 in any definable sense1 are always applicable4 ,moreover1 the purpose of the theory we are examining is to be1 as far as possible1 physiological and behaviourist1 and this purpose is not achieved if we introduce such a conception as consciousness or will4 ,nevertheless1 it is necessary for our purpose to find some way of distinguishing between voluntary and reflex movements1 since the results would be too paradoxical1 if we were to say that reflex movements also involve beliefs47 ,according to this definition1 a content is said to be believed when it causes us to move4 ,the images aroused are the same if you say to me1 ,suppose there were an escaped tiger coming along the street1 and if you say to me1 ,there is an escaped tiger coming along the street4 ,but my actions will be very different in the two cases3 in the first1 ,i shall remain calm2 in the second1 it is possible that ,i may not4 ,it is suggested1 by the theory we are considering1 that this difference of effects constitutes what is meant by saying that in the second case ,i believe the proposition suggested1 while in the first case ,i do not4 ,according to this view1 images or words are believed when they cause bodily movements4 ,i do not think this theory is adequate1 but ,i think it is suggestive of truth1 and not so easily refutable as it might appear to be at first sight4 ,it might be objected to the theory that many things which we certainly believe do not call for any bodily movements4 ,i believe that ,great ,britain is an island1 that whales are mammals1 that ,charles ,i was executed1 and so on2 and at first sight it seems obvious that such beliefs1 as a rule1 do not call for any action on my part4 ,but when we investigate the matter more closely1 it becomes more doubtful4 ,to begin with1 we must distinguish belief as a mere ,,disposition from actual active belief4 ,we speak as if we always believed that ,charles ,i was executed1 but that only means that we are always ready to believe it when the subject comes up4 ,the phenomenon we are concerned to analyse is the active belief1 not the permanent disposition4 ,now1 what are the occasions when1 we actively believe that ,charles ,i was executed8 ,primarily3 examinations1 when we perform the bodily movement of writing it down2 conversation1 when we assert it to display our historical erudition2 and political discourses1 when we are engaged in showing what ,soviet government leads to4 ,in all these cases bodily movements 7writing or speaking7 result from our belief4 ,but there remains the belief which merely occurs in thinking4 ,one may set to work to recall some piece of history one has been reading1 and what one recalls is believed1 although it probably does not cause any bodily movement whatever4 ,it is true that what we believe always ,,may influence action4 ,suppose ,i am invited to become ,king of ,georgia3 ,i find the prospect attractive1 and go to ,cook's to buy a third-class ticket to my new realm4 ,at the last moment ,i remember ,charles ,i and all the other monarchs who have come to a bad end2 ,i change my mind1 and walk out without completing the transaction4 ,but such incidents are rare1 and cannot constitute the whole of my belief that ,charles ,i was executed4 ,the conclusion seems to be that1 although a belief always ,,may influence action if it becomes relevant to a practical issue1 it often exists actively 7not as a mere disposition7 without producing any voluntary movement whatever4 ,if this is true1 we cannot define belief by the effect on voluntary movements4 ,there is another1 more theoretical1 ground for rejecting the view we are examining4 ,it is clear that a proposition can be either believed or merely considered1 and that the content is the same in both cases4 ,we can expect an egg for breakfast1 or merely entertain the supposition that there may be an egg for breakfast4 ,a moment ago ,i considered the possibility of being invited to become ,king of ,georgia1 but ,i do not believe that this will happen4 ,now1 it seems clear that1 since believing and considering have different effects if one produces bodily movements while the other does not1 there must be some intrinsic difference between believing and considering992 for if they were precisely similar1 their effects also would be precisely similar4 ,we have seen that the difference between believing a given proposition and merely considering it does not lie in the content2 therefore there must be1 in one case or in both1 something additional to the content which distinguishes the occurrence of a belief from the occurrence of a mere consideration of the same content4 ,so far as the theoretical argument goes1 this additional element may exist only in belief1 or only in consideration1 or there may be one sort of additional element in the case of belief1 and another in the case of consideration4 ,this brings us to the second view which we have to examine4 99 ,cf4 ,brentano1 ,psychologie vom empirischen ,standpunkte1 p4 #bfh 7criticizing ,bain1 ,the ,emotions and the ,will74 7#a7 ,the theory which we have now to consider regards belief as belonging to every idea which is entertained1 except in so far as some positive counteracting force interferes4 ,in this view belief is not a positive phenomenon1 though doubt and disbelief are so4 ,what we call belief1 according to this hypothesis1 involves only the appropriate content1 which will have the effects characteristic of belief unless something else operating simultaneously inhibits them4 ,james 7,psychology1 vol4 ii1 p4 #bhh7 quotes with approval1 though inaccurately1 a passage from ,spinoza embodying this view3 ,let us conceive a boy imagining to himself a horse1 and taking note of nothing else4 ,as this imagination involves the existence of the horse1 ,,and ,,the ,,boy ,,has ,,no ,,perception ,,which ,,annuls ,,its ,,existence ,james's italics1 he will necessarily contemplate the horse as present1 nor will he be able to doubt of its existence1 however little certain of it he may be4 ,i deny that a man in so far as he imagines percipit affirms nothing4 ,for what is it to imagine a winged horse but to affirm that the horse that horse1 namely has wings8 ,for if the mind had nothing before it but the winged horse1 it would contemplate the same as present1 would have no cause to doubt of its existence1 nor any power of dissenting from its existence1 unless the imagination of the winged horse were joined to an idea which contradicted tollit its existence 7,ethics1 vol4 ii1 p4 #di1 ,scholium74 ,to this doctrine ,james entirely assents1 adding in italics3 ,,any ,,object ,,which ,,remains ,,uncontradicted ,,is ,,ipso ,,facto ,,believed ,,and ,,posited ,,as ,,absolute ,,reality4 ,if this view is correct1 it follows 7though ,james does not draw the inference7 that there is no need of any specific feeling called belief1 and that the mere existence of images yields all that is required4 ,the state of mind in which we merely consider a proposition1 without believing or disbelieving it1 will then appear as a sophisticated product1 the result of some rival force adding to the image-proposition a positive feeling which may be called suspense or non-belief--a feeling which may be compared to that of a man about to run a race waiting for the signal4 ,such a man1 though not moving1 is in a very different condition from that of a man quietly at rest ,and so the man who is considering a proposition without believing it will be in a state of tension1 restraining the natural tendency to act upon the proposition which he would display if nothing interfered4 ,in this view belief primarily consists merely in the existence of the appropriate images without any counteracting forces4 ,there is a great deal to be said in favour of this view1 and ,i have some hesitation in regarding it as inadequate4 ,it fits admirably with the phenomena of dreams and hallucinatory images1 and it is recommended by the way in which it accords with mental development4 ,doubt1 suspense of judgment and disbelief all seem later and more complex than a wholly unreflecting assent4 ,belief as a positive phenomenon1 if it exists1 may be regarded1 in this view1 as a product of doubt1 a decision after debate1 an acceptance1 not merely of ,,this1 but of ,,this-,,rather-,,than-,,that4 ,it is not difficult to suppose that a dog has images 7possible olfactory7 of his absent master1 or of the rabbit that he dreams of hunting4 ,but it is very difficult to suppose that he can entertain mere imagination-images to which no assent is given4 ,i think it must be conceded that a mere image1 without the addition of any positive feeling that could be called belief1 is apt to have a certain dynamic power1 and in this sense an uncombated image has the force of a belief4 ,but although this may be true1 it accounts only for some of the simplest phenomena in the region of belief4 ,it will not1 for example1 explain memory4 ,nor can it explain beliefs which do not issue in any proximate action1 such as those of mathematics4 ,i conclude1 therefore1 that there must be belief-feelings of the same order as those of doubt or disbelief1 although phenomena closely analogous to those of belief can be produced by mere uncontradicted images4 7#c7 ,i come now to the view of belief which ,i wish to advocate4 ,it seems to me that there are at least three kinds of belief1 namely memory1 expectation and bare assent4 ,each of these ,i regard as constituted by a certain feeling or complex of sensations1 attached to the content believed4 ,we may illustrate by an example4 ,suppose ,i am believing1 by means of images1 not words1 that it will rain4 ,we have here two interrelated elements1 namely the content and the expectation4 ,the content consists of images of 7say7 the visual appearance of rain1 the feeling of wetness1 the patter of drops1 interrelated1 roughly1 as the sensations would be if it were raining4 ,thus the content is a complex fact composed of images4 ,exactly the same content may enter into the memory it was raining or the assent rain occurs4 ,the difference of these cases from each other and from expectation does not lie in the content4 ,the difference lies in the nature of the belief-feeling4 ,i1 personally1 do not profess to be able to analyse the sensations constituting respectively memory1 expectation and assent2 but ,i am not prepared to say that they cannot be analysed4 ,there may be other belief-feelings1 for example in disjunction and implication2 also a disbelief-feeling4 ,it is not enough that the content and the belief-feeling should coexist3 it is necessary that there should be a specific relation between them1 of the sort expressed by saying that the content is what is believed4 ,if this were not obvious1 it could be made plain by an argument4 ,if the mere co-existence of the content and the belief-feeling sufficed1 whenever we were having 7say7 a memory-feeling we should be remembering any proposition which came into our minds at the same time4 ,but this is not the case1 since we may simultaneously remember one proposition and merely consider another4 ,we may sum up our analysis1 in the case of bare assent to a proposition not expressed in words1 as follows3 7a7 ,we have a proposition1 consisting of interrelated images1 and possibly partly of sensations2 7b7 we have the feeling of assent1 which is presumably a complex sensation demanding analysis2 7c7 we have a relation1 actually subsisting1 between the assent and the proposition1 such as is expressed by saying that the proposition in question is what is assented to4 ,for other forms of belief-feeling or of content1 we have only to make the necessary substitutions in this analysis4 ,if we are right in our analysis of belief1 the use of words in expressing beliefs is apt to be misleading4 ,there is no way of distinguishing1 in words1 between a memory and an assent to a proposition about the past3 ,i ate my breakfast and ,caesar conquered ,gaul have the same verbal form1 though 7assuming that ,i remember my breakfast7 they express occurrences which are psychologically very different4 ,in the one case1 what happens is that ,i remember the content eating my breakfast2 in the other case1 ,i assent to the content ,caesar's conquest of ,gaul occurred4 ,in the latter case1 but not in the former1 the pastness is part of the content believed4 ,exactly similar remarks apply to the difference between expectation1 such as we have when waiting for the thunder after a flash of lightning1 and assent to a proposition about the future1 such as we have in all the usual cases of inferential knowledge as to what will occur4 ,i think this difficulty in the verbal expression of the temporal aspects of beliefs is one among the causes which have hampered philosophy in the consideration of time4 ,the view of belief which ,i have been advocating contains little that is novel except the distinction of kinds of belief-feeling--such as memory and expectation4 ,thus ,james says3 ,everyone knows the difference between imagining a thing and believing in its existence1 between supposing a proposition and acquiescing in its truth444,,in ,,its ,,inner ,,nature1 ,,belief1 ,,or ,,the ,,sense ,,of ,,reality1 ,,is ,a ,,sort ,,of ,,feeling ,,more ,,allied ,,to ,,the ,,emotions ,,than ,,to ,,anything ,,else 7,psychology1 vol4 ii1 p4 #bhc4 ,james's italics74 ,he proceeds to point out that drunkenness1 and1 still more1 nitrous-oxide intoxication1 will heighten the sense of belief3 in the latter case1 he says1 a man's very soul may sweat with conviction1 and he be all the time utterly unable to say what he is convinced of4 ,it would seem that1 in such cases1 the feeling