,library1 ,case ,western ,reserve ,university 7http3_/_/library4case4edu_/digitalcase_ /7 ,note3 ,images of the original pages are available through ,digital ,case1 the ,kelvin ,smith ,library1 ,case ,western ,reserve ,university4 ,see http3_/_/digitalcase4case4edu3#ijjj_/;fe dora_/get_/ksl3binmin#jj_/;binmin#jj4pdf ,transcriber's ,note3 ,references are made to footnotes in other footnotes and index4 ,the footnotes are serially numbered and placed at the end of each chapter4 ,consequently the references in the footnotes and index have been corrected to indicate the footnote number4 ,international ,scientific ,series4 ,volume ,,lxxxix4 7,the ,international ,scientific ,series7 ,edited by ,f4 ,legge ,,the ,,mind ,,and ,,the ,,brain by ,,alfred ,,binet ,directeur du ,laboratoire de ,psychologie la ,sorbonne ,being the ,authorised ,translation of ,l'me et le ,corps ,london ,kegan ,paul1 ,trench1 ,trbner ,co4 ,ltd ,dryden ,house1 ,gerrard ,street1 ,w4 #aijg ,,contents ,,book ,i ,,the ,,definition ,,of ,,matter ,,chapter ,i ,,introduction ,the distinction between mind and matter--,knowable not homogeneous--,criterion employed1 enumeration not concepts ,,chapter ,,ii ,,our ,,knowledge ,,of ,,external ,,objects ,,only ,,sensation ,modern theories of matter--,outer world only known to us by our sensations--,instances--,mill's approval of proposition1 and its defects--,nervous system only intermediary between self and outer world--,the great ,x of ,matter--,nervous system does not give us true image--,mller's law of specificity of the nerves--,the nervous system itself a sensation--,relations of sensation with the unknowable the affair of metaphysics ,,chapter ,,iii ,,the ,,mechanical ,,theories ,,of ,,matter ,,are ,,only ,,symbols ,physicists vainly endeavour to reduce the rle of sensation--,mathematical1 energetical1 and mechanical theories of universe--,mechanical model formed from sensation--,instance of tuning-fork--,no one sensation any right to hegemony over others ,,chapter ,,iv ,,answers ,,to ,,some ,,objections1 ,,and ,,summary ,objections of spiritualists--,of ,german authors who contend that nervous system does give true image--,of metaphysicians--,common ground of objection that nervous system not intermediary--,answer to this--,summary of preceding chapters ,,book ,,ii ,,the ,,definition ,,of ,,mind ,,chapter ,i ,,the ,,distinction ,,between ,,cognition ,,and ,,its ,,object ,necessity for inventory of mental phenomena--,objects of cognition and acts of cognition--,definition of consciousness ,,chapter ,,ii ,,definition ,,of ,,sensation ,sensation defined by experimental psychology--,a state of consciousness--,considered self-evident by ,mill1 ,renouvier1 and ,hume--,psycho-physical according to ,reid and ,hamilton--,reasons in favour of last definition--,other opinions examined and refuted ,,chapter ,,iii ,,definition ,,of ,,the ,,image ,perception and ideation cannot be separated--,perception constituted by addition of image to sensation--,hallucinations--,objections anticipated and answered ,,chapter ,,iv ,,definition ,,of ,,the ,,emotions ,contrary opinions as to nature of emotions--,emotion a phenomenon sui generis--,intellectualist theory of emotion supported by ,lange and ,james--,is emotion only a perception8 ,is effort8--,question left unanswered ,,chapter ,v ,,definition ,,of ,,the ,,consciousness--,,the ,,relation ,,subject-,,object ,can thoughts be divided into subject and object8--,this division cannot apply to the consciousness--,subject of cognition itself an object--,james' opinion examined--,opinion that subject is spiritual substance and consciousness its faculty refuted ,,chapter ,,vi ,,definition ,,of ,,the ,,consciousness--,,categories ,,of ,,the ,,understanding ,principle of relativity doubted--,tables of categories3 ,aristotle1 ,kant1 and ,renouvier--,kantian idealism--,phenomenism of ,berkeley examined and rejected--,argument of a priorists--,the intelligence only an inactive consciousness--,huxley's epiphenomenal consciousness--,is the consciousness necessary8--,impossibility of answering this question ,,chapter ,,vii ,,definition ,,of ,,the ,,consciousness--,,the ,,separability ,,of ,,the ,,consciousness ,,from ,,its ,,object--,,discussion ,,of ,,idealism ,can the consciousness be separated from its object8--,idealists consider the object a modality of the consciousness and thus inseparable1 from it--,futility of this doctrine--,object can exist without consciousness ,,chapter ,,viii ,,definition ,,of ,,the ,,consciousness--,,the ,,separation ,,of ,,the ,,consciousness ,,from ,,its ,,object--,,the ,,unconscious ,can ideas exist without consciousness8--,no consciousness without an object--,can the consciousness die8--,enfeeblement of consciousness how accounted for--,doubling of consciousness in hysterics--,relations of physiological phenomena to consciousness--,consciousness cannot become unconscious and yet exist ,,chapter ,,ix ,,definitions ,,of ,,psychology ,difficulty of defining psychology--,definition by substance--,psychology not the science of the soul--,definition by enumeration3 its error--,definition by method contradicts idea of consciousness--,externospection and introspection sometimes confused--,definition by content--,facts cannot be divided into those of consciousness and of unconsciousness--,descartes' definition of psychology insufficient--,within and without simile unanalogous--,definition by point of view--,inconsistencies of ,ebbinghaus' contention--,w4 ,james' teleological theory--,definition by the peculiar nature of mental laws only one possible3 why8 ,,book ,,iii ,,the ,,union ,,of ,,the ,,soul ,,and ,,the ,,body ,,chapter ,i ,,the ,,mind ,,has ,,an ,,incomplete ,,life ,problem of union of mind and body stated--,axiom of heterogeneity must be rejected--,phenomena of consciousness incomplete--,aristotle's relatum and correlatum applied to the terms mind and matter ,,chapter ,,ii ,,spiritualism ,,and ,,idealism ,spiritualist view that death cuts link between soul and body--,explanation of link fatal to system--,consciousness cannot exercise functions without objects of cognition--,idealism a kaleidoscopic system--,four affirmations of idealism3 their inconsistency--,advantages of historical method ,,chapter ,,iii ,,materialism ,,and ,,parallelism ,materialism oldest doctrine of all3 many patristic authors lean towards it--,modern form of1 receives impulse from advance of physical science--,karl ,vogt's comparison of secretions of brain with that of kidneys--,all materialist doctrines opposed to principle of heterogeneity--,modern materialism would make object generate consciousness--,materialists cannot demonstrate how molecular vibrations can be transformed into objects--,parallelism avoids issue by declaring mind to be function of brain--,parallelists declare physical and psychical life to be two parallel currents--,bain's support of this--,objections to3 most important that it postulates consciousness as a complete whole ,,chapter ,,iv ,,modern ,,theories ,berkeley's idealism revived by ,bergson1 though with different standpoint--,admirable nature of ,bergson's exposition--,fallacy of1 part assigned to sensory nerves--,conscious sensations must be subsequent to excitement of sensory nerves and dependent on their integrity ,,chapter ,v ,,conclusion ,author's own theory only a hypothesis--,important conditions for solution of problem--,manifestations of consciousness conditioned by brain1 but this last unconscious--,consciousness perceives only external object--,specificity of nerves not absolute--,why repeated excitements of nerve tend to become unconscious--,formation of habit and instinct--,resemblance to and distinction of this from parallelism--,advantages of new theory ,,chapter ,,vi ,,recapitulation ,description of matter--,definition of mind--,objections to1 answered--,incomplete existence of mind--,other theories--,nervous system must add its own effect to that of its excitant ,,book ,i ,,the ,,definition ,,of ,,matter ,,the ,,mind ,,and ,,the ,,brain#a ,,chapter ,i ,,introduction ,this book is a prolonged effort to establish a distinction between what is called mind and what is called matter4 ,nothing is more simple than to realise this distinction when you do not go deeply into it2 nothing is more difficult when you analyse it a little4 ,at first sight1 it seems impossible to confuse things so far apart as a thought and a block of stone2 but on reflection this great contrast vanishes1 and other differences have to be sought which are less apparent and of which one has not hitherto dreamed4 ,first let us say how the question presents itself to us4 ,the fact which we must take as a starting point1 for it is independent of every kind of theory1 is that there exists something which is knowable4 ,not only science1 but ordinary life and our everyday conversation1 imply that there are things that we know4 ,it is with regard to these things that we have to ask ourselves if some belong to what we call the mind and others to what we call matter4 ,let us suppose1 by way of hypothesis1 the knowable to be entirely and absolutely homogeneous4 ,in that case we should be obliged to set aside the question as one already decided4 ,where everything is homogeneous1 there is no distinction to be drawn4 ,but this hypothesis is1 as we all know1 falsified by observation4 ,the whole body of the knowable is formed from an agglomeration of extremely varied elements1 amongst which it is easy to distinguish a large number of divisions4 ,things may be classified according to their colour1 their shape1 their weight1 the pleasure they give us1 their quality of being alive or dead1 and so on2 one much given to classification would only be troubled by the number of possible distinctions4 ,since so many divisions are possible1 at which shall we stop and say3 this is the one which corresponds exactly to the opposition of mind and matter8 ,the choice is not easy to make2 for we shall see that certain authors put the distinction between the physical and the mental in one thing1 others in another4 ,thus there have been a very large number of distinctions proposed1 and their number is much greater than is generally thought4 ,since we propose to make ourselves judges of these distinctions1 since1 in fact1 we shall reject most of them in order to suggest entirely new ones1 it must be supposed that we shall do so by means of a criterion4 ,otherwise1 we should only be acting fantastically4 ,we should be saying peremptorily1 ,in my opinion this is mental1 and there would be no more ground for discussion than1 if the assertion were ,i prefer the ,romanticists to the ,classicists1 or ,i consider prose superior to poetry4 ,the criterion which ,i have employed1 and which ,i did not analyse until the unconscious use ,i had made of it revealed its existence to me1 is based on the two following rules3-- #a4 ,a ,rule of ,method4--,the distinction between mind and matter must not only apply to the whole of the knowable1 but must be the deepest which can divide the knowable1 and must further be one of a permanent character4 ,a priori1 there is nothing to prove the existence of such a distinction2 it must be sought for and1 when found1 closely examined4 #b4 ,an ,indication of the ,direction in which the ,search must be ,made4--,taking into account the position already taken up by the majority of philosophers1 the manifestation of mind1 if it exists1 must be looked for in the domain of facts dealt with by psychology1 and the manifestation of matter in the domain explored by physicists4 ,i do not conceal from myself that there may be much that is arbitrary in my own criterion2 but this does not seem to me possible to avoid4 ,we must therefore appeal to psychology1 and ask whether it is cognisant of any phenomenon offering a violent1 lasting1 and ineffaceable contrast with all the rest of the knowable4 ,the ,method of ,concepts and the ,method of ,enumeration4--,many authors are already engaged in this research1 and employ a method which ,i consider very bad and very dangerous--the method of concepts4 ,this consists in looking at real and concrete phenomena in their most abstract form4 ,for example1 in studying the mind1 they use this word mind as a general idea which is supposed to contain all the characteristics of psychical phenomena2 but they do not wait to enumerate these characteristics or to realise them1 and they remain satisfied with the extremely vague idea springing from an unanalysed concept4 ,consequently they use the word mind with the imprudence of a banker who should discount a trade bill without ascertaining whether the payment of that particular piece of paper had been provided for4 ,this amounts to saying that the discussion of philosophical problems takes especially a verbal aspect2 and the more complex the phenomena a concept thus handled1 contains1 the more dangerous it is4 ,a concept of the colour red has but a very simple content1 and by using it1 this content can be very clearly represented4 ,but how can the immense meaning of the word mind be realised every time that it is used8 ,for example1 to define mind and to separate it from the rest of the knowable which is called matter1 the general mode of reasoning is as follows3 all the knowable which is apparent to our senses is essentially reduced to motion2 mind1 that something which lives1 feels1 and judges1 is reduced to thought4 ,to understand the difference between matter and mind1 it is necessary to ask one's self whether there exists any analogy in nature between motion and thought4 ,now this analogy does not exist1 and what we comprehend1 on the contrary1 is their absolute opposition4 ,thought is not a movement1 and has nothing in common with a movement4 ,a movement is never anything else but a displacement1 a transfer1 a change of place undergone by a particle of matter4 ,what relation of similarity exists between this geometrical fact and a desire1 an emotion1 a sensation of bitterness8 ,far from being identical1 these two facts are as distinct as any facts can be1 and their distinction is so deep that it should be raised to the height of a principle1 the principle of heterogeneity4 ,this is almost exactly the reasoning that numbers of philosophers have repeated for several years without giving proof of much originality4 ,this is what ,i term the metaphysics of concept1 for it is a speculation which consists in juggling with abstract ideas4 ,the moment that a philosopher opposes thought to movement1 ,i ask myself under what form he can think of a thought1 ,i suppose he must very poetically and very vaguely represent to himself something light and subtle which contrasts with the weight and grossness of material bodies4 ,and thus our philosopher is punished in the sinning part2 his contempt of the earthly has led him into an abuse of abstract reasoning1 and this abuse has made him the dupe of a very nave physical metaphor4 ,at bottom ,i have not much faith in the nobility of many of our abstract ideas4 ,in a former psychological study#b ,i have shown that many of our abstractions are nothing else than embryonic1 and1 above all1 loosely defined concrete ideas1 which can satisfy only an indolent mind1 and are1 consequently1 full of snares4 ,the opposition between mind and matter appears to me to assume a very different meaning if1 instead of repeating ready-made formulas and wasting time on the game of setting concept against concept1 we take the trouble to return to the study of nature1 and begin by drawing up an inventory of the respective phenomena of mind and matter1 examining with each of these phenomena the characteristics in which the first-named differ from the second4 ,it is this last method1 more slow but more sure than the other1 that we shall follow2 and we will commence by the study of matter4 ,,footnotes3 ,footnote #a3 ,l',ame et la ,corps4--,disagreeable as it is to alter an author's title1 the words ,soul and ,body had to be abandoned because of their different connotation in ,english4 ,the title ,mind and ,body was also preoccupied by ,bain's work of that name in this series4 ,the title chosen has ,m4 ,binet's approval4--,,ed4 ,footnote #b3 tude expermentale de l',intelligence4 ,paris3 ,schleicher4 ,,chapter ,,ii ,,our ,,knowledge ,,of ,,external ,,objects ,,is ,,only ,,sensations ,of late years numerous studies have been published on the conception of matter1 especially by physicists1 chemists1 and mathematicians4 ,among these recent contributions to science ,i will quote the articles of ,duhem on the ,evolution of ,mechanics published in #aijc in the ,revue gnrale des ,sciences1 and other articles by the same author1 in #aijd1 in the ,revue de ,philosophie4 ,duhem's views have attracted much attention1 and have dealt a serious blow at the whole theory of the mechanics of matter4 ,let me also quote that excellent work of ,dastre1 ,la ,vie et la ,mort1 wherein the author makes so interesting an application to biology of the new theories on energetics2 the discussion between ,ostwald and ,brillouin on matter1 in which two rival conceptions find themselves engaged in a veritable hand-to-hand struggle 7,revue gnrale des ,sciences1 ,nov4 and ,dec4 #ahie72 the curious work of ,dantec on les ,lois ,naturelles1 in which the author ingeniously points out the different sensorial districts into which science is divided1 although1 through a defect in logic1 he accepts mechanics as the final explanation of things4 ,and last1 it is impossible to pass over1 in silence1 the rare works of ,lord ,kelvin1 so full1 for ,french readers1 of unexpected suggestions1 for they show us the entirely practical and empirical value which the ,english attach to mechanical models4 ,my object is not to go through these great studies in detail4 ,it is the part of mathematical and physical philosophers to develop their ideas on the inmost nature of matter1 while seeking to establish theories capable of giving a satisfactory explanation of physical phenomena4 ,this is the point of view they take up by preference1 and no doubt they are right in so doing4 ,the proper rle of the natural sciences is to look at phenomena taken by themselves and apart from the observer4 ,my own intention1 in setting forth these same theories on matter1 is to give prominence to a totally different point of view4 ,instead of considering physical phenomena in themselves1 we shall seek to know what idea one ought to form of their nature when one takes into account that they are observed phenomena4 ,while the physicist withdraws from consideration the part of the observer in the verification of physical phenomena1 our rle is to renounce this abstraction1 to re-establish things in their original complexity1 and to ascertain in what the conception of matter consists when it is borne in mind that all material phenomena are known only in their relation to ourselves1 to our bodies1 our nerves1 and our intelligence4 ,this at once leads us to follow1 in the exposition of the facts1 an order which the physicist abandons4 ,since we seek to know what is the physical phenomenon we perceive1 we must first enunciate this proposition1 which will govern the whole of our discussion3 to wit-- ,of the outer world we know nothing except our sensations4 ,before demonstrating this proposition1 let us develop it by an example which will at least give us some idea of its import4 ,let us take as example one of those investigations in which1 with the least possible recourse to reasoning1 the most perfected processes of observation are employed1 and in which one imagines that one is penetrating almost into the very heart of nature4 ,we are1 let us suppose1 dissecting an animal4 ,after killing it1 we lay bare its viscera1 examine their colour1 form1 dimensions1 and connections2 then we dissect the organs in order to ascertain their internal nature1 their texture1 structure1 and function2 then1 not content with ocular anatomy1 we have recourse to the perfected processes of histology3 we take a fragment of the tissues weighing a few milligrammes1 we fix it1 we mount it1 we make it into strips of no more than a thousandth of a millimetre thick1 we colour it and place it under the microscope1 we examine it with the most powerful lenses1 we sketch it1 and we explain it4 ,all this work of complicated and refined observation1 sometimes lasting months and years1 results in a monograph containing minute descriptions of organs1 of cells1 and of intra-cellular structures1 the whole represented and defined in words and pictures4 ,now1 these descriptions and drawings are the display of the various sensations which the zoologist has experienced in the course of his labours2 to those sensations are added the very numerous interpretations derived from the memory1 reasoning1 and often1 also1 from the imagination on the part of the scholar1 the last a source at once of errors and of discoveries4 ,but everything properly experimental in the work of the zoologist proceeds from the sensations he has felt or might have felt1 and in the particular case treated of1 these sensations are almost solely visual4 ,this observation might be repeated with regard to all objects of the outer world which enter into relation with us4 ,whether the knowledge of them be of the common-place or of a scientific order matters little4 ,sensation is its limit1 and all objects are known to us by the sensations they produce in us1 and are known to us solely in this manner4 ,a landscape is nothing but a cluster of sensations4 ,the outward form of a body is simply sensation2 and the innermost and most delicate material structure1 the last visible elements of a cell1 for example1 are all1 in so far as we observe them with the microscope1 nothing but sensation4 ,this being understood1 the question is1 why we have just admitted--with the majority of authors--that we cannot really know a single object as it is in itself1 and in its own nature1 otherwise than by the intermediary of the sensations it provokes in us8 ,this comes back to saying that we here require explanations on the two following points3 why do we admit that we do not really perceive the objects1 but only something intermediate between them and us2 and why do we call this something intermediate a sensation8 ,on this second point ,i will offer1 for the time being1 one simple remark3 we use the term sensation for lack of any other to express the intermediate character of our perception of objects2 and this use does not1 on our part1 imply any hypothesis4 ,especially do we leave completely in suspense the question whether sensation is a material phenomenon or a state of being of the mind4 ,these are questions we will deal with later4 ,for the present it must be understood that the word sensation is simply a term for the something intermediate between the object and our faculty of cognition4#c ,we have1 therefore1 simply to state why we have admitted that the external perception of objects is produced mediately or by procuration4 ,there are a few philosophers1 and those not of the lowest rank1 who have thought that this intermediate character of all perception was so evident that there was no need to insist further upon it4 ,john ,stuart ,mill1 who was certainly and perhaps more than anything a careful logician1 commences an exposition of the idealist thesis to which he was so much attached1 by carelessly saying3 ,it goes without saying that objects are known to us through the intermediary of our senses4444 ,the senses are equivalent to our sensations2#d and on those propositions he rears his whole system1 ,it goes without saying 444 is a trifle thoughtless4 ,i certainly think he was wrong in not testing more carefully the solidity of his starting point4 ,in the first place1 this limit set to our knowledge of the objects which stimulate our sensations is only accepted without difficulty by well-informed persons2 it much astonishes the uninstructed when first explained to them4 ,and this astonishment1 although it may seem so1 is not a point that can be neglected1 for it proves that1 in the first and simple state of our knowledge1 we believe we directly perceive objects as they are4 ,now1 if we1 the cultured class1 have1 for the most part1#e abandoned this primitive belief1 we have only done so on certain implicit conditions1 of which we must take cognisance4 ,this is what ,i shall now demonstrate as clearly as ,i can4 ,take the case of an unlearned person4 ,to prove to him that he knows sensations alone and not the bodies which excite them1 a very striking argument may be employed which requires no subtle reasoning and which appeals to his observation4 ,this is to inform him1 supposing he is not aware of the fact1 that1 every time he has the perception of an exterior object1 there is something interposed between the object and himself1 and that that something is his nervous system4 ,if we were not acquainted with the existence of our nervous system1 we should unhesitatingly admit that our perception of objects consisted in some sort of motion towards the places in which they were fixed4 ,now1 a number of experiments prove to us that objects are known to us as excitants of our nervous system which only act on this system by entering into communication1 or coming into contact with1 its terminal extremities4 ,they then produce1 in the interior of this system1 a peculiar modification which we are not yet able to define4 ,it is this modification which follows the course of the nerves and is carried to the central parts of the system4 ,the speed of the propagation of this nerve modification has been measured by certain precise experiments in psychometry2 the journey is made slowly1 at the rate of #bj to #cj metres per second1 and it is of interest that this rate of speed lets us know at what moment and1 consequently1 by what organic excitement1 the phenomenon of consciousness is produced4 ,this happens when the cerebral centres are affected2 the phenomenon of consciousness is therefore posterior to the fact of the physical excitement4 ,i believe it has required a long series of accepted observations for us to have arrived at this idea1 now so natural in appearance1 that the modifications produced within our nervous system are the only states of which we can have a direct consciousness2 and as experimental demonstration is always limited1 there can be no absolute certainty that things never happen otherwise1 that we never go outside ourselves1 and that neither our consciousness nor our nervous influx can exteriorise itself1 shoot beyond our material organs1 and travel afar in pursuit of objects in order to know or to modify them4 99 99 99 99 99 ,before going further1 we must make our terminology more precise4 ,we have just seen the necessity of drawing a distinction between the sensations of which we are conscious and the unknown cause which produces these sensations by acting on our nervous systems4 ,this exciting cause ,i have several times termed1 in order to be understood1 the external object4 ,but under the name of external object are currently designated groups of sensations1 such as those which make up for us a chair1 a tree1 an animal1 or any kind of body4 ,i see a dog pass in the street4 ,i call this dog an external object2 but1 as this dog is formed1 for me who am looking at it1 of my sensations1 and as these sensations are states of my nervous centres1 it happens that the term external object has two meanings4 ,sometimes it designates our sensations2 at another1 the exciting cause of our sensations4 ,to avoid all confusion we will call this exciting cause1 which is unknown to us1 the ,x of matter4 ,it is1 however1 not entirely unknown1 for we at least know two facts with regard to it4 ,we know1 first1 that this ,x exists1 and in the second place1 that its image must not be sought in the sensations it excites in us4 ,how can we doubt1 we say1 that it exists8 ,the same external observation proves to us at once that there exists an object distinct from our nerves1 and that our nerves separate us from it4 ,i insist on this point1 for the reason that some authors1 after having unreservedly admitted that our knowledge is confined to sensations1 have subsequently been hard put to it to demonstrate the reality of the excitant distinct from the sensations4#f ,of this we need no demonstration1 and the testimony of our senses suffices4 ,we have seen the excitant1 and it is like a friend who should pass before us in disguise so well costumed and made up that we can attribute to his real self nothing of what we see of him1 but yet we know that it is he4 ,and1 in fact1 let us remember what it is that we have argued upon--viz4 on an observation4 ,i look at my hand1 and ,i see an object approaching it which gives me a sensation of feeling4 ,i at first say that this object is an excitant4 ,it is pointed out to me that ,i am in error4 ,this object1 which appears to me outside my nervous system1 is composed1 ,i am told1 of sensations4 ,be it so1 ,i have the right to answer2 but if all that ,i perceive is sensation1 my nervous system itself is a sensation2 if it is only that1 it is no longer an intermediary between the excitant and myself1 and it is the fact that we perceive things as they are4 ,for it to be possible to prove that ,i perceive1 not the object1 but that tertium quid which is sensation1 it has to be admitted that the nervous system is a reality external to sensation and that objects which assume1 in relation to it1 the rle of excitants and of which we perceive the existence1 are likewise realities external to sensation4 ,this is what is demonstrated by abstract reasoning1 and this reasoning is further supported by a common-sense argument4 ,the outer world cannot be summarised in a few nervous systems suspended like spiders in empty space4 ,the existence of a nervous system implies that of a body in which it is lodged4 ,this body must have complicated organs2 its limbs presuppose the soil on which the animal rests1 its lungs the existence of oxygen vivifying its blood1 its digestive tube1 aliments which it digests and assimilates to its substance1 and so on4 ,we may indeed admit that this outer world is not1 in itself1 exactly as we perceive it2 but we are compelled to recognise that it exists by the same right as the nervous system1 in order to put it in its proper place4 ,the second fact of observation is that the sensations we feel do not give us the true image of the material ,x which produces them4 ,the modification made in our substance by this force ,x does not necessarily resemble in its nature the nature of that force4 ,this is an assertion opposed to our natural opinions1 and must consequently be demonstrated4 ,it is generally proved by the experiments which reveal what is called the law of the specific energy of the nerves4 ,this is an important law in physiology discovered by ,mller two centuries ago1 and consequences of a philosophical order are attached to it4 ,the facts on which this law is based are these4 ,it is observed that1 if the sensory nerves are agitated by an excitant which remains constant1 the sensations received by the patient differ according to the nerve affected4 ,thus1 the terminals of an electric current applied to the ball of the eye give the sensation of a small luminous spark2 to the auditory apparatus1 the current causes a crackling sound2 to the hand1 the sensation of a shock2 to the tongue1 a metallic flavour4 ,conversely1 excitants wholly different1 but affecting the same nerve1 give similar sensations2 whether a ray of light is projected into the eye1 or the eyeball be excited by the pressure of a finger2 whether an electric current is directed into the eye1 or1 by a surgical operation1 the optic nerve is severed by a bistoury1 the effect is always the same1 in the sense that the patient always receives a sensation of light4 ,to sum up1 in addition to the natural excitant of our sensory nerves1 there are two which can produce the same sensory effects1 that is to say1 the mechanical and the electrical excitants4 ,whence it has been concluded that the peculiar nature of the sensation felt depends much less on the nature of the excitant producing it than on that of the sensory organ which collects it1 the nerve which propagates it1 or the centre which receives it4 ,it would perhaps be going a little too far to affirm that the external object has no kind of resemblance to the sensations it gives us4 ,it is safer to say that we are ignorant of the degree in which the two resemble or differ from each other4 ,on thinking it over1 it will be found that this contains a very great mystery1 for this power of distinction 7specificit7 of our nerves is not connected with any detail observable in their structure4 ,it is very probably the receiving centres which are specific4 ,it is owing to them and to their mechanism that we ought to feel1 from the same excitant1 a sensation of sound or one of colour1 that is to say1 impressions which appear1 when compared1 as the most different in the world4 ,now1 so far as we can make out1 the histological structure of our auditory centre is the same as that of our visual centre4 ,both are a collection of cells diverse in form1 multipolar1 and maintained by a conjunctive pellicule 7stroma74 ,the structure of the fibres and cells varies slightly in the motor and sensory regions1 but no means have yet been discovered of perceiving a settled difference between the nerve-cells of the optic centre and those of the auditory centre4 ,there should be a difference1 as our mind demands it2 but our eye fails to note it4 ,let us suppose1 however1 that to-morrow1 or several centuries hence1 an improved technique should show us a material difference between the visual and the auditory neurone4 ,there is no absurdity in this supposition2 it is a possible discovery1 since it is of the order of material facts4 ,such a discovery1 however1 would lead us very far1 for what terribly complicates this problem is that we cannot directly know the structure of our nervous system4 ,though close to us1 though1 so to speak1 inside us1 it is not known to us otherwise than is the object we hold in our hands1 the ground we tread1 or the landscape which forms our horizon4 ,for us it is but a sensation1 a real sensation when we observe it in the dissection of an animal1 or the autopsy of one of our own kind2 an imaginary and transposed sensation1 when we are studying anatomy by means of an anatomical chart2 but still a sensation4 ,it is by the intermediary of our nervous system that we have to perceive and imagine what a nervous system is like2 consequently we are ignorant as to the modification impressed on our perceptions and imaginations by this intermediary1 the nature of which we are unable to grasp4 ,therefore1 when we attempt to understand the inmost nature of the outer world1 we stand before it as before absolute darkness4 ,there probably exists in nature1 outside of ourselves1 neither colour1 odour1 force1 resistance1 space1 nor anything that we know as sensation4 ,light is produced by the excitement of the optic nerve1 and it shines only in our brain2 as to the excitement itself1 there is nothing to prove that it is luminous2 outside of us is profound darkness1 or even worse1 since darkness is the correlation of light4 ,in the same way1 all the sonorous excitements which assail us1 the creakings of machines1 the sounds of nature1 the words and cries of our fellows are produced by excitements of our acoustic nerve2 it is in our brain that noise is produced1 outside there reigns a dead silence4 ,the same may be said of all our other senses4 ,not one of our senses1 absolutely none1 is the revealer of external reality4 ,from this point of view there is no higher and no lower sense4 ,the sensations of sight1 apparently so objective and so searching1 no more take us out of ourselves than do the sensations of taste which are localised in the tongue4 ,in short1 our nervous system1 which enables us to communicate with objects1 prevents us1 on the other hand1 from knowing their nature4 ,it is an organ of relation with the outer world2 it is also1 for us1 a cause of isolation4 ,we never go outside ourselves4 ,we are walled in4 ,and all we can say of matter and of the outer world is1 that it is revealed to us solely by the sensations it affords us1 that it is the unknown cause of our sensations1 the inaccessible excitant of our organs of the senses1 and that the ideas we are able to form as to the nature and the properties of that excitant1 are necessarily derived from our sensations1 and are subjective to the same degree as those sensations themselves4 ,but we must make haste to add that this point of view is the one which is reached when we regard the relations of sensation with its unknown cause the great ,x of matter4#g ,positive science and practical life do not take for an objective this relation of sensation with the ,unknowable2 they leave this to metaphysics4 ,they distribute themselves over the study of sensation and examine the reciprocal relations of sensations with sensations4 ,those last1 condemned as misleading appearances when we seek in them the expression of the ,unknowable1 lose this illusory character when we consider them in their reciprocal relations4 ,then they constitute for us reality1 the whole of reality and the only object of human knowledge4 ,the world is but an assembly of present1 past1 and possible sensations2 the affair of science is to analyse and co-ordinate them by separating their accidental from their constant relations4 ,,footnotes3 ,footnote #c3 ,connaissance4--,the word cognition is used throughout as the ,english equivalent of this1 except in places where the context shows that it means acquaintance merely4--,,ed4 ,footnote #d3 ,j4 ,s4 ,,mill1 ,an ,examination of ,sir ,wm4 ,hamilton's ,philosophy1 pp4 #e and #f4 ,london4 #ahfe4 ,footnote #e3 ,a few subtle philosophers have returned to it1 as ,i shall show later in chapter iv4 ,footnote #f3 ,thus1 the perplexity in which ,john ,stuart ,mill finds himself is very curious4 ,having admitted unreservedly that our knowledge is confined to sensations1 he is powerless to set up a reality outside this1 and acknowledges that the principle of causality cannot legitimately be used to prove that our sensations have a cause which is not a sensation1 because this principle cannot be applied outside the world of phenomena4 ,footnote #g3 ,see p4 #ah1 sup4--,,ed4 ,,chapter ,,iii ,,the ,,mechanical ,,theories ,,of ,,matter ,,are ,,only ,,symbols ,if we keep firmly in mind the preceding conclusion--a conclusion which is neither exclusively my own1 nor very new--we shall find a certain satisfaction in watching the discussions of physicists on the essence of matter1 on the nature of force and of energy1 and on the relations of ponderable and imponderable matter4 ,we all know how hot is the fight raging on this question4 ,at the present time it is increasing in intensity1 in consequence of the disturbance imported into existing theories by the new discoveries of radio-activity4#h ,we psychologists can look on very calmly at these discussions1 with that selfish pleasure we unavowedly feel when we see people fighting while ourselves safe from knocks4 ,we have1 in fact1 the feeling that1 come what may from the discussions on the essence of matter1 there can be no going beyond the truth that matter is an excitant of our nervous system1 and is only known in connection with1 the perception we have of this last4 ,if we open a work on physics or physiology we shall note with astonishment how the above considerations are misunderstood4 ,observers of nature who seek1 and rightly1 to give the maximum of exactness to their observations1 show that they are obsessed by one constant prejudice3 they mistrust sensation4 ,a great part of their efforts consists1 by what they say1 in reducing the rle of sensation to its fitting part in science2 and the invention of mechanical aids to observation is constantly held up as a means of remedying the imperfection of our senses4 ,in physics the thermometer replaces the sensation of heat that our skin--our hand1 for example--experiences by the measurable elevation of a column of mercury1 and the scale-pan of a precise balance takes the place of the vague sensation of trifling weights2 in physiology a registering apparatus replaces the sensation of the pulse which the doctor feels with the end of his forefinger by a line on paper traced with indelible ink1 of which the duration and the intensity1 as well as the varied combinations of these two elements1 can be measured line by line4 ,learned men who pride themselves on their philosophical attainments vaunt in very eloquent words the superiority of the physical instrument over mere sensation4 ,evidently1 however1 the earnestness of this eulogy leads them astray4 ,the most perfect registering apparatus must1 in the long-run1 after its most scientific operations1 address itself to our senses and produce in us some small sensation4 ,the reading of the height reached by the column of mercury in a thermometer when heated is accomplished by a visual sensation1 and it is by the sight that the movements of the balance are controlled2 and that the traces of the sphygmograph are analysed4 ,we may readily admit to physicists and physiologists all the advantages of these apparatus4 ,this is not the question4 ,it simply proves that there are sensations and sensations1 and that certain of these are better and more precise than others4 ,the visual sensation of relation in space seems to be par excellence the scientific sensation which it is sought to substitute for all the rest4 ,but1 after all1 it is but a sensation4 ,let us recognise that there is1 in all this contempt on the part of physicists for sensation1 only differences in language1 and that a paraphrase would suffice to correct them without leaving any trace4 ,be it so4 ,but something graver remains4 ,when one is convinced that our knowledge of the outer world is limited to sensations1 we can no longer understand how it is possible to give oneself up1 as physicists do1 to speculations upon the constitution of matter4 ,up to the present there have been three principal ways of explaining the physical phenomena of the universe4 ,the first1 the most abstract1 and the furthest from reality1 is above all verbal4 ,it consists in the use of formulas in which the quality of the phenomena is replaced by their magnitude1 in which this magnitude1 ascertained by the most precise processes of measurement1 becomes the object of abstract reasoning which allows its modifications to be foreseen under given experimental conditions4 ,this is pure mathematics1 a formal science depending upon logic4 ,another conception1 less restricted than the above1 and of fairly recent date1 consists in treating all manifestations of nature as forms of energy4 ,this term energy has a very vague content4 ,at the most it expresses but two things3 first1 it is based on a faint recollection of muscular force1 and it reminds one dimly of the sensation experienced when clenching the fists2 and1 secondly1 it betrays a kind of very natural respect for the forces of nature which1 in all the images man has made of them1 constantly appear superior to his own4 ,we may say the energy of nature2 but we should never say1 what would be experimentally correct2 the weakness of nature4 ,the word weakness we reserve for ourselves4 ,apart from these undecided suggestions1 the term energy is quite the proper term to designate phenomena1 the intimate nature of which we do not seek to penetrate1 but of which we only wish to ascertain the laws and measure the degrees4 ,a third conception1 more imaginative and bolder than the others1 is the mechanical or kinetic theory4 ,this last absolutely desires that we should represent to ourselves1 that we should imagine1 how phenomena really take place2 and in seeking for the property of nature the most clearly perceived1 the easiest to define and analyse1 and the most apt to lend itself to measurement and calculation1 it has chosen motion4 ,consequently all the properties of matter have been reduced to this one1 and in spite of the apparent contradiction of our senses1 it has been supposed that the most varied phenomena are produced1 in the last resort1 by the displacement of material particles4 ,thus1 sound1 light1 heat1 electricity1 and even the nervous influx would be due to vibratory movements1 varying only by their direction and their periods1 and all nature is thus explained as a problem of animated geometry4 ,this last theory1 which has proved very fertile in explanations of the most delicate phenomena of sound and light1 has so strongly impressed many minds that it has led them to declare that the explanation of phenomena by the laws of mechanics alone has the character of a scientific explanation4 ,even recently1 it seemed heresy to combat these ideas4 ,still more recently1 however1 a revulsion of opinion has taken place4 ,against the physicists1 the mathematicians in particular have risen up1 and taking their stand on science1 have demonstrated that all the mechanisms invented have crowds of defects4 ,first1 in each particular case1 there is such a complication that that which is defined is much more simple than the definition2 then there is such a want of unity that quite special mechanisms adapted to each phenomenal detail have to be imagined2 and1 lastly--most serious argument of all--so much comprehensiveness and suppleness is employed1 that no experimental law is found which cannot be understood mechanically1 and no fact of observation which shows an error in the mechanical explanation--a sure proof that this mode of explanation has no meaning4 ,my way of combating the mechanical theory starts from a totally different point of view4 ,psychology has every right to say a few words here1 as upon the value of every kind of scientific theory2 for it is acquainted with the nature of the mental needs of which these theories are the expression and which these theories seek to satisfy4 ,it has not yet been sufficiently noticed that psychology does not allow itself to be confined1 like physics or sociology1 within the logical table of human knowledge1 for it has1 by a unique privilege1 a right of supervision over the other sciences4 ,we shall see that the psychological discussion of mechanics has a wider range than that of the mathematicians4 ,since our cognition cannot go beyond sensation1 shall we first recall what meaning can be given to an explanation of the inmost nature of matter8 ,it can only be an artifice1 a symbol1 or a process convenient for classification in order to combine the very different qualities of things in one unifying synthesis--a process having nearly the same theoretical value as a memoria technica1 which1 by substituting letters for figures1 helps us to retain the latter in our minds4 ,this does not mean that figures are1 in fact1 letters1 but it is a conventional substitution which has a practical advantage4 ,what memoria technica is to the ordinary memory1 the theory of mechanics should be for our needed unification4 ,unfortunately1 this is not so4 ,the excuse we are trying to make for the mechanicians is illusory4 ,there is no mistaking their ambition1 ,notwithstanding the prudence of some and the equivocations in which others have rejoiced1 they have drawn their definition in the absolute and not in the relative4 ,to take their conceptions literally1 they have thought the movement of matter to be something existing outside our eye1 our hands1 and our sense2 in a word1 something noumenal1 as ,kant would have said4 ,the proof that this is their real idea1 is that movement is presented to us as the true outer and explanatory cause of our sensations1 the external excitement to our nerves4 ,the most elementary works on physics are impregnated with this disconcerting conception4 ,if we open a description of acoustics1 we read that sound and noise are subjective states which have no reality outside our auditory apparatus2 that they are sensations produced by an external cause1 which is the vibratory movement of sonorous bodies--whence the conclusion that this vibratory movement is not itself a sensation4 ,or1 shall we take another proof1 still more convincing4 ,this is the vibratory and silent movement which is invoked by physicists to explain the peculiarities of subjective sensation2 so that the interferences1 the pulsations of sound1 and1 in fine1 the whole physiology of the ear1 is treated as a problem in kinematics1 and is explained by the composition of movements4 ,what kind of reality do physicists then allow to the displacements of matter8 ,where do they place them1 since they recognise otherwise that the essence of matter is unknown to us8 ,are we to suppose that1 outside the world of noumena1 outside the world of phenomena and sensations1 there exists a third world1 an intermediary between the two former1 the world of atoms and that of mechanics8 ,a short examination will1 moreover1 suffice to show of what this mechanical model is formed which is presented to us as constituting the essence of matter4 ,this can be nothing else than the sensations1 since we are incapable of perceiving or imagining anything else4 ,it is the sensations of sight1 of touch1 and even of the muscular sense4 ,motion is a fact seen by the eye1 felt by the hand2 it enters into us by the perception we have of the solid masses visible to the naked eye which exist in our field of observation1 of their movements and their equilibrium and the displacement we ourselves effect with our bodies4 ,here is the sensory origin1 very humble and very gross1 of all the mechanics of the atoms4 ,here is the stuff of which our lofty conception is formed4 ,our mind can1 it is true1 by a work of purification1 strip movement of most of its concrete qualities1 separate it even from the perception of the object in motion1 and make of it a something or other ideal and diagrammatic2 but there will still remain a residuum of visual1 tactile1 and muscular sensations1 and consequently it is still nothing else than a subjective state1 bound to the structure of our organs4 ,we are1 for the rest1 so wrapped up in sensations that none of our boldest conceptions can break through the circle4 ,but it is not the notion of movement alone which proceeds from sensation4 ,there is also that of exteriority1 of space1 of position1 and1 by opposition1 that of external or psychological events4 ,without declaring it to be certain1 ,i will remind you that it is infinitely probable that these notions are derived from our muscular experience4 ,free motion1 arrested motion1 the effort1 the speed1 and the direction of motion1 such are the sensorial elements1 which1 in all probability1 constitute the foundation of our ideas on space and its properties4 ,and those are so many subjective notions which we have no right to treat as objects belonging to the outer world4 ,what is more remarkable1 also1 is that even the ideas of object1 of body1 and of matter1 are derived from visual and tactile sensations which have been illegitimately set up as entities4 ,we have come1 in fact1 to consider matter as a being separate from sensations1 superior to our sensations1 distinct from the properties which enable us to know it1 and binding together these properties1 as it were1 in a sheaf4 ,here again is a conception at the base of visualisation and muscularisation2 it consists in referring to the visual and other sensations1 raised for the occasion to the dignity of external and permanent causes1 the other sensations which are considered as the effects of the first named upon our organs of sense4 ,it demands a great effort to clear our minds of these familiar conceptions which1 it is plain are nothing but nave realism4 ,yes6 the mechanical conception of the universe is nothing but nave realism4 ,to recapitulate our idea1 and1 to make it more plain by an illustration1 here is a tuning-fork on the table before me4 ,with a vigorous stroke of the bow ,i set it vibrating4 ,the two prongs separate1 oscillate rapidly1 and a sound of a certain tone is heard4 ,i connect this tuning-fork1 by means of electric wires1 with a ,dprez recording apparatus which records the vibrations on the blackened surface of a revolving cylinder2 and we can thus1 by an examination of the trace made under our eyes1 ascertain all the details of the movement which animates it4 ,we see1 parallel to each other1 two different orders of phenomena2 the visual phenomena which show us that the tuning-fork is vibrating1 and the auditory phenomena which convey to us the fact that it is making a sound4 ,the physicist1 asked for an explanation of all this1 will answer3 ,it is the vibration of the tuning-fork which1 transmitted by the air1 is carried to our auditory apparatus1 causes a vibration in the tympanum1 the movements of which are communicated to the small bones of the middle ear1 thence 7abridging details7 to the terminations of the auditory nerve1 and so produces in us the subjective sensation of sound4 ,well1 in so saying1 the physicist commits an error of interpretation2 outside our ears there exists something we do not know which excites them2 this something cannot be the vibratory movement of the tuning-fork1 for this vibratory movement which we can see is likewise a subjective sensation2 it no more exists outside our sight than sound exists outside our ears4 ,in any case1 it is as absurd to explain a sensation of sound by one of sight1 as a sensation of sight by one of sound4 ,one would be neither further from nor nearer to the truth if we answered that physicist as follows3 ,you give the preponderance to your eye2 ,i myself give it to my ear4 ,this tuning-fork appears to you to vibrate4 ,wrong6 ,this is how the thing occurs4 ,this tuning-fork produces a sound which1 by exciting our retina1 gives us a sense of movement4 ,this visual sensation of vibration is a purely subjective one1 the external cause of the phenomenon is the sound4 ,the outer world is a concert of sounds which rises in the immensity of space4 ,matter is noise and nothingness is silence4 ,this theory of the above experiment is not absurd2 but1 as a matter of fact1 it is probable that no one would or could accept it1 except verbally for amusement1 as a challenge1 or for the pleasure of talking metaphysics4 ,the reason is that all our evolution1 for causes which would take too long to detail1 has established the hegemony of certain of our senses over the others4 ,we have1 above all1 become visual and manual beings4 ,it is the eye and the hand which give us the perceptions of the outer world of which we almost exclusively make use in our sciences2 and we are now almost incapable of representing to ourselves the foundation of phenomena otherwise than by means of these organs4 ,thus all the preceding experiment from the stroke of the bow to the final noise presents itself to us in visual terms1 and further1 these terms are not confined to a series of detached sensations4 ,visual sensation combines with the tactile and muscular sensations1 and forms sensorial constructions which succeed each1 other1 continue1 and arrange themselves logically3 in lieu of sensations1 there are objects and relations of space between these objects1 and the actions which connect them1 and the phenomena which pass from one to the other4 ,all that is only sensation1 if you will2 but merely as the agglutinated molecules of cement and of stone are a palace4 ,thus the whole series of visual events which compose our experiment with the tuning-fork can be coherently explained4 ,one understands that ,it is the movement of my hand equipped with the bow which is communicated to the tuning-fork4 ,one understands that this movement passing into the fork has changed its form and rhythm1 that the waves produced by the fork transmit themselves1 by the oscillations of the air-molecules1 to our tympanum1 and so on4 ,there is in all this series of experiments an admirable continuity which fully satisfies our minds4 ,however much we might be convinced by the theoretical reasons given above1 that we have quite as much right to represent the same series of events in an auditory form1 we should be incapable of realising that form to ourselves4 ,what would be the structure of the ear to any one who only knew it through the sense of hearing8 ,what would become of the tympanum1 the small bones1 the cochlea1 and the terminations of the acoustic nerve1 if it were only permitted to represent them in the language of sound8 ,it is very difficult to imagine4 ,since1 however1 we are theorising1 let us not be stopped by a few difficulties of comprehension4 ,perhaps a little training might enable us to overcome them4 ,perhaps musicians1 who discern as much reality in what one hears as in what one sees1 would be more apt than other folk to understand the necessary transposition4 ,some of them1 in their autobiographies1 have made1 by the way1 very suggestive remarks on the importance they attribute to sound3 and1 moreover1 the musical world1 with its notes1 its intervals1 and its orchestration1 lives and develops in a manner totally independent of vibration4 ,perhaps we can here quote one or two examples which may give us a lead4 ,to measure the length of a body instead of applying to it a yard-wand1 one might listen to its sound2 for the pitch of the sound given by two cords allows us to deduce their difference of length1 and even the absolute length of each4 ,the chemical composition of a body might be noted by its electric resistance and the latter verified by the telephone2 that is to say1 by the ear4 ,or1 to take a more subtle example4 ,we might make calculations with sounds of which we have studied the harmonic relations as we do nowadays with figures4 ,a sum in rule of three might even be solved sonorously2 for1 given three sounds1 the ear can find a fourth which should have the same relation to the third as the second to the first4 ,every musical ear performs this operation easily2 now1 this fourth sound1 what else is it but the fourth term in a rule of three8 ,and by taking into consideration the number of its vibrations a numerical solution would be found to the problem4 ,this novel form of calculating machine might serve to fix the price of woollen stuffs1 to calculate brokerages and percentages1 and the solution would be obtained without the aid of figures1 without calculation1 without visualisation1 and by the ear alone4 ,by following up this idea1 also1 we might go a little further4 ,we might arrive at the conviction that our present science is human1 petty1 and contingent2 that it is closely linked with the structure of our sensory organs2 that this structure results from the evolution which fashioned these organs2 that this evolution has been an accident of history2 that in the future it may be different2 and that1 consequently1 by the side or in the stead of our modern science1 the work of our eyes and hands--and also of our words--there might have been constituted1 there may still be constituted1 sciences entirely and extraordinarily new--auditory1 olfactory1 and gustatory sciences1 and even others derived from other kinds of sensations which we can neither foresee nor conceive because they are not1 for the moment1 differentiated in us4 ,outside the matter we know1 a very special matter fashioned of vision and touch1 there may exist other matter with totally different properties4 ,but let us bring our dream to an end4 ,the interest of our discussion does not lie in the hypothetical substitution of hearing or any other sense for sight4 ,it lies in the complete suppression of all explanation of the noumenal object in terms borrowed from the language of sensation4 ,and that is our last word4 ,we must1 by setting aside the mechanical theory1 free ourselves from a too narrow conception of the constitution of matter4 ,and this liberation will be to us a great advantage which we shall soon reap4 ,we shall avoid the error of believing that mechanics is the only real thing and that all that cannot be explained by mechanics must be incomprehensible4 ,we shall then gain more liberty of mind for understanding what the union of the soul with the body#i may be4 ,,footnotes3 ,footnote #h3 ,i would draw attention to a recent volume by ,,gustave ,,le ,,bon1 on ,evolution de la ,matire1 a work full of original and bold ideas4 ,footnote #i3 ,see ,note #a on p4 #c4--;,,ed4 ,,chapter ,,iv ,,answers ,,to ,,some ,,objections1 ,,and ,,summary ,i have set forth the foregoing ideas by taking the road which to me seemed the best4 ,on reflection it has occurred to me that my manner of exposition and demonstration may be criticised much more than my conclusion4 ,now1 as it is the conclusion alone which here is of importance1 it is expedient not to make it responsible for the arguments by which ,i have supported it4 ,these arguments resolve themselves into the attestation that between objects and our consciousness there exists an intermediary1 our nervous system4 ,we have even established that the existence of this intermediary is directly proved by observation1 and from this ,i have concluded that we do not directly perceive the object itself but a tertium quid1 which is our sensations4 ,several objections to this might be made4 ,let us enumerate them4 #a4 ,it is not inconceivable that objects may act directly on our consciousness without taking the intermediary of our nervous system4 ,some authors1 the spiritualists notably1 believe in the possibility of disembodied souls1 and they admit by implication that these souls remain in communication with the terrestrial world1 witness our actions1 and hear our speech4 ,since they no longer have organs of sense1 we must suppose that these wandering souls1 if they exist1 can directly perceive material objects4 ,it is evident that such hypotheses have1 up till now1 nothing scientific in them1 and that the demonstrations of them which are given raise a feeling of scepticism more than anything else4 ,nevertheless1 we have not the right to exclude1 by a priori argument1 the possibility of this category of phenomena4 #b4 ,several ,german authors have maintained in recent years1 that if the nervous system intervenes in the perception of external objects1 it is a faithful intermediary which should not work any change on those physical actions which it gathers from outside to transmit to our consciousness4 ,from this1 point of view colour would exist as colour1 outside our eyes1 sound would exist as sound1 and in a general way there would not be1 in matter1 any mysterious property left1 since we should perceive matter as it is4 ,this is a very unexpected interpretation1 by which men of science have come to acknowledge the correctness of the common belief3 they rehabilitate an opinion which philosophers have till now turned to ridicule1 under the name of nave realism4 ,all which proves that the navet of some may be the excessive refinement of others4 ,to establish scientifically this opinion they batter down the theory of the specific energy of the nerves4 ,i have recalled in a previous page#aj of what this theory consists4 ,i have shown that if1 by mechanical or electrical means1 our different sensory nerves are excited1 notwithstanding the identity of the excitant1 a different sensation is provoked in each case--light when the optic nerve is stimulated1 sound when the acoustic1 and so on4 ,it is now answered to this argument based on fact that the nature of these excitants must be complex4 ,it is not impossible1 it is thought1 that the electric force contains within itself both luminous and sonorous actions2 it is not impossible that a mechanical excitement should change the electric state of the nerve affected1 and that1 consequently1 these subsidiary effects explain how one and the same agent may1 according to the nerves employed1 produce different effects4 #c4 ,after the spiritualists and the experimentalists1 let us take the metaphysicians4 ,among them one has always met with the most varying specimens of opinions and with arguments for and against all possible theories4 ,thus it is1 for example1 with the external perception4 ,some have supposed it indirect1 others1 on the contrary1 that it acts directly on the object4 ,those who uphold the direct theory are inspired by ,berkeley1 who asserts that the sensitive qualities of the body have no existence but in our own minds1 and consist really in representative ideas4 ,this doctrine is expressly based on this argument--that thought differs too much in nature from matter for one to be able to suppose any link between these two substances4 ,in this particular1 some authors often make an assertion without endeavouring to prove it4 ,they are satisfied with attesting1 or even with supposing1 that mind can have no consciousness of anything but its own states4 ,other philosophers1 as ,i have said1 maintain that things which have a real existence are the very things we perceive4 ,it is ,thomas ,reid who has upheld1 in some passages of his writings at all events1 the theory of instantaneous perception1 or intuition4 ,it has also been defended by ,hamilton in a more explicit manner4#aa ,it has been taken up again in recent years1 by a profound and subtle philosopher1 ,m4 ,bergson1 who1 unable to admit that the nervous system is a substratum of knowledge and serves us as a percipient1 takes it to be solely a motor organ1 and urges that the sensory parts of the system--that is to say1 the centripetal1 optic1 acoustic1 c1 nerves--do not call forth1 when excited1 any kind of sensation1 their sole purpose being to convey disturbances from periphery to periphery1 or1 say1 from external objects to the muscles of the body4 ,this hypothesis1 surely a little difficult to comprehend1 places1 if ,i mistake not1 the mind1 as a power of perception and representation1 within the interval comprised between the external object and the body1 so that the mind is in direct contact with external objects and knows them as they are4 ,it will be noticed that these three interpretations1 the spiritualistic1 the experimental1 and the metaphysical1 are in formal opposition with that which ,i have set forth earlier in these pages4 ,they deny the supposition that the nervous system serves us as an intermediary with nature1 and that it transforms nature before bringing it to our consciousness4 ,and it might seem that by contradicting my fundamental proposition1 those three new hypotheses must lead to a totally different conclusion4 ,now1 this is not so at all4 ,the conclusion ,i have enunciated remains entirely sound1 notwithstanding this change in the starting point1 and for the following reason4 ,it is easy to see that we cannot represent to ourselves the inner structure of matter by using all our sensations without distinction1 because it is impossible to bring all these sensations within one single and identical synthetic construction3 for this they are too dissimilar4 ,thus1 we should try in vain to unite in any kind of scheme a movement of molecules and an odour2 these elements are so heterogeneous that there is no way of joining them together and combining them4 ,the physicists have more or less consciously perceived this1 and1 not being able to overcome by a frontal attack the difficulty created by the heterogeneity of our sensations1 they have turned its flank4 ,the ingenious artifice they have devised consists in retaining only some of these sensations1 and in rejecting the remainder2 the first being considered as really representing the essence of matter1 and the latter as the effects of the former on our organs of sense2 the first being reputed to be true1 we may say1 and the second being reputed false--that is subjective1 that is not representing the ,x of matter4#ab ,i have refuted this argument by showing that all our sensations without exception are subjective and equally false in regard to the ,x of matter1 and that no one of them1 consequently1 has any claim to explain the others4 ,now1 by a new interpretation2 we are taught that all sensations are equally true1 and that all faithfully represent the great ,x4 ,if they be all equally true1 it is absolutely the same as if they were all false2 no one sensation can have any privilege over the others1 none can be truer than the others1 none can be capable of explaining the others1 none can usurp to itself the sole right of representing the essence of matter2 and we thus find ourselves1 in this case1 as in the preceding1 in presence of the insurmountable difficulty of creating a synthesis with heterogeneous elements4 ,all that has been said above is summed up in the following points3-- #a4 ,of the external world1 we only know our sensations4 ,all the physical properties of matter resolve themselves for us into sensations1 present1 past1 or possible4 ,we may not say that it is by the intermediary1 by the means of sensation1 that we know these properties1 for that would mean that the properties are distinct from the sensations4 ,objects are to us in reality only aggregates of sensations4 #b4 ,the sensations belong to the different organs of the senses--sight1 hearing1 touch1 the muscular sense1 c4 ,whatever be the sense affected1 one sensation has the same rights as the others1 from the point of view of the cognition of external objects4 ,it is impossible to distinguish them into subjective and objective1 by giving to this distinction the meaning that certain sensations represent objects as they are1 while certain others simply represent our manner of feeling4 ,this is an illegitimate distinction1 since all sensations have the same physiological condition1 the excitement of a sensory nerve1 and result from the properties of this nerve when stimulated4 #c4 ,consequently1 it is impossible for us to form a conception of matter in terms of movement1 and to explain by the modalities of movement the properties of bodies2 for this theory amounts to giving to certain sensations1 especially those of the muscular sense1 the hegemony over the others4 ,we cannot explain1 we have not the right to explain1 one sensation by another1 and the mechanical theory of matter has simply the value of a symbol4 ,,footnotes3 ,footnote #aj3 ,see p4 #bb1 sup4--,,ed4 ,footnote #aa3 ,see ,j4 ,s4 ,,mill',s ,examination of ,sir ,wm4 ,hamilton's ,philosophy1 chap4 x4 p4 #agf1 et4 seq4 ,footnote #ab3 ,see p4 #ah1 sup4--,,ed4 ,,book ,,ii ,,the ,,definition ,,of ,,mind ,,chapter ,i ,,the ,,distinction ,,between ,,cognition#ac ,,and ,,its ,,object ,after having thus studied matter and reduced it to sensations1 we shall apply the same method of analysis to mind1 and inquire whether mind possesses any characteristic which allows it to be distinguished from matter4 ,before going any further1 let me clear up an ambiguity4 ,all the first part of this work has been devoted to the study of what is known to us in and by sensation2 and ,i have taken upon myself1 without advancing any kind of justifying reason1 to call that which is known to us1 by this method1 by the name of matter1 thus losing sight of the fact that matter only exists by contra-distinction and opposition to mind1 and that if mind did not exist1 neither would matter4 ,i have thus appeared to prejudge the question to be resolved4 ,the whole of this terminology must now be considered as having