of belief exists unattached1 without its usual relation to a content believed1 just as the feeling of familiarity may sometimes occur without being related to any definite familiar object4 ,the feeling of belief1 when it occurs in this separated heightened form1 generally leads us to look for a content to which to attach it4 ,much of what passes for revelation or mystic insight probably comes in this way3 the belief-feeling1 in abnormal strength1 attaches itself1 more or less accidentally1 to some content which we happen to think of at the appropriate moment4 ,but this is only a speculation1 upon which ,i do not wish to lay too much stress4 ,,lecture ,,xiii4 ,,truth ,,and ,,falsehood ,the definition of truth and falsehood1 which is our topic to-day1 lies strictly outside our general subject1 namely the analysis of mind4 ,from the psychological standpoint1 there may be different kinds of belief1 and different degrees of certainty1 but there cannot be any purely psychological means of distinguishing between true and false beliefs4 ,a belief is rendered true or false by relation to a fact1 which may lie outside the experience of the person entertaining the belief4 ,truth and falsehood1 except in the case of beliefs about our own minds1 depend upon the relations of mental occurrences to outside things1 and thus take us beyond the analysis of mental occurrences as they are in themselves4 ,nevertheless1 we can hardly avoid the consideration of truth and falsehood4 ,we wish to believe that our beliefs1 sometimes at least1 yield ,,knowledge1 and a belief does not yield knowledge unless it is true4 ,the question whether our minds are instruments of knowledge1 and1 if so1 in what sense1 is so vital that any suggested analysis of mind must be examined in relation to this question4 ,to ignore this question would be like describing a chronometer without regard to its accuracy as a time-keeper1 or a thermometer without mentioning the fact that it measures temperature4 ,many difficult questions arise in connection with knowledge4 ,it is difficult to define knowledge1 difficult to decide whether we have any knowledge1 and difficult1 even if it is conceded that we sometimes have knowledge to discover whether we can ever know that we have knowledge in this or that particular case4 ,i shall divide the discussion into four parts3 ,i4 ,we may regard knowledge1 from a behaviourist standpoint1 as exhibited in a certain kind of response to the environment4 ,this response must have some characteristics which it shares with those of scientific instruments1 but must also have others that are peculiar to knowledge4 ,we shall find that this point of view is important1 but not exhaustive of the nature of knowledge4 ,,ii4 ,we may hold that the beliefs that constitute knowledge are distinguished from such as are erroneous or uncertain by properties which are intrinsic either to single beliefs or to systems of beliefs1 being in either case discoverable without reference to outside fact4 ,views of this kind have been widely held among philosophers1 but we shall find no reason to accept them4 ,,iii4 ,we believe that some beliefs are true1 and some false4 ,this raises the problem of ,,verifiability3 are there any circumstances which can justifiably give us an unusual degree of certainty that such and such a belief is true8 ,it is obvious that there are circumstances which in fact cause a certainty of this sort1 and we wish to learn what we can from examining these circumstances4 ,,iv4 ,finally1 there is the formal problem of defining truth and falsehood1 and deriving the objective reference of a proposition from the meanings of its component words4 ,we will consider these four problems in succession4 ,i4 ,we may regard a human being as an instrument1 which makes various responses to various stimuli4 ,if we observe these responses from outside1 we shall regard them as showing knowledge when they display two characteristics1 ,,accuracy and ,,appropriateness4 ,these two are quite distinct1 and even sometimes incompatible4 ,if ,i am being pursued by a tiger1 accuracy is furthered by turning round to look at him1 but appropriateness by running away without making any search for further knowledge of the beast4 ,i shall return to the question of appropriateness later2 for the present it is accuracy that ,i wish to consider4 ,when we are viewing a man from the outside1 it is not his beliefs1 but his bodily movements1 that we can observe4 ,his knowledge must be inferred from his bodily movements1 and especially from what he says and writes4 ,for the present we may ignore beliefs1 and regard a man's knowledge as actually consisting in what he says and does4 ,that is to say1 we will construct1 as far as possible1 a purely behaviouristic account of truth and falsehood4 ,if you ask a boy ,what is twice two8 and the boy says four1 you take that as prima facie evidence that the boy knows what twice two is4 ,but if you go on to ask what is twice three1 twice four1 twice five1 and so on1 and the boy always answers four1 you come to the conclusion that he knows nothing about it4 ,exactly similar remarks apply to scientific instruments4 ,i know a certain weather-cock which has the pessimistic habit of always pointing to the north-east4 ,if you were to see it first on a cold ,march day1 you would think it an excellent weather-cock2 but with the first warm day of spring your confidence would be shaken4 ,the boy and the weather-cock have the same defect3 they do not vary their response when the stimulus is varied4 ,a good instrument1 or a person with much knowledge1 will give different responses to stimuli which differ in relevant ways4 ,this is the first point in defining accuracy of response4 ,we will now assume another boy1 who also1 when you first question him1 asserts that twice two is four4 ,but with this boy1 instead of asking him different questions1 you make a practice of asking him the same question every day at breakfast4 ,you find that he says five1 or six1 or seven1 or any other number at random1 and you conclude that he also does not know what twice two is1 though by good luck he answered right the first time4 ,this boy is like a weather-cock which1 instead of being stuck fast1 is always going round and round1 changing without any change of wind4 ,this boy and weather-cock have the opposite defect to that of the previous pair3 they give different responses to stimuli which do not differ in any relevant way4 ,in connection with vagueness in memory1 we already had occasion to consider the definition of accuracy4 ,omitting some of the niceties of our previous discussion1 we may say that an instrument is ,,accurate when it avoids the defects of the two boys and weather-cocks1 that is to say1 when-- 7a7 ,it gives different responses to stimuli which differ in relevant ways2 7b7 ,it gives the same response to stimuli which do not differ in relevant ways4 ,what are relevant ways depends upon the nature and purpose of the instrument4 ,in the case of a weather-cock1 the direction of the wind is relevant1 but not its strength2 in the case of the boy1 the meaning of the words of your question is relevant1 but not the loudness of your voice1 or whether you are his father or his schoolmaster ,if1 however1 you were a boy of his own age1 that would be relevant1 and the appropriate response would be different4 ,it is clear that knowledge is displayed by accuracy of response to certain kinds of stimuli1 e4g4 examinations4 ,can we say1 conversely1 that it consists wholly of such accuracy of response8 ,i do not think we can2 but we can go a certain distance in this direction4 ,for this purpose we must define more carefully the kind of accuracy and the kind of response that may be expected where there is knowledge4 ,from our present point of view1 it is difficult to exclude perception from knowledge2 at any rate1 knowledge is displayed by actions based upon perception4 ,a bird flying among trees avoids bumping into their branches2 its avoidance is a response to visual sensations4 ,this response has the characteristic of accuracy1 in the main1 and leads us to say that the bird knows1 by sight1 what objects are in its neighbourhood4 ,for a behaviourist1 this must certainly count as knowledge1 however it may be viewed by analytic psychology4 ,in this case1 what is known1 roughly1 is the stimulus2 but in more advanced knowledge the stimulus and what is known become different4 ,for example1 you look in your calendar and find that ,easter will be early next year4 ,here the stimulus is the calendar1 whereas the response concerns the future4 ,even this can be paralleled among instruments3 the behaviour of the barometer has a present stimulus but foretells the future1 so that the barometer might be said1 in a sense1 to know the future4 ,however that may be1 the point ,i am emphasizing as regards knowledge is that what is known may be quite different from the stimulus1 and no part of the cause of the knowledge-response4 ,it is only in sense-knowledge that the stimulus and what is known are1 with qualifications1 identifiable4 ,in knowledge of the future1 it is obvious that they are totally distinct1 since otherwise the response would precede the stimulus4 ,in abstract knowledge also they are distinct1 since abstract facts have no date4 ,in knowledge of the past there are complications1 which we must briefly examine4 ,every form of memory will be1 from our present point of view1 in one sense a delayed response4 ,but this phrase does not quite clearly express what is meant4 ,if you light a fuse and connect it with a heap of dynamite1 the explosion of the dynamite may be spoken of1 in a sense1 as a delayed response to your lighting of the fuse4 ,but that only means that it is a somewhat late portion of a continuous process of which the earlier parts have less emotional interest4 ,this is not the case with habit4 ,a display of habit has two sorts of causes3 7a7 the past occurrences which generated the habit1 7b7 the present occurrence which brings it into play4 ,when you drop a weight on your toe1 and say what you do say1 the habit has been caused by imitation of your undesirable associates1 whereas it is brought into play by the dropping of the weight4 ,the great bulk of our knowledge is a habit in this sense3 whenever ,i am asked when ,i was born1 ,i reply correctly by mere habit4 ,it would hardly be correct to say that getting born was the stimulus1 and that my reply is a delayed response ,but in cases of memory this way of speaking would have an element of truth4 ,in an habitual memory1 the event remembered was clearly an essential part of the stimulus to the formation of the habit4 ,the present stimulus which brings the habit into play produces a different response from that which it would produce if the habit did not exist4 ,therefore the habit enters into the causation of the response1 and so do1 at one remove1 the causes of the habit4 ,it follows that an event remembered is an essential part of the causes of our remembering4 ,in spite1 however1 of the fact that what is known is ,,sometimes an indispensable part of the cause of the knowledge1 this circumstance is1 ,i think1 irrelevant to the general question with which we are concerned1 namely ,what sort of response to what sort of stimulus can be regarded as displaying knowledge8 ,there is one characteristic which the response must have1 namely1 it must consist of voluntary movements4 ,the need of this characteristic is connected with the characteristic of ,,appropriateness1 which ,i do not wish to consider as yet4 ,for the present ,i wish only to obtain a clearer idea of the sort of ,,accuracy that a knowledge-response must have4 ,it is clear from many instances that accuracy1 in other cases1 may be purely mechanical4 ,the most complete form of accuracy consists in giving correct answers to questions1 an achievement in which calculating machines far surpass human beings4 ,in asking a question of a calculating machine1 you must use its language3 you must not address it in ,english1 any more than you would address an ,englishman in ,chinese4 ,but if you address it in the language it understands1 it will tell you what is #cdeba times #aiihg1 without a moment's hesitation or a hint of inaccuracy4 ,we do not say the machine ,,knows the answer1 because it has no purpose of its own in giving the answer3 it does not wish to impress you with its cleverness1 or feel proud of being such a good machine4 ,but as far as mere accuracy goes1 the machine leaves nothing to be desired4 ,accuracy of response is a perfectly clear notion in the case of answers to questions1 but in other cases it is much more obscure4 ,we may say generally that an object whether animate or inanimate1 is sensitive to a certain feature of the environment if it behaves differently according to the presence or absence of that feature4 ,thus iron is sensitive to anything magnetic4 ,but sensitiveness does not constitute knowledge1 and knowledge of a fact which is not sensible is not sensitiveness to that fact1 as we have seen in distinguishing the fact known from the stimulus4 ,as soon as we pass beyond the simple case of question and answer1 the definition of knowledge by means of behaviour demands the consideration of purpose4 ,a carrier pigeon flies home1 and so we say it knows the way4 ,but if it merely flew to some place at random1 we should not say that it knew the way to that place1 any more than a stone rolling down hill knows the way to the valley4 ,on the features which distinguish knowledge from accuracy of response in general1 not much can be said from a behaviourist point of view without