simply a conventional value1 and must be set aside for the present4 ,these are the precise terms in which this question presents itself to my mind4 ,a part of the knowable consists in sensations4 ,we must1 therefore1 without troubling to style this aggregate of sensations matter rather than mind1 make an analysis of the phenomena known by the name of mind1 and see whether they differ from the preceding ones4 ,let us1 therefore1 make an inventory of mind4 ,by the process of enumeration1 we find quoted as psychological phenomena1 the sensations1 the perceptions1 the ideas1 the recollections1 the reasonings1 the emotions1 the desires1 the imaginations1 and the acts of attention and of will4 ,these appear to be1 at the first glance1 the elements of mind2 but1 on reflection1 one perceives that these elements belong to two distinct categories1 of which it is easy to recognise the duality1 although1 in fact and in reality1 these two elements are constantly combined4 ,the first of these elements may receive the generic name of objects of cognition1 or objects known1 and the second that of acts of cognition4 ,here are a few examples of concrete facts1 which only require a rapid analysis to make their double nature plain4 ,in a sensation which we feel are two things3 a particular state1 or an object which one knows1 and the act of knowing it1 of feeling it1 of taking cognisance of it2 in other words1 every sensation comprises an impression and a cognition4 ,in a recollection there is1 in like manner1 a certain image of the past and the fact consisting in the taking cognisance of this image4 ,it is1 in other terms1 the distinction between the intelligence and the object4 ,similarly1 all reasoning has an object2 there must be matter on which to reason1 whether this matter be supplied by the facts or the ideas4 ,again1 a desire1 a volition1 an act of reflection1 has need of a point of application4 ,one does not will in the air1 one wills something2 one does not reflect in the void1 one reflects over a fact or over some difficulty4 ,we may then provisionally distinguish in an inventory of the mind a something which is perceived1 understood1 desired1 or willed1 and1 beyond that1 the fact of perceiving1 of understanding1 or desiring1 or of willing4 ,to illustrate this distinction by an example1 ,i shall say that an analogous separation can be effected in an act of vision1 by showing that the act of vision1 which is a concrete operation1 comprises two distinct elements3 the object seen and the eye which sees4 ,but this is1 of course1 only a rough comparison1 of which we shall soon see the imperfections when we are further advanced in the study of the question4 ,to this activity which exists and manifests itself in the facts of feeling1 perceiving1 c41 we can give a name in order to identify and recognise it3 we will call it the consciousness#ad 7la conscience71 and we will call object everything which is not the act of consciousness4 ,after this preliminary distinction1 to which we shall often refer1 we will go over the principal manifestations of the mind1 and we will first study the objects of cognition1 reserving for another chapter the study of the acts of cognition--that is to say1 of consciousness4 ,we will thus examine successively sensation1 idea1 emotion1 and will4 ,it has been often maintained that the peculiar property of mind is to perceive sensations4 ,it has also been said that thought--that is1 the property of representing to one's self that which does not exist--distinguishes mind from matter4 ,lastly1 it has not failed to be affirmed that one thing which the mind brings into the material world is its power of emotion2 and moralists1 choosing somewhat arbitrarily among certain emotions1 have said that the mind is the creator of goodness4 ,we will endeavour to analyse these different affirmations4 ,,footnotes3 ,footnote #ac3 ,see ,note #c1 sup4 on p4 #ae4--;,,ed4 ,footnote #ad3 ,the word conscience is one of those which has been used in the greatest number of different meanings4 ,let it be1 at least1 understood that ,i use it here in an intellectual and not a moral sense4 ,i do not attach to the conscience the idea of a moral approbation or disapprobation1 of a duty1 of a remorse4 ,the best example to illustrate conscience has1 perhaps1 been formed by ,,ladd4 ,it is the contrast between a person awake and sleeping a dreamless sleep4 ,the first has consciousness of a number of things2 the latter has consciousness of nothing4 ,let me now add that we distinguish from consciousness that multitude of things of which one has consciousness of4 ,of these we make the object of consciousness4 ,conscience has throughout been rendered consciousness4--,,ed4 ,,chapter ,,ii ,,definition ,,of ,,sensation ,when making the analysis of matter we impliedly admitted two propositions3 first1 that sensation is the tertium quid which is interposed between the excitant of our sensory nerves and ourselves2 secondly1 that the aggregate of our sensations is all we can know of the outer world1 so that it is correct to define this last as the collection of our present1 past1 and possible sensations4 ,it is not claimed that the outer world is nothing else than this1 but it is claimed with good reason that the outer world is nothing else to us4 ,it would be possible to draw from the above considerations a clear definition of sensation1 and especially it would be possible to decide henceforth from the foregoing whether sensation is a physical or a mental phenomenon1 and whether it belongs to matter or to mind4 ,this is the important point1 the one which we now state1 and which we will endeavour to resolve4 ,to make the question clearer1 we will begin it afresh1 as if it were new1 and as if the facts hitherto analysed did not already prejudge the solution4 ,let us begin by giving a definition of sensation from the point of view of experimental psychology4 ,sensation1 then1 is the phenomenon which is produced and which one experiences when an excitant has just acted on one of our organs of sense4 ,this phenomenon is therefore composed of two parts3 an action exercised from outside by some body or other on our nervous substance2 and1 then1 the fact of feeling this action4 ,this fact of feeling1 this state of consciousness1 is necessary to constitute sensation2 when it does not exist1 it is preferable to give the phenomenon another name1 otherwise the fault is committed of mixing up separate facts4 ,physiologists have1 on this point1 some faults of terminology with which to reproach themselves3 for they have employed the word sensibility with too little of the critical spirit4 ,sensibility1 being capacity for sensation1 presupposes1 like sensation itself1 consciousness4 ,it has1 therefore1 been wrong1 in physiology1 to speak of the sensibility of the tissues and organs1 which1 like the vegetable tissues or the animal organs of vegetative life1 properly speaking1 feel nothing1 but react by rapid or slow movements to the excitements they are made to receive4 ,reaction1 by a movement or any kind of modification1 to an excitement1 does not constitute a sensation unless consciousness is joined with it1 and1 consequently1 it would be wiser to give unfelt excitements and reactions the name of excitability4 ,the clearest examples of sensation are furnished by the study of man1 and are taken from cases where we perceive an external object4 ,the object produces upon us an action1 and this action is felt2 only1 in such cases1 the fact of sensation comprises but a very small part of the event4 ,it only corresponds1 by definition1 to the actual action of the object4 ,analysis after analysis has shown that we constantly perceive far beyond this actual action of objects4 ,our mind1 as we say1 outruns our senses4 ,to our sensations1 images come to attach themselves which result from sensations anteriorly felt in analogous circumstances4 ,these images produce in us an illusion1 and we take them for sensations1 so that we think we perceive something which is but a remembrance or an idea2 the reason being that our mind cannot remain in action in the presence of a sensation1 but unceasingly labours to throw light upon it1 to sound it1 and to arrive at its meaning1 and consequently alters it by adding to it4 ,this addition is so constant1 so unavoidable1 that the existence of an isolated sensation which should be perceived without the attachment of images1 without modification or interpretation1 is well-nigh unrealisable in the consciousness of an adult4 ,it is a myth4 ,let us1 however1 imagine this isolation to be possible1 and that we have before us a sensation free from any other element4 ,what is this sensation8 ,does it belong to the domain of physical or of moral things8 ,is it a state of matter or of mind8 ,i can neither doubt nor dispute that sensation is1 in part1 a psychological phenomenon1 since ,i have admitted1 by the very definition ,i have given of it1 that sensation implies consciousness4 ,we must1 therefore1 acknowledge those who define it as a state of consciousness to be right1 but it would be more correct to call it the consciousness of a state1 and it is with regard to the nature of this state that the question presents itself4 ,it is only this state which we will now take into consideration4 ,it is understood that sensation contains both an impression and a cognition4 ,let us leave till later the study of the act of cognition1 and deal with the impression4 ,is this impression now of a physical or a mental nature8 ,both the two opposing opinions have been upheld4 ,in this there is nothing astonishing1 for in metaphysics one finds the expression of every possible opinion4 ,but a large1 an immense majority of philosophers has declared in favour of the psychological nature of the impression4 ,without even making the above distinction between the impression and the act of cognition1 it has been admitted that the entire sensation1 taken en bloc1 is a psychological phenomenon1 a modification of our consciousness and a peculiar state of our minds4 ,descartes has even employed this very explicit formula3 ,the objects we perceive are within our understanding4 ,it is curious to see how little trouble authors take to demonstrate this opinion2 they declare it to be self-evident1 which is a convenient way of avoiding all proof4 ,john ,stuart ,mill has no hesitation in affirming that3 ,the mind1 in perceiving external objects1 can only take notice of its own conditions4 ,and ,renouvier expresses the same arbitrary assertion with greater obscurity when he writes3 ,the monad is constituted by this relation3 the connection of the subject with the object within the subject4#ae ,in other words1 it is laid down as an uncontrovertible principle that the mental can only enter into direct relations with the mental4 ,that is what may be called the principle of ,idealism4 ,this principle seems to me very disputable1 and it is to me an astonishing thing that the most resolute of sceptics--,hume1 for example--should have accepted it without hesitation4 ,i shall first enunciate my personal opinion1 then make known another which only differs from mine by a difference of words1 and finally ,i will discuss a third opinion1 which seems to me radically wrong4 ,my personal opinion is that sensation is of a mixed nature4 ,it is psychical in so far as it implies an act of consciousness1 and physical otherwise4 ,the impression on which the act of cognition operates1 that impression which is directly produced by the excitant of the nervous system1 seems to me1 without any doubt1 to be of an entirely physical nature4 ,this opinion1 which ,i make mine own1 has only been upheld by very few philosophers--,thomas ,reid perhaps1 and ,william ,hamilton for certain2 but neither has perceived its deep-lying consequences4 ,what are the arguments on which ,i rely8 ,they are of different orders1 and are arguments of fact and arguments of logic4 ,i shall first appeal to the natural conviction of those who have never ventured into metaphysics4 ,so long as no endeavour has been made to demonstrate the contrary to them1 they believe1 with a natural and nave belief1 that matter is that which is seen1 touched and felt1 and that1 consequently1 matter and our senses are confounded4 ,they would be greatly astonished to be informed that when we appear to perceive the outer world1 we simply perceive our ideas2 that when we take the train for ,lyons we enter into one state of consciousness in order to attain another state of consciousness4 ,now1 the adherents of this natural and nave opinion have1 as they say in the law1 the right of possession 7possession d'tat72 they are not plaintiffs but defendants2 it is not for them to prove they are in the right1 it has to be proved against them that they are in the wrong4 ,until this proof is forthcoming they have a presumption in their favour4 ,are we here making use of the argument of common opinion of mankind1 of which ancient philosophy made so evident an abuse8 ,yes1 and no4 ,yes1 for we here adopt the general opinion4 ,no1 for we only adopt it till the contrary be proved4 ,but who can exhibit this proof to the contrary8 ,on a close examination of the question1 it will be perceived that sensation1 taken as an object of cognition1 becomes confused with the properties of physical nature1 and is identified with them1 both by its mode of apparition and by its content4 ,by its mode of apparition1 sensation holds itself out as independent of us1 for it is at every instant an unexpected revelation1 a source of fresh cognitions1 and it offers a development which takes place without and in spite of our will2 while its laws of co-existence and of succession declare to us the order and march of the material universe4 ,besides1 by its content1 sensation is confounded with matter4 ,when a philosopher seeks to represent to himself the properties of a material object1--of a brain1 for example--in order to contrast them with the properties of a psychical activity1 it is the properties of sensation that he describes as material2 and1 in fact1 it is by sensation1 and sensation alone1 that we know these properties4 ,sensation is so little distinct from them that it is an error to consider it as a means1 a process1 an instrument for the knowledge of matter4 ,all that we know of matter is not known in or by sensation1 but constitutes sensation itself2 it is not by the aid of sensation that we know colour2 colour is a sensation1 and the same may be said of form1 resistance1 and the whole series of the properties of matter4 ,they are only our sensations clothed with external bodies4 ,it is therefore absolutely legitimate to consider a part of our sensations1 the object part1 as being of physical nature4 ,this is the opinion to which ,i adhere4 ,we come to the second opinion we have formulated4 ,it is1 in appearance at least1 very different from the first4 ,its supporters agree that the entire sensation1 taken en bloc and unanalysed1 is to be termed a psychological phenomenon4 ,in this case1 the act of consciousness1 included in the sensation1 continues to represent a psychical element4 ,they suppose1 besides1 that the object on which this act operates is psychical2 and finally1 they suppose that this object or this impression was provoked in us by a physical reality which is kept in concealment1 which we do not perceive1 and which remains unknowable4 ,this opinion is nowise absurd in itself3 but let us examine its consequences4 ,if we admit this thesis1 that sensations are manifestations of mind which1 although provoked by material causes1 are of a purely mental nature1 we are forced to the conclusion that we know none of the properties of material bodies1 since we do not enter into relations with these bodies4 ,the object we apprehend by perception is1 according to this hypothesis1 solely mental4 ,to draw therefrom any notion on material objects1 it would have to be supposed that1 by some mysterious action1 the mental which we know resembles the physical which we do not know1 that it retains the reflection of it1 or even that it allows its colour and form to pass1 like a transparent pellicle applied on the contour of bodies4 ,here are hypotheses very odd in their realism4 ,unless we accept them1 how is it comprehensible that we can know anything whatever of physical nature8 ,we should be forced to acknowledge1 following the example of several philosophers1 that the perception of the physical is an illusion4 ,as a compensation1 that which this system takes from matter it attributes to mind1 which turns our familiar conceptions upside down4 ,the qualities of sensation detached from matter will1 when applied to mind1 change its physiognomy4 ,there are sensations of extent1 weight1 space1 and form4 ,if these sensations are turned into psychical events1 we shall have to grant to these events1 to these manifestations of the mind1 the properties of extent1 of weight1 of form4 ,we shall have to say that mind is a resisting thing1 and that it has colour4 ,it may be said that this fantasy of language is not very serious4 ,so be it4 ,but then what remains of the dualism of mind and matter8 ,it is at least singularly compromised4 ,we may continue to suppose that matter exists1 and even that it is matter which provokes in our mind those events which we call our sensations2 but we cannot know if by its nature1 its essence1 this matter differs from that of mind1 since we shall be ignorant of all its properties4 ,our ignorance on this point will be so complete that we shall not even be able to know whether any state which we call mental may not be physical4 ,the distinction between physical and mental will have lost its raison d'tre1 since the existence of the physical is necessary to give a meaning to the existence of the mental4 ,we are brought1 whether we like it or not1 to an experimental monism1 which is neither psychical nor physical2 panpsychism and panmaterialism will have the same meaning4#af ,but this monism can be only transitory1 for it is more in the words than in the thing itself4 ,it is brought about by the terminology adopted1 by the resolution to call mental all the phenomena that it is possible to know4 ,luckily1 our speculations are not at the mercy of such trifling details as the details of language4 ,whatever names may be given to this or that1 it will remain none the less true that nature will continue to present to us a contrast between phenomena which are flints1 pieces of iron1 clods of earth1 brains--and some other phenomena which we call states of consciousness4 ,whatever be the value of this dualism1 it will have to be discussed even in the hypothesis of panpsychism4#ag ,as for myself1 ,i shall also continue to make a distinction between what ,i have called objects of cognition and acts of cognition1 because this is the most general distinction that can be traced in the immense field of our cognitions4 ,there is no other which succeeds1 to the same degree1 in dividing this field into two1 moreover1 this distinction is derived directly from observation1 and does not depend for its validity on the physical or mental nature of the objects4 ,here is1 then1 a duality1 and this duality1 even when it does not bear the names physical and moral1 should necessarily play the same part1 since it corresponds to the same distinction of fact4 ,in the end1 nothing will be changed1 and this second opinion must gradually merge into the one first stated by me1 and of which ,i take the responsibility4 ,we may1 therefore1 put it out of consideration4 ,i have mentioned a third opinion1 stating that it appeared to me to be radically false4 ,outwardly it is the same as the last2 looked at superficially it seems even confused with it2 but1 in reality it is of a totally different nature4 ,it supposes that sensation is an entirely psychological phenomenon4 ,then1 having laid down this thesis1 it undertakes to demonstrate it by asserting that sensation differs from the physical fact1 which amounts to supposing that we cannot know anything but sensations1 and that physical facts are known to us directly and by another channel4 ,this is where the contradiction comes in4 ,it is so apparent that one wonders how it has been overlooked by so many excellent minds4 ,in order to remove it1 it will be sufficient to recollect that we do not know anything other than sensations2 it is therefore impossible to make any distinction between the physical object and the object of cognition contained in every sensation4 ,the line of demarcation between the physical and the moral cannot pass this way1 since it would separate facts which are identical4 ,we can1 therefore1 only deplore the error of all those who1 to express the difference between mind and matter1 have sought a contrast between sensation and physical facts4 ,physiologists1 with hardly an exception1 have fallen into this error2 when contemplating in imagination the material working of the brain1 they have thought that between the movement of cerebral matter and sensation there was a gulf fixed4 ,the comparison1 to have been correct1 required to be presented in quite another way4 ,a parallel1 for instance1 should have been drawn between a certain cerebral movement and the act of consciousness1 and there should have been said3 ,the cerebral motion is the physical phenomenon1 the act of consciousness the psychical4 ,but this distinction has not been made4 ,it is sensation en bloc which is compared to the cerebral movement1 as witness a few passages ,i will quote as a matter of curiosity1 which are borrowed from philosophers and1 especially1 from physiologists4 ,while philosophers take as a principle of idealism1 that the mental can only know the mental1 physiologists take1 as a like principle1 the heterogeneity existing1 or supposed to exist1 between the nerve impression and the sensation4 ,however much we may follow the excitement through the whole length of the nerve1 writes ,lotze1#ah or cause it to change its form a thousand times and to metamorphose itself into more and more delicate and subtle movements1 we shall never succeed in showing that a movement thus produced can1 by its very nature1 cease to exist as movement and be reborn in the shape of sensation4444 ,it will be seen that it is on the opposition between molecular movement and sensation1 that ,lotze insists4 ,in like manner ,ferrier3 ,but how is it that the molecular modifications in the cerebral cells coincide with the modifications of the consciousness2 how1 for instance1 do luminous vibrations falling upon the retina excite the modification of consciousness called visual sensation8 ,these are problems we cannot solve4 ,we may succeed in determining the exact nature of the molecular changes which take place in the cerebral cells when a sensation is felt1 but this will not bring us an inch nearer to the explanation of the fundamental nature of sensation4 ,finally1 ,du ,bois ,reymond1 in his famous discussion in #ahhj1 on the seven enigmas of the world1 speaks somewhat as follows3 ,the astronomical knowledge of the encephalon1 that is1 the most intimate to which we can aspire1 only reveals to us matter in motion4 ,but no arrangement nor motion of material particles can act as a bridge by which we can cross over into the domain of intelligence4444 ,what imaginable link is there between certain movements of certain molecules in my brain1 on the one hand1 and on the other hand primitive1 undefinable1 undeniable facts such as3 ,i have the sensation of softness1 ,i smell the odour of a rose1 ,i hear the sound of an organ1 ,i see a red colour1 c4444 ,these three quotations show very conclusively that their authors thought they could establish the heterogeneity of the two phenomena by opposing matter to sensation4 ,it must be recognised that they have fallen into a singular error2 for matter1 whatever it may be1 is for us nothing but sensation2 matter in motion1 ,i have often repeated1 is only a quite special kind of sensation2 the organic matter of the brain1 with its whirling movements of atoms1 is only sensation4 ,consequently1 to oppose the molecular changes in the brain to the sensation of red1 blue1 green1 or to an undefined sensation of any sort1 is not crossing a gulf1 and bringing together things which cannot be compared1 it is simply comparing one sensation to another sensation4 ,there is evidently something equivocal in all this2 and ,i pointed this out when outlining and discussing the different theories of matter4 ,it consists in taking from among the whole body of sensations certain of them which are considered to be special1 and which are then invested with the privilege of being more important than the rest and the causes of all the others4 ,this is about as illegitimate as to choose among men a few individuals to whom is attributed the privilege of commanding others by divine right4 ,these privileged sensations which belong to the sight1 the touch1 and the muscular sense1 and which are of large extent1 are indeed extensive4 ,they have been unduly considered as objective and as representing matter because they are better known and measurable1 while the other sensations1 the unextensive sensations of the other senses1 are considered as subjective for the reasons that they are less known and less measurable3 and they are therefore looked on as connected with our sensibility1 our ,ego1 and are used to form the moral world4 ,we cannot subscribe to this way of establishing the contrast between matter and thought1 since it is simply a contrast between two categories of sensations1 and ,i have already asserted that the partitioning-out of sensations into two groups having different objective values1 is arbitrary4 ,,footnotes3 ,footnote #ae3 ,,ch4 ,,renouvier et ,l4 ,,prat1 ,la ,nouvelle ,monadologie1 p4 #adh4 ,footnote #af3 ,an ,american author1 ,,morton ,,prince1 lately remarked this3 ,philosophical ,review1 ,july #aijd1 p4 #dej4 ,footnote #ag3 ,this ,,flournoy recently has shown very wittily4 ,see in ,arch4 de ,psychol41 ,nov4 #aijd1 his article on ,panpsychism4 ,footnote #ah3 ,this extract1 together with the two subsequent1 are borrowed from an excellent lecture by ,,flournoy1 on ,mtaphysique et ,physiologie4 ,georg3 ,geneva1 #ahij4 ,,chapter ,,iii ,,definition ,,of ,,the ,,image ,going on with our inventory1 after sensations come images1 ideas1 and concepts2 in fact1 quite a collection of phenomena1 which1 are generally considered as essentially psychological4 ,so long as one does not carefully analyse the value of ideas1 one remains under the impression that ideas form a world apart1 which is sharply distinguished from the physical world1 and behaves towards it as an antithesis4 ,for is not conception the contrary of perception8 and is not the ideal in opposition to reality8 ,thoughts have some characteristics of fancy1 of freedom1 even of unreality1 which are wanting to the prosaicness of heavy material things4 ,thoughts sport with the relations of time and space2 they fly in a moment across the gulf between the most distant objects2 they travel back up the course of time2 they bring near to us events centuries away2 they conceive objects which are unreal2 they imagine combinations which upset all physical laws1 and1 further1 these conceptions remain invisible to others as well as to ourselves4 ,they are outside the grip of reality1 and constitute a world which becomes1 for any one with the smallest imagination1 as great and as important as the world called real4 ,one may call in evidence the poets1 novelists1 artists1 and the dreamers of all kinds4 ,when life becomes too hard for us1 we fly to the ideal world1 there to seek forgetfulness or compensation4 ,it is1 therefore1 easy to understand1 that it should have been proposed to carry into ideation the dichotomy between the physical and the moral4 ,many excellent authors have made the domain of the mind begin in the ideal4 ,matter is that which does not think4 ,descartes1 in his ,discours de la ,mthode 7#dth part71 remarking that he may pretend not to have a body1 and that there is no world or place in which he exists1 but that he cannot pretend that he does not think1 concludes by saying that the mind is a substance1 all whose essence or nature is merely to think1 and which has no need of either place or any other material thing1 in order to exist2 in short1 that the soul is absolutely distinct from the body4#ai ,let us1 then1 examine in what measure this separation between perception and ideation can be legitimately established4 ,if we accept this separation1 we must abandon the distinction ,i proposed between acts and objects of cognition1 or1 at least1 admit that this distinction does not correspond to that between the physical and the moral1 since thoughts1 images1 recollections1 and even the most abstract conceptions1 all constitute1 in a certain sense1 objects of cognition4 ,they are phenomena which1 when analysed1 are clearly composed of two parts1 an object and a cognition4 ,their logical composition is1 indeed1 that of an external perception1 and there is in ideation exactly the same duality as in sensation4 ,consequently1 if we maintain the above distinction as a principle of classification for all knowable phenomena1 we shall be obliged to assign the same position to ideas as to sensations4 ,the principal difference we notice between sensation and idea is1 it would seem1 the character of unreality in the last named2 but this opposition has not the significance we imagine4 ,our mental vision only assumes this wholly special character of unreality under conditions in which it is unable to harmonise with the real vision4 ,taine has well described the phases of the reduction of the image by sensation3 it is at the moment when it receives the shock of an image which contradicts it1 that the image appears as illusory4#bj ,let us suppose that we are sitting down dreaming and watching the passing by of our images4 ,if1 at this moment1 a sudden noise calls us back to reality1 the whole of our mental phantasmagoria disappears as if by the wave of a magic wand1 and it is by thus vanishing that the image shows its falsity4 ,it is false because it does not accord with the present reality4 ,but1 when we do not notice a disagreement between these two modes of cognition1 both alike give us the impression of reality4 ,if ,i evoke a reminiscence and dwell attentively on the details1 ,i have the impression that ,i am in face of the reality itself4 ,i feel as if ,i were there still1 is a common saying2 and1 among the recollections ,i evoke1 there are some which give me the same certitude as the perception of the moment4 ,certain witnesses would write their depositions with their blood4 ,one does not see this every day2 but still one does see it4 ,further1 there are thousands of circumstances where the ideation is neither in conflict with the perception nor isolated from it1 but in logical continuity with it4 ,this continuity must even be considered as the normal condition4 ,we think in the direction of that which we perceive4 ,the image seems to prepare the adaptation of the individual to his surroundings2 it creates the foresight1 the preparation of the means1 and1 in a word1 everything which constitutes for us a final cause4 ,now1 it is very necessary that the image appear real to be usefully the substitute of the sensation past or to come4 ,let us establish one thing more4 ,acting as a substitute1 the image not only appears as real as the sensation1 it appears to be of the same nature2 and the proof is that they are confounded one with the other1 and that those who are not warned of the fact take one for the other4 ,every time a body is perceived1 as ,i previously explained1 there are images which affix themselves to the sensation unnoticed4 ,we think we perceive when we are really remembering or imagining4 ,this addition of the image to the sensation is not a petty and insignificant accessory2 it forms the major part1 perhaps nine-tenths1 of perception4 ,hence arise the illusions of the senses1 which are the result1 not of sensations but of ideas4 ,from this also comes the difficulty of knowing exactly what1 under certain circumstances1 is observation or perception1 where the fact perceived ends1 and where conjecture begins4 ,once acquainted with all these possibilities of errors1 how can we suppose a radical separation between the sensation and the image8 ,examined more closely1 images appear to us to be divisible into as many kinds as sensations3 visual images correspond to visual sensations1 tactile to tactile1 and so on with all the senses4 ,that which we experience in the form of sensation1 we can experience over again in the form of image1 and the repetition1 generally weaker in intensity and poorer in details1 may1 under certain favourable circumstances1 acquire an exceptional intensity1 and even equal reality3 as is shown by hallucinations4 ,here1 certainly1 are very sound reasons for acknowledging that the images which are at the bottom of our thoughts1 and form the object of them1 are the repetition1 the modification1 the transposition1 the analysis or the synthesis of sensations experienced in the past1 and possessing1 in consequence1 all the characteristics of bodily states4 ,i believe that there is neither more nor less spirituality in the idea than in the sensation4 ,that which forms its spirituality is the implied act of cognition2 but its object is material4 ,i foresee a final objection3 ,i shall be told that even when the unreality of the image is not the rule1 and appears only under certain circumstances1 it nevertheless exists4 ,this is an important fact4 ,it has been argued from the unreality of dreams and hallucinations in which we give a body to our ideas1 that we do not in reality perceive external bodies1 but simply psychical states and modifications of our souls4 ,if our ideas consist--according to the hypothesis ,i uphold--in physical impressions which are felt1 we shall be told that these particular impressions must participate in the nature of everything physical2 that they are real1 and always real2 that they cannot be unreal1 fictitious1 and mendacious1 and that1 consequently1 the fictitious character of ideation becomes inexplicable4 ,two words of answer are necessary to this curious argument1 which is nothing less than an effort to define the mental by the unreal1 and to suppose that an appearance cannot be physical4 ,no doubt1 we say1 every image1 fantastical as it may seem as signification1 is real in a certain sense1 since it is the perception of a physical impression2 but this physical nature of images does not prevent our making a distinction between true and false images4 ,to take an analogous example3 we are given a sheet of proofs to correct1 we delete certain redundant letters1 and1 although they are printed with the same type as the other letters1 we have the right to say they are false4 ,again1 in a musical air1 we may hear a false note1 though it is as real as the others1 since it has been played4 ,this distinction between reality and truth ought to be likewise applied to mental images4 ,all are real1 but some are false4 ,they are false when they do not accord with the whole reality2 they are true when they agree2 and every image is partly false because1 being an image1 it does not wholly accord with the actual perceptions4 ,it creates a belief in a perception which does not occur2 and by developing these ideas we could easily demonstrate how many degrees of falsehood there are4 ,physiologically1 we may very easily reconcile the falsity of the image with the physical character of the impression on which it is based4 ,the image results from a partial cerebral excitement1 which sensation results from an excitement which also acts upon the peripheral sensory nerves1 and corresponds to an external object--an excitant which the image does not possess4 ,this difference explains how it is that the image1 while resulting from a physical impression1 may yet be in a great number of cases declared false--that is to say1 may be recognised as in contradiction to the perceptions4 ,to other minds1 perhaps1 metaphysical reasoning will be more satisfactory4 ,for those1 we propose to make a distinction between two notions1 ,existence or ,reality1 on the one hand1 and ,truth1 on the other4 ,existence or ,reality is that of which we have an immediate apprehension4 ,this apprehension occurs in several ways4 ,in perception1 in the first place4 ,i perceive the reality of my body1 of a table1 the sky1 the earth1 in proportion to my perception of them4 ,they exist1 for if they did not1 ,i could not perceive them4 ,another way of understanding reality is conception or thought4 ,however much ,i may represent a thing to myself as imaginary1 it nevertheless exists in a certain manner1 since ,i can represent it to myself4 ,i therefore1 in this case1 say that it is real or it exists4 ,it is of course understood1 that in these definitions ,i am going against the ordinary acceptation of the terms2 ,i am taking the liberty of proposing new meanings4 ,this reality is1 then1 perceived in one case and conceived in the other4 ,perceptibility or conceivability are1 then1 the two forms which reality may assume4 ,but reality is not synonymous with truth2 notwithstanding the custom to the contrary1 we may well introduce a difference between these two terms4 ,reality is that which is perceived or conceived2 truth is that which accords with the whole of our knowledge4 ,reality is a function of the senses or of ideation2 truth is a function of reasoning or of the reason4 ,for cognition to be complete1 it requires the aid of all these functions4 ,and1 in fact1 what does conception by itself give8 ,it allows us to see if a thing is capable of representation4 ,this is not a common-place thing1 ,i will observe in passing2 for many things we name are not capable of representation1 and there is often a criticism to be made2 we think we are representing1 and we are not4 ,what is capable of representation exists as a representation1 but is it true8 ,some philosophers have imagined so1 but they are mistaken2 what we succeed in conceiving is alone possible4 ,let us now take the ,perceptible4 ,is what one perceives true8 ,yes1 in most cases it is so in fact2 but an isolated perception may be false1 and disturbed by illusions of all kinds4 ,it is all very well to say1 ,i see1 ,i touch4 ,there is no certainty through the senses alone in many circumstances that the truth has been grasped4 ,if ,i am shown the spirit of a person ,i know to be dead1 ,i shall not1 notwithstanding the testimony of my eyes1 believe it to be true1 for this apparition would upset all my system of cognitions4 ,truth is that which1 being deemed conceivable1 and being really perceived1 has also the quality of finding its place1 its relation1 and its confirmation in the whole mass of cognitions previously acquired4 ,these distinctions1#ba if developed1 would readily demonstrate that the advantages of observation are not eclipsed by those of speculation2 and that those of speculation1 in their turn1 do not interfere with those of observation4 ,but we have not time to develop these rules of logic2 it will be sufficient to point out their relation to the question of the reality of mental images4 ,here are my conclusions in two words4 ,physical phenomena and images are always real1 since they are perceived or conceived2 what is sometimes wanting to them1 and makes them false1 is that they do not accord with the rest of our cognitions4#bb ,thus1 then1 are all objections overruled1 in my opinion at least4 ,we can now consider the world of ideas as a physical world2 but it is one of a peculiar nature1 which is not1 like the other1 accessible to all1 and is subject to its own laws1 which are laws of association4 ,by these very different characteristics1 it separates itself so sharply from the outer world that all endeavour to bring the two together seems shocking2 and it is very easy to understand that many minds should wish to remain faithful to the conception that ideas form a mental or moral world4 ,no metaphysical reasoning could prevail against this sentiment1 and we must give up the idea of destroying it4 ,but we think we have shown that idea1 like sensation1 comprises at the same time the physical and the mental4 ,,footnotes3 ,footnote #ai3 ,let me say1 in passing1 that this separation that ,,descartes thinks he can establish between perception and ideation1 is only conceivable on condition that it be not too closely examined1 and that no exact definition of ideation be given4 ,if we remark1 in fact1 that all thought is a reproduction1 in some degree1 of a sensation1 we arrive at this conclusion3 that a thought operated by a soul distinct from the body would be a thought completely void and without object1 it would be the thought of nothingness4 ,it is not1 therefore1 conceivable4 ,consequently the criterion1 already so dangerous1 which ,,descartes constantly employs--to wit3 that what we clearly conceive is true--cannot apply to thought1 if we take the trouble to analyse it and to replace a purely verbal conception by intuition4 ,footnote #bj3 ,i somewhat regret that ,,taine fell into the common-place idea of the opposition of the brain and thought2 he took up again this old idea without endeavouring to analyse it1 and only made it his own by the ornamentation of his style4 ,and as his was a mind of powerful systematisation1 the error which he committed led him into much wider consequences than the error of a more common mind would have done4 ,footnote #ba3 ,i have just come across them again in an ingenious note of ,c4 ,l4 ,,herrick3 ,the ,logical and ,psychological ,distinction between the ,true and the ,real 7,psych4 ,rev41 ,may #aijd74 ,i entirely agree with this author4 ,but it is not he who exercised a suggestion over my mind2 it was ,m4 ,,bergson4 ,see ,matire et ,mmoire1 p4 #aei4 ,footnote #bb3 ,in order to remain brief1 ,i have not thought fit to allude in the text to a question of metaphysics which closely depends on the one broached by me3 the existence of an outer world4 ,philosophers who define sensation as a modality of our ,ego are much embarrassed later in demonstrating the existence of an outer world4 ,having first admitted that our perception of it is illusory1 since1 when we think we perceive this world1 we have simply the feeling of the modalities of our ,ego1 they find themselves powerless to demonstrate that this illusion corresponds to a truth1 and invoke in despair1 for the purpose of their demonstration1 instinct1 hallucination1 or some a priori law of the mind4 ,the position we have taken in the discussion is far more simple4 ,since every sensation is a fragment of matter perceived by a mind1 the aggregate of sensations constitutes the aggregate of matter4 ,there is in this no deceptive appearance1 and consequently no need to prove a reality distinct from appearances4 ,as to the argument drawn from dreams and hallucinations which might be brought against this1 ,i have shown how it is set aside by a distinction between perceptibility and truth4 ,it is no longer a matter of perception1 but of reasoning4 ,in other words1 all that we see1 even in dreams1 is real1 but is not in its due place4 ,,chapter ,,iv ,,definition ,,of ,,the ,,emotions ,after sensations and images1 we have to name among the phenomena of consciousness1 the whole series of affective states--our pleasures and our pains1 our joys and our griefs1 our sentiments1 our emotions1 and our passions4 ,it is universally admitted that these states are of a mental nature1 for several reasons4 7#a7 ,we never objectivate them as we do our sensations1 but we constantly consider them as indwelling or subjective states4 ,this rule1 however1 allows an exception for the pleasure and the pain termed physical1 which are often localised in particular parts of our bodies1 although the position attributed to them is less precise than with indifferent sensations4 7#b7 ,we do not alienate them as we do our indifferent sensations4 ,the sensations of weight1 of colour1 and of form serve us for the construction of bodies which appear to us as perceived by us1 but as being other than ourselves4 ,on the contrary1 we constantly and without hesitation refer our emotional states to our ,ego4 ,it is ,i who suffer1 we say1 ,i who complain1 ,i who hope4 ,it is true that this attribution is not absolutely characteristic of mental phenomena1 for it happens that we put a part of our ,ego into material objects1 such as our bodies1 and even into objects separate from our bodies1 and whose sole relation to us is that of a legal proprietorship4 ,we must guard against the somewhat frequent error of identifying the ,ego with the psychical4 ,these two reasons sufficiently explain the tendency to see only psychological states in the emotional ones2 and1 in fact1 those authors who have sought to oppose mind to matter have not failed to introduce emotion into their parallel as representing the essence of mind4 ,on this point ,i will recall the fine ironical image used by ,tyndall1 the illustrious ,english physicist1 to show the abyss which separates thought from the molecular states of the brain4 ,let us suppose1 he says1 that the sentiment love1 for example1 corresponds to a right-hand spiral movement of the molecules of the brain and the sentiment hatred to a left-hand spiral movement4 ,we should then know that when we love1 a movement is produced in one direction1 and when we hate1 in another4 ,but the ,why would remain without an answer4 ,the question of knowing what place in our metaphysical theory we ought to secure for emotion seems difficult to resolve1 and we even find some pleasure in leaving it in suspense1 in order that it may be understood that a metaphysician is not compelled to explain everything4 ,besides1 the difficulties which atop us here are peculiarly of a psychological order4 ,they proceed from the fact that studies on the nature of the emotions are still very little advanced4 ,the physical conditions of these states are pretty well known1 and their psychical and social effects have been abundantly described2 but very little is known as to what distinguishes an emotion from a thought4 ,two principal opinions may be upheld in the actual state of our acquaintance with the psychology of the feelings4 ,when we endeavour to penetrate their essential and final nature1 we have a choice between two contrary theories4 ,the first and traditional one consists in seeing in emotion a phenomenon sui generis2 this is very simple1 and leaves nothing more to be said4 ,the second bears the name of the intellectualist theory4 ,it consists in expunging the characteristic of the affective states4 ,we consider them as derivative forms of particular modes of cognition1 and they are only confused intelligence4 ,this intellectualist thesis is of early date2 it will be found in ,herbart1 who1 by-the-by1 gave it a peculiar form1 by causing the play of images to intervene in the formation of the feelings4 ,however1 this particular point is of slight ,importance4 ,the intellectualist theory is more vast than ,herbartism2 it exists in all doctrines in which the characteristic difference between thought and feeling is expunged and feeling is brought back to thought4 ,one of the clearest means of so doing consists in only seeing in the feeling the fact of perceiving something4 ,to perceive is1 in fact1 the property of intelligence2 to reason1 to imagine1 to judge1 to understand1 is always1 in a certain sense1 to perceive4 ,it has been imagined that emotion is nothing else than a perception of a certain kind1 an intellectual act strictly comparable to the contemplation of a landscape4 ,only1 in the place of a landscape with placid features you must put a storm1 a cataclysm of nature2 and1 instead of supposing this storm outside us1 let it burst within us1 let it reach us1 not by the outer senses of sight and condition1 but by the inner senses4 ,what we then perceive will be an emotion4 ,such is the theory that two authors--,w4 ,james and ,lange--happened to discover almost at the same time1 ,lange treating it as a physiologist and ,w4 ,james as a philosopher4 ,their theory1 at first sight1 appears singular1 like everything which runs counter to our mental habits4 ,it lays down that the symptoms which we all till now have considered as the physiological consequence1 the translation1 and the distant effects of the emotions1 constitute their essential base4 ,these effects are3 the expression of the physiognomy1 the gesture1 the cry1 and the speech2 or the reflex action on the circulation1 the pallor or blushing1 the heat mounting to the head1 or the cold of the shiver which passes over the body4 ,or it is the heart1 which hastens or slackens its beats1 or makes them irregular1 or enfeebles1 or augments them4 ,or the respiration1 which changes its rhythm1 or increases1 or is suspended4 ,or else it is the secretion of the saliva or of the sweat1 which flows in abundance or dries up4 ,or the muscular force1 which is increased or decays4 ,or the almost undefinable organic troubles revealed to us by the singing in the ears1 constriction of the epigastrium1 the jerks1 the trembling1 vertigo1 or nausea--all this collection of organic troubles which comes more or less confusedly to our consciousness under the form of tactile1 muscular1 thermal1 and other sensations4 ,until now this category of phenomena has been somewhat neglected1 because we saw in it effects and consequences of which the rle in emotion itself seemed slight1 since1 if they could have been suppressed1 it was supposed that emotion would still remain4 ,the new theory commences by changing the order of events4 ,it places the physical symptoms of the emotions at the very beginning1 and considers them the direct effects of the external excitant1 which is expressed by this elegant formula3 ,it used to be said1 ',i perceive a danger2 ,i am frightened1 ,i tremble4' ,now we must say1 ',i tremble before a danger1 first1 and it is after having trembled that ,i am frightened4' ,this is not a change in order only2 it is something much more serious4 ,the change is directed to the nature of emotion4 ,it is considered to exist in the organic derangements indicated above4 ,these derangements are the basis of emotion1 its physical basis1 and to be moved is to perceive them4 ,take away from the consciousness this physical reflex1 and emotion ceases4 ,it is no longer anything but an idea4 ,this theory has at least the merit of originality4 ,it also pleases one by its great clearness--an entirely intellectual clearness1 we may say2 for it renders emotion comprehensible by enunciating it in terms of cognition4 ,it eliminates all difference which may exist between a perception and an emotion4 ,emotion is no longer anything but a certain kind of perception1 the perception of the organic sensations4 ,this reduction1 if admitted1 would much facilitate the introduction of emotion into our system1 which1 being founded on the distinction between the consciousness and the object1 is likewise an intellectualist system4 ,the definition of emotion1 as it is taught by ,w4 ,james1 seems expressly made for us who are seeking to resolve all intellectual states into physical impressions accompanied by consciousness4 ,by the side of emotion we may place1 as demanding the same analytical study1 the feeling of effort4 ,we ought to inquire with effort1 as has been done with emotion1 what is the psychological nature of this phenomenon2 and in the same way that there exists an intellectualist theory of the emotions1 viz4 that of ,james1 who reduces all the history of the emotions to intelligence1 so there exists an intellectualist theory of effort1 which likewise tends to bring back1 all will to intelligence4 ,it is again the same author1 that true genius1 ,w4 ,james1 who has attempted this reduction4 ,i do not know whether he has taken into account the parallelism of the two theories1 but it is nevertheless evident4 ,effort1 that basis of activity1 that state of consciousness which so many psychologists have described as something sui generis1 becomes to ,james a phenomenon of perception4 ,it is the perception of sensations proceeding from the muscles1 the tendons1 the articulations1 the skin1 and from all the organs directly or indirectly concerned in the execution of movement4 ,to be conscious of an effort would then be nothing else than to receive all these centripetal sensations2 and what proves this is1 that the consciousness of effort when most clearly manifested is accompanied by some muscular energy1 some strong contraction1 or some respiratory trouble1 and yields if we render the respiration again regular and put the muscles back into repose4 ,to my great regret ,i can state nothing very clear regarding these problems4 ,the attempt to intellectualise all psychical problems is infinitely interesting1 and leads to a fairly clear conception1 by which everything is explained by a mechanism reflected in a mirror1 which is the consciousness4 ,but we remain perplexed1 and we ask ourselves whether this clearness of perception is not somewhat artificial1 whether affectivity1 emotivity1 tendency1 will1 are really all reduced to perceptions1 or whether they are not rather irreducible elements which should be added to the consciousness4 ,does not1 for instance1 desire represent a complement of the consciousness8 ,do not desire and consciousness together represent a something which does not belong to the physical domain and which forms the moral world8 ,this question ,i leave unanswered4 ,,chapter ,v ,,definition ,,of ,,the ,,consciousness--,,the ,,relation ,,subject-,,object ,after having separated from the consciousness that which it is not1 let us try to define what it is4 ,this and the two following chapters are devoted to this study4 ,a theory has often been maintained with regard to the consciousness2 namely1 that it supposes a relation between two terms--a subject and an object1 and that it consists exactly in the feeling of this relation4 ,by subject is understood the something that has consciousness2 the object is the something of which we are conscious4 ,every thought1 we are told1 implies subject and object1 the representer and the represented1 the sentiens and the sensum--the one active1 the other passive1 the active acting on the passive1 the ego opposed to the non ego4 ,this opinion is almost legitimised by current language4 ,when speaking of our states of consciousness1 we generally say1 ,i am conscious2 it is ,i who have consciousness1 and we attribute to our ,i1 to our ,ego1 to our personality1 the rle of subject4 ,but this is not a peremptory argument in favour of the above opinion2 it is only a presumption1 and1 closely examined1 this presumption seems very weak4 ,hitherto1 when analysing the part of mind1 we have employed non-committal terms3 we have said that sensation implied consciousness1 and not that sensation implied something which is conscious4#bc ,the difference may appear too subtle1 but it is not2 it consists in taking from consciousness the notion of a subject being conscious and replacing it by the very act of consciousness4 ,my description applies very exactly1 ,i think1 to the facts4 ,when we are engaged in a sensation1 or when we perceive something1 a phenomenon occurs which simply consists in having consciousness of a thing4 ,if to this we add the idea of the subject1 which has consciousness1 we distort the event4 ,at the very moment when it is taking place1 it is not so complicated2 we complicate it by adding to it the work of reflection4 ,it is reflection which constructs the notion of the subject1 and it is this which afterwards introduces this construction into the states of consciousness2 in this way the state of consciousness1 by receiving this notion of subject1 acquires a character of duality it did not previously possess4 ,there are1 in short1 two separate acts of consciousness1 and one is made the subject of the other4 ,primitively1 says ,rabier1 there is neither representative nor represented2 there are sensations1 representations1 facts of consciousness1 and that is all4 ,nothing is more exact1 in my opinion1 than this view of ,condillac's3--that primitively1 the inanimate statue is entirely the sensation that it feels4 ,to itself it is all odour and all savour2 it is nothing more1 and this sensation includes no duality for the consciousness4 ,it is of an absolute simplicity4 ,two arguments may be advanced in favour of this opinion4 ,the first is one of logic4 ,we have divided all knowledge into two groups--objects of cognition1 and acts of cognition4 ,what is the subject of cognition8 ,does it form a new group8 ,by no means2 it forms part of the first group1 of the object group2 for it is something to be known4 ,our second argument is one of fact4 ,it consists in remembering that which in practice we understand by the subject of cognition2 or rather1 metaphorically we represent this subject to ourselves as an organ--the eye that sees or the hand that touches--and we represent to ourselves the relation subject-object in the shape of a material relation between two distinct bodies which are separated by an interval and between which some action is produced which unites them4 ,or else1 confusing the subject and the ,ego1 which are nevertheless two different notions1 we place the ,ego in the consciousness of the muscular effort struggling against something which resists4 ,or1 finally and still more frequently1 we represent the subject to ourselves by confusing it with our own personality2 it is a part of our biography1 our name1 our profession1 our social status1 our body1 our past life foreshortened1 our character1 or1 in a word1 our civil personality1 which becomes the subject of the relation subject-object4 ,we artificially endow this personality with the faculty of having consciousness2 and it results from this that the entity consciousness1 so difficult to define and to imagine1 profits by all this factitious addition and becomes a person1 visible and even very large1 in flesh and bone1 distinct from the object of cognition1 and capable of living a separate life4 ,it is not difficult to explain that all this clearness in the representation of ideas is acquired by a falsification of the facts4 ,so sensorial a representation of consciousness is very unfaithful2 for our biography does not represent what we have called acts of consciousness1 but a large slice of our past experience--that is to say1 a synthesis of bygone sensations and images1 a synthesis of objects of consciousness2 therefore a complete confusion between the acts of consciousness and their objects4 ,the formation of the personality seems to me to have1 above all1 a legal and social importance4#bd ,it is a peculiar grouping of states of consciousness imposed by our relations with other individuals4 ,but1 metaphysically1 the subject thus understood is not distinguished from the object1 and there is nothing to add to our distinction between the object and the act of consciousness4 ,those who defend the existence of the subject point out that this subject properly constitutes the ,ego1 and that the distinction of the subject and the object corresponds to the distinction of the ,ego and non-,ego1 and furnishes the separation between the physical and the moral so long sought4 ,it is evidently very enticing to make of the ,ego thus a primitive notion of the consciousness2 but this view of the ,ego as opposed to the non-,ego in no way corresponds to that of the mental and the physical4 ,the notion of the ,ego is much larger1 much more extensible1 than that of the mental2 it is as encroaching as human pride1 it grasps in its conquering talons all that belongs to us2 for we do not1 in life1 make any great difference between what is we and what is ours--an insult to our dog1 our dwelling1 or our work wounds us as much as an insult to ourselves4 ,the possessive pronoun expresses both possession and possessor4 ,in fact1 we consider our body as being ourselves4 ,here1 then1 are numbers of material things introducing themselves into the category of mental things4 ,if we wished to expel them and to reduce the domain of the ,ego to the domain of the mental1 we could only do so if we already possessed the criterion of what is essentially mental4 ,the notion of the ,ego cannot therefore supply us with this criterion4 ,another opinion consists in making of the subject a spiritual substance1 of which the consciousness becomes a faculty4 ,by substance is understood an entity which possesses the two following principal characteristics1 unity and identity1 this latter merging into unity1 for it is nothing else but the persistence of unity through the course of time4 ,certain philosophers have asserted that through intuition we can all establish that we are a spiritual substance4 ,i am compelled to reject this idea1 because ,i think the expression spiritual substance has no meaning2 nothing but the sonorous value of six syllables4 ,it has also been supposed1 that there exists a corporeal substance hidden under the sensations1 in which are implanted the qualities of bodies1 as the various organs of a flower are in its calyx4 ,i will return later to this conception of a material substance4 ,that of a spiritual substance cannot be defended1 and the chief and fatal argument ,i urge against it is1 that we cannot represent it to our minds1 we cannot think it1 and we cannot see in these words spiritual substance any intelligible idea2 for that which is mental is limited to that which is of the consciousness4 ,so soon as we endeavour to go beyond the fact of having consciousness to imagine a particular state which must be mental1 one of two things happen2 either we only grasp the void1 or else we construct a material and persistent object in which we recognise psychical attributes4 ,these are two conclusions which ought to be rejected4 ,,footnotes3 ,footnote #bc3 ,this second method of expression1 which ,i consider inexact1 is constantly found in ,,descartes4 ,different philosophers have explicitly admitted that every act of cognition implies a relation subject-object4 ,this is one of the corner-stones of the neo-criticism of ,,renouvier4 ,he asserts that all representation is double-faced1 and that what is known to us presents itself in the character of both representative and represented4 ,he follows this up by describing separately the phenomena and laws of the representative and of the represented respectively4 ,footnote #bd3 ,the preceding ten lines in the text ,i wrote after reading a recent article of ,,william ,,james1 who wishes to show that the consciousness does not exist1 but results simply from the relation or the opposition raised between one part of our experience 7the actual experience1 for instance1 in the example of the perception of an object7 and another part1 the remembrance of our person4 ,but the argument of ,,james goes too far2 he is right in contesting the relation subject-object1 but not in contesting the existence of the consciousness 7,w4 ,,james3 ,does consciousness exist8 in ,j4 of ,philosophy1 c41 ,sept4 #aijd74 ,,chapter ,,vi ,,definition ,,of ,,the ,,consciousness--,,categories ,,of ,,the ,,understanding ,it has often been said that the rle of intelligence consists in uniting or grasping the relations of things4 ,an important question1 therefore1 to put1 is1 if we know whereof these relations consist1 and what is the rle of the mind in the establishment of a relation8 ,it now and then happens to us to perceive an isolated object1 without comparing it with any other1 or endeavouring to find out whether it differs from or resembles another1 or presents with any other a relation of cause to effect1 or of sign to thing signified1 or of co-existence in time and space4 ,thus1 ,i may see a red colour1 and occupy all the intellect at my disposal in the perception of this colour1 seeing nothing but it1 and thinking of nothing but it4 ,theoretically1 this is not impossible to conceive1 and1 practically1 ,i ask myself if these isolated and solitary acts of consciousness do not sometimes occur4 ,it certainly seems to me that ,i have noticed in myself moments of intellectual tonelessness1 when in the country1 during the vacation1 ,i look at the ground1 or the grass1 without thinking of anything--or at least1 of anything but what ,i am looking at1 and without comparing my sensation with anything4 ,i do not think we should admit in principle1 as do many philosophers1 that we take no cognisance save of relations4 ,this is the principle of relativity1 to which so much attention has been given4 ,taken in this narrow sense1 it seems to me in no way imperative for our thoughts4 ,we admit that it is very often applied1 but without feeling obliged to admit that it is of perpetual and necessary application4 ,these reserves once made1 it remains to remark1 that the objects we perceive very rarely present themselves in a state of perfect isolation4 ,on the contrary1 they are brought near to other objects by manifold relations of resemblance1 of difference1 or of connection in time or space2 and1 further1 they are compared with the ideas which define them best4 ,we do not have consciousness of an object1 but of the relations existing between several objects4 ,relation is the new state produced by the fact that one perceives a plurality of objects1 and perceives them in a group4 ,show me two colours in juxtaposition1 and ,i do not see two colours only1 but1 in addition1 their resemblance in colour or value4 ,show me two lines1 and ,i do not see only their respective lengths but their difference in length4 ,show me two points marked on a white sheet of paper1 and ,i do not see only the colour1 form1 and dimension of the points1 but their distance from each other4 ,in our perceptions1 as in our conceptions1 we have perpetually to do with the relations between things4 ,the more we reflect1 the more we understand things1 the more clearly we see their relations2 the multiplication of relations is the measure of the depth of cognition4#be ,the nature of these relations is more difficult to ascertain than that of objects4 ,it seems to be more subtle4 ,when two sounds make themselves heard in succession1 there is less difficulty in making the nature of these two sounds understood than the nature of the fact that one occurs before the other4 ,it would appear that1 in the perception of objects1 our mind is passive and reduced to the state of reception1 working like a registering machine or a sensitive surface1 while in the perception of relations it assumes a more important part4 ,two principal theories have been advanced1 of which one puts the relations in the things perceived1 and the other makes them a work of the mind4 ,let us begin with this last opinion4 ,it consists in supposing that the relations are given to things by the mind itself4 ,these relations have been termed categories4 ,the question of categories plays an important part in the history of philosophy4 ,three great philosophers1 ,aristotle1 ,kant1 and ,renouvier have drawn up a list1 or1 as it is called1 a table of them1 and this table is very long4 ,to give a slight idea of it1 ,i will quote a few examples1 such as time1 space1 being1 resemblance1 difference1 causality1 becoming1 finality1 c4 ,by making the categories the peculiar possession of the mind1 we attribute to these cognitions the essential characteristic of being anterior to sensation1 or1 as it is also termed1 of existing a priori3 we are taught that not only are they not derived from experience1 nor taught us by observation1 but further that they are presupposed by all observation1 for they set up1 in scholastic jargon1 the conditions which make experience possible4 ,they represent the personal contribution of the mind to the knowledge of nature1 and1 consequently1 to admit them is to admit that the mind is not1 in the presence of the world1 reduced to the passive state of a tabula rasa1 and that the faculties of the mind are not a transformation of sensation4 ,only these categories do not supplement sensation1 they do not obviate it1 nor allow it to be conjectured beforehand4 ,they remain empty forms so long as they are not applied to experience2 they are the rules of cognition and not the objects of cognition1 the means of knowing and not the things known2 they render knowledge possible1 but do not of themselves constitute it1 ,experience through the senses still remains a necessary condition to the knowledge of the external world4 ,it may be said that the senses give the matter of knowledge1 and that the categories of the understanding give the form of it4 ,matter cannot exist without form1 nor form without matter2 it is the union of the two which produces cognition4 ,such is the simplest idea that can be given of the ,kantian theory of categories1 or1 if it is preferred to employ the term often used and much discussed1 such is the theory of the ,kantian idealism1 ,this theory1 ,i will say frankly1 hardly harmonises with the ideas ,i have set forth up to this point4 ,to begin with1 let us scrutinise the relation which can exist between the subject and the object4 ,we have seen that the existence of the subject is hardly admissible1 for it could only be an object in disguise4 ,cognition is composed in reality of an object and an act of consciousness4 ,now1 how can we know if this act of consciousness1 by adding itself to the object1 modifies it and causes it to appear other than it is8 ,this appears to me an insoluble question1 and probably1 even1 a factitious one4 ,the idea that an object can be modified in its nature or in its aspect comes to us through the perception of bodies4 ,we see that1 by attacking a metal with acids1 this metal is modified1 and that by heating a body its colour and form become changed2 or that by electrifying a thread it acquires new properties2 or that when we place glasses before our eyes we change the visible aspect of objects2 or that1 if we have inflammation of the eyelids1 light is painful1 and so on4 ,all these familiar experiments represent to us the varied changes that a body perceived can undergo2 but it must be carefully remarked that in cases of this kind the alteration in the body is produced by the action of a second body1 that the effect is due to an intercourse between two objects4 ,on the contrary1 when we take the ,kantian hypothesis1 that the consciousness modifies that which it perceives1 we are attributing to the consciousness an action which has been observed in the case of the objects1 and are thus transporting into one domain that which belongs to a different one2 and we are falling into the very common error which consists in losing sight of the proper nature of the consciousness and making out of it an object4 ,if we set aside this incorrect assimilation1 there no longer remains any reason for refusing to admit that we perceive things as they are1 and that the consciousness1 by adding itself to objects1 does not modify them4 ,phenomena and appearances do not1 then1 strictly speaking1 exist4 ,till proof to the contrary1 we shall admit that everything we perceive is real1 that we perceive things always as they are1 or1 in other words1 that we always perceive noumena4#bf ,after having examined the relations of