referring to purpose4 ,but the necessity of ,,something besides accuracy of response may be brought out by the following consideration3 ,suppose two persons1 of whom one believed whatever the other disbelieved1 and disbelieved whatever the other believed4 ,so far as accuracy and sensitiveness of response alone are concerned1 there would be nothing to choose between these two persons4 ,a thermometer which went down for warm weather and up for cold might be just as accurate as the usual kind2 and a person who always believes falsely is just as sensitive an instrument as a person who always believes truly4 ,the observable and practical difference between them would be that the one who always believed falsely would quickly come to a bad end4 ,this illustrates once more that accuracy of response to stimulus does not alone show knowledge1 but must be reinforced by appropriateness1 i4e4 suitability for realizing one's purpose4 ,this applies even in the apparently simple case of answering questions3 if the purpose of the answers is to deceive1 their falsehood1 not their truth1 will be evidence of knowledge4 ,the proportion of the combination of appropriateness with accuracy in the definition of knowledge is difficult2 it seems that both enter in1 but that appropriateness is only required as regards the general type of response1 not as regards each individual instance4 ,,ii4 ,i have so far assumed as unquestionable the view that the truth or falsehood of a belief consists in a relation to a certain fact1 namely the objective of the belief4 ,this view has1 however1 been often questioned4 ,philosophers have sought some intrinsic criterion by which true and false beliefs could be distinguished499 ,i am afraid their chief reason for this search has been the wish to feel more certainty than seems otherwise possible as to what is true and what is false4 ,if we could discover the truth of a belief by examining its intrinsic characteristics1 or those of some collection of beliefs of which it forms part1 the pursuit of truth1 it is thought1 would be a less arduous business than it otherwise appears to be4 ,but the attempts which have been made in this direction are not encouraging4 ,i will take two criteria which have been suggested1 namely1 7#a7 self-evidence1 7#b7 mutual coherence4 ,if we can show that these are inadequate1 we may feel fairly certain that no intrinsic criterion hitherto suggested will suffice to distinguish true from false beliefs4 99 ,the view that such a criterion exists is generally held by those whose views are in any degree derived from ,hegel4 ,it may be illustrated by the following passage from ,lossky1 ,the ,intuitive ,basis of ,knowledge 7,macmillan1 #aiai71 p4 #bfh3 ,strictly speaking1 a false judgment is not a judgment at all4 ,the predicate does not follow from the subject ,s alone1 but from the subject plus a certain addition ,c1 ,,which ,,in ,,no ,,sense ,,belongs ,,to ,,the ,,content ,,of ,,the ,,judgment4 ,what takes place may be a process of association of ideas1 of imagining1 or the like1 but is not a process of judging4 ,an experienced psychologist will be able by careful observation to detect that in this process there is wanting just the specific element of the objective dependence of the predicate upon the subject which is characteristic of a judgment4 ,it must be admitted1 however1 that an exceptional power of observation is needed in order to distinguish1 by means of introspection1 mere combination of ideas from judgments4 7#a7 ,self-evidence4--,some of our beliefs seem to be peculiarly indubitable4 ,one might instance the belief that two and two are four1 that two things cannot be in the same place at the same time1 nor one thing in two places1 or that a particular buttercup that we are seeing is yellow4 ,the suggestion we are to examine is that such3 beliefs have some recognizable quality which secures their truth1 and the truth of whatever is deduced from them according to self-evident principles of inference4 ,this theory is set forth1 for example1 by ,meinong in his book1 ,ueber die ,erfahrungsgrundlagen unseres ,wissens4 ,if this theory is to be logically tenable1 self-evidence must not consist merely in the fact that we believe a proposition4 ,we believe that our beliefs are sometimes erroneous1 and we wish to be able to select a certain class of beliefs which are never erroneous4 ,if we are to do this1 it must be by some mark which belongs only to certain beliefs1 not to all2 and among those to which it belongs there must be none that are mutually inconsistent4 ,if1 for example1 two propositions p and q were self-evident1 and it were also self-evident that p and q could not both be true1 that would condemn self-evidence as a guarantee of truth4 ,again1 self-evidence must not be the same thing as the absence of doubt or the presence of complete certainty4 ,if we are completely certain of a proposition1 we do not seek a ground to support our belief4 ,if self-evidence is alleged as a ground of belief1 that implies that doubt has crept in1 and that our self-evident proposition has not wholly resisted the assaults of scepticism4 ,to say that any given person believes some things so firmly that he cannot be made to doubt them is no doubt true4 ,such beliefs he will be willing to use as premisses in reasoning1 and to him personally they will seem to have as much evidence as any belief can need4 ,but among the propositions which one man finds indubitable there will be some that another man finds it quite possible to doubt4 ,it used to seem self-evident that there could not be men at the ,antipodes1 because they would fall off1 or at best grow giddy from standing on their heads4 ,but ,new ,zealanders find the falsehood of this proposition self-evident4 ,therefore1 if self-evidence is a guarantee of truth1 our ancestors must have been mistaken in thinking their beliefs about the ,antipodes self-evident4 ,meinong meets this difficulty by saying that some beliefs are falsely thought to be self-evident1 but in the case of others it is self-evident that they are self-evident1 and these are wholly reliable4 ,even this1 however1 does not remove the practical risk of error1 since we may mistakenly believe it self-evident that a certain belief is self-evident4 ,to remove all risk of error1 we shall need an endless series of more and more complicated self-evident beliefs1 which cannot possibly be realized in practice4 ,it would seem1 therefore1 that self-evidence is useless as a practical criterion for insuring truth4 ,the same result follows from examining instances4 ,if we take the four instances mentioned at the beginning of this discussion1 we shall find that three of them are logical1 while the fourth is a judgment of perception4 ,the proposition that two and two are four follows by purely logical deduction from definitions3 that means that its truth results1 not from the properties of objects1 but from the meanings of symbols4 ,now symbols1 in mathematics1 mean what we choose2 thus the feeling of self-evidence1 in this case1 seems explicable by the fact that the whole matter is within our control4 ,i do not wish to assert that this is the whole truth about mathematical propositions1 for the question is complicated1 and ,i do not know what the whole truth is4 ,but ,i do wish to suggest that the feeling of self-evidence in mathematical propositions has to do with the fact that they are concerned with the meanings of symbols1 not with properties of the world such as external observation might reveal4 ,similar considerations apply to the impossibility of a thing being in two places at once1 or of two things being in one place at the same time4 ,these impossibilities result logically1 if ,i am not mistaken1 from the definitions of one thing and one place4 ,that is to say1 they are not laws of physics1 but only part of the intellectual apparatus which we have manufactured for manipulating physics4 ,their self-evidence1 if this is so1 lies merely in the fact that they represent our decision as to the use of words1 not a property of physical objects4 ,judgments of perception1 such as this buttercup is yellow1 are in a quite different position from judgments of logic1 and their self-evidence must have a different explanation4 ,in order to arrive at the nucleus of such a judgment1 we will eliminate1 as far as possible1 the use of words which take us beyond the present fact1 such as buttercup and yellow4 ,the simplest kind of judgment underlying the perception that a buttercup is yellow would seem to be the perception of similarity in two colours seen simultaneously4 ,suppose we are seeing two buttercups1 and we perceive that their colours are similar4 ,this similarity is a physical fact1 not a matter of symbols or words2 and it certainly seems to be indubitable in a way that many judgments are not4 ,the first thing to observe1 in regard to such judgments1 is that as they stand they are vague4 ,the word similar is a vague word1 since there are degrees of similarity1 and no one can say where similarity ends and dissimilarity begins4 ,it is unlikely that our two buttercups have ,,exactly the same colour1 and if we judged that they had we should have passed altogether outside the region of self-evidence4 ,to make our proposition more precise1 let us suppose that we are also seeing a red rose at the same time4 ,then we may judge that the colours of the buttercups are more similar to each other than to the colour of the rose4 ,this judgment seems more complicated1 but has certainly gained in precision4 ,even now1 however1 it falls short of complete precision1 since similarity is not prima facie measurable1 and it would require much discussion to decide what we mean by greater or less similarity4 ,to this process of the pursuit of precision there is strictly no limit4 ,the next thing to observe 7although ,i do not personally doubt that most of our judgments of perception are true7 is that it is very difficult to define any class of such judgments which can be known1 by its intrinsic quality1 to be always exempt from error4 ,most of our judgments of perception involve correlations1 as when we judge that a certain noise is that of a passing cart4 ,such judgments are all obviously liable to error1 since there is no correlation of which we have a right to be certain that it is invariable4 ,other judgments of perception are derived from recognition1 as when we say this is a buttercup1 or even merely this is yellow4 ,all such judgments entail some risk of error1 though sometimes perhaps a very small one2 some flowers that look like buttercups are marigolds1 and colours that some would call yellow others might call orange4 ,our subjective certainty is usually a result of habit1 and may lead us astray in circumstances which are unusual in ways of which we are unaware4 ,for such reasons1 no form of self-evidence seems to afford an absolute criterion of truth4 ,nevertheless1 it is perhaps true that judgments having a high degree of subjective certainty are more apt to be true than other judgments4 ,but if this be the case1 it is a result to be demonstrated1 not a premiss from which to start in defining truth and falsehood4 ,as an initial guarantee1 therefore1 neither self-evidence nor subjective certainty can be accepted as adequate4 7#b7 ,coherence4--,coherence as the definition of truth is advocated by idealists1 particularly by those who in the main follow ,hegel4 ,it is set forth ably in ,mr4 ,joachim's book1 ,the ,nature of ,truth 7,oxford1 #aijf74 ,according to this view1 any set of propositions other than the whole of truth can be condemned on purely logical grounds1 as internally inconsistent2 a single proposition1 if it is what we should ordinarily call false1 contradicts itself irremediably1 while if it is what we should ordinarily call true1 it has implications which compel us to admit other propositions1 which in turn lead to others1 and so on1 until we find ourselves committed to the whole of truth4 ,one might illustrate by a very simple example3 if ,i say so-and-so is a married man1 that is not a self-subsistent proposition4 ,we cannot logically conceive of a universe in which this proposition constituted the whole of truth4 ,there must be also someone who is a married woman1 and who is married to the particular man in question4 ,the view we are considering regards everything that can be said about any one object as relative in the same sort of way as so-and-so is a married man4 ,but everything1 according to this view1 is relative1 not to one or two other things1 but to all other things1 so that from one bit of truth the whole can be inferred4 ,the fundamental objection to this view is logical1 and consists in a criticism of its doctrine as to relations4 ,i shall omit this line of argument1 which ,i have developed elsewhere499 ,for the moment ,i will content myself with saying that the powers of logic seem to me very much less than this theory supposes4 ,if it were taken seriously1 its advocates ought to profess that any one truth is logically inferable from any other1 and that1 for example1 the fact that ,caesar conquered ,gaul1 if adequately considered1 would enable us to discover what the weather will be to-morrow4 ,no such claim is put forward in practice1 and the necessity of empirical observation is not denied2 but according to the theory it ought to be4 99 ,in the article on ,the ,monistic ,theory of ,truth in ,philosophical ,essays 7,longmans1 #aiaj71 reprinted from the ,proceedings of the ,aristotelian ,society1 #aijf-g4 ,another objection is that no endeavour is made to show that we cannot form a consistent whole composed