the consciousness with its objects1 let us see what concerns the perception1 by the consciousness1 of the relations existing between these objects themselves4 ,the question is to ascertain whether the a priorists are right in admitting that the establishment of these relations is the work of the consciousness4 ,the rle of synthetic power that is thus attributed to consciousness is difficult to conceive unless we alter the definition of consciousness to fit the case4 ,in accordance with the definition we have given and the idea we have of it1 the consciousness makes us acquainted with what a thing is1 but it adds nothing to it4 ,it is not a power which begets objects1 nor is it a power which begets relations4 ,let us carefully note the consequence at which we should arrive1 if1 while admitting1 on the one hand1 that our consciousness lights up and reveals the objects without creating them1 we were1 on the other hand1 to admit that it makes up for this passivity by creating relations between objects4 ,we dare not go so far as to say that this creation of relations is arbitrary and corresponds in no way to reality2 or that1 when we judge two neighbouring or similar objects1 the relations of contiguity and resemblance are pure inventions of our consciousness1 and that these objects are really neither contiguous nor similar4 ,it must therefore be supposed that the relation is already1 in some manner1 attracted into the objects2 it must be admitted that our intelligence does not apply its categories haphazard or from the caprice of the moment2 and it must be admitted that it is led to apply them because it has perceived in the objects themselves a sign and a reason which are an invitation to this application1 and its justification4 ,on this hypothesis1 therefore1 contiguity and resemblance must exist in the things themselves1 and must be perceived2 for without this we should run the risk of finding similar that which is different1 and contiguous that which has no relation of time or space4 ,whence it results1 evidently1 that our consciousness cannot create the connection completely1 and then we are greatly tempted to conclude that it only possesses the faculty of perceiving it when it exists in the objects4#bg ,according to this conception1 the rle of the consciousness in the perception of a connection is that of a witness1 as in the perception of objects4 ,the consciousness does not create1 but it verifies4 ,resemblance is a physical property of objects1 like colour2 and contiguity is a physical property of objects1 like form4 ,the connections between the objects form part of the group object and not of the group consciousness1 and they are just as independent of consciousness as are the objects themselves4 ,against this conclusion we must anticipate several objections4 ,one of them will probably consist in accentuating the difference existing between the object and the connection from the dynamical point of view4 ,that the object may be passively contemplated by the consciousness can be understood1 it will be said2 but the relation is not only an object of perception--it is1 further1 a principle of action1 a power of suggestion1 and an agent of change4 ,it might1 then1 he supposed that the consciousness here finds a compensation for the rle that has been withdrawn from it4 ,if it is not the thing that creates the relation1 it will be said1 at least it is that which creates its efficacity of suggestion4 ,many psychologists have supposed that a relation has the power of evocation only when it has been perceived4 ,the perception of resemblance precedes the action of resemblance4 ,it is consequently the consciousness which assembles the ideas and gives them birth by perceiving their relations4 ,this error1 for it is one1 has long been wide-spread--indeed1 it still persists4#bh ,we have1 however1 no difficulty in understanding that the perception of a resemblance between two terms supposes them to be known2 so long as only one of the terms is present to the consciousness1 this perception does not exist2 it cannot therefore possess the property of bringing to light the second term4 ,suggestion is therefore distinct from recognition2 it is when suggestion has acted1 when the resemblance in fact has brought the two terms together1 that the consciousness1 taking cognisance of the work accomplished1 verifies the existence of a resemblance1 and that this resemblance explains the suggestion4 ,second objection3 we are told that the relations between the objects--that is1 the principal categories--must be of a mental nature1 because they are a priori4 ,that they are a priori means that they are at once anterior and superior to the experience4 ,let us see what this argument is worth4 ,it appears that it is somewhat misused4 ,with regard to many of the categories1 we are content to lay down the necessity of an abstract idea in order to explain the comprehension of a concrete one4 ,it is said1 for example3 how can it be perceived that two sensations are successive1 if we do not already possess the idea of time8 ,the argument is not very convincing1 because1 for every kind of concrete perception it is possible to establish an abstract category4 ,it might be said of colour that it is impossible to perceive it unless it is known beforehand what colour is2 and so on for a heap of other things4 ,a more serious argument consists in saying that relations are a priori because they have a character of universality and of necessity which is not explained by experience1 this last being always contingent and peculiar4 ,but it is not necessary that a function should be mental for it to be a priori4 ,the identification of the a priori with the mental is entirely gratuitous4 ,we should here draw a distinction between the two senses of the a priori3 anteriority and superiority4 ,a simple physical mechanism may be a priori1 in the sense of anteriority4 ,a house is a priori1 in regard to the lodgers it receives2 this book is a priori1 in regard to its future readers4 ,there is no difficulty in imagining the structure of our nervous system to be a priori1 in regard to the excitements which are propagated in it4 ,a nerve cell is formed1 with its protoplasm1 its nucleus and its nucleoli before being irritated2 its properties precede its functions4 ,if it be possible to admit that as a consequence of ancestral experiences the function has created the organ1 the latter is now formed1 and this it is which in its turn becomes anterior to the function4 ,the notion of a priori has therefore nothing in it which is repugnant to physical nature4 ,let us now take the a priori in the sense of superiority4 ,certain judgments of ours are1 we are told1 universal and necessary1 and through this double character go beyond the evidence of experience4 ,this is an exact fact which deserves to be explained1 but it is not indispensable to explain it by allowing to the consciousness a source of special cognitions4 ,the ,english school of philosophy have already attacked this problem in connection with the origin of axioms4 ,the principle of their explanation lies in the virtue of what they have termed inseparable association4 ,they have supposed that when an association is often repeated it creates a habit of thought against which no further strife is possible4 ,the mechanism of association itself should then add a special virtue to the contingency of facts4 ,a hundred repetitions of related facts1 for example1 would give rise to so firm an association1 that no further repetition would increase it4 ,i consider this explanation a very sound one in principle4 ,it is right to put into association something more than into experience4 ,i would only suggest a slight correction in detail4 ,it is not the association forged by repetition which has this virtue of conveying the idea of necessity and universality1 it is simply the uncontradicted association4 ,it has been objected1 in fact1 and with reason1 to the solution of ,mill1 that it insists on a long duration of experience1 while axioms appear to be of an irresistible and universal truthfulness the moment they are conceived4 ,and this is quite just4 ,i should prefer to lay down as a law that every representation appears true1 and that every link appears necessary and universal as soon as it is formed4 ,this is its character from the first4 ,it preserves it so long as no contradiction in fact1 in reasoning1 or in idea1 comes to destroy it4#bi ,what seems to stand out most clearly after all these explanations is the rle which we ought to attribute to the consciousness4 ,two rival theories have been maintained3 that of the mirror-consciousness and that of the focus-consciousness4 ,it would seem--,i merely say it would seem--that the first of these best harmonises with the preceding facts4 ,for what seems most probable is1 that the consciousness illuminates and reveals but does not act4 ,the theory of the focus-consciousness adapts itself less to the mechanism of the association of ideas4 ,from this we come quite naturally to see in the intelligence only an inactive consciousness2 at one moment it apprehends an object1 and it is a perception or an idea2 at another time it perceives a connection1 and it is a judgment2 at yet another1 it perceives connections between connections1 and it is an act of reason4 ,but however subtle the object it contemplates may become1 it does not depart from its contemplative attitude1 and cognition is but a consciousness4 ,one step further1 and we should get so far as to admit that the consciousness serves no purpose whatever1 and that it is a useless luxury1 since1 if all efficacious virtue is to be found in the sensations and the ideas which we consider as material facts1 the consciousness which reveals them adds nothing to1 takes nothing from and modifies nothing in them2 and everything would go on the same1 nor would anything in this world be changed1 if one day the light of consciousness were1 by chance1 to be put out4 ,we might imagine a collection of automatons forming a human society as complicated as1 and not different in appearance from1 that of conscious beings2 these automatons would make the same gestures1 utter the same words as ourselves1 would dispute1 complain1 cry1 and make love like us2 we might even imagine them capable1 like us1 of psychology4 ,this is the thesis of the epiphenomenal consciousness which ,huxley has boldly carried to its uttermost conclusions4 ,i indicate here these possible conclusions1 without discussing them4 ,it is a question ,i prefer to leave in suspense2 it seems to me that one can do nothing on this subject but form hypotheses4 ,,footnotes3 ,footnote #be3 ,at the risk of being deemed too subtle1 ,i ask whether we are conscious of a relation between objects1 or whether that which occurs is not rather the perception of an object which has been modified in its nature by its relation with another object4 ,footnote #bf3 ,this conclusion may seem contradictory to that which ,i enunciated when studying the constitution of matter4 ,i then asserted that we only know our sensations and not the excitants which produce them4 ,but these sensations are matter2 they are matter modified by other matter1 viz4 our nervous centres4 ,we therefore take up very distinctly an opposite standpoint to the principle of relativity3 in other terms1 we reject the phenomenism of ,berkeley4 ,when we go into metaphysics we are continually astounded to see how different conceptions of things which have a classic value are independent of each other4 ,in general1 phenomenism is opposed to substantialism1 and it is supposed that those who do not accept the former doctrine must accept the latter1 while1 on the contrary1 those who reject substantialism must be phenomenists4 ,we know that it is in this manner that ,berkeley conquered corporeal substantialism and taught phenomenism2 while ,hume1 more radical than he1 went so far as to question the substantialism of mind4 ,on reflection1 it seems to me that1 after having rejected phenomenism1 we are in no way constrained to accept substance4 ,by saying that we perceive things as they are1 and not through a deluding veil1 we do not force ourselves to acknowledge that we perceive the substance of bodies--that is to say1 that something which should be hidden beneath its qualities and should be distinct from it4 ,the distinction between the body and its qualities is a thing useful in practice1 but it answers to no perception or observation4 ,the body is only a group1 a sheaf of qualities4 ,if the qualities seem unable to exist of themselves and to require a subject1 this is only a grammatical difficulty1 which is due to the fact that1 while calling certain sensations qualities1 we suppose a subject to be necessary4 ,on the other hand1 the representation which we make to ourselves of a material substance and its rle as the support of the qualities1 is a very nave and mechanical representation1 thanks to which certain sensations become the supports of other and less important sensations4 ,it would suffice to insist on the detail of this representation and on its origin to show its artificial character4 ,the notion we have of the stability of bodies and of the persistence of their identity1 notwithstanding certain superficial changes1 is the reason for which ,i thought proper to attribute a substance to them1 that is to say1 an invariable element4 ,but we can attain the same end without this useless hypothesis2 we have only to remark that the identity of the object lies in the aggregate of its properties1 including the name it bears4 ,if the majority of its properties1 especially of those most important to us1 subsists without alteration1 or if this alteration1 though of very great extent1 takes place insensibly and by slow degrees1 we decide that the object remains the same4 ,we have no need for that purpose to give it a substance one and indestructible4 ,thus we are neither adherents of phenomenism1 nor of substantialism4 ,footnote #bg3 ,i borrow from ,,rabier this argument1 which has thoroughly convinced me 7see ,psychologie1 p4 #bha74 ,footnote #bh3 ,,pilon is the psychologist who has the most forcibly demonstrated that resemblance acts before being perceived4 ,i refer the readers to my ,psychologie du ,raisonnement1 where ,i have set forth this little problem in detail4 ,footnote #bi3 ,we think spontaneously of the general and the necessary4 ,it is this which serves as a basis for the suggestion and the catchword 7rclame71 and it explains how minds of slender culture always tend towards absolute assertions and hasty generalisations4 ,,chapter ,,vii ,,definition ,,of ,,the ,,consciousness--,,the ,,separability ,,of ,,the ,,consciousness ,,from ,,its ,,object--,,discussion ,,of ,,idealism ,one last question suggests itself with regard to the consciousness4 ,in what measure is it separable from the object8 ,do the consciousness and its object form two things or only one8 ,under observation these two terms constantly show themselves united4 ,we experience a sensation and have consciousness of it2 it is the same fact expressed in two different ways4 ,all facts of our perception thus present themselves1 and they are one4 ,but our reason may outstrip our observation4 ,we are able to make a distinction between the two elements being and being perceived4 ,this is not an experimental but an ideological distinction1 and an abstraction that language makes easy4 ,can we go further1 and suppose one of the parts thus analysed capable of existing without the other8 ,can sensation exist as physical expression1 as an object2 without being illuminated by the consciousness8 ,can the consciousness exist without having an object8 ,let us first speak of the existence of the object when considered as separated from the consciousness4 ,the problem is highly complicated4 ,it has sometimes been connected with the idealist thesis according to which the object of consciousness1 being itself a modality of the consciousness1 cannot exist apart from it--that is to say1 outside the periods in which it is perceived4 ,it would therefore result from this that this separation between existence and perception might be made1 when it is admitted 7contrary to the idealist hypothesis7 that the object perceived is material and the consciousness which perceives it mental4 ,in this case1 it will be thought1 there is no link of solidarity between the consciousness and its continuity4 ,but ,i am not of that opinion4 ,the union of the consciousness and its object is one of fact1 which presents itself outside any hypothesis on the nature of the object4 ,it is observation which demonstrates to us that we must perceive an object to be assured of its existence2 the reason1 moreover1 confirms the necessity of this condition1 which remains true whatever may be the stuff of the object4 ,having stated this1 the question is simply to know whether this observation of fact should be generalised or not4 ,we may1 it seems to me1 decline to generalise it without falling into a contradiction in terms4 ,it may be conceived that the objects which we are looking at continue to exist1 without change1 during the moments when we have lost sight of them4 ,this seems reasonable enough1 and is the opinion of common sense4#cj ,the ,english philosophers1 ,bain and ,mill1 have combated this proposition with extraordinary ardour1 like believers combating a heresy4 ,but notwithstanding their attacks it remains intelligible1 and the distinction between being and being perceived preserves its logical legitimacy4 ,this may be represented1 or may be thought2 but can it be realised8 ,so far as regards external objects1 ,i think we all1 in fact1 admit it4 ,we all admit a distinction1 between the existence of the outer world and the perception we have of it2 its existence is one thing1 and our perception of it is another4 ,the existence of the world continues without interruption2 our perception is continually interrupted by the most fortuitous causes1 such as change of position1 or even the blinking of the eyes2 its existence is general1 universal1 independent of time and space2 our perception is partial1 particular1 local1 limited by the horizon of our senses1 determined by the geographical position of our bodies1 riddled by the distractions of our intelligence1 deceived by the illusions of our minds1 and above all diminished by the infirmity of our intelligence1 which is able to comprehend so little of what it perceives4 ,this is what we all admit in practice2 the smallest of our acts implies the belief in something perceptible which is wider and more durable than our astonished perceptions4 ,i could not write these lines unless ,i implicitly supposed that my inkstand1 my paper1 my pen1 my room1 and the surrounding world subsist when ,i do not see them4 ,it is a postulate of practical life4 ,it is also a postulate of science1 which requires for its explanations of phenomena the supposition in them of an indwelling continuity4 ,natural science would become unintelligible if we were forced to suppose that with every eclipse of our perceptions material actions were suspended4 ,there would be beginnings without sequences1 and ends without beginnings4 ,let us note also that acquired notions on the working of our nervous system allow us to give this postulate a most precise form3 the external object is distinct from the nervous system and from the phenomena of perception which are produced when the nervous system is excited2 it is therefore very easy to understand that this object continues to exist and to develop its properties1 even when no brain vibrates in its neighbourhood4 ,might we not1 with the view of strengthening this conclusion as to the continuous existence of things1 dispense with this postulate1 which seems to have the character of a grace1 of an alms granted to us8 ,might not this continuous existence of objects during the eclipses of our acts of consciousness1 be demonstrated8 ,it does not seem to me impossible4 ,let us suppose for a moment the correctness of the idealist thesis3 all our legitimate knowledge of objects is contained within the narrow limits of actual sensation2 then1 we may ask1 of what use is the reason8 ,what is the use of the memory8 ,these functions have precisely for their object the enlarging of the sphere of our sensations1 which is limited in two principal ways1 by time and by space4 ,thanks to the reason1 we manage to see in some way that which our senses are unable to perceive1 either because it is too distant from us1 or because there are obstacles between us and the object1 or because it is a past event or an event which has not yet taken place which is in question4 ,that the reason may be deceived is agreed4 ,but will it be asserted that it is always deceived8 ,shall we go so far as to believe that this is an illegitimate mode of cognition8 ,the idealist thesis1 if consistent1 cannot refuse to extend itself to this extreme conclusion2 for a reasoned conclusion contains1 when it has a meaning1 a certain assertion on the order of nature1 and this assertion is not a perception1 since its precise object is to fill up the gaps in our perceptions4 ,not being a perception1 it must be rejected1 if one is an idealist4 ,the idealist will therefore keep strictly to the perception of the moment1 and this is so small a thing when deprived of all the conjectures which enrich it1 that the world1 if reduced to this alone1 would be but the skeleton of a world4 ,there would then be no more science1 no possibility of knowledge4 ,but who could make up his mind thus to shut himself up in perception8 ,i suppose1 indeed1 that there will here be quibbling4 ,this objection will be made3 that in the hypothesis of a discontinuous existence of things1 reason may continue to do its work1 provided the intervention of a possible perception be supposed4 ,thus1 ,i notice this morning1 on going into my garden1 that the pond which was dry yesterday is full of water4 ,i conclude from this1 ,it has rained in the night4 ,to be consistent with idealism1 one must simply add3 ,if some one had been in the garden last night1 he would have seen it rain4 ,in this manner one must re-establish every time the rights of perception4 ,be it so4 ,but let us notice that this addition has no more importance than a prescribed formula in a notarial act2 for instance1 the presence of a second notary prescribed by the law1 but always dispensed with in practice4 ,this prescribed formula can always be imagined or even understood4 ,we shall be in accord with idealism by the use of this easy little formula1 ,if some one had been there1 or even by saying1 ,for a universal consciousness4444 ,the difference of the realist and idealist theory becomes then purely verbal4 ,this amounts to saying that it disappears4 ,but there is always much verbalism in idealism4 ,one more objection3 if this witness--the consciousness--suffices to give objects a continuity of existence1 we may content ourselves with a less important witness4 ,why a man8 ,the eyes of a mollusc would suffice1 or those of infusoria1 or even of a particle of protoplasm3 living matter would become a condition of the existence of dead matter4 ,this1 we must acknowledge1 is a singular condition1 and this conclusion condemns the doctrine4 ,,footnotes3 ,footnote #cj3 ,that is to say1 the sense of the multitude4--,,ed4 ,,chapter ,,viii ,,definition ,,of ,,the ,,consciousness--,,the ,,separation ,,of ,,the ,,consciousness ,,from ,,its ,,object--,,the ,,unconscious ,i ask myself whether it is possible1 by going further along this road of the separation between the consciousness and its object1 to admit that ideas may subsist during the periods when we are not conscious of them4 ,it is the problem of unconsciousness that ,i am here stating4 ,one of the most simple processes of reasoning consists in treating ideas in the same manner as we have treated the external objects4 ,we have admitted that the consciousness is a thing superadded to the external objects1 like the light which lights up a landscape1 but does not constitute it and may be extinguished without destroying it4 ,we continue the same interpretation by saying that ideas prolong their existence while they are not being thought1 in the same way and for the same motive that material bodies continue theirs while they are not being perceived4 ,all that it seems permissible to say is that this conception is not unrealisable4 ,let us now place ourselves at the point of view of the consciousness4 ,we have supposed up to the present the suppression of the consciousness1 and have seen that we can still imagine the object continuing to exist4 ,is the converse possible8 ,let us suppose that the object is suppressed4 ,can the consciousness then continue to exist8 ,on this last point it seems that doubt is not possible1 and we must answer in the negative4 ,a consciousness without an object1 an empty consciousness1 in consequence1 cannot be conceived2 it would be a zero--a pure nothingness2 it could not manifest itself4 ,we might admit1 in strictness1 that such a consciousness might exist virtually as a power which is not exercised1 a reserve1 a potentiality1 or a possibility of being2 but we cannot comprehend that this power can realise or actualize itself4 ,there is therefore no actual consciousness without an object4 ,the problem we have just raised1 that of the separability of the elements which compose an act of consciousness1 is continued by another problem--that of unconsciousness4 ,it is almost the same problem1 for to ask one's self what becomes of a known thing when we separate from it the consciousness which at first accompanied it1 is to ask one's self in what an unconscious phenomenon consists4 ,we have1 till now1 considered the two principal forms of unconsciousness--that in nature and that in thought4 ,the first named unconsciousness does not generally bear that name1 but is rather discussed under the name of idealism and realism4 ,whatever be their names1 these two kinds of unconsciousness are conceivable1 and the more so that they both belong to physical nature4 ,if we allow ourselves to be guided by the concept of separability1 we shall now find that we have exhausted the whole series of possible problems1 for we have examined all the possible separations between the consciousness and its objects2 but if we use another concept1 that of unconsciousness1 we can go further and propound a new problem3 can the consciousness become unconscious8 ,but it is proper first to make a few distinctions4 ,it is the rle of metaphysics to make distinctions4#ca ,unconsciousness presupposes a death of the consciousness2 but this death has its degrees1 and before complete extinction we may conceive it to undergo many attenuations4 ,there is1 first1 the diminution of consciousness4 ,consciousness is a magnitude capable of increase and decrease1 like sensation itself4 ,according to the individual1 consciousness may have a very large or a very small field1 and may embrace at the same time a variable number of objects4 ,i can pay attention to several things at the same time1 but when ,i am tired it becomes more difficult to me4 ,i lose in extension1 or1 as is still said1 the field of consciousness is restricted4 ,it may also lose not only in extent of surface1 but in depth4 ,we have all of us observed in our own selves moments of obscure consciousness when we understand dimly1 and moments of luminous consciousness which carry one almost to the very bottom of things4 ,it is difficult to consider those in the wrong who admit1 with ,leibnitz1 the existence of small states of consciousness4 ,the lessening of the consciousness is already our means of understanding the unconscious2 unconsciousness is the limit of this reduction4#cb ,this singular fact has also been noticed1 that1 in the same individual there may co-exist several kinds of consciousness which do not enter into communication with each other and which are not acquainted with each other4 ,there is a principal consciousness which speaks1 and1 in addition1 accessory kinds of consciousness which do not speak1 but reveal their existence by the use of other modes of expression1 of which the most frequent is writing4 ,this doubling or fractionation of the consciousness and personality have often been described in the case of hysterical subjects4 ,they sometimes occur quite spontaneously1 but mostly they require a little suggestion and cultivation4 ,in any case1 that they are produced in one way or other proves that they are possible1 and1 for the theory1 this possibility is essential4 ,facts of this kind do not lead to a theory of the unconscious1 but they enable us to understand how certain phenomena1 unconscious in appearance1 are conscious to themselves1 because they belong to states of consciousness which have been separated from each other4 ,a third thesis1 more difficult of comprehension than the other two1 supposes that the consciousness may be preserved in an unconscious form4 ,this is difficult to admit1 because unconsciousness is the negation of consciousness4 ,it is like saying that light can be preserved when darkness is produced1 or that an object still exists when1 by the hypothesis1 it has been radically destroyed4 ,this idea conveys no intelligible meaning1 and there is no need to dwell on it4 ,we have not yet exhausted all the concepts whereby we may get to unconsciousness4 ,here is another1 the last ,i shall quote1 without1 however1 claiming that it is the last which exists4 ,we might call it the physiological concept1 for it is the one which the physiologists employ for choice4 ,it is based upon the observation of the phenomena which are produced in the nervous system during our acts of consciousness2 these phenomena precede consciousness as a rule1 and condition it4 ,according to a convenient figure which has been long in use1 the relations of the physiological phenomenon to the consciousness are represented as follows3 the physiological phenomenon consists in an excitement which1 at one time1 follows a direct and short route from the door by which it enters the nervous system to the door by which it makes its exit4 ,in this case1 it works like a simple mechanical phenomenon2 but sometimes it makes a longer journey1 and takes a circuitous road by which it passes into the higher nerve centres1 and it is at the moment when it takes this circuitous road that the phenomenon of consciousness is produced4 ,the use of this figure does not prejudge any important question4 ,going further1 many contemporary authors do not content themselves with the proposition that the consciousness is conditioned by the nervous phenomenon1 but suggest also that it is continually accompanied by it4 ,every psychical fact of perception1 of emotion1 or of idea should have1 it is supposed1 a physiological basis4 ,it would therefore be1 taken in its entirety1 psycho-physiological4 ,this is called the parallelist theory4 ,we cannot discuss this here1 as we shall meet with it again in the third part of this book4 ,it has the advantage of leading to a very simple definition of unconsciousness4 ,the unconscious is that which is purely physiological4 ,we represent to ourselves the mechanical part of the total phenomenon continuing to produce itself1 in the absence of the consciousness1 as if this last continued to follow and illuminate it4 ,such are the principal conceptions that may be formed of the unconscious4 ,they are probably not the only ones1 and our list is not exhaustive4 ,after having indicated what the unconscious is1 we will terminate by pointing out what it is not and what it cannot be4 ,we think1 or at least we have impliedly supposed in the preceding definitions1 that the unconscious is only something unknown1 which may have been known1 or which might become known under certain conditions1 and which only differs from the known by the one characteristic of not being actually known4 ,if this notion be correct1 one has really not the right to arm this unconsciousness with formidable powers4 ,it has the power of the reality to which it corresponds1 but its character of unconsciousness adds nothing to this4 ,it is the same with it as with the science of the future4 ,no scholar will hesitate to admit that that science will be deeper and more refined than that already formed4 ,but it is not from the fact that it is unknown that it will deserve its superiority3 it is from the phenomena that it will embrace4 ,to give to that which is unconscious1 as we here understand it1 an overwhelming superiority over the conscious as such1 we must admit that the consciousness is not only a useless luxury1 but the dethronement of the forces that it accompanies4 ,in the next place1 ,i decline to admit that the consciousness itself can become unconscious1 and yet continue in some way under an unconscious form4 ,this would be1 in my opinion1 bringing together two conceptions which contradict each other1 and thus denying after having affirmed4 ,from the moment that the consciousness dies1 there remains nothing of it1 unless it be the conditions of its appearance1 conditions which are distinct from itself4 ,between two moments of consciousness separated by time or by a state of unconsciousness1 there does not and cannot exist any link4 ,i feel incapable of imagining of what this link could be composed1 unless it were material--that is to say1 unless it were supplied from the class of objects4 ,i have already said that the substantialist thesis endeavours to establish a continuity between one consciousness and another separated by time1 by supposing a something durable1 of which the consciousness would be a property of intermittent manifestation4 ,they would thus explain the interruptions of consciousness as the interruptions in the light of a lamp4 ,when the light is extinguished1 the lamp remains in darkness1 but is still capable of being lighted4 ,let us discard this metaphor1 which may lead to illusion4 ,the concept of consciousness can furnish no link and no mental state which remains when the consciousness is not made real2 if this link exists1 it is in the permanence of the material objects and of the nervous organism which allows the return of analogous conditions of matter4 ,,footnotes3 ,footnote #ca3 ,in metaphysics we reason1 not on facts1 but most often on conceptions4 ,now just as facts are precise so conceptions are vague in outline4 ,facts are like crystallised bodies1 ideas like liquids and gases4 ,we think we have an idea1 and it changes form without our perceiving it4 ,we fancy we recognise one idea1 and it is but another1 which differs slightly from the preceding one4 ,by means of distinctions we ought to struggle against this flowing away and flight of ideas4 ,footnote #cb3 ,i think ,i have come across in ,,aristotle the ingenious idea that the enfeeblement of the consciousness and its disorder may be due to the enfeeblement and disorder of the object4 ,it is a theory which is by no means improbable4 ,,chapter ,,ix ,,definitions ,,of ,,psychology ,let us resume the study of the preceding ideas in another form4 ,since1 moreover1 to define mind is at the same time to define psychology1 let us seek for the truth which we can glean from the definitions of this science4 ,our object is not to discover an exact definition1 but to make use of those already existing4 ,to define psychology is to describe the features of the domain over which this science holds sway1 and at the same time to indicate the boundaries which separate it from its neighbours4 ,at first sight this is an affair of geometric survey1 presenting no kind of difficulty2 for psychology does not merge by insensible transitions into the neighbouring sciences1 as physics does with chemistry1 for example1 or chemistry with biology4 ,to all the sciences of external nature psychology offers the violent opposition of the moral to the physical world4 ,it cannot be put in line with the physical sciences4 ,it occupies1 on the contrary1 a position apart4 ,it is the starting point1 the most abstract and simple of the moral sciences2 and it bears the same relation to them that mechanics does to the physical4 ,all this is doubtless true2 and yet a very great difficulty has been experienced in condensing into a clear definition the essence of psychology4 ,this is proved by the multiplicity of definitions attempted4 ,they are so many because none of them has proved completely satisfactory4 ,their abundance shows their insufficiency4 ,i will try to introduce a little order into these attempts1 and propose to distribute the definitions of psychology into the following categories3-- #a4 ,the definition by substance2 the metaphysical definition par excellence4 #b4 ,the definition by enumeration4 #c4 method4 #d4 degree of certainty4 #e4 content4 #f4 point of view4 #g4 the peculiar nature of mental laws4 ,we will rapidly run through this series of efforts at definition1 and shall criticise and reject nearly the whole of them2 for the last alone seems exact--that is to say1 in harmony with the ideas laid down above4 ,metaphysical definition has to-day taken a slightly archaistic turn4 ,psychology used to be considered as the science of the soul4 ,this is quite abandoned4 ,modern authors have adopted the expression and also the idea of ,lange1#cc who was1 ,i think1 the first to declare that we ought to cultivate a soulless psychology4 ,this categorical declaration caused an uproar1 and a few ill-informed persons interpreted it to mean that the new psychology which has spread in ,france under cover of the name of ,ribot1 sought to deny the existence of the soul1 and was calculated to incline towards materialism4 ,this is an error4 ,it is very possible1 indeed1 that several adepts of the new or experimental psychology may be materialists from inward conviction4 ,the exclusive cultivation of external facts1 of phenomena termed material1 evidently tends--this is a mystery to none--to incline the mind towards the metaphysical doctrine of materialism4 ,but1 after making this avowal1 it is right to add at once that psychology1 as a science of facts1 is the vassal of no metaphysical doctrine4 ,it is neither spiritualist1 materialist1 nor monist1 but a science of facts solely4 ,ribot and his pupils have proclaimed this aloud at every opportunity4 ,consequently it must be recognised that the rather amphibological expression soulless psychology implies no negation of the existence of the soul4 ,it is--and this is quite a different thing--rather an attitude of reserve in regard to this problem4 ,we do not solve this problem2 we put it on one side4 ,and1 certainly1 we are right to do so4 ,the soul1 viewed as a substance--that is1 as a something distinct from psychical phenomena1 which1 while being their cause and support1 yet remains inaccessible to our direct means of cognition--is only an hypothesis1 and it cannot serve as objective to a science of facts4 ,this would imply a contradiction in terms4 ,unfortunately2 we must confess that if it be right to relegate to metaphysics the discussion on the concept of the soul1 it does not really suffice to purge our minds of all metaphysics2 and a person who believes himself to be a simple and strict experimentalist is often a metaphysician without knowing it4 ,these excommunications of metaphysics also seem rather childish at the present day4 ,there is less risk than some years ago in declaring that3 ,here metaphysics commence and positive science ends1 and ,i will go no further4 ,there is even a tendency in modern psychologists to interest themselves in the highest philosophical problems1 and to take up a certain position with regard to them4 ,the second kind of definition is1 we have said1 that by enumeration4 ,it consists in placing before the eyes of the reader an assortment of psychological phenomena and then saying3 ,these are the things psychology studies4 ,one will take readily as samples the ideas1 reasonings1 emotions1 and other manifestations of mental life4 ,if this is only a strictly provisional definition1 a simple introduction to the subject1 we accept it literally4 ,it may serve to give us a first impression of things1 and to refresh the memories of those who1 by a rather extraordinary chance1 would not doubt that psychology studies our thoughts4 ,but whatever may be the number of these deeply ignorant persons1 they constitute1 ,i think1 a negligible quantity2 and1 after these preliminaries1 we must come to a real definition and not juggle with the problem1 which consists in indicating in what the spiritual is distinguished from the material4 ,let us leave on one side1 therefore1 the definitions by enumeration4 ,now comes the definition by method4 ,numbers of authors have supposed that it is by its method that psychology is distinguished from the other sciences4 ,to the mind is attached the idea of the within1 to nature the idea of being without the mind1 of constituting a without 7un dehors74 ,it is a vague idea1 but becomes precise in a good many metaphors1 and has given rise to several forms of speech4 ,since the days of ,locke1 we have always spoken of the internal life of the mind as contrasted with the external life1 of subjective reality as contrasted with objective reality2 and in the same way we oppose the external senses to the inner sense 7the internal perception71 which it has at times been proposed to erect into a sixth sense4 ,though no longer quite the ,cartesian dualism1 this is still a dualism4 ,it has also been said that psychology is the science of introspection1 and1 in addition1 that scientific psychology is a controlled introspection4 ,this science of the internal facts of man would thus be distinguished from the other natural sciences which are formed by the use of our outer senses1 by external observation--that is to say1 to use a neologism1 by externospection4 ,this verbal symmetry may satisfy for a moment minds given to words1 but on reflection it is perceived that the distinction between introspection and externospection does not correspond to a fundamental and constant difference in the nature of things or in the processes of cognition4 ,i acknowledge it with some regret1 and thus place myself in contradiction with myself2 for ,i for a long time believed1 and have even said in print1 that psychology is the science of introspection4 ,my error arose from my having made too many analyses of detail1 and not having mounted to a sufficiently wide-reaching conception4 ,the definition ,i have given of consciousness is the implied condemnation of the above ideas4 ,consciousness1 being nothing but an act of revelation1 has neither a within nor a without2 it does not correspond to a special domain which would be an inner one with regard to another domain4 ,every consideration on the position of things is borrowed from the sphere of the object1 and remains foreign to the sphere of the consciousness4 ,it is by an abuse of language that we speak of the outer world in relation to the world of consciousness1 and it is pure imagination on the part of philosophers to have supposed that our sensations are first perceived as internal states and states of consciousness1 and are subsequently projected without to form the outer world4 ,the notion of internal and external is only understood for certain objects which we compare by position to certain others4 ,in fact1 we find that the opposition between an external and an internal series is generally founded on two characteristics3 sensation is considered external in relation to the idea1 and an object of cognition is considered as internal when it is accessible only to ourselves4 ,when these two characteristics are isolated from each other1 one may have doubts2 but when they co-exist1 then the outwardness or inwardness appears fully evidenced4 ,we see then that this distinction has nothing to do with the value of consciousness1 and has nothing mental about it4 ,it is thus that our ideas are judged from internal events4 ,it is our microcosm opposed to the macrocosm4 ,it is the individual opposed to the social4 ,looking at an external object1 we remain in communion with our fellows1 for we receive1 or think we receive1 identical sensations4 ,at all events1 we receive corresponding sensations4 ,on the other hand1 my thought is mine1 and is known to me alone2 it is my sanctuary1 my private closet1 where others do not enter4 ,every one can see what ,i see1 but no one knows what ,i think4 ,but this difference in the accessibility of phenomena is not due to their peculiar nature4 ,it is connected with a different fact1 with the modes of excitement which call them forth4 ,if the visual sensation is common to all1 it is because the exciting cause of the sensation is an object external to our nervous systems1 and acting at a distance on all4#cd ,the tactile sensation is at the beginning more personal to the one who experiences it1 since it requires contact2 and the lower sensations are in this intimacy still in progress4 ,and then1 the same object can give rise1 in common-place circumstances1 to a sensation either common to all beings or special to one alone4 ,the capsule of antipyrine which ,i swallow is1 before my doing so1 visible to all eyes2 once in my mouth1 ,i am the only one to perceive it4 ,it is therefore possible that the same sensation1 according to the displacements of the object which excites it1 may make part of the internal or of the external series2 and as all psychic life is sensation1 even effort1 and1 as we are assured1 emotion1 it follows that our argument extends to all the psychical elements4 ,finally1 the internal or external character of events1 which might be called their geographical position1 is a characteristic which has no influence upon the method destined to take cognisance of it4 ,the method remains one4 ,introspection does not represent a source of cognition distinct from externospection1 for the same faculties of the mind--reason1 attention1 and reflection--act on sensation1 the source of the so-called external sciences1 and on the idea1 the source of the so-called inner science4 ,a fact can be studied by essentially the same process1 whether regarded by the eyes or depicted by the memory4 ,the consciousness changes its object and orientation1 not its nature4 ,it is as if1 with the same opera-glass1 we looked in turn at the wall of the room and through the window4 ,i can even quote on this point a significant fact3 there are observers who are organised in such a way that they especially observe by memory4 ,placed before the sensorial phenomenon which strikes their senses1 they are sometimes amazed1 as if hypnotised2 they require to get away from it to regain consciousness of themselves1 to analyse the fact1 and to master it1 and it is by means of the memory that they study it1 on condition1 of course1 of afterwards coming back to verify their conclusions by a fresh observation from nature4 ,will it be said that the physicist1 the chemist1 or the biologist who follows this slow method1 and who thus observes retroactively1 practises physics and biology by introspection8 ,evidently this would be ridiculous4 ,conversely1 introspection may1 in certain cases1 adopt the procedure of externospection4 ,no doubt it would be inexact to say that the perception of one of our ideas always takes place through the same mechanism as the perception of one of our sensations4 ,to give an account of what we think does not imply the same work as in the case of what we see2 for1 generally1 our thoughts and our images do not appear to us spontaneously4 ,they are first sought for by us1 and are only realised after having been wished for4 ,we go from the vague to the precise1 from the confused to the clear2 the direction of thought precedes1 then1 its realisation in images2 and the latter1 being expected1 is necessarily comprehended when it is formed4 ,but we may come across curious circumstances in which it is the image which has precedence over its appearance1 and in that case it is exact to say that this uninvoked image must be interpreted and recognised as if it were an external object4 ,in cases of this kind1 there passes through our mind something which surprises us4 ,i see1 by internal vision1 a face with a red nose1 and ,i have to search my memory for a long time1 even for days1 in order to give precision to the vague feeling that ,i have seen it before1 so as to finally say with confidence1 ,it is ,so and ,so6 ,or else ,i hear in my inner ear a certain voice1 with a metallic tone and authoritative inflections3 this voice pronounces scientific phrases1 gives a series of lectures1 but ,i know not to whom it belongs1 and it costs me a long effort to reach the interpretation3 it is the voice of ,m4 ,dastre6 ,there is1 then1 a certain space of time1 more or less long1 in which we can correctly assert that we are not aware of what we are thinking2 we are in the presence of a thought in the same state of uncertainty as in that of an external1 unknown1 and novel object4 ,the labour of classification and of interpretation cast upon us is of the same order2 and1 when this labour is effected incorrectly1 it may end in an illusion4 ,therefore illusions of thought are quite as possible as illusions of the senses1 though rarer for the reasons above stated4 ,but the question of frequency has no theoretical importance4 ,i have shown elsewhere1 by experiments on hysterics1 that it is possible by the intermediary of their insensibility to touch to suggest ideas on the value of which the patients make mistakes4 ,for instance1 you take the finger in which they have no sensation1 you touch it1 you bend it4 ,the patient1 not seeing what is done1 does not feel it1 but the tactile sensation unfelt by their principal consciousness somehow awakes the visual image of the finger2 this enters into the field of consciousness1 and most often is not recognised by the subject1 who describes the occurrence in his own way2 he claims1 for instance1 that he thinks of sticks or of columns4 ,in reality he does not know of what he is thinking1 and we know better than he4 ,he is thinking of his finger1 and does not recognise it4 ,all these examples show that the clearly defined characteristics into which it is sought to divide extrospection and introspection do not exist4 ,there is1 however1 a reason for preserving the distinction1 because it presents a real interest for the psychology of the individual4 ,these two words introspection and extrospection admirably convey the difference in the manner of thinking between those who from preference look1 and those who from preference reflect4 ,on the one hand1 the observers1 who are often men of action2 on the other1 the speculators1 who are often mystics4 ,but it would be no more legitimate by this means to separate psychology and physics than to say1 for instance1 ,there are two kinds of geology3 one is the geology of ,france1 for one is acquainted with it without going from home1 and the other is that of the rest of the world1 because in order to know it one must cross the frontier4 ,we reject1 therefore1 the definition drawn from the difference of method4 ,at bottom there is no difference of method1 but only differences of process1 of technique4 ,the method is always the same1 for it is derived from the application of a certain number of laws to the objects of cognition1 and these laws remain the same in all spheres of application4 ,here is another difference of method which1 if it were true1 would have an incalculable importance4 ,psychology1 we are told1 is a science of direct and immediate experiment2 it studies facts as they present themselves to our consciousness1 while the natural sciences are sciences of indirect and mediate experiment1 for they are compelled to interpret the facts of consciousness and draw from them conclusions on nature4 ,it has also been said1 in a more ambitious formula1 ,the science of physical objects is relative2 logical science is absolute4 ,let us examine this by the rapid analysis of any perception taken at haphazard4 ,what ,i perceive directly1 immediately1 we are told1 is not the object1 it is my state of consciousness2 the object is inferred2 concluded1 and taken cognisance of through the intermediary of my state of consciousness4 ,we only know it1 says ,lotze1 circa rem4 ,it is therefore apprehended less immediately1 and every natural science employs a more roundabout method than that of psychology4 ,this last1 by studying states of consciousness1 which alone are known to us directly1 comprehends reality itself1 absolute reality4 ,there is more absolute reality1 ,m4 ,rabier boldly says1 in the simple feeling that a man1 or even an animal1 has of its pain when beaten than in all the theories of physics1 for1 beyond these theories1 it can be asked1 what are the things that exist4 ,but it is an absurdity to ask one's self if1 beyond the pain of which one is conscious1 there be not another pain different from that one4#ce ,let us excuse in psychologists this petty and common whim for exaggerating the merit of the science they pursue4 ,but here the limit is really passed1 and no scholar will admit that the perception and representation of a body1 as it may take place in the brain of a ,berthelot1 can present any inferiority as a cognition of the absolute1 to the pain felt by the snail ,i crush under my foot4 ,nobody except metaphysicians will acknowledge that psychology is a more precise and certain science than physics or chemistry4 ,the criterion furnished by the development of the respective sciences would prove just the contrary4 ,the observations of psychology are always rather unprecise4 ,psychological phenomena1 notwithstanding the efforts of ,fechner and his school1 are not yet measured with the same strictness and ease as the tangible reality4 ,to speak plainly1 the psychologist who vaunts the superiority of his method1 and only shows inferior results1 places himself in a somewhat ridiculous and contradictory position2 he deserves to be compared to those spiritualists who claim the power of evoking the souls of the illustrious dead and only get from them platitudes4 ,in the main the arguments of the metaphysicians given above appear to me to contain a grave error4 ,this consists in supposing that the natural sciences study the reality hidden beneath sensation1 and only make use of this fact as of a sign which enables them to get back from effect to cause4 ,this is quite inexact4 ,that the natural sciences are limited by sensation is true2 but they do not go outside it1 they effect their constructions with sensation alone4 ,and the reason is very simple3 it is the only thing they know4 ,to the metaphysical psychologist1 who claims sensation as his own property1 saying1 ,but this sensation is a state of my consciousness1 it is mine1 it is myself1 the physicist has the right to answer3 ,i beg your pardon6 this sensation is the external object that ,i am studying2 it is my column of mercury1 my spring1 my precipitate1 my amoeba2 ,i comprehend these objects directly1 and ,i want no other4 ,psychology finds itself1 therefore1 exactly on the same footing as the other sciences in the degree in which it studies sensations that it considers as its own property4 ,i have already said that the sensations proper to psychology are hardly represented otherwise than by the emotional sensations produced by the storms in the apparatus of organic life4 ,we now come to the definitions by content4 ,they have been numerous1 but we shall only quote a few4 ,the most usual consists in saying1 that ,psychology studies the facts of consciousness4 ,this formula passes1 in general1 as satisfactory4 ,the little objection raised against it is1 that it excludes the unconscious facts which play so important a part in explaining the totality of mental life2 but it only requires some usual phrase to repair this omission4 ,one might add1 for instance1 to the above formula3 conscious facts and those which1 while unconscious under certain conditions1 are yet conscious in others4 ,this is not1 however1 the main difficulty1 which is far more serious4 ,on close examination1 it is seen that the term1 fact of consciousness1 is very elastic1 and that for a reason easy to state4 ,this is1 that all facts which exist and are revealed to us reach us by the testimony of the consciousness1 and are1 consequently1 facts of consciousness4 ,if ,i look at a locomotive1 and analyse its machinery1 ,i act like a mechanic2 if ,i study under the microscope the structure of infusoria1 ,i practise biology2 and yet the sight of the locomotive1 the perception of the infusoria1 are just facts of consciousness1 and should belong to psychology1 if one takes literally the above definition1 which is so absolute that it absorbs the entire world into the science of the mind4 ,it might1 indeed1 be remarked that certain phenomena would remain strictly psychological1 such as1 for instance1 the emotions1 the study of which would not be disputed by any physical science2 for the world of nature offers us nothing comparable to an emotion or an effort of will1 while1 on the other hand1 everything which is the object of physical science--that is1 everything which can be perceived by our external senses--may be claimed by psychology4 ,therefore1 it is very evident the above definition is much too wide1 and does not agree with solo definito4 ,it does not succeed in disengaging the essential characteristic of physics4 ,this characteristic indeed exists1 and we foresee it1 but we do not formulate it4 ,another definition by content has not been much more happy4 ,to separate the material from the moral1 the conception of ,descartes was remembered1 and we were told that3 ,psychology is the science of what exists only in time1 while physics is the science of what exists at once in time and in space4 ,to this theoretical reasoning it might already be objected that1 in fact1 and in the life we lead1 we never cease to localise in space1 though somewhat vaguely1 our thought1 our ,ego1 and our intellectual whole4 ,at this moment ,i am considering myself1 and taking myself as an example4 ,i am writing these lines in my study1 and no metaphysical argument can cause me to abandon my firm conviction that my intellectual whole is in this room1 on the second floor of my house at ,meudon4 ,i am here1 and not elsewhere4 ,my body is here2 and my soul1 if ,i have one1 is here4 ,i am where my body is2 ,i believe even that ,i am within my body4 ,this localisation1 which certainly has not the exactness nor even the characteristics of the localisation of a material body in space1 seems to me to result from the very great importance we attach1 to the existence of our body in perception and in movement4 ,our body accompanies all our perceptions2 its changes of position cause these perceptions to vary2 the accidents which happen to it bring us pleasure or pain4 ,some of its movements are under our orders2 we observe that others are the consequences of our thoughts and our emotions4 ,it occupies1 therefore1 among the objects of cognition a privileged place1 which renders it more intimate and more dear to us than other objects4 ,there is no need to inquire here whether1 in absolute reality1 ,i am lodged within it1 for this ,i is an artificial product manufactured from memories4 ,i have before explained what is the value of the relation subject-object4 ,it is indisputable that in the manufacture of the subject we bring in the body4 ,this is too important an element for it not to have the right to form part of the synthesis2 it is really its nucleus4 ,as1 on the other hand1 all the other elements of the synthesis are psychical1 invisible1 and reduced to being faculties and powers1 it may be convenient to consider them as occupying the centre of the body or of the brain4 ,there is no need to discuss this synthesis1 for it is one of pure convenience4 ,as well inquire whether the personality of a public company is really localised at its registered offices1 round the green baize cover which adorns the table in the boardroom4 ,another definition of psychology1 which is at once a definition by content and a definition by method1 has often been employed by philosophers and physiologists4 ,it consists in supposing that there really exist two ways of arriving at the cognition of objects3 the within and the without4 ,these two ways are as opposed to each other as the right and wrong side of a stuff4 ,it is in this sense that psychology is the science of the within and looks at the wrong side of the stuff1 while the natural sciences look at the right side4 ,and it is so true1 they add1 that the same phenomenon appears under two radically different forms according as we look at it from the one or the other point of view4 ,thus1 it is pointed out to us1 every one of our thoughts is in correlation with a particular state of our cerebral matter2 our thought is the subjective and mental face2 the corresponding cerebral process is the objective and material face4 ,then the difference between representation1 which is a purely psychological phenomenon1 and a cerebral state which is a material one1 and reducible to movement1 is insisted upon2 and it is declared that these two orders of phenomena are separated by irreducible differences4 ,lastly1 to take account of the meaning of these differences1 and to explain them1 it is pointed out that they are probably connected with the modes of cognition which intervene to comprehend the mental and the physical4 ,the mental phenomenon1 we are told1 is comprehended by itself1 and as it is2 it is known without any mystery1 and in its absolute reality4 ,the physical phenomenon1 on the contrary1 only reaches us through the intermediary of our nerves1 more or less transformed in consequence by the handling in transport4 ,it is an indirect cognition which causes us to comprehend matter2 we have of this last only a relative and apparent notion1 which sufficiently explains how it may differ from a phenomenon of thought4 ,i have already had occasion to speak of this dualism1 when we were endeavouring to define sensation4 ,we return to its criticism once more1 for it is a conception which in these days has become classic2 and it is only by repeatedly attacking it that it will be possible to demonstrate its error4 ,to take an example3 ,i look at the plain before me1 and see a flock of sheep pass over it4 ,at the same time an observer is by my side and is not looking at the same thing as myself4 ,it is not at the plain that he looks2 it is1 ,i will suppose1 within my brain4 ,armed with a microscope la ,jules ,verne1 he succeeds in seeing what is passing beneath my skull1 and he notices within my fibres and nerve cells those phenomena of undulation which physiologists have hitherto described hypothetically4 ,this observer notices then1 that1 while ,i am looking over the plain1 my optic nerve conveys a certain kind of movements--these are1 ,i suppose1 displacements of molecules which execute a complicated kind of dance4 ,the movement follows the course of the optic nerve1 traverses the chiasma1 goes along the fascia1 passes the internal capsule1 and finally arrives at the visual centres of the occipital region4 ,here1 then1 are the two terms of comparison constituted3 on the one hand1 we have a certain representation--that is1 my own2 and on the other hand1 coinciding with this representation we have the dynamic changes in the nerve centres4 ,these are the two things constituting the right and wrong side of the stuff4 ,we shall be told3 ,see how little similarity there is here6 ,a representation is a physical fact1 a movement of molecules a material fact4 ,and further1 ,if these two facts are so little like each other1 it is because they reach us by two different routes4 ,i think both these affirmations equally disputable4 ,let us begin with the second4 ,where does one see that we possess two different sources of knowledge8 ,or that we can consider an object under two different aspects8 ,where are our duplicate organs of the senses1 of which the one is turned inward and the other outward8 ,in the example chosen for this discussion1 ,i have supposed two persons1 each of whom experiences a visual perception4 ,one looks at one object1 the other at another2 but both are looking with the same organs of sense1 that is1 with their eyes4 ,how is it possible to understand that these eyes can1 in turn1 according to the necessity of the moment1 see the two faces1 physical and mental1 of the same object8 ,they are the two faces of an identical object1 is the answer made to us1 because the two visions1 although applied to the same object1 are essentially different4 ,on the one hand is a sensation of displacement1 of movement1 of a dance executed by the molecules of some proteid substance2 on the other hand is a flock of sheep passing over the plain at a distance of a hundred metres away4 ,it seems to me that here also the argument advanced is not sound4 ,in the first place1 it is essential to notice that not only are the two paths of cognition identical1 but also that the perceptions are of the same nature4 ,there is in this no opposition between the physical and the mental4 ,what is compared are the two phenomena1 which are both mixed and are physico-mental--physical1 through the object to which they are applied1 mental1 through the act of cognition they imply4 ,to perceive an object in the plain and to perceive a dynamic state of the brain are two operations which each imply an act of cognition2 and1 in addition1 the object of this knowledge is as material in the one as in the other case4 ,a flock of sheep is matter just as much as my brain4 ,no doubt1 here are objects which differ2 my observer and myself have not the same perception4 ,i acknowledge1 but do not wonder at it4 ,how could our two perceptions be similar8 ,i look at the sheep1 and he at the interior of my brain4 ,it is not astonishing that1 looking at such different objects1 we should receive images also different4 ,or1 again1 if this other way of putting it be preferred1 ,i would say3 the individual ,a looks at the flock through the intermediary of his nervous system1 while ,b looks at it through that of two nervous systems1 put as it were end to end 7though not entirely71 his own nervous system first1 and then that of ,a4 ,how1 then1 could they experience the same sensation8 ,they could only have an identical sensation if the idea of the ancients were to be upheld1 who understood the external perception of bodies to result from particles detaching themselves from their bodies1 and after a more or less lengthy flight1 striking and entering into our organs of sense4#cf ,let us imagine1 just for a moment1 one of our nerves--the optic nerve1 for instance--transformed into a hollow tube1 along which the emissions of miniatures should wend their way4 ,in this case1 evidently1 if so strange a disposition were to be realised1 and if ,b could see what was flowing in the optic nerve of ,a1 he would experience a sensation almost analogous to that of ,a4 ,whenever the latter saw a dog1 a sheep1 or a shepherd1 ,b would likewise see in the optic canal minute dogs1 microscopic sheep1 and ,lilliputian shepherds4 ,at the cost of such a childish conception1 a parity of content in the sensations of our two spectators ,a and ,b might be supposed4 ,but ,i will not dwell on this4 ,the above considerations seem to me to explain the difference generally noticed between thought and the physiological process4 ,it is not a difference of nature1 an opposition of two essences1 or of two worlds--it is simply a difference of object2 just that which separates my visual perception of a tree and my visual perception of a dog4 ,there remains to know in what manner we understand the relation of these two processes3 this is another problem which we will examine later4 ,since the content does not give us the differentiation we desire1 we will abandon the definitions of psychology by content4 ,what now remains8 ,the definitions from the point of view4 ,the same fact may he looked at1 like a landscape1 from different points of view1 and appears different with the changes therein4 ,it is so with the facts we consider psychical1 and the autonomy of psychology would thus be a matter of point of view4 ,it has1 then1 been supposed--and this is a very important proposition--that the distinctive feature of psychical facts does not consist in their forming a class of particular events4 ,on the contrary1 their characteristic is to be studied in their dependency on the persons who bring them about4 ,this interesting affirmation is not new3 it may be read in the works of ,mach1 ,klpe1 ,mnsterberg1 and1 especially1 of ,ebbinghaus1 from whom ,i quote the following lines of quite remarkable clearness3 ,psychology is not distinguished from sciences like physics and biology1 which are generally and rightly opposed to it1 by a different content1 in the way that1 for instance1 zoology is distinguished from mineralogy or astronomy4 ,it has the same content1 but considers it from a different point of view and with a different object4 ,it is the science1 not of a given part of the world1 but of the whole world1 considered1 however1 in a certain relation4 ,it studies1 in the world1 those formations1 processes1 and relations1 the properties of which are essentially determined by the properties and functions of an organism1 of an organised individual4444 ,psychology1 in short1 considers the world from an individual and subjective point of view1 while the science of physics studies it as if it were independent of us4 ,over these definitions by point of view1 one might quibble a little2 for those who thus define psychology are not always consistent with themselves4 ,in other passages of their writings they do not fail to oppose psychical to physiological phenomena1 and they proclaim the irreducible heterogeneity of these two orders of phenomena and the impossibility of seeing in physics the producing cause of the moral4 ,ebbinghaus is certainly one of the modern writers who have most strongly insisted on this idea of opposition between the physiological and the psychical1 and he is a convinced dualist4 ,now ,i do not very clearly understand in what the principle of heterogeneity can consist to a mind which admits1 on the other hand1 that psychology does not differ from the physical sciences by its content4 ,however1 ,i confine myself here to criticising the consequences and not the starting point4 ,the definition of the psychical phenomenon by the point of view seems to me correct1 although it has more concision than clearness2 for it rests especially upon a material metaphor1 and the expression point of view hardly applies except to the changes of perspective furnished by visible objects4 ,it would be more exact to say that psychology specially studies certain objects of cognition1 such as those which have the character of representations 7reminiscences1 ideas1 concepts71 the emotions1 the volitions1 and the reciprocal influences of these objects among themselves4 ,it studies1 then1 a part of the material world1 of that world which till now has been called psychological1 because it does not come under the senses1 and because it is subjective and inaccessible to others than ourselves2 it studies the laws of those objects1 which laws have been termed mental4#cg ,these laws