partly or wholly of false propositions1 as in a novel4 ,leibniz's conception of many possible worlds seems to accord much better with modern logic and with the practical empiricism which is now universal4 ,the attempt to deduce the world by pure thought is attractive1 and in former times was largely supposed capable of success4 ,but nowadays most men admit that beliefs must be tested by observation1 and not merely by the fact that they harmonize with other beliefs4 ,a consistent fairy-tale is a different thing from truth1 however elaborate it may be4 ,but to pursue this topic would lead us into difficult technicalities2 ,i shall therefore assume1 without further argument1 that coherence is not sufficient as a definition of truth4 ,,iii4 ,many difficult problems arise as regards the verifiability of beliefs4 ,we believe various things1 and while we believe them we think we know them4 ,but it sometimes turns out that we were mistaken1 or at any rate we come to think we were4 ,we must be mistaken either in our previous opinion or in our subsequent recantation2 therefore our beliefs are not all correct1 and there are cases of belief which are not cases of knowledge4 ,the question of verifiability is in essence this3 can we discover any set of beliefs which are never mistaken or any test which1 when applicable1 will always enable us to discriminate between true and false beliefs8 ,put thus broadly and abstractly1 the answer must be negative4 ,there is no way hitherto discovered of wholly eliminating the risk of error1 and no infallible criterion4 ,if we believe we have found a criterion1 this belief itself may be mistaken2 we should be begging the question if we tried to test the criterion by applying the criterion to itself4 ,but although the notion of an absolute criterion is chimerical1 there may be relative criteria1 which increase the probability of truth4 ,common sense and science hold that there are4 ,let us see what they have to say4 ,one of the plainest cases of verification1 perhaps ultimately the only case1 consists in the happening of something expected4 ,you go to the station believing that there will be a train at a certain time2 you find the train1 you get into it1 and it starts at the expected time ,this constitutes verification1 and is a perfectly definite experience4 ,it is1 in a sense1 the converse of memory instead of having first sensations and then images accompanied by belief1 we have first images accompanied by belief and then sensations4 ,apart from differences as to the time-order and the accompanying feelings1 the relation between image and sensation is closely similar in the two cases of memory and expectation2 it is a relation of similarity1 with difference as to causal efficacy--broadly1 the image has the psychological but not the physical effects that the sensation would have4 ,when an image accompanied by an expectation-belief is thus succeeded by a sensation which is the meaning of the image1 we say that the expectation-belief has been verified4 ,the experience of verification in this sense is exceedingly familiar2 it happens every time that accustomed activities have results that are not surprising1 in eating and walking and talking and all our daily pursuits4 ,but although the experience in question is common1 it is not wholly easy to give a theoretical account of it4 ,how do we know that the sensation resembles the previous image8 ,does the image persist in presence of the sensation1 so that we can compare the two8 ,and even if ,,some image does persist1 how do we know that it is the previous image unchanged8 ,it does not seem as if this line of inquiry offered much hope of a successful issue4 ,it is better1 ,i think1 to take a more external and causal view of the relation of expectation to expected occurrence4 ,if the occurrence1 when it comes1 gives us the feeling of expectedness1 and if the expectation1 beforehand1 enabled us to act in a way which proves appropriate to the occurrence1 that must be held to constitute the maximum of verification4 ,we have first an expectation1 then a sensation with the feeling of expectedness related to memory of the expectation4 ,this whole experience1 when it occurs1 may be defined as verification1 and as constituting the truth of the expectation4 ,appropriate action1 during the period of expectation1 may be regarded as additional verification1 but is not essential4 ,the whole process may be illustrated by looking up a familiar quotation1 finding it in the expected words1 and in the expected part of the book4 ,in this case we can strengthen the verification by writing down beforehand the words which we expect to find4 ,i think all verification is ultimately of the above sort4 ,we verify a scientific hypothesis indirectly1 by deducing consequences as to the future1 which subsequent experience confirms4 ,if somebody were to doubt whether ,caesar had crossed the ,rubicon1 verification could only be obtained from the future4 ,we could proceed to display manuscripts to our historical sceptic1 in which it was said that ,caesar had behaved in this way4 ,we could advance arguments1 verifiable by future experience1 to prove the antiquity of the manuscript from its texture1 colour1 etc4 ,we could find inscriptions agreeing with the historian on other points1 and tending to show his general accuracy4 ,the causal laws which our arguments would assume could be verified by the future occurrence of events inferred by means of them4 ,the existence and persistence of causal laws1 it is true1 must be regarded as a fortunate accident1 and how long it will continue we cannot tell4 ,meanwhile verification remains often practically possible4 ,and since it is sometimes possible1 we can gradually discover what kinds of beliefs tend to be verified by experience1 and what kinds tend to be falsified2 to the former kinds we give an increased degree of assent1 to the latter kinds a diminished degree4 ,the process is not absolute or infallible1 but it has been found capable of sifting beliefs and building up science4 ,it affords no theoretical refutation of the sceptic1 whose position must remain logically unassailable2 but if complete scepticism is rejected1 it gives the practical method by which the system of our beliefs grows gradually towards the unattainable ideal of impeccable knowledge4 ,,iv4 ,i come now to the purely formal definition of the truth or falsehood of a belief4 ,for this definition it is necessary first of all to consider the derivation of the objective reference of a proposition from the meanings of its component words or images4 ,just as a word has meaning1 so a proposition has an objective reference4 ,the objective reference of a proposition is a function 7in the mathematical sense7 of the meanings of its component words4 ,but the objective reference differs from the meaning of a word through the duality of truth and falsehood4 ,you may believe the proposition to-day is ,tuesday both when1 in fact1 to-day is ,tuesday1 and when to-day is not ,tuesday4 ,if to-day is not ,tuesday1 this fact is the objective of your belief that to-day is ,tuesday4 ,but obviously the relation of your belief to the fact is different in this case from what it is in the case when to-day is ,tuesday4 ,we may say1 metaphorically1 that when to-day is ,tuesday1 your belief that it is ,tuesday points ,,towards the fact1 whereas when to-day is not ,tuesday your belief points ,,away ,,from the fact4 ,thus the objective reference of a belief is not determined by the fact alone1 but by the direction of the belief towards or away from the fact499 ,if1 on a ,tuesday1 one man believes that it is ,tuesday while another believes that it is not ,tuesday1 their beliefs have the same objective1 namely the fact that it is ,tuesday but the true belief points towards the fact while the false one points away from it4 ,thus1 in order to define the reference of a proposition we have to take account not only of the objective1 but also of the direction of pointing1 towards the objective in the case of a true proposition and away from it in the case of a false one4 99 ,i owe this way of looking at the matter to my friend ,ludwig ,wittgenstein4 ,this mode of stating the nature of the objective reference of a proposition is necessitated by the circumstance that there are true and false propositions1 but not true and false facts4 ,if to-day is ,tuesday1 there is not a false objective to-day is not ,tuesday1 which could be the objective of the false belief to-day is not ,tuesday4 ,this is the reason why two beliefs which are each other's contradictories have the same objective4 ,there is1 however1 a practical inconvenience1 namely that we cannot determine the objective reference of a proposition1 according to this definition1 unless we know whether the proposition is true or false4 ,to avoid this inconvenience1 it is better to adopt a slightly different phraseology1 and say3 ,the meaning of the proposition to-day is ,tuesday consists in pointing to the fact to-day is ,tuesday if that is a fact1 or away from the fact to-day is not ,tuesday if that is a fact4 ,the meaning of the proposition to-day is not ,tuesday will be exactly the opposite4 ,by this hypothetical form we are able to speak of the meaning of a proposition without knowing whether it is true or false4 ,according to this definition1 we know the meaning of a proposition when we know what would make it true and what would make it false1 even if we do not know whether it is in fact true or false4 ,the meaning of a proposition is derivative from the meanings of its constituent words4 ,propositions occur in pairs1 distinguished 7in simple cases7 by the absence or presence of the word not4 ,two such propositions have the same objective1 but opposite meanings3 when one is true1 the other is false1 and when one is false1 the other is true4 ,the purely formal definition of truth and falsehood offers little difficulty4 ,what is required is a formal expression of the fact that a proposition is true when it points towards its objective1 and false when it points away from it1 ,in very simple cases we can give a very simple account of this3 we can say that true propositions actually resemble their objectives in a way in which false propositions do not4 ,but for this purpose it is necessary to revert to image-propositions instead of word-propositions4 ,let us take again the illustration of a memory-image of a familiar room1 and let us suppose that in the image the window is to the left of the door4 ,if in fact the window is to the left of the door1 there is a correspondence between the image and the objective2 there is the same relation between the window and the door as between the images of them4 ,the image-memory consists of the image of the window to the left of the image of the door4 ,when this is true1 the very same relation relates the terms of the objective 7namely the window and the door7 as relates the images which mean them4 ,in this case the correspondence which constitutes truth is very simple4 ,in the case we have just been considering the objective consists of two parts with a certain relation 7that of left-to-right71 and the proposition consists of images of these parts with the very same relation4 ,the same proposition1 if it were false1 would have a less simple formal relation to its objective4 ,if the image-proposition consists of an image of the window to the left of an image of the door1 while in fact the window is not to the left of the door1 the proposition does not result from the objective by the mere substitution of images for their prototypes4 ,thus in this unusually simple case we can say that a true proposition corresponds to its objective in a formal sense in which a false proposition does not4 ,perhaps it may be possible to modify this notion of formal correspondence in such a way as to be more widely applicable1 but if so1 the modifications required will be by no means slight4 ,the reasons for this must now be considered4 ,to begin with1 the simple type of correspondence we have been exhibiting can hardly occur when words are substituted for images1 because1 in word-propositions1 relations are usually expressed by words1 which are not themselves relations4 ,take such a proposition as ,socrates precedes ,plato4 ,here the word precedes is just as solid as the words ,socrates and ,plato2 it ,,means a relation1 but is not a relation4 ,thus the objective which makes our proposition true consists of ,,two terms with a relation between them1 whereas our proposition consists of ,,three terms with a relation of order between them4 ,of course1 it would be perfectly possible1 theoretically1 to indicate a few chosen relations1 not by words1 but by relations between the other words4 ,socrates-,plato might be used to mean ,socrates precedes ,plato2 ,plato-,socrates might be used to mean ,plato was born before ,socrates and died after him2 and so on4 ,but the possibilities of such a method would be very limited4 ,for aught ,i know1 there may be languages that use it1 but they are not among the languages with which ,i am acquainted4 ,and in any case1 in view of the multiplicity of relations that we wish to express1 no language could advance far without words for relations4 ,but as soon as we have words for relations1 word-propositions have necessarily more terms than the facts to which they refer1 and cannot therefore correspond so simply with their objectives as some image-propositions can4 ,the consideration of negative propositions and negative facts introduces further complications4 ,an image-proposition is necessarily positive3 we can image the window to the left