are not recognised1 popularly speaking1 either in physics or in biology2 they constitute for us a cognition apart from that of the natural world4 ,association by resemblance1 for example1 is a law of consciousness2 it is a psychological law which has no application nor counterpart in the world of physics or biology4 ,we may therefore sum up what has been said by the statement that psychology is the study of a certain number of laws1 relations1 and connections4 ,as to the particular feature which distinguishes mental from physical laws1 we can formulate it1 as does ,william ,james1 by saying that the essence of a mental law is to be teleological1 or1 if the phrase be preferred1 we can say that mental activity is a finalistic activity1 which expends itself as will in the pursuit of future ends1 and as intelligence in the choice of the means deemed capable of serving those ends4 ,an act of intelligence is recognised by the fact of its aiming at an end1 and employing for this end one means chosen out of many4 ,finality and intelligence are thus synonymous4 ,in opposition to mental law1 physical law is mechanical1 by which expression is simply implied the absence of finality4 ,finality opposed to mechanism2 such is the most concise and truest expression in which must be sought the distinctive attribute of psychology and of the moral sciences1 the essential characteristic by which psychological are separated from physical facts4 ,i think it may be useful to dwell a little on the mental laws which ,i have just opposed to the physical1 and whose object is to assure preadaptation and form a finality4#ch ,their importance cannot be exaggerated4 ,thanks to his power of preadaptation1 the being endowed with intelligence acquires an enormous advantage over everything which does not reason4 ,no doubt1 as has been shrewdly remarked1 natural selection resembles a finality1 for it ends in an adaptation of beings to their surroundings4 ,there is therefore1 strictly speaking1 such a thing as finality without intelligence4 ,but the adaptation resulting therefrom is a crude one1 and proceeds by the elimination of all that does not succeed in adapting itself2 it is a butchery4 ,real finalism saves many deaths1 many sufferings1 and many abortions4#ci ,let us examine1 then1 the process of preadaptation2 it will enable us to thoroughly comprehend1 not only the difference between the physical and the psychical laws1 but the reason why the psychical manages in some fashion to mould itself upon the physical law4 ,now1 the means employed by preadaptation is1 if we take the matter in its simplest form1 to be aware of sensations before they are experienced4 ,if we reflect that all prevision implies a previous knowledge of the probable trend of events1 it will be understood that the part played by intelligence consists in becoming imbued with the laws of nature1 for the purpose of imitating its workings4 ,by the laws of nature1 we understand here only that order of real sensations1 the knowledge of which is sufficient to fulfil the wants of practical life4 ,to us there are always gaps in this order1 because the sensation it is important for us to know is separated from us either by the barriers of time or of space1 or by the complication of useless sensations4 ,thence the necessity of interpolations4 ,that which we do not perceive directly by our senses1 we are obliged to represent to ourselves by our intelligence2 the image does the work of sensation1 and supplements the halting sensation in everything which concerns adaptation4 ,to replace the inaccessible sensation by the corresponding image1 is therefore to create in ourselves a representation of the outer world which is1 on all the points most useful to us1 more complete than the direct and sensorial presentation of the moment4 ,there is in us a power of creation1 and this power exercises itself in the imitation of the work of nature2 it imitates its order1 it reconstitutes on the small scale adapted to our minds1 the great external order of events4 ,now1 this work of imitation is only really possible if the imitator has some means at his disposal analogous to those of the model4 ,our minds could not divine the designs of nature1 if the laws of images had nothing in common with the laws of nature4 ,we are thus led to confront these two orders of laws with each other2 but1 before doing so1 one more preliminary word is necessary4 ,we have up till now somewhat limited the problem1 in order to understand it4 ,we have reduced the psychological being to one single function1 the intellectual1 and to one single object of research1 the truth4 ,this is1 however1 an error which has often been committed1 which is now known and catalogued1 called intellectualism1 or the abuse of intellectualism4 ,it is committed for this very simple reason1 that it is the intellectual part of our being which best allows itself to be understood1 and1 so to speak1 intellectualised4 ,but this leaves out of the question a part of our entire mental being so important and so eminent1 that if this part be suppressed1 the intelligence would cease to work and would have no more utility than a machine without motive power4 ,our own motive power is the will1 the feeling1 or the tendency4 ,will is perhaps the most characteristic psychical function1 since1 as ,i have already had occasion to say1 nothing analogous to it is met with in the world of nature4 ,let us therefore not separate the will from the intelligence1 let us incarnate them one in the other2 and1 instead of representing the function of the mind as having for its aim knowledge1 foresight1 the combination of means1 and self-adaptation1 we shall be much nearer the truth in representing to ourselves a being who wills to know1 wills to foresee1 and wills to adapt himself1 for1 after all1 he wills to live4 ,having said this1 let us compare the psychological law and that of nature4 ,are they identical8 ,we shall be told that they are not1 since1 as a fact1 errors are committed at every moment by the sudden failures of human reason4 ,this is the first idea which arises4 ,human error1 it would seem1 is the best proof that the two laws in question are not alike1 and we will readily add that a falling stone does not mistake its way1 that the crystal1 in the course of formation does not miss taking the crystalline shape1 because they form part of physical nature1 and are subject in consequence to its determinism4 ,but this is faulty reasoning1 and a moment of reflection demonstrates it in the clearest possible manner2 for adaptation may miss its aim without the being who adapts himself and his surroundings necessarily obeying different laws4 ,when the heat of a too early spring causes buds to burst forth prematurely which are afterwards destroyed by frost1 there is produced a fault of adjustment which resembles an error of adaptation1 and the bringing forward of this error does not necessarily imply that the tree and the whole of physical nature are obeying different laws4 ,moreover1 the difference between the laws of nature and those of the understanding does not need deduction by reasoning from an abstract principle2 it is better to say that it is directly observable1 and this is how ,i find that it presents itself to us4 ,the essential law of nature is relatively easy to formulate1 as it is comprised in the very definition of law4 ,it simply consists in the sentence3 uniformity under similar conditions4 ,we might also say3 a constant relation between two or several phenomena1 which can also be expressed in a more abstract way by declaring that the law of nature rests on the combination of two notions1 identity and constancy4 ,on the other hand1 the laws of our psychical activity partly correspond to the same tendencies1 and it would be easy to demonstrate that the microcosm of our thoughts is governed by laws which are also an expression of these two combined notions of constancy and identity4 ,it is1 above all1 in the working of the intellectual machine1 the best known and the most clearly analysed up till now1 that we see the application of this mental law which resembles1 as we say1 on certain sides1 the physical law3 and the best we can do for our demonstration will doubtless be to dissect our reasoning powers4 ,reason1 a process essential to thought in action1 is developed in accordance with a law which resembles in the most curious manner a physical law4 ,it resembles it enough to imitate it1 to conform to it1 and1 so to speak1 to mould itself on it4 ,now1 the reason does not follow the caprices of thought1 it is subject to rules2 it results from the properties of the images1 those properties which we have above referred to1 the material character of which we have recognised1 and which are two in number--similarity and contiguity1 as they are termed in the jargon of the schools4 ,they are properties which have for their aim to bring things together1 to unite1 and to synthetise4 ,they are unceasingly at work1 and so apparent in their labour that they have long been known4 ,we know1 since the time of ,aristotle1 that two facts perceived at the same time reproduce themselves together in the memory--this is the law of contiguity2 and that two facts perceived separately1 but which are similar1 are brought together in our mind--this is the law of similarity4 ,now1 similarity and contiguity form by combination the essential part of all kinds of reasoning1 and this reasoning1 thus understood1 works in a fashion which much resembles 7we shall see exactly in what degree7 a physical law4 ,i wish to show this in a few words4 ,what renders my demonstration difficult and perhaps obscure is1 that we shall be obliged to bring together rather unexpectedly categories of phenomena which are generally considered separate4 ,the distinctive attribute of the reason consists1 as ,i have said1 in the setting to work of these two elementary properties1 similarity and contiguity4 ,it consists1 in fact1 in extending continuity by similarity2 in endowing with identical properties and similar accompaniments things which resemble each other2 in other words1 it consists in impliedly asserting that the moment two things are identical in one point they are so for all the rest4 ,this will be fairly well understood by imagining what takes place when mental images having the above-mentioned properties meet4 ,suppose that ,b is associated with ,c1 and that ,a resembles ,b4 ,in consequence of their resemblance the passing from ,a to ,b is easy2 and then ,b suggesting ,c by contiguity1 it happens that this ,c is connected with ,a connected1 though1 in reality1 they have never been tried together4 ,i say they are associated on the basis of their relation to ,b1 which is the rallying point4 ,it is thus that1 on seeing a piece of red-hot iron 7,a71 ,i conclude it is hot 7,c71 because ,i recollect distinctly or unconsciously another piece of red-hot iron 7,b71 of which ,i once experienced the heat4 ,it is this recollection ,b which logicians1 in their analysis of logical1 verbal1 and formal argument1 call the middle term4 ,our representation of the process of reasoning is not special to argument4 ,it also expresses the process of invention1 and every kind of progress from the known to the unknown4 ,it is an activity which creates relations1 which assembles and binds together1 and the connections made between different representations are due to their partial identities1 which act as solder to two pieces of metal4 ,it will now be understood that these relations between the images curiously resemble the external order of things1 the order of our sensations1 the order of nature1 the physical law4 ,this is because this physical law also has the same character and expresses itself similarly4 ,we might say all things which resemble each other have the same properties1 or all things alike on one point resemble each other on all other points4 ,but immediately we do so1 the difference between the physical and the mental law becomes apparent4 ,the formula we have given is only true on condition that many restrictions and distinctions are made4 ,the process of nature is so to do that the same phenomenon always unfolds itself in the same order4 ,but this process is not always comprehended in real life1 for it is hidden from our eyes by the manifold combinations of chance2 in the reality that we perceive there is a crowd of phenomena which resemble each other but are not really the same4 ,there are a number of phenomena which co-exist or follow each other without this order of co-existence or succession being necessary or constant4 ,in other words1 there are resemblances which are the marks of something1 as a logician would say1 and others which are not the marks of anything2 there are relations of time and space which are the expression of a law2 there are some which are accidental1 and may possibly never be reproduced4 ,it would be a wonderful advantage if every scientific specialist would make out a list of the non-significant properties that he recognises in matter4 ,the chemist1 for example1 would show us that specific weight has hardly any value in diagnosis1 that the crystalline form of a salt is often not its own1 that its colour especially is almost negligible because an immense number of crystals are white or colourless1 that precipitation by a given substance does not ordinarily suffice to characterise a body1 and so on4 ,the botanist1 on his part1 would show us that1 in determining plants1 absolute dimension is less important than proportion1 colour less important than form1 certain structures of organs less important than others4 ,the pathologist would teach us that most pathological symptoms have but a trivial value2 the cries1 the enervation1 the agitation of a patient1 even the delirium which so affects the bystanders1 are less characteristic of fever than the rate of his pulse1 and the latter less than the temperature of the armpit or the dryness of the tongue1 c4 ,at every moment the study of science reveals resemblances of facts and contiguities of facts which must be neglected for the sake of others4 ,and if we pass from this profound knowledge of the objects to the empirical knowledge1 to the external perception of bodies1 it is in immense number that one espies around one traps laid by nature4 ,the sound we hear resembles several others1 all produced by different causes2 many of our visual sensations likewise lend themselves to the most varied interpretations2 by the side of the efficient cause of an event we find a thousand entangled contingencies which appear so important that to disentangle them we are as much perplexed as the savage1 who1 unable to discriminate between causes and coincidences1 returns to drink at the well which has cured him1 carefully keeping to the same hour1 the same gestures1 and the same finery4 ,the reason of this is that the faculty of similarity and the faculty of contiguity do not give the distinction1 necessary as it is1 between resemblances and co-existences which are significant and those which are not4 ,the causal nexus between two phenomena is not perceived as something apart and sui generis2 it is not even perceived at all4 ,we perceive only their relation in time and space1 and it is our mind which raises a succession to the height of a causal connection1 by intercalating between cause and effect something of what we ourselves feel when we voluntarily order the execution of a movement4 ,this is not the place to inquire what are the experimental conditions in which we subject phenomena to this anthropomorphic transformation2 it will suffice for us to repeat here that1 in perception1 a chance relation between phenomena impresses us in the same way as when it is the expression of a law4 ,our intellectual machine sometimes works in accord with the external law and at others makes mistakes and goes the wrong way4 ,then we are obliged to correct it1 and to try a better adjustment1 either by profounder experimenting with nature 7methods of concordance1 discordance1 variations1 c471 or by a comparison of different judgments and arguments made into a synthesis2 and this collaboration of several concordant activities ends in a conclusion which can never represent the truth1 but only the probable truth4 ,the study of the laws of the mind shows us too clearly1 in fact1 their fluidity with regard to the laws of nature for us not to accept probabilism4 ,there exists no certitude--only very varied degrees of probability4 ,daily practice contents itself with a very low degree of probability2 judicial logic demands a rather higher one1 especially when it is a question of depriving one of our fellow-creatures of liberty or life4 ,science claims one higher still4 ,but there is never anything but differences of degrees in probability and conjecture4 ,this1 then1 is the definition of psychology that we propose4 ,it studies a certain number of laws which we term mental1 in opposition to those of external nature1 from which they differ1 but which1 properly speaking1 do not deserve the qualification of mental1 since they are--or at least the best known of them are--laws of the images1 and the images are material elements4 ,although it may seem absolutely paradoxical1 psychology is a science of matter--the science of a part of matter which has the property of preadaptation4 ,,footnotes3 ,footnote #cc3 ,,lange1 ,histoire du ,matrialisme1 ,,ii41 #bme4 partie1 chap4 iii4 ,footnote #cd3 ,let us remark1 in passing1 how badly nature has organised the system of communication between thinking beings4 ,in what we experience we have nothing in common with our fellows2 each one experiences his own sensations and not those of others4 ,the only meeting point of different minds is found in the inaccessible domain of the noumena4 ,footnote #ce3 ,e4 ,,rabier1 ,leons de ,philosophie1 ,psychologie1 p4 #cc4 ,footnote #cf3 ,this seems to have been the opinion of ,democritus4 ,the modern doctrine of radiation from the human body1 if established1 would go nearly as far as the supposition in the text4 ,up till now1 however1 it lacks confirmation4--,,ed4 ,footnote #cg3 ,i am compelled1 much against my will1 to use throughout this passage an equivocal expression1 that of mental law1 or law of consciousness1 or psychological law4 ,i indicate by this the laws of contiguity and of similarity2 as they result from the properties of the images1 and as these are of a material nature1 they are really physical and material laws like those of external nature4 ,but how can all these laws be called physical laws without running the risk of confusing them one with the other8 ,footnote #ch3 ,finality seems to be here used in the sense of the doctrine which regards perfection as the final cause of existence4--,,ed4 ,footnote #ci3 ,see a very interesting article by ,e4 ,,goblot1 ,la ,finalit sans ,intelligence1 ,revue de ,mtaphysique1 ,july #aijj4 ,,book ,,iii ,,the ,,union ,,of ,,the ,,soul#dj ,,and ,,the ,,body ,,chapter ,i ,,the ,,mind ,,has ,,an ,,incomplete ,,life ,the problem of the union of the mind and the body is not one of those which present themselves in pure speculation2 it has its roots in experimental facts1 and is forced upon us by the necessity of explaining observations such as those we are about to quote4 ,the force of our consciousness1 the correctness of our judgments1 our tempers and our characters1 the state of health of our minds1 and also their troubles1 their weaknesses1 and even their existence1 are all in a state of strict dependence on the condition of our bodies1 more precisely with that of our nervous systems1 or1 more precisely still1 with the state of those three pounds of proteid substance which each of us has at the back of his forehead1 and which are called our brains4 ,this is daily demonstrated by thousands upon thousands of observations4 ,the question is to know how this union of the body with the consciousness is to be explained1 it being assumed that the two terms of this union present a great difference in their nature4 ,the easier it seems to demonstrate that this union exists1 the more difficult it appears to explain how it is realised2 and the proof of this difficulty is the number of divergent interpretations given to it4 ,were it a simple question of fact1 the perpetual discussions and controversies upon it would not arise4 ,many problems here present themselves4 ,the first is that of the genesis or origin of the consciousness4 ,it has to be explained how a psychical phenomenon can appear in the midst of material ones4 ,in general1 one begins by supposing that the material phenomena are produced first2 they consist1 for instance1 in the working of the nervous centres4 ,all this is physical or chemical1 and therefore material4 ,then at a given moment1 after this mechanical process1 a quite different phenomenon emerges4 ,this is thought1 consciousness1 emotion4 ,then comes the question whether this production of thought in the midst of physical phenomena is capable of explanation1 and how thought is connected with its physical antecedents4 ,what is the nature of the link between them8 ,is it a relation of cause to effect1 of genesis8 or a coincidence8 or the interaction of two distinct forces8 ,is this relation constant or necessary8 ,can the mind enjoy an existence independent of the brain8 ,can it survive the death of the brain8 ,the second question is that of knowing what is the rle1 the utility1 and the efficacity of the psychical phenomenon4 ,once formed1 this phenomenon evolves in a certain direction and assumes to us who have consciousness of it a very great importance4 ,what is its action on the material phenomena of the brain which surround it8 ,does it develop according to laws of its own1 which have no relation to the laws of brain action8 ,does it exercise any action on these intra-cerebral functions8 ,does it exercise any action on the centrifugal currents which go to the motor nerves8 ,is it capable of exciting a movement8 or is it deprived of all power of creating effect8 ,we will briefly examine the principal solutions which the imagination of mankind has found for these very difficult problems4 ,some of the best known of these solutions bear the names of spiritualism1 materialism1 parallelism1 and monism4 ,we will speak of these and of some others also4 ,before beginning our critical statement1 let us recall some of the results of our previous analyses which here intrude themselves1 to use the ambitious language of ,kant1 as the prolegomena to every future solution which claims the title of science4 ,in fact1 we are now no longer at the outset of our investigation4 ,we have had to acknowledge the exactness of certain facts1 and we are bound to admit their consequences4 ,notably1 the definition of psychical phenomena at which we arrived1 not without some trouble1 will henceforth play a rather large part in our discussion4 ,it will force us to question a great metaphysical principle which1 up till now1 has been almost universally considered as governing the problem of the union of the mind with the body4 ,this principle bears the name of the axiom of heterogeneity1 or the principle of psycho-physical dualism4 ,no philosopher has more clearly formulated it1 and more logically deduced its consequences1 than ,flournoy4 ,this author has written a little pamphlet called ,mtaphysique et ,psychologie1 wherein he briefly sets forth all the known systems of metaphysics by reducing them to the so-called principle of heterogeneity2 after this1 the same principle enables him to execute them4 ,he formulates it in the following terms3 body and mind1 consciousness and the molecular cerebral movement of the brain1 the psychical fact and the physical fact1 although simultaneous1 are heterogeneous1 unconnected1 irreducible1 and obstinately two4#da ,the same author adds3 this is evident of itself1 and axiomatic4 ,every physical1 chemical1 or physiological event1 in the last resort1 simply consists1 according to science1 in a more or less rapid displacement of a certain number of material elements1 in a change of their mutual distances or of their modes of grouping4 ,now1 what can there be in common1 ,i ask you1 what analogy can you see1 between this drawing together or moving apart of material masses in space1 and the fact of having a feeling of joy1 the recollection of an absent friend1 the perception of a gas jet1 a desire1 or of an act of volition of any kind8 ,and further on3 ,all that we can say to connect two events so absolutely dissimilar is1 that they take place at the same time4444 ,this does not mean that we wish to reduce them to unity1 or to join them together by the link of causality 444 it is impossible to conceive any real connection1 any internal relation between these two unconnected things4 ,let us not hesitate to denounce as false this proposition which is presented to us as an axiom4 ,on looking closely into it1 we shall perceive that the principle of heterogeneity does not contain the consequences it is sought to ascribe to it4 ,it seems to me it should be split up into two propositions of very unequal value3 #a1 the mind and body are heterogeneous2 #b1 by virtue of this heterogeneity it is not possible to understand any direct relation between the two4 ,now1 if the first proposition is absolutely correct1 in the sense that consciousness and matter are heterogeneous1 the second proposition seems to us directly contrary to the facts1 which show us that the phenomena of consciousness are incomplete phenomena4 ,the consciousness is not sufficient for itself2 as we have said1 it cannot exist by itself4 ,this again1 if you like1 is an axiom1 or rather it is a fact shown by observation and confirmed by reflection4 ,mind and matter brought down to the essential1 to the consciousness and its object1 form a natural whole1 and the difficulty does not consist in uniting but in separating them4 ,consider the following fact3 ,i experience a sensation1 and ,i have consciousness of it4 ,this is the coupling of two things--a sensation and a cognition4 ,the two elements1 if we insist upon it1 are heterogeneous1 and they differ qualitatively2 but notwithstanding the existing prejudice by reason of which no direct relation1 no commerce1 can be admitted between heterogeneous facts1 the alliance of the consciousness and the sensation is the natural and primitive fact4 ,they can only be separated by analysis1 and a scrupulous mind might even ask whether one has the right to separate them4 ,i have a sensation1 and ,i have consciousness of it4 ,if not two facts1 they are one and the same4 ,now1 sensation is matter and my consciousness is mind4 ,if ,i am judging an assortment of stuffs1 this assortment1 or the sensation ,i have of them1 is a particle of matter1 a material state1 and my judgment on this sensation is the psychical phenomenon4 ,we can neither believe1 nor desire1 nor do any act of our intelligence without realising this welding together of mind and matter4 ,they are as inseparable as motion and the object that moves2 and this comparison1 though far-fetched1 is really very convenient4 ,motion cannot exist without a mobile object2 and an object1 on the other hand1 can exist without movement4 ,in the same way1 sensation may exist without the consciousness2 but the converse proposition1 consciousness without sensation1 without an object1 an empty consciousness or a pure thought1 cannot be understood4 ,let us mark clearly how this union is put forward by us4 ,we describe it after nature4 ,it is observation which reveals to us the union and the fusion of the two terms into one4 ,or1 rather1 we do not even perceive their union until the moment when1 by a process of analysis1 we succeed in convincing ourselves that that which we at first considered single is really double1 or1 if you like1 can be made into two by the reason1 without being so in reality4 ,thus it happens that we bring this big problem in metaphysics on to the field of observation4 ,our solution vaguely resembles that which has sometimes been presented under the ancient name of physical influx1 or under the more modern name of inter-actionism4 ,there are many authors who maintain that the soul can act directly on the body and modify it1 and this is what is called inter-actionism4 ,thereby is understood1 if ,i mistake not1 an action from cause to effect1 produced between two terms which enjoy a certain independence with regard to each other4 ,this interpretation is indubitably close to ours1 though not to be confused with it4 ,my personal interpretation sets aside the idea of all independence of the mind1 since it attributes to the mind an incomplete and1 as it were1 a virtual existence4 ,if we had to seek paternity for ideas ,i would much rather turn to ,aristotle4 ,it was not without some surprise that ,i was able to convince myself that the above theory of the relations between the soul and the body is to be found almost in its entirety in the great philosopher4 ,it is true that it is mixed up with many accessory ideas which are out of date and which we now reject2 but the essential of the theory is there very clearly formulated1 and that is the important point4 ,a few details on this subject will not be out of place4 ,i give them1 not from the original source1 which ,i am not erudite enough to consult direct1 but from the learned treatise which ,bain has published on the psychology of ,aristotle1 as an appendix to his work on the ,senses and the ,intelligence4 ,the whole metaphysics of ,aristotle is dominated by the distinction between form and matter4 ,this distinction is borrowed from the most familiar fact in the sensible world--the form of solid objects4 ,we may name a substance without troubling ourselves as to the form it possesses1 and we may name the form without regard to the substance that it clothes4 ,but this distinction is a purely abstract one1 for there can be no real separation of form from matter1 no form without matter1 and no matter without form4 ,the two terms are correlative2 each one implies the other1 and neither can be realised or actualised without the other4 ,every individual substance can be considered from a triple point of view3 #ast1 form2 #bnd1 matter2 and #crd1 the compound or aggregate of form and matter1 the inseparable ,ens1 which transports us out of the domain of logic and abstraction into that of reality4 ,aristotle recognises between these two logical correlatives a difference in rank4 ,form is superior1 nobler1 the higher in dignity1 nearer to the perfect entity2 matter is inferior1 more modest1 more distant from perfection4 ,on account of its hierarchical inferiority1 matter is often presented as the second1 or correlatum1 and form as the first1 or relatum4 ,this difference in rank is so strongly marked1 that these two correlations are likewise conceived in a different form--that of the potential and the actual4 ,matter is the potential1 imperfect1 roughly outlined element which is not yet actual1 and may perhaps never become so4 ,form is the actual1 the energy1 the entelechy which actualises the potential and determines the final compound4 ,these few definitions will make clear the singularly ingenious idea of ,aristotle on the nature of the body1 the soul1 and of their union4 ,the body is matter which is only intelligible as the correlatum of form2 it can neither exist by itself nor be known by itself--that is to say1 when considered outside this relation4 ,the soul is form1 the actual4 ,by uniting with the body it constitutes the living subject4 ,the soul is the relatum1 and is unintelligible and void of sense without its correlatum4 ,the soul1 says ,aristotle1 is not a variety of body1 but it could not exist without a body3 the soul is not a body1 but something which belongs or is relative to a body4 ,the animated subject is a form plunged and engaged in matter1 and all its actions and passions are so likewise4 ,each has its formal side which concerns the soul1 and its material side which concerns the body4 ,the emotion which belongs to the animated subject or aggregate of soul and body is a complex fact having two aspects logically distinguishable from each other1 each of which is correlative to the other and implies it4 ,it is thus not only with our passions1 but also with our perceptions1 our imaginations1 reminiscences1 reasonings1 and efforts of attention to learn4 ,intelligence1 like emotion1 is a phenomenon not simply of the corporeal organism nor of the ,greek3 ,nous only1 but of the commonalty or association of which they are members1 and when the intelligence weakens it is not because the ,greek3 ,nous is altered1 but because the association is destroyed by the ruin of the corporeal organism4 ,these few notes1 which ,i have taken in their integrity from ,bain's text1 allow us thoroughly to comprehend the thought of ,aristotle1 and it seems to me that the ,greek philosopher1 by making of the soul and body two correlative terms1 has formed a comparison of great exactness4 ,i also much admire his idea according to which it is through the union of the body and soul that the whole1 which till then was only possible1 goes forth from the domain of logic and becomes actual4 ,the soul actualises the body1 and becomes1 as he said1 its entelechy4 ,these views are too close to those ,i have myself just set forth for it to be necessary to dwell on their resemblance4 ,the latter would become still stronger if we separated from the thought of ,aristotle a few developments which are not essential1 though he allowed them great importance3 ,i refer to the continual comparison he makes with the form and matter of corporeal objects4 ,happy though it may be1 this comparison is but a metaphor which perhaps facilitates the understanding of ,aristotle's idea1 but is not essential to his theory4 ,for my part1 ,i attach far greater importance to the character of relatum1 and correlatum ascribed to the two terms mind and matter1 and to the actualisation#db produced by their union4 ,let me add another point of comparison4 ,aristotle's theory recalls in a striking manner that of ,kant on the a priori forms of thought4 ,the form of thought1 or the category1 is nothing without the matter of cognition1 and the latter is nothing without the application of form4 ,thoughts without content given by sensation are empty2 intuitions without concept furnished by the understanding are blind4 ,there is nothing astonishing in finding here the same illustration1 since there is throughout a question of describing the same phenomenon1--the relation of mind to matter4 ,there remains to us to review the principal types of metaphysical systems4 ,we shall discuss these by taking as our guide the principle we have just evolved1 and which may be thus formulated3 ,the phenomena of consciousness constitute an incomplete mode of existence4 ,,footnotes3 ,footnote #dj3 ,see ,note #a on p4 #c4 ,footnote #da3 ,for reference1 see ,note #ah on p4 #gc4--;,,ed4 ,footnote #db3 i4e4 rendering actual4--,,ed4 ,,chapter ,,ii ,,spiritualism#dc ,,and ,,idealism ,flournoy has somewhere written that the chief interest of the systems of metaphysics lies less in the intellectual constructions they raise than in the aspirations of the mind and of the heart to which they correspond4 ,without taking literally this terribly sceptical opinion1 it would be highly useful to begin the study of any metaphysical system by the psychology of its author4 ,the value of each system would be better understood1 and their reasons would be comprehended4 ,this book is too short to permit us to enter into such biographical details4 ,i am obliged to take the metaphysical systems en bloc1 as if they were anonymous works1 