of the door1 or to the right of the door1 but we can form no image of the bare negative the window not to the left of the door4 ,we can ,,disbelieve the image-proposition expressed by the window to the left of the door1 and our disbelief will be true if the window is not to the left of the door4 ,but we can form no image of the fact that the window is not to the left of the door4 ,attempts have often been made to deny such negative facts1 but1 for reasons which ,i have given elsewhere199 ,i believe these attempts to be mistaken1 and ,i shall assume that there are negative facts4 99 ,monist1 ,january1 #aiai1 p4 #db ff4 ,word-propositions1 like image-propositions1 are always positive facts4 ,the fact that ,socrates precedes ,plato is symbolized in ,english by the fact that the word precedes occurs between the words ,socrates and ,plato4 ,but we cannot symbolize the fact that ,plato does not precede ,socrates by not putting the word precedes between ,plato and ,socrates4 ,a negative fact is not sensible1 and language1 being intended for communication1 has to be sensible4 ,therefore we symbolize the fact that ,plato does not precede ,socrates by putting the words does not precede between ,plato and ,socrates4 ,we thus obtain a series of words which is just as positive a fact as the series ,socrates precedes ,plato4 ,the propositions asserting negative facts are themselves positive facts2 they are merely different positive facts from those asserting positive facts4 ,we have thus1 as regards the opposition of positive and negative1 three different sorts of duality1 according as we are dealing with facts1 image-propositions1 or word-propositions4 ,we have1 namely3 7#a7 ,positive and negative facts2 7#b7 ,image-propositions1 which may be believed or disbelieved1 but do not allow any duality of content corresponding to positive and negative facts2 7#c7 ,word-propositions1 which are always positive facts1 but are of two kinds3 one verified by a positive objective1 the other by a negative objective4 ,owing to these complications1 the simplest type of correspondence is impossible when either negative facts or negative propositions are involved4 ,even when we confine ourselves to relations between two terms which are both imaged1 it may be impossible to form an image-proposition in which the relation of the terms is represented by the same relation of the images4 ,suppose we say ,caesar was #b1jjj years before ,foch1 we express a certain temporal relation between ,caesar and ,foch2 but we cannot allow #b1jjj years to elapse between our image of ,caesar and our image of ,foch4 ,this is perhaps not a fair example1 since #b1jjj years before is not a direct relation4 ,but take a case where the relation is direct1 say1 the sun is brighter than the moon4 ,we can form visual images of sunshine and moonshine1 and it may happen that our image of the sunshine is the brighter of the two1 but this is by no means either necessary or sufficient4 ,the act of comparison1 implied in our judgment1 is something more than the mere coexistence of two images1 one of which is in fact brighter than the other4 ,it would take us too far from our main topic if we were to go into the question what actually occurs when we make this judgment4 ,enough has been said to show that the correspondence between the belief and its objective is more complicated in this case than in that of the window to the left of the door1 and this was all that had to be proved4 ,in spite of these complications1 the general nature of the formal correspondence which makes truth is clear from our instances4 ,in the case of the simpler kind of propositions1 namely those that ,i call atomic propositions1 where there is only one word expressing a relation1 the objective which would verify our proposition1 assuming that the word not is absent1 is obtained by replacing each word by what it means1 the word meaning a relation being replaced by this relation among the meanings of the other words4 ,for example1 if the proposition is ,socrates precedes ,plato1 the objective which verifies it results from replacing the word ,socrates by ,socrates1 the word ,plato by ,plato1 and the word precedes by the relation of preceding between ,socrates and ,plato4 ,if the result of this process is a fact1 the proposition is true2 if not1 it is false4 ,when our proposition is ,socrates does not precede ,plato1 the conditions of truth and falsehood are exactly reversed4 ,more complicated propositions can be dealt with on the same lines4 ,in fact1 the purely formal question1 which has occupied us in this last section1 offers no very formidable difficulties4 ,i do not believe that the above formal theory is untrue1 but ,i do believe that it is inadequate4 ,it does not1 for example1 throw any light upon our preference for true beliefs rather than false ones4 ,this preference is only explicable by taking account of the causal efficacy of beliefs1 and of the greater appropriateness of the responses resulting from true beliefs4 ,but appropriateness depends upon purpose1 and purpose thus becomes a vital part of theory of knowledge4 ,,lecture ,,xiv4 ,,emotions ,,and ,,will ,on the two subjects of the present lecture ,i have nothing original to say1 and ,i am treating them only in order to complete the discussion of my main thesis1 namely that all psychic phenomena are built up out of sensations and images alone4 ,emotions are traditionally regarded by psychologists as a separate class of mental occurrences3 ,i am1 of course1 not concerned to deny the obvious fact that they have characteristics which make a special investigation of them necessary4 ,what ,i am concerned with is the analysis of emotions4 ,it is clear that an emotion is essentially complex1 and we have to inquire whether it ever contains any non-physiological material not reducible to sensations and images and their relations4 ,although what specially concerns us is the analysis of emotions1 we shall find that the more important topic is the physiological causation of emotions4 ,this is a subject upon which much valuable and exceedingly interesting work has been done1 whereas the bare analysis of emotions has proved somewhat barren4 ,in view of the fact that we have defined perceptions1 sensations1 and images by their physiological causation1 it is evident that our problem of the analysis of the emotions is bound up with the problem of their physiological causation4 ,modern views on the causation of emotions begin with what is called the ,james-,lange theory4 ,james states this view in the following terms 7,psychology1 vol4 ii1 p4 #ddi73 ,our natural way of thinking about these coarser emotions1 grief1 fear1 rage1 love1 is that the mental perception of some fact excites the mental affection called the emotion1 and that this latter state of mind gives rise to the bodily expression4 ,my theory1 on the contrary1 is that ,,the ,,bodily ,,changes ,,follow ,,directly ,,the ,,perception ,,of ,,the ,,exciting ,,fact1 ,,and ,,that ,,our ,,feeling ,,of ,,the ,,same ,,changes ,,as ,,they ,,occur ,,is ,,the ,,emotion 7,james's italics74 ,common sense says3 we lose our fortune1 are sorry and weep2 we meet a bear1 are frightened and run2 we are insulted by a rival1 are angry and strike4 ,the hypothesis here to be defended says that this order of sequence is incorrect1 that the one mental state is not immediately induced by the other1 that the bodily manifestations must first be interposed between1 and that the more rational statement is that we feel sorry because we cry1 angry because we strike1 afraid because we tremble1 and not that we cry1 strike1 or tremble1 because we are sorry1 angry1 or fearful1 as the case may be4 ,without the bodily states following on the perception1 the latter would be purely cognitive in form1 pale1 colourless1 destitute of emotional warmth4 ,round this hypothesis a very voluminous literature has grown up4 ,the history of its victory over earlier criticism1 and its difficulties with the modern experimental work of ,sherrington and ,cannon1 is well told by ,james ,r4 ,angell in an article called ,a ,reconsideration of ,james's ,theory of ,emotion in the ,light of ,recent ,criticisms499 ,in this article ,angell defends ,james's theory and to me--though ,i speak with diffidence on a question as to which ,i have little competence--it appears that his defence is on the whole successful4 99 ,psychological ,review1 #aiaf4 ,sherrington1 by experiments on dogs1 showed that many of the usual marks of emotion were present in their behaviour even when1 by severing the spinal cord in the lower cervical region1 the viscera were cut off from all communication with the brain1 except that existing through certain cranial nerves4 ,he mentions the various signs which contributed to indicate the existence of an emotion as lively as the animal had ever shown us before the spinal operation had been made499 ,he infers that the physiological condition of the viscera cannot be the cause of the emotion displayed under such circumstances1 and concludes3 ,we are forced back toward the likelihood that the visceral expression of emotion is ,,secondary to the cerebral action occurring with the psychical state4444 ,we may with ,james accept visceral and organic sensations and the memories and associations of them as contributory to primitive emotion1 but we must regard them as re-enforcing rather than as initiating the psychosis499 99 ,quoted by ,angell1 loc4 cit4 ,angell suggests that the display of emotion in such cases may be due to past experience1 generating habits which would require only the stimulation of cerebral reflex arcs4 ,rage and some forms of fear1 however1 may1 he thinks1 gain expression without the brain4 ,rage and fear have been especially studied by ,cannon1 whose work is of the greatest importance4 ,his results are given in his book1 ,bodily ,changes in ,pain1 ,hunger1 ,fear and ,rage 7,d4 ,appleton and ,co41 #aiaf74 ,the most interesting part of ,cannon's book consists in the investigation of the effects produced by secretion of adrenin4 ,adrenin is a substance secreted into the blood by the adrenal glands4 ,these are among the ductless glands1 the functions of which1 both in physiology and in connection with the emotions1 have only come to be known during recent years4 ,cannon found that pain1 fear and rage occurred in circumstances which affected the supply of adrenin1 and that an artificial injection of adrenin could1 for example1 produce all the symptoms of fear4 ,he studied the effects of adrenin on various parts of the body2 he found that it causes the pupils to dilate1 hairs to stand erect1 blood vessels to be constricted1 and so on4 ,these effects were still produced if the parts in question were removed from the body and kept alive artificially499 99 ,cannon's work is not unconnected with that of ,mosso1 who maintains1 as the result of much experimental work1 that the seat of the emotions lies in the sympathetic nervous system4 ,an account of the work of both these men will be found in ,goddard's ,psychology of the ,normal and ,sub-normal 7,kegan ,paul1 #aiai71 chap4 vii and ,appendix4 ,cannon's chief argument against ,james is1 if ,i understand him rightly1 that similar affections of the viscera may accompany dissimilar emotions1 especially fear and rage4 ,various different emotions make us cry1 and therefore it cannot be true to say1 as ,james does1 that we feel sorry because we cry1 since sometimes we cry when we feel glad4 ,this argument1 however1 is by no means conclusive against ,james1 because it cannot be shown that there are no visceral differences for different emotions1 and indeed it is unlikely that this is the case4 ,as ,angell says 7loc4 cit473 ,fear and joy may both cause cardiac palpitation1 but in one case we find high tonus of the skeletal muscles1 in the other case relaxation and the general sense of weakness4 ,angell's conclusion1 after discussing the experiments of ,sherrington and ,cannon1 is3 ,i would therefore submit that1 so far as concerns the critical suggestions by these two psychologists1 ,james's essential contentions are not materially affected4 ,if it were necessary for me to take sides on this question1 ,i should agree with this conclusion2 but ,i think my thesis as to the analysis of emotion can be maintained without coming to a probably premature conclusion upon the doubtful parts of the physiological problem4 ,according to our definitions1 if ,james is right1 an emotion may be regarded as involving a confused perception of the viscera concerned in its causation1 while if ,cannon and ,sherrington are right1 an emotion involves a confused perception of its external stimulus4 ,this follows from what was said in ,lecture ,,vii4 ,we there defined a perception as an appearance1 however irregular1 of one or more objects external to the brain4 ,and in order to be an appearance of one or more objects1 it is only necessary that the occurrence in question should be connected with them by a continuous chain1 and should vary when they are varied sufficiently4 ,thus the question whether a mental occurrence can be called a perception turns upon the question whether anything can be inferred from it as to its causes outside the brain3 if such inference is possible1 the occurrence in question will come within our definition of a perception4 ,and in that case1 according to the definition in ,lecture ,,viii1 its non-mnemic elements will be sensations4 ,accordingly1 whether emotions are caused by changes in the viscera or by sensible objects1 they contain elements which are sensations according to our definition4 ,an emotion in its entirety is1 of course1 something much more complex than a perception4 ,an emotion is essentially a process1 and it will be only what one may call a cross-section of the emotion that will be a perception1 of a bodily condition according to ,james1 or 7in certain cases7 of an external object according to his opponents4 ,an emotion in its entirety contains dynamic elements1 such as motor impulses1 desires1 pleasures and pains4 ,desires and pleasures and pains1 according to the theory adopted in ,lecture ,,iii1 are characteristics of processes1 not separate ingredients4 ,an emotion--rage1 for example--will be a certain kind of process1 consisting of perceptions and 7in general7 bodily movements4 ,the desires and pleasures and pains involved are properties of this process1 not separate items in the stuff of which the emotion is composed4 ,the dynamic elements in an emotion1 if we are right in our analysis1 contain1 from our point of view1 no ingredients beyond those contained in the processes considered in ,lecture ,,iii4 ,the ingredients of an emotion are only sensations and images and bodily movements succeeding each other according to a certain pattern4 ,with this conclusion we may leave the emotions and pass to the consideration of the will4 ,the first thing to be defined when we are dealing with ,will is a ,,voluntary ,,movement4 ,we have already defined vital movements1 and we have maintained that1 from a behaviourist standpoint1 it is impossible to distinguish which among such movements are reflex and which voluntary4 ,nevertheless1 there certainly is a distinction4 ,when we decide in the morning that it is time to get up1 our consequent movement is voluntary4 ,the beating of the heart1 on the other hand1 is involuntary3 we can neither cause it nor prevent it by any decision of our own1 except indirectly1 as e4g4 by drugs4 ,breathing is intermediate between the two3 we normally breathe without the help of the will1 but we can alter or stop our breathing if we choose4 ,james 7,psychology1 chap4 xxvi7 maintains that the only distinctive characteristic of a voluntary act is that it involves an idea of the movement to be performed1 made up of memory-images of the kinaesthetic sensations which we had when the same movement occurred on some former occasion4 ,he points out that1 on this view1 no movement can be made voluntarily unless it has previously occurred involuntarily499 99 ,psychology1 ,vol4 ii1 pp4 #dib-c4 ,i see no reason to doubt the correctness of this view4 ,we shall say1 then1 that movements which are accompanied by kinaesthetic sensations tend to be caused by the images of those sensations1 and when so caused are called ,,voluntary4 ,volition1 in the emphatic sense1 involves something more than voluntary movement4 ,the sort of case ,i am thinking of is decision after deliberation4 ,voluntary movements are a part of this1 but not the whole4 ,there is1 in addition to them1 a judgment3 ,this is what ,i shall do2 there is also a sensation of tension during doubt1 followed by a different sensation at the moment of deciding4 ,i see no reason whatever to suppose that there is any specifically new ingredient2 sensations and images1 with their relations and causal laws1 yield all that seems to be wanted for the analysis of the will1 together with the fact that kinaesthetic images tend to cause the movements with which they are connected4 ,conflict of desires is of course essential in the causation of the emphatic kind of will3 there will be for a time kinaesthetic images of incompatible movements1 followed by the exclusive image of the movement which is said to be willed4 ,thus will seems to add no new irreducible ingredient to the analysis of the mind4 ,,lecture ,,xv4 ,,characteristics ,,of ,,mental ,,phenomena ,at the end of our journey it is time to return to the question from which we set out1 namely3 ,what is it that characterizes mind as opposed to matter8 ,or1 to state the same question in other terms3 ,how is psychology to be distinguished from physics8 ,the answer provisionally suggested at the outset of our inquiry was that psychology and physics are distinguished by the nature of their causal laws1 not by their subject matter4 ,at the same time we held that there is a certain subject matter1 namely images1 to which only psychological causal laws are applicable2 this subject matter1 therefore1 we assigned exclusively to psychology4 ,but we found no way of defining images except through their causation2 in their intrinsic character they appeared to have no universal mark by which they could be distinguished from sensations4 ,in this last lecture ,i propose to pass in review various suggested methods of distinguishing mind from matter4 ,i shall then briefly sketch the nature of that fundamental science which ,i believe to be the true metaphysic1 in which mind and matter alike are seen to be constructed out of a neutral stuff1 whose causal laws have no such duality as that of psychology1 but form the basis upon which both physics and psychology are built4 ,in search for the definition of mental phenomena1 let us begin with consciousness1 which is often thought to be the essence of mind4 ,in the first lecture ,i gave various arguments against the view that consciousness is fundamental1 but ,i did not attempt to say what consciousness is4 ,we must find a definition of it1 if we are to feel secure in deciding that it is not fundamental4 ,it is for the sake of the proof that it is not fundamental that we must now endeavour to decide what it is4 ,consciousness1 by those who regard it as fundamental1 is taken to be a character diffused throughout our mental life1 distinct from sensations and images1 memories1 beliefs and desires1 but present in all of them499 ,dr4 ,henry ,head1 in an article which ,i quoted in ,lecture ,,iii1 distinguishing sensations from purely physiological occurrences1 says3 ,sensation1 in the strict sense of the term1 demands the existence of consciousness4 ,this statement1 at first sight1 is one to which we feel inclined to assent1 but ,i believe we are mistaken if we do so4 ,sensation is the sort of thing of which we ,,may be conscious1 but not a thing of which we ,,must be conscious4 ,we have been led1 in the course of our inquiry1 to admit unconscious beliefs and unconscious desires4 ,there is1 so far as ,i can see1 no class of mental or other occurrences of which we are always conscious whenever they happen4 99 ,cf4 ,lecture ,,vi4 ,the first thing to notice is that consciousness must be of something4 ,in view of this1 ,i should define consciousness in terms of that relation of an image of a word to an object which we defined1 in ,lecture ,,xi1 as meaning4 ,when a sensation is followed by an image which is a copy of it1 ,i think it may be said that the existence of the image constitutes consciousness of the sensation1 provided it is accompanied by that sort of belief which1 when we reflect upon it1 makes us feel that the image is a sign of something other than itself4 ,this is the sort of belief which1 in the case of memory1 we expressed in the words this occurred2 or which1 in the case of a judgment of perception1 makes us believe in qualities correlated with present sensations1 as e4g41 tactile and visual qualities are correlated4 ,the addition of some element of belief seems required1 since mere imagination does not involve consciousness of anything1 and there can be no consciousness which is not of something4 ,if images alone constituted consciousness of their prototypes1 such imagination-images as in fact have prototypes would involve consciousness of them2 since this is not the case1 an element of belief must be added to the images in defining consciousness4 ,the belief must be of that sort that constitutes objective reference1 past or present4 ,an image1 together with a belief of this sort concerning it1 constitutes1 according to our definition1 consciousness of the prototype of the image4 ,but when we pass from consciousness of sensations to consciousness of objects of perception1 certain further points arise which demand an addition to our definition4 ,a judgment of perception1 we may say1 consists of a core of sensation1 together with associated images1 with belief in the present existence of an object to which sensation and images are referred in a way which is difficult to analyse4 ,perhaps we might say that the belief is not fundamentally in any ,,present existence1 but is of the nature of an expectation3 for example1 when we see an object1 we expect certain sensations to result if we proceed to touch it4 ,perception1 then1 will consist of a present sensation together with expectations of future sensations4 7,this1 of course1 is a reflective analysis1 not an account of the way perception appears to unchecked introspection47 ,but all such expectations are liable to be erroneous1 since they are based upon correlations which are usual but not invariable4 ,any such correlation may mislead us in a particular case1 for example1 if we try to touch a reflection in a looking-glass under the impression that it is real4 ,since memory is fallible1 a similar difficulty arises as regards consciousness of past objects4 ,it would seem odd to say that we can be conscious of a thing which does not or did not exist4 ,the only way to avoid this awkwardness is to add to our definition the proviso that the beliefs involved in consciousness must be ,,true4 ,in the second place1 the question arises as to whether we can be conscious of images4 ,if we apply our definition to this case1 it seems to demand images of images4 ,in order1 for example1 to be conscious of an image of a cat1 we shall require1 according to the letter of the definition1 an image which is a copy of our image of the cat1 and has this image for its prototype4 ,now1 it hardly seems probable1 as a matter of observation1 that there are images of images1 as opposed to images of sensations4 ,we may meet this difficulty in two ways1 either by boldly denying consciousness of images1 or by finding a sense in which1 by means of a different accompanying belief1 an image1 instead of meaning its prototype1 can mean another image of the same prototype4 ,the first alternative1 which denies consciousness of images1 has already been discussed when we were dealing with ,introspection in ,lecture ,,vi4 ,we then decided that there must be1 in some sense1 consciousness of images4 ,we are therefore left with the second suggested way of dealing with knowledge of images4 ,according to this second hypothesis1 there may be two images of the same prototype1 such that one of them means the other1 instead of meaning the prototype4 ,it will be remembered that we defined meaning by association a word or image means an object1 we said1 when it has the same associations as the object4 ,but this definition must not be interpreted too absolutely3 a word or image will not have ,,all the same associations as the object which it means4 ,the word cat may be associated with the word mat1 but it would not happen except by accident that a cat would be associated with a mat4 ,and in like manner an image may have certain associations which its prototype will not have1 e4g4 an association with the word image4 ,when these associations are active1 an image means an image1 instead of meaning its prototype4 ,if ,i have had images of a given prototype many times1 ,i can mean one of these1 as opposed to the rest1 by recollecting the time and place or any other distinctive association of that one occasion4 ,this happens1 for example1 when a place recalls to us some thought we previously had in that place1 so that we remember a thought as opposed to the occurrence to which it referred4 ,thus we may say that we think of an image ,a when we have a similar image ,b associated with recollections of circumstances connected with ,a1 but not with its prototype or with other images of the same prototype4 ,in this way we become aware of images without the need of any new store of mental contents1 merely by the help of new associations4 ,this theory1 so far as ,i can see1 solves the problems of introspective knowledge1 without requiring heroic measures such as those proposed by ,knight ,dunlap1 whose views we discussed in ,lecture ,,vi4 ,according to what we have been saying1 sensation itself is not an instance of consciousness1 though the immediate memory by which it is apt to be succeeded is so4 ,a sensation which is remembered becomes an object of consciousness as soon as it begins to be remembered1 which will normally be almost immediately after its occurrence 7if at all72 but while it exists it is not an object of consciousness4 ,if1 however1 it is part of a perception1 say of some familiar person1 we may say that the person perceived is an object of consciousness4 ,for in this case the sensation is a ,,sign of the perceived object in much the same way in which a memory-image is a sign of a remembered object4 ,the essential practical function of consciousness and thought is that they enable us to act with reference to what is distant in time or space1 even though it is not at present stimulating our senses4 ,this reference to absent objects is possible through association and habit4 ,actual sensations1 in themselves1 are not cases of consciousness1 because they do not bring in this reference to what is absent4 ,but their connection with consciousness is very close1 both through immediate memory1 and through the correlations which turn sensations into perceptions4 ,enough has1 ,i hope1 been said to show that consciousness is far too complex and accidental to be taken as the fundamental characteristic of mind4 ,we have seen that belief and images both enter into it4 ,belief itself1 as we saw in an earlier lecture1 is complex4 ,therefore1 if any definition of mind is suggested by our analysis of consciousness1 images are what would naturally suggest themselves4 ,but since we found that images can only be defined causally1 we cannot deal with this suggestion1 except in connection with the difference between physical and psychological causal laws4 ,i come next to those characteristics of mental phenomena which arise out of mnemic causation4 ,the possibility of action with reference to what is not sensibly present is one of the things that might be held to characterize mind4 ,let us take first a very elementary example4 ,suppose you are in a familiar room at night1 and suddenly the light goes out4 ,you will be able to find your way to the door without much difficulty by means of the picture of the room which you have in your mind4 ,in this case visual images serve1 somewhat imperfectly it is true1 the purpose which visual sensations would otherwise serve4 ,the stimulus to the production of visual images is the desire to get out of the room1 which1 according to what we found in ,lecture ,,iii1 consists essentially of present sensations and motor impulses caused by them4 ,again1 words heard or read enable you to act with reference to the matters about which they give information2 here1 again1 a present sensible stimulus1 in virtue of habits formed in the past1 enables you to act in a manner appropriate to an object which is not sensibly present4 ,the whole essence of the practical efficiency of thought consists in sensitiveness to signs3 the sensible presence of ,a1 which is a sign of the present or future existence of ,b1 enables us to act in a manner appropriate to ,b4 ,of this1 words are the supreme example1 since their effects as signs are prodigious1 while their intrinsic interest as sensible occurrences on their own account is usually very slight4 ,the operation of signs may or may not be accompanied by consciousness4 ,if a sensible stimulus ,a calls up an image of ,b1 and we then act with reference to ,b1 we have what may be called consciousness of ,b4 ,but habit may enable us to act in a manner appropriate to ,b as soon as ,a appears1 without ever having an image of ,b4 ,in that case1 although ,a operates as a sign1 it operates without the help of consciousness4 ,broadly speaking1 a very familiar sign tends to operate directly in this manner1 and the intervention of consciousness marks an imperfectly established habit4 ,the power of acquiring experience1 which characterizes men and animals1 is an example of the general law that1 in mnemic causation1 the causal unit is not one event at one time1 but two or more events at two or more times4 ,a burnt child fears the fire1 that is to say1 the neighbourhood of fire has a different effect upon a child which has had the sensations of burning than upon one which has not4 ,more correctly1 the observed effect1 when a child which has been burnt is put near a fire1 has for its cause1 not merely the neighbourhood of the fire1 but this together with the previous burning4 ,the general formula1 when an animal has acquired experience through some event ,a1 is that1 when ,b occurs at some future time1 the animal to which ,a has happened acts differently from an animal which ,a has not happened4 ,thus ,a and ,b together1 not either separately1 must be regarded as the cause of the animal's behaviour1 unless we take account of the effect which ,a has had in altering the animal's nervous tissue1 which is a matter not patent to external observation except under very special circumstances4 ,with this possibility1 we are brought back to causal laws1 and to the suggestion that many things which seem essentially mental are really neural4 ,perhaps it is the nerves that acquire experience rather than the mind4 ,if so1 the possibility of acquiring experience cannot be used to define mind499 99 ,cf4 ,lecture ,,iv4 ,very similar considerations apply to memory1 if taken as the essence of mind4 ,a recollection is aroused by something which is happening now1 but is different from the effect which the present occurrence would have produced if the recollected event had not occurred4 ,this may be accounted for by the physical effect of the past event on the brain1 making it a different instrument from that which would have resulted from a different experience4 ,the causal peculiarities of memory may1 therefore1 have a physiological explanation4 ,with every special class of mental phenomena this possibility meets us afresh4 ,if psychology is to be a separate science at all1 we must seek a wider ground for its separateness than any that we have been considering hitherto4 ,we have found that consciousness is too narrow to characterize mental phenomena1 and that mnemic causation is too wide4 ,i come now to a characteristic which1 though difficult to define1 comes much nearer to what we require1 namely subjectivity4 ,subjectivity1 as a characteristic of mental phenomena1 was considered in ,lecture ,,vii1 in connection with the definition of perception4 ,we there decided that those particulars which constitute the physical world can be collected into sets in two ways1 one of which makes a bundle of all those particulars that are appearances of a given thing from different places1 while the other makes a bundle of all those particulars which are appearances of different things from a given place4 ,a bundle of this latter sort1 at a given time1 is called a perspective2 taken throughout a period of time1 it is called a biography4 ,subjectivity is the characteristic of perspectives and biographies1 the characteristic of giving the view of the world from a certain place4 ,we saw in ,lecture ,,vii that this characteristic involves none of the other characteristics that are commonly associated with mental phenomena1 such as consciousness1 experience and memory4 ,we found in fact that it is exhibited by a photographic plate1 and1 strictly speaking1 by any particular taken in conjunction with those which have the same passive place in the sense defined in ,lecture ,,vii4 ,the particulars forming one perspective are connected together primarily by simultaneity2 those forming one biography1 primarily by the existence of direct time-relations between them4 ,to these are to be added relations derivable from the laws of perspective4 ,in all this we are clearly not in the region of psychology1 as commonly understood2 yet we are also hardly in the region of physics4 ,and the definition of perspectives and biographies1 though it does not yet yield anything that would be commonly called mental1 is presupposed in mental phenomena1 for example in mnemic causation3 the causal unit in mnemic causation1 which gives rise to ,semon's engram1 is the whole of one perspective--not of any perspective1 but of a perspective in a place where there is nervous tissue1 or at any rate living tissue of some sort4 ,perception also1 as we saw1 can only be defined in terms of perspectives4 ,thus the conception of subjectivity1 i4e4 of the passive place of a particular1 though not alone sufficient to define mind1 is clearly an essential element in the definition4 ,i have maintained throughout these lectures that the data of psychology do not differ in1 their intrinsic character from the data of physics4 ,i have maintained that sensations are data for psychology and physics equally1 while images1 which may be in some sense exclusively psychological data1 can only be distinguished from sensations by their correlations1 not by what they are in themselves4 ,it is now necessary1 however1 to examine the notion of a datum1 and to obtain1 if possible1 a definition of this notion4 ,the notion of data is familiar throughout science1 and is usually treated by men of science as though it were perfectly clear4 ,psychologists1 on the other hand1 find great difficulty in the conception4 ,data are naturally defined in terms of theory of knowledge3 they are those propositions of which the truth is known without demonstration1 so that they may be used as premisses in proving other propositions4 ,further1 when a proposition which is a datum asserts the existence of something1 we say that the something is a datum1 as well as the proposition asserting its existence4 ,thus those objects of whose existence we become certain through perception are said to be data4 ,there is some difficulty in connecting this epistemological definition of data with our psychological analysis of knowledge2 but until such a connection has been effected1 we have no right to use the conception data4 ,it is clear1 in the first place1 that there can be no datum apart from a belief4 ,a sensation which merely comes and goes is not a datum2 it only becomes a datum when it is remembered4 ,similarly1 in perception1 we do not have a datum unless we have a ,,judgment of perception4 ,in the sense in which objects 7as opposed to propositions7 are data1 it would seem natural to say that those objects of which we are conscious are data4 ,but consciousness1 as we have seen1 is a complex notion1 involving beliefs1 as well as mnemic phenomena such as are required for perception and memory4 ,it follows that no datum is theoretically indubitable1 since no belief is infallible2 it follows also that every datum has a greater or less degree of vagueness1 since there is always some vagueness in memory and the meaning of images4 ,data are not those things of which our consciousness is earliest in time4 ,at every period of life1 after we have become capable of thought1 some of our beliefs are obtained by inference1 while others are not4 ,a belief may pass from either of these classes into the other1 and may therefore become1 or cease to be1 a belief giving a datum4 ,when1 in what follows1 ,i speak of data1 ,i do not mean the things of which we feel sure before scientific study begins1 but the things which1 when a science is well advanced1 appear as affording grounds for other parts of the science1 without themselves being believed on any ground except observation4 ,i assume1 that is to say1 a trained observer1 with an analytic attention1 knowing the sort of thing to look for1 and the sort of thing that will be important4 ,what he observes is1 at the stage of science which he has reached1 a datum for his science4 ,it is just as sophisticated and elaborate as the theories which he bases upon it1 since only trained habits and much practice enable a man to make the kind of observation that will be scientifically illuminating4 ,nevertheless1 when once it has been observed1 belief in it is not based on inference and reasoning1 but merely upon its having been seen4 ,in this way its logical status differs from that of the theories which are proved by its means4 ,in any science other than psychology the datum is primarily a perception1 in which only the sensational core is ultimately and theoretically a datum1 though some such accretions as turn the sensation into a perception are practically unavoidable4 ,but if we postulate an ideal observer1 he will be able to isolate the sensation1 and treat this alone as datum4 ,there is1 therefore1 an important sense in which we may say that1 if we analyse as much as we ought1 our data1 outside psychology1 consist of sensations1 which include within themselves certain spatial and temporal relations4 ,applying this remark to physiology1 we see that the nerves and brain as physical objects are not truly data2 they are to be replaced1 in the ideal structure of science1 by the sensations through which the physiologist is said to perceive them4 ,the passage from these sensations to nerves and brain as physical objects belongs really to the initial stage in the theory of physics1 and ought to be placed in the reasoned part1 not in the part supposed to be observed4 ,to say we see the nerves is like saying we hear the nightingale2 both are convenient but inaccurate expressions4 ,we hear a sound which we believe to be causally connected with the nightingale1 and we see a sight which we believe to be causally connected with a nerve4 ,but in each case it is only the sensation that ought1 in strictness1 to be called a datum4 ,now1 sensations are certainly among the data of psychology4 ,therefore all the data of the physical sciences are also psychological data4 ,it remains to inquire whether all the data of psychology are also data of physical science1 and especially of physiology4 ,if we have been right in our analysis of mind1 the ultimate data of psychology are only sensations and images and their relations4 ,beliefs1 desires1 volitions1 and so on1 appeared to us to be complex phenomena consisting of sensations and images variously interrelated4 ,thus 7apart from certain relations7 the occurrences which seem most distinctively mental1 and furthest removed from physics1 are1 like physical objects1 constructed or inferred1 not part of the original stock of data in the perfected science4 ,from both ends1 therefore1 the difference between physical and psychological data is diminished4 ,is there ultimately no difference1 or do images remain as irreducibly and exclusively psychological8 ,in view of the causal definition of the difference between images and sensations1 this brings us to a new question1 namely3 ,are the causal laws of psychology different from those of any other science1 or are they really physiological8 ,certain ambiguities must be removed before this question can be adequately discussed4 ,first1 there is the distinction between rough approximate laws and such as appear to be precise and general4 ,i shall return to the former presently2 it is the latter that ,i wish to discuss now4 ,matter1 as defined at the end of ,lecture ,v1 is a logical fiction1 invented because it gives a convenient way of stating causal laws4 ,except in cases of perfect regularity in appearances 7of which we can have no experience71 the actual appearances of a piece of matter are not members of that ideal system of regular appearances which is defined as being the matter in question4 ,but the matter is1 after all1 inferred from its appearances1 which are used to ,,verify physical laws4 ,thus1 in so far as physics is an empirical and verifiable science1 it must assume or prove that the inference from appearances to matter is1 in general1 legitimate1 and it must be able to tell us1 more or less1 what appearances to expect4 ,it is through this question of verifiability and empirical applicability to experience that we are led to a theory of matter such as ,i advocate4 ,from the consideration of this question it results that physics1 in so far as it is an empirical science1 not a logical phantasy1 is concerned with particulars of just the same sort as those which psychology considers under the name of sensations4 ,the causal laws of physics1 so interpreted1 differ from those of psychology only by the fact that they connect a particular with other appearances in the same piece of matter1 rather than with other appearances in the same perspective4 ,that is to say1 they group together particulars having the same active place1 while psychology groups together those having the same passive place4 ,some particulars1 such as images1 have no active place1 and therefore belong exclusively to psychology4 ,we can now understand the distinction between physics and psychology4 ,the nerves and brain are matter3 our visual sensations when we look at them may be1 and ,i think are1 members of the system constituting irregular appearances of this matter1 but are not the whole of the system4 ,psychology is concerned1 inter alia1 with our sensations when we see a piece of matter1 as opposed to the matter which we see4 ,assuming1 as we must1 that our sensations have physical causes1 their causal laws are nevertheless radically different from the laws of physics1 since the consideration of a single sensation requires the breaking up of the group of which it is a member4 ,when a sensation is used to verify physics1 it is used merely as a sign of a certain material phenomenon1 i4e4 of a group of particulars of which it is a member4 ,but when it is studied by psychology1 it is taken away from that group and put into quite a different context1 where it causes images or voluntary movements4 ,it is primarily this different grouping that is characteristic of psychology as opposed to all the physical sciences1 including physiology2 a secondary difference is that images1 which belong to psychology1 are not easily to be included among the aspects which constitute a physical thing or piece of matter4 ,there remains1 however1 an important question1 namely3 ,are mental events causally dependent upon physical events in a sense in which the converse dependence does not hold8 ,before we can discuss the answer to this question1 we must first be clear as to what our question means4 ,when1 given ,a1 it is possible to infer ,b1 but given ,b1 it is not possible to infer ,a1 we say that ,b is dependent upon ,a in a sense in which ,a is not dependent upon ,b4 ,stated in logical terms1 this amounts to saying that1 when we know a many-one relation of ,a to ,b1 ,b is dependent upon ,a in respect of this relation4 ,if the relation is a causal law1 we say that ,b is causally dependent upon ,a4 ,the illustration that chiefly concerns us is the system of appearances of a physical object4 ,we can1 broadly speaking1 infer distant appearances from near ones1 but not vice versa4 ,all men look alike when they are a mile away1 hence when we see a man a mile off we cannot tell what he will look like when he is only a yard away4 ,but when we see him a yard away1 we can tell what he will look like a mile away4 ,thus the nearer view gives us more valuable information1 and the distant view is causally dependent upon it in a sense in which it is not causally dependent upon the distant view4 ,it is this greater causal potency of the near appearance that leads physics to state its causal laws in terms of that system of regular appearances to which the nearest appearances increasingly approximate1 and that makes it value information derived from the microscope or telescope4 ,it is clear that our sensations1 considered as irregular appearances of physical objects1 share the causal dependence belonging to comparatively distant appearances2 therefore in our sensational life we are in causal dependence upon physical laws4 ,this1 however1 is not the most important or interesting part of our question4 ,it is the causation of images that is the vital problem4 ,we have seen that they are subject to mnenic causation1 and that mnenic causation may be reducible to ordinary physical causation in nervous tissue4 ,this is the question upon which our attitude must turn towards what may be called materialism4 ,one sense of materialism is the view that all mental phenomena are causally dependent upon physical phenomena in the above-defined sense of causal dependence4 ,whether this is the case or not1 ,i do not profess to know4 ,the question seems to me the same as the question whether mnemic causation is ultimate1 which we considered without deciding in ,lecture ,,iv4 ,but ,i think the bulk of the evidence points to the materialistic answer as the more probable4 ,in considering the causal laws of psychology1 the distinction between rough generalizations and exact laws is important4 ,there are many rough generalizations in psychology1 not only of the sort by which we govern our ordinary behaviour to each other1 but also of a more nearly scientific kind4 ,habit and association belong among such laws4 ,i will give an illustration of the kind of law that can be obtained4 ,suppose a person has frequently experienced ,a and ,b in close temporal contiguity1 an association will be established1 so that ,a1 or an image of ,a1 tends to cause an image of ,b4 ,the question arises3 will the association work in either direction1 or only from the one which has occurred earlier to the one which has occurred later8 ,in an article by ,mr4 ,wohlgemuth1 called ,the ,direction of ,associations 7,british ,journal of ,psychology1 vol4 v1 part iv1 ,march1 #aiac71 it is claimed to be proved by experiment that1 in so far as motor memory 7i4e4 memory of movements7 is concerned1 association works only from earlier to later1 while in visual and auditory memory this is not the case1 but the later of two neighbouring experiences may recall the earlier as well as the earlier the later4 ,it is suggested that motor memory is physiological1 while visual and auditory memory are more truly psychological4 ,but that is not the point which concerns us in the illustration4 ,the point which concerns us is that a law of association1 established by purely psychological observation1 is a purely psychological law1 and may serve as a sample of what is possible in the way of discovering such laws4 ,it is1 however1 still no more than a rough generalization1 a statistical average4 ,it cannot tell us what will result from a given cause on a given occasion4 ,it is a law of tendency1 not a precise and invariable law such as those of physics aim at being4 ,if we wish to pass from the law of habit1 stated as a tendency or average1 to something more precise and invariable1 we seem driven to the nervous system4 ,we can more or less guess how an occurrence produces a change in the brain1 and how its repetition gradually produces something analogous to the channel of a river1 along which currents flow more easily than in neighbouring paths4 ,we can perceive that in this way1 if we had more knowledge1 the tendency to habit through repetition might be replaced by a precise account of the effect of each occurrence in bringing about a modification of the sort from which habit would ultimately result4 ,it is such considerations that make students of psychophysiology materialistic in their methods1 whatever they may be in their metaphysics4 ,there are1 of course1 exceptions1 such as ,professor ,j4 ,s4 ,haldane199 who maintains that it is theoretically impossible to obtain physiological explanations of psychical phenomena1 or physical explanations of physiological phenomena4 ,but ,i think the bulk of expert opinion1 in practice1 is on the other side4 99,see his book1 ,the ,new ,physiology and ,other ,addresses 7,charles ,griffin ,co41 #aiai74 ,the question whether it is possible to obtain precise causal laws in which the causes are psychological1 not material1 is one of detailed investigation4 ,i have done what ,i could to make clear the nature of the question1 but ,i do not believe that it is possible as yet to answer it with any confidence4 ,it seems to be by no means an insoluble question1 and we may hope that science will be able to produce sufficient grounds for regarding one answer as much more probable than the other4 ,but for the moment ,i do not see how we can come to a decision4 ,i think1 however1 on grounds of the theory of matter explained in ,lectures ,v and ,,vii1 that an ultimate scientific account of what goes on in the world1 if it were ascertainable1 would resemble psychology rather than physics in what we found to be the decisive difference between them4 ,i think1 that is to say1 that such an account would not be content to speak1 even formally1 as though matter1 which is a logical fiction1 were the ultimate reality4 ,i think that1 if our scientific knowledge were adequate to the task1 which it neither is nor is likely to become1 it would exhibit the laws of correlation of the particulars constituting a momentary condition of a material unit1 and would state the causal laws99 of the world in terms of these particulars1 not in terms of matter4 ,causal laws so stated would1 ,i believe1 be applicable to psychology and physics equally2 the science in which they were stated would succeed in achieving what metaphysics has vainly attempted1 namely a unified account of what really happens1 wholly true even if not the whole of truth1 and free from all convenient fictions or unwarrantable assumptions of metaphysical entities4 ,a causal law applicable to particulars would count as a law of physics if it could be stated in terms of those fictitious systems of regular appearances which are matter2 if this were not the case1 it would count as a law of psychology if one of the particulars were a sensation or an image1 i4e4 were subject to mnemic causation4 ,i believe that the realization of the complexity of a material unit1 and its analysis into constituents analogous to sensations1 is of the utmost importance to philosophy1 and vital for any understanding of the relations between mind and matter1 between our perceptions and the world which they perceive4 ,it is in this direction1 ,i am convinced1 that we must look for the solution of many ancient perplexities4 99 ,in a perfected science1 causal laws will take the form of differential equations--or of finite-difference equations1 if the theory of quanta should prove correct4 ,it is probable that the whole science of mental occurrences1 especially where its initial definitions are concerned1 could be simplified by the development of the fundamental unifying science in which the causal laws of particulars are sought1 rather than the causal laws of those systems of particulars that constitute the material units of physics4 ,this fundamental science would cause physics to become derivative1 in the sort of way in which theories of the constitution of the atom make chemistry derivative from physics2 it would also cause psychology to appear less singular and isolated among sciences4 ,if we are right in this1 it is a wrong philosophy of matter which has caused many of the difficulties in the philosophy of mind--difficulties which a right philosophy of matter would cause to disappear4 ,the conclusions at which we have arrived may be summed up as follows3 ,i4 ,physics and psychology are not distinguished by their material4 ,mind and matter alike are logical constructions2 the particulars out of which they are constructed1 or from which they are inferred1 have various relations1 some of which are studied by physics1 others by psychology4 ,broadly speaking1 physics group particulars by their active places1 psychology by their passive places4 ,,ii4 ,the two most essential characteristics of the causal laws which would naturally be called psychological are ,,subjectivity and ,,mnemic ,,causation2 these are not unconnected1 since the causal unit in mnemic causation is the group of particulars having a given passive place at a given time1 and it is by this manner of grouping that subjectivity is defined4 ,,iii4 ,habit1 memory and thought are all developments of mnemic causation4 ,it is probable1 though not certain1 that mnemic causation is derivative from ordinary physical causation in nervous 7and other7 tissue4 ,,iv4 ,consciousness is a complex and far from universal characteristic of mental phenomena4 ,v4 ,mind is a matter of degree1 chiefly exemplified in number and complexity of habits4 ,,vi4 ,all our data1 both in physics and psychology1 are subject to psychological causal laws2 but physical causal laws1 at least in traditional physics1 can only be stated in terms of matter1 which is both inferred and constructed1 never a datum4 ,in this respect psychology is nearer to what actually exists4