and to efface all the shades1 occasionally so curious1 that the thought of each author has introduced into them4 ,yet1 however brief our statement1 it seems indispensable to indicate clearly the physical or moral idea concealed within each system4 ,,spiritualism ,it is known that spiritualism is a doctrine which has for its chief aim the raising of the dignity of man1 by recognising in him faculties superior to the properties of matter4 ,we constantly meet1 in spiritualism1 with the notion of superior and inferior1 understood not only in an intellectual sense but also in the sense of moral worth4 ,it will also be remarked1 as a consequence of the above principle1 that a spiritualist does not confine himself to discussing the ideas of his habitual adversary1 the materialist2 he finds them not only false1 but dangerous1 and is indignant with them2 some persons even ingenuously acknowledge that they hold firmly to certain principles because they fear to be converted to materialism4 ,i can also discern in this system a very natural horror of death1 which inspires in so many people1 of whom ,i am one1 both hatred and disgust4 ,the spiritualist revolts against the prospect of a definitive annihilation of thought1 and the system he adopts is largely explained as an effort towards immortality4 ,this effort has led to the theory of two substances1 the soul and the body1 which are represented as being as thoroughly separated as possible4 ,the soul has not its origin in the body1 and it derives none of its properties from its fellow2 it is a substance created in complete independence relatively to the body2 the soul1 in its essence1 has nothing in common with matter4 ,the essence of the soul1 said ,descartes1 is thought2 the essence of the body is extent4 ,it follows from this that the soul1 in its determinations and actions1 is liberated from the laws and necessities of the corporeal nature2 it is a free power1 a power of indetermination1 capable of choice1 capable of introducing new1 unforeseen1 and unforeseeable actions1 and on this point opposes itself to corporeal phenomena1 which are all subject to a determinism so rigorous that any event could be foreseen if its antecedents were known4 ,another consequence of spiritualism is the admission of the immortality of the soul1 which1 being widely distinct from the body1 is not affected by its dissolution2 it is1 on the contrary1 liberated1 since death cuts the link which binds them together4 ,but there is a link1 and the explanation of this link brings with it the ruin of the whole system4 ,one is forced to admit that this principle of the separation of body and soul is liable1 in fact1 to many exceptions4 ,even if they are two isolated powers1 the necessities of life oblige them to enter continually into communication with each other4 ,in the case of perceptions1 it is the body which acts on the soul and imparts sensations to it2 in movements1 it is the soul1 on the contrary1 which acts on the body1 to make it execute its desires and its will4 ,spiritualists must acknowledge that they are at some trouble to explain this traffic between the two substances2 for1 with their respect for the principle of heterogeneity mentioned above1 they do not manage to conceive how that contact of the physical and the mental can be made which is constantly necessary in the life of relation4 ,by what means1 have they long asked themselves1 can that which is only extent act on that which is only thought8 ,how can we represent to ourselves this local union of matter with an immaterial principle1 which1 by its essence1 does not exist in space8 ,the two substances have been so completely separated1 to insure the liberty of the soul and its superiority over the body1 that it has become impossible to bring them together4 ,the scission has been too complete4 ,they cannot be sewn together again4 ,such are the principal objections raised against spiritualism4 ,these objections are derived from points of view which are not ours1 and we have therefore no need to estimate their value4 ,from our point of view1 the spiritualist conception has chosen an excellent starting point4 ,by establishing the consciousness and the object of cognition as two autonomous powers1 neither of which is the slave of the other1 spiritualism has arrived at an opinion of irreproachable exactness2 it is indeed thus that the relations of these two terms must be stated2 each has the same importance and the right to the same autonomy4#dd ,yet1 spiritualism has not rested there1 and1 by a lamentable exaggeration1 it has thought that the consciousness1 which it calls the soul1 could exercise its functions in complete independence of the object of cognition1 which it calls matter4 ,there is the error4 ,it consists in misunderstanding the incomplete and1 as it were1 virtual existence of the consciousness4 ,this refutation is enough as regards spiritualism4 ,nothing more need be added4 ,,idealism ,idealism is an exceedingly complex system1 varying much with varying authors1 very polymorphous1 and consequently very difficult to discuss4 ,the ancient hylozoism1 the monadism of ,leibnitz1 and the recent panpsychism of ,m4 ,strong are only different forms of the same doctrine4 ,like spiritualism1 with which it is connected by many ties1 idealism is a philosophy which expresses some disdain for matter1 but the thoughts which have sought to shelter themselves under this philosophy are so varied that it would be perilous to try to define them briefly4 ,there can be discussed in idealism a certain number of affirmations which form the basis of the system4 ,none of these affirmations is1 strictly speaking1 demonstrated or demonstrable2 but they offer very different degrees of probability1 and it is for this reason that we shall notice them4 ,amongst these affirmations there are some that we have already met with in our study of the definition of sensation2 others will be newer to us4 #a4 ,here is one which seems to arise directly from the facts1 and appears for a long time to have constituted an impregnable position for idealists4 ,it may be expressed in three words3 esse est percipi4 ,starting with the observation that every time we bear witness to the existence of the external world1 it is because we perceive it1 idealists admit that the existence of this external world shares exactly the lot of our perception1 and that like it it is discontinuous and intermittent4 ,when we close our eyes1 it ceases to exist1 like a torch which is extinguished1 and lights up again when we open them4 ,we have already discussed this proposition1 and have shown that it contains nothing imperative2 and we may very well decline to subscribe to it4 #b4 ,there follows a second proposition1 barely distinct from the previous one4 ,there should be nothing else in objects but that which we perceive1 and that of which we have consciousness should be1 in the fullest possible acceptation of the words1 the measure of what is4 ,consequently there should be no need to seek1 under the object perceived1 another and larger reality1 a source from which might flow wider knowledge than that we at present possess4 ,this is as disputable as the preceding affirmation1 and for the same reasons4 #c4 ,the third proposition is the heart of the idealist thesis4 ,it is sometimes presented as a deduction from the foregoing1 but it is nevertheless thoroughly distinct from it1 and the preceding affirmations might legitimately be accepted and this new one rejected4 ,this proposition may be expressed thus3 ,everything that is perceived is psychical4 ,it is not only idealists who subscribe to this opinion1 however1 and we have seen1 when dealing with the definition of matter1 that it is widely spread4 ,we understand by it that the objects we perceive exist in the consciousness1 are of the consciousness1 and are constituted by ideas2 the whole world is nothing but idea and representation2 and1 since our mind is taken to be of a psychical nature1 the result is that everything1 absolutely everything1 the person who knows and the thing known1 are all psychical4 ,this is panpsychism4 ,flournoy1 on this point1 says1 with a charm coloured by irony3 ,we henceforth experience a sweet family feeling1 we find ourselves1 so to speak1 at home in the midst of this universe 444#de ,we have demonstrated above that the unity here attained is purely verbal1 since we cannot succeed in suppressing the essential differences of things4 #d4 ,now comes an affirmation on the genesis of things4 ,after having admitted that the object is an idea of the mind1 one of its manifestations1 or one of its moods1 the idealists go so far as to say that the consciousness is the generating power of ideas1 and1 consequently1 the generating cause of the universe4 ,it is thought which creates the world4 ,that is the final conclusion4 ,i indicated1 beforehand1 in the chapters on the definition of sensation and on the distinction between the consciousness and the object1 the reasons which lead me to reject the premises of idealism4 ,it will be sufficient to offer here a criticism on its last conclusion3 ,it is the mind that creates the world4 ,this thesis strikes at the duality--consciousness and object2 it gives the supremacy to the consciousness by making of the object an effect or property of the former4 ,we can object that this genesis cannot be clearly represented1 and that for the very simple reason that it is impossible to clearly accept mind as a separate entity and distinct from matter4 ,it is easy to affirm this separation1 thanks to the psittacism of the words1 which are here used like counterfeit coin1 but we cannot represent it to ourselves1 for it corresponds to nothing4 ,the consciousness constitutes all that is mental in the world2 nothing else can be described as mental4 ,now this consciousness only exists as an act2 it is1 in other terms1 an incomplete form of existence1 which does not exist apart from its object1 of which the true name is matter4 ,it is therefore very difficult to understand this affirmation1 ,it is the mind that creates the world1 since to be able to do so1 we should have to imagine a consciousness without an object4 ,moreover1 should we even succeed in doing so1 we should be none the more disposed1 on that account1 to give assent to this proposition4 ,consciousness and matter represent to us the most different and antithetical terms of the whole of the knowable4 ,were the hypothesis to be advanced that one of these elements is capable of engendering the other1 we should immediately have to ask ourselves why this generating power and this pre-eminence should be attributed to one rather than to the other element4 ,who can claim that one solution is more clear1 more reasonable1 or more probable than the other8 ,one of the great advantages of the history of philosophy here asserts itself4 ,this history shows us that different minds when reflecting on the same problems have come to conceive solutions which have appeared to them clear1 and consequently were possible2 now1 as these solutions are often contradictory1 nothing shows better than their collation the distance between possibility and fact4 ,thus the materialists1 who1 like the idealists1 have put forward a genetic theory of the mind1 have conceived mind as produced by matter2--a conception diametrically opposed to that of the idealists4 ,it may be said that these two conceptions1 opposed in sense1 annul each other1 and that each of these two philosophical systems has rendered us service by demonstrating the error of the opposing system4 ,,footnotes3 ,footnote #dc3 ,it is1 perhaps1 needless to point out that by spiritualism ,m4 ,binet does not mean the doctrine of the spirit-rappers1 whom he1 like other scientific writers1 designates as spiritists1 but the creed of all those who believe in disembodied spirits or existences4--,,ed4 ,footnote #dd3 ,i do not insist on the difference between my conception and the spiritualistic conception2 my distinction between consciousness and matter does not correspond1 it is evident1 to that of facts of consciousness and physical facts which spiritualism sets up4 ,footnote #de3 ,archives de ,psychologie1 vol4 iv4 ,no4 #ad1 ,nov4 #aijd1 p4 #acb 7article on ,panpsychism74 ,,chapter ,,iii ,,materialism ,,and ,,parallelism ,materialism is a very ancient doctrine4 ,it is even the most ancient of all1 which simply proves that amongst the different explanations given of our double physico-mental nature1 this doctrine is the easiest to understand4 ,the origin of materialism is to be found in the beliefs of savage tribes1 and is again found1 very clearly defined1 in the philosophy of those ancient ,greeks who philosophized before ,plato and ,aristotle4 ,a still stranger fact is that the thoughts of a great number of the ,fathers of the ,church inclined towards the philosophy of matter4 ,then1 in the course of its evolution1 there occurred a moment of eclipse1 and materialism ceased to attract attention till the contemporary period in which we assist at its re-birth1 ,nowadays1 it constitutes a powerful doctrine1 the more so that it has surreptitiously crept into the thoughts of many learned men without their being clearly conscious of it4 ,there are many physicists and physiologists who think and speak as materialists1 though they have made up their minds to remain on the battle-ground of observed facts and have a holy horror of metaphysics4 ,in a certain sense1 it may be said that materialism is the metaphysics of those who refuse to be metaphysicians4 ,it is very evident that in the course of its long history1 materialism has often changed its skin4 ,like all knowledge1 it has been subject to the law of progress2 and1 certainly1 it would not have been of a nature to satisfy the intellectual wants of contemporary scholars1 had it not stripped itself of the rude form under which it first manifested itself in the mind of primitive man4 ,yet what has enabled the doctrine to keep its unity through all its changes is that it manifests a deeply human tendency to cling by preference to everything visible and tangible4 ,whatever strikes the eyes1 or can be felt by the hand1 seems to us in the highest degree endowed with reality or existence4 ,it is only much later1 after an effort of refined thought1 that we come to recognise an existence in everything that can be perceived in any way whatever1 even in an idea4 ,it is still later that we understand that existence is not only that which is perceived but also that which is linked logically with the rest of our knowledge4 ,a good deal of progress has been necessary to reach this point4 ,as ,i have not the slightest intention of giving even an abridged history of materialism1 let us come at once to the present day1 and endeavour to say in what consists the scientific form this doctrine has assumed4 ,its fundamental basis has not changed4 ,it still rests on our tendency to give chief importance to what can be seen and touched2 and it is an effect of the hegemony of three of our senses1 the visual1 the tactile1 and the muscular4 ,the extraordinary development of the physical sciences has no doubt given an enormous encouragement to materialism1 and it may be said that in the philosophy of nature it occupies a principal place1 and that it is there in its own domain and unassailable4 ,it has become the expression of the idea that everything that can be explained scientifically1 everything susceptible of being measured1 is a material phenomenon4 ,it is the representation of the material explanation pushed to its last limits1 and all experiments1 all calculations1 all inductions resting on the grand principle of the conservation of matter and energy plead in its favour4 ,we will examine with some precision how far such a doctrine solves the problem of the existence of the intellectual functions4 ,the doctrine has understood this connection as being purely material1 and has sought its image in other phenomena which are entirely so4 ,thus1 it has borrowed from physiology the principle of its explanation1 it has transported into the domain of thought the idea of function1 and it has supposed that the soul is to the body in the relation of function to organ4 ,intelligence would thus be a cerebral function4 ,to explain intelligence1 materialists link it with matter1 turn it into a property of matter1 and compare it to a movement of matter1 and sometimes even to a secretion4 ,so ,karl ,vogt1 the illustrious ,genevan naturalist1 one day declared1 to the great scandal of every one1 that the brain secretes the thought as the kidney does urine4 ,this bold comparison seemed shocking1 puerile1 and false1 for a secretion is a material thing while thought is not4 ,karl ,vogt also employed another comparison3 the brain produces the thought as the muscle produces movement1 and it at once seems less offensive to compare the thought to a movement than to compare it to a liquid secretion4 ,at the present day1 an illustration still more vague would be used1 such as that of a transformation of energy3 chemical energy disengaged by the nerve centres would be thus looked upon as transformed into psychical energy4 ,however1 it matters little what metaphors are applied to for help in explaining the passage from the physical to the mental4 ,what characterises materialist philosophy is its belief in the possibility of such a passage1 and its considering it as the genesis of thought4 ,one calls materialist1 says ,renouvier1 with great exactness1 every philosophy which defines thought as the product of a compound whose elements do not imply thought4 ,a sweeping formula which allows us to foresee all the future avatars of the materialist doctrine1 and to class them beforehand in the same category4 ,the criticisms which have been directed against materialism are all1 or nearly all1 variations of the principle of heterogeneity4 ,we will not dwell long on this1 but simply recollect that1 according to this principle1 it is impossible to attribute to the brain the capacity of generating consciousness4 ,physical force can indeed generate physical force under the same or a different form1 and it thus produces all the effects which are determined by the laws of nature4 ,but it is impossible to comprehend how physical force can enrich itself at a given moment by a conscious force4 ,physical force is reduced to movements of bodies and to displacements of atoms2 how could a change of position in any inert objects give rise to a judgment1 a reasoning1 or any phenomenon of the consciousness8 ,it is further said3 this idea of function1 which materialists here introduce to render more comprehensible the passage from a material body to a spiritual action1 contains only an empty explanation1 for the function is not essentially distinct by its nature from the organ2 it is simply the organ in activity1 it adds to the organ taken in a state of repose but one change1 viz4 activity1 that is to say movement1 and1 consequently1 the function of an organ is material by the same right as the organ4 ,when a muscle contracts1 this contraction1 which is the proper function of the muscular fibre1 consists in a condensation of the muscular protoplasm1 and this condensation is a material fact4 ,when a gland enters into activity1 a certain quantity of liquid flows into the channels of the gland1 and this liquid is caused by a physical and chemical modification of the cellular protoplasm2 it is a melting1 or a liquefaction1 which likewise is material4 ,the function of the nerve cell is to produce movement1 or to preserve it1 or to direct it2 ii is material like the cells4 ,there is therefore nothing in all those functional phenomena which might lead us to understand how a material cause should be capable of engendering a conscious effect4 ,it seems that all materialists have acknowledged that here is the vulnerable point in their theory1 for it is the principle of heterogeneity which they have especially combated4 ,but their defence is wanting in frankness1 and principally consists in subterfuges4 ,in brief1 it affirms that we are surrounded with mystery1 that we are not sufficiently learned to have the right to impose limits to the power of matter1 and to say to it3 ,thou shalt not produce this phenomenon4 ,a materialist theologian declares that he sees no impossibility in stones thinking and arguing1 if ,god1 in ,his infinite power1 has decided to unite thought with brute matter4 ,this argument is not really serious2 it demands the intervention of so powerful a ,deus ex machina1 that it can be applied equally to all problems2 to solve all is to solve none4 ,modern materialists rightly do not bring ,god into the question4 ,their mode of argument takes another form2 but it remains to be seen if1 at bottom1 it is not the same as the other4 ,it simply consists in affirming that up till now we know certain properties of matter only1 but that science every day discovers new ones2 that matter is a reservoir of unknown forces1 and that it is not impossible that the origin of psychical forces may yet be discovered in matter4 ,this idea is clearly hinted at by ,littr4 ,the physicist ,tyndall gave it a definite formula when he uttered at the ,belfast ,congress this phrase so often quoted3 ,if ,i look back on the limits of experimental science1 ,i can discern in the bosom of that matter 7which1 in our ignorance1 while at the same time professing our respect for its ,creator1 we have1 till now1 treated with opprobrium7 the promise and the power of all forms and qualities of life4 ,the opponents of the doctrine have not ceased to answer that the matter of to-morrow1 like the matter of to-day1 can generate none but material effects1 and that a difficulty is not solved by putting off its solution to some indefinite date in our scientific evolution3 and it certainly seems that the counter-stroke is decisive1 if we admit the principle of heterogeneity with its natural consequence4 ,we will now criticise the above doctrine by making use of the ideas ,i have above enunciated4 ,the criticism we have to apply to materialism is not the same as that just summarised4 ,the axis of the discussion changes its position4 ,in the first place1 ,i reproach materialism with presenting itself as a theory of the generation of the consciousness by the object4 ,we have already reproached idealism with putting itself forward as a theory of the generation of the object by the consciousness4 ,the error of the two systems is produced in a converse direction1 but is of the same gravity4 ,the consciousness and its object1 we say yet again1 constitute the widest division it is possible to effect in the domain of cognition2 it is quite as illegitimate to reduce the first term to the second as to reduce the second to the first4 ,to reduce one to the other1 by way of affiliation or otherwise1 there must first be discovered1 then1 an identity of nature which does not exist4 ,in the second place1 when one examines closely the explanation materialism has imagined in order to derive thought from an action of matter1 it is seen that this representation is rendered completely impossible by all we know of the nature of thought4 ,for the materialist to suppose for one moment that thought is a cerebral function1 he must evidently make an illusion for himself as to what thought is1 and must juggle with concepts4 ,perhaps1 could we penetrate into his own inmost thought1 we should discover that at the moment he supposes a mere cell can manufacture the phenomena of consciousness1 some vague image suggests itself to him whereby he identifies these phenomena with a light and subtle principle escaping from the nerve cell1 something which resembles an electric effluve1 or a will-of-the-wisp1 or the flame from a punch-bowl4#df ,i cannot1 of course1 tell whether my supposition is correct4 ,but what ,i assert1 with the calmness of perfect certitude1 is that the materialist has not taken the pains to analyse attentively what he calls the phenomenon of consciousness4 ,had he made this analysis and kept the elements in his mind1 he would have seen that it is almost impossible to hook in any way a phenomenon of consciousness on to a material molecule4 ,in fact1 also1 to take this into account1 we will not remain within the vagueness of the concept1 but will take a particular example to argue upon1 viz4 that of an external perception4 ,i open my window on a fine day1 and ,i see before me a sunny plain1 with1 as far as the eye can reach1 houses amongst the trees1 and again more houses1 the most distant of which are outlined against my far-off horizon4 ,this is my mental phenomenon4 ,and while ,i am at my window1 my eyes fixed on the view1 the anatomist declares that1 starting from my retina1 molecular vibrations travel along the optic nerve1 cross each other at the chiasma1 enter into the fascia1 pass through the internal capsule and reach the hemispheres1 or rather the occipital regions1 of the brain1 where1 for the moment1 we agree to localise the centre of projection of the visual sensations4 ,this is my physical phenomenon4 ,it now becomes the question of passing from this physical phenomena to the mental one4 ,and here we are stopped by a really formidable difficulty4 ,my mental phenomenon is not entirely mental1 as is usually supposed from the deceitful brevity of the phrase4 ,it is in great part physical1 for it can be decomposed into two elements1 a consciousness and its object2 and this object of the consciousness1 this group of little houses ,i see in the plain1 belongs to sensation--that is to say1 to something physical--or1 in other words1 to matter4 ,let us examine in its turn the physical process which is supposed to be discovered in my nervous centres while ,i am in course of contemplating the landscape4 ,this pretended physical process itself1 quite as much as my conscious perception of the landscape1 is a physico-psychical phenomenon2 for my cerebral movements are perceived1 hypothetically at least1 by an observer4 ,this is a perception1 consequently it can be decomposed into two things1 a consciousness and its object4 ,as a further consequence1 when we wish1 by a metaphysical effort1 to attach the consciousness to a material state of the brain and to establish a link between the two events1 it will be found that we wrongly hook one physico-mental phenomenon on to another4 ,but1 evidently1 this objection is not a refutation4 ,we may if we choose suppose that the so-called cerebral process is capable of subsisting at moments when no one perceives it1 and that it exists of itself1 is sufficient for itself1 and is entirely physical4 ,but can we subject the mental process of perception to the same purification8 ,can we separate these two elements1 the consciousness and its object1 retain the element consciousness and reject the element object1 which is physical1 thus constituting a phenomenon entirely mental1 which might then be possibly placed beside the entirely physical phenomenon1 so as to study their relation to each other8 ,this is quite impossible1 and the impossibility is double1 for it exists de facto and de jure4 ,de jure1 because we have already established that a consciousness empty and without object cannot be conceived4 ,de facto1 because the existence of the object that consciousness carries with it is very embarrassing for the materialist2 for this object is material1 and as real and material as the fibres and cells of the brain4 ,it might1 indeed1 be supposed that by transformation or otherwise there goes forth from the cerebral convolution a purely psychical phenomenon resembling a wave4 ,but how can we conceive the transformation of this convolution into a semi-material phenomenon8 ,how can we comprehend that there should issue from this convolution the material object of a perception--for example1 a plain dotted with houses8 ,an ,english histologist remarked one day1 with some eloquence1 how little the most minute study of the brain aided us to understand thought4 ,he was thus answering ,auguste ,comte1 who1 in a moment of aberration1 claimed that psychology1 in order to become a science1 ought to reject the testimony of the consciousness1 and to use exclusively as its means of study the histology of the nerve centres and the measurement of the cranium4 ,our histologist1 who had passed part of his life examining1 under the microscope1 fragments of cerebral matter1 in following the forms of the cells1 the course of the fibres1 and the grouping and distribution of the fascia1 made the following remark3 ,it is the fact that the study1 however patient1 minute1 and thorough it might be1 of this nerve-skein can never enable us to know what a state of consciousness is1 if we do not know it otherwise2 for never across the field of the microscope is there seen to pass a memory1 an emotion1 or an act of volition4 ,and1 he added1 he who confines himself to peering into these material structures remains as ignorant of the phenomena of the mind as the ,london cabman who1 for ever travelling through the streets of the great city1 is ignorant of what is said and what is going on in the interior of the houses4 ,this picturesque comparison1 the truth of which has never been questioned1 is based on this supposition1 that the psychical act is entirely immaterial and invisible1 and therefore escapes the piercing eye of the microscope4 ,but a deeper analysis of the mind shows how little exact is this assertion4 ,from the moment each psychical act implies a material object1 we can ask ourselves two things3 7#a7 ,why is it that the anatomist does not discover these material objects in the interior of the brain8 ,we ought to see them1 for they are material1 and therefore visible4 ,we ought to see them with their aspect and colour1 or be able to explain why they are not seen4 ,in general1 all that is described to us in the brain is the molecular vibrations4 ,but we are not conscious of them4 ,where1 then1 is that of which we are conscious8 7#b7 ,it should next be explained to us by what elaboration1 transmutation1 or metamorphosis a molecular disturbance1 which is material1 can transform itself into the objects which are equally material4 ,this is the criticism we have to address to materialism4 ,until proof to the contrary1 ,i hold it to be irrefutable4 ,,parallelism ,for this exposition to follow the logical order of ideas1 the discussion on materialism should be immediately succeeded by that on parallelism4 ,these two doctrines are near akin2 they resemble each other as the second edition of a book1 revised and corrected1 resembles the first4 ,parallelism is the materialist doctrine of those forewarned folk1 who have perceived the errors committed and endeavour to avoid them1 while cherishing all that can be saved of the condemned doctrine4 ,that which philosophers criticised in materialism was the misunderstanding of the principle of heterogeneity4 ,the parallelists have seen this mistake1 and have taken steps to respect this principle3 we shall see in what way4 ,they are especially prudent1 and they excel in avoiding being compromised4 ,they put forth their hypothesis as a provisional one1 and they vaunt its convenience4 ,it is1 say they1 a practical method of avoiding many difficulties2 it becomes for philosophers an equivalent of that phrase which so many timorous ministers repeat3 ,above all1 no scrapes6 ,let us study the exact point on which parallelism has amended materialism4 ,we have seen that every materialist doctrine is the expression of this idea1 that physical phenomena are the only ones that are determined1 measurable1 explicable1 and scientific4 ,this idea does wonders in the natural sciences1 but is at fault when1 from the physical1 we pass into the moral world1 and we have seen how the materialistic doctrine fails when it endeavours to attach the physical to the mental4 ,there are then two great difficulties which the materialistic explanation finds before it2 one is a difficulty of mechanism and the other of genesis4 ,by connecting the mind with the brain1 like a function to its organ1 this doctrine seeks to solve these two problems1 and with what little success we have seen4 ,parallelism1 has tried to avoid these two problems2 not only does it not solve them1 but it arranges so as not to propound them4 ,the expedient adopted consists in avoiding the meeting of the physical and the mental2 instead of placing them end to end and welding one to the other1 they are placed in parallel fashion side by side4 ,to explain their correlation1 which so many observations vaguely demonstrate1 the following hypothesis is advanced4 ,physical and psychical life form two parallel currents1 which never mingle their waters2 to every state of definite consciousness there corresponds the counterpart of an equally definite state of the nerve centres2 the fact of consciousness has its antecedents and its consequences in the consciousness2 and the physical fact equally takes its place in a chain of physical facts4 ,the two series are thus evolved1 and correspond strictly to each other according to a necessary law2 so that the scholar who was perfectly instructed1 and to whom one of these states was presented1 could describe its fellow4 ,but never does any of the terms of one series influence the terms of the other4 ,observation and the testimony of the consciousness seem to attest this dual progress2 but they are1 according to the parallelist hypothesis1 illusions4 ,when ,i move my arm by a voluntary act1 it is not my will1 qua act of consciousness1 which determines the movement of the arm--for this is a material fact4 ,the movement is produced by the coming into play of groups of muscles4 ,each muscle1 composed of a semi-fluid substance1 being excited1 contracts in the direction of its greatest length4 ,the excitant of the muscles is also a material fact1 a material influx which starts from the motor cells of the encephalon1 and of which we know the course down through the pyramidal fascium1 the anterior roots of the spinal cord1 and the nerves of the periphery to its termination in the motor plates of the muscles4 ,it is this excitement which is the physical1 direct1 and veritable cause of voluntary movements4 ,and it is the same with all acts and signs1 all expressions of our conscious states2 the trembling of fear1 the redness of anger1 the movements of walking1 down to the words we utter--all these are physical effects produced by physical processes1 which act physically1 and of which the mental counterpart has in itself no effective action4 ,let it be understood that ,i am here pointing out one of the forms1 and that the most usual1 of the parallelist theory4 ,each author varies it according to his fancy2 some widen the correspondence between the physical and the moral1 others prefer to narrow it4 ,at one time a vague relation is supposed which is only true on a large scale1 and is a union rather than an equivalence4 ,at another1 it is an exact counterpart1 a complete duplicate in which the smallest physical event corresponds to a mental one4 ,in one of the forms of this theory that has been recently invented1 parallelists have gone so far as to assert that there exists no real cohesion in the mental chain1 and that no mental phenomenon can have the property of provoking another mental phenomenon by an act of true causality4 ,it is within the nervous tissue1 they say1 that the nexus of psychic states should be enclosed4 ,these should succeed in time without being directly connected with one another2 they should succeed because the physical basis of them is excited in succession4 ,some of them would be like an air on the piano3 the notes follow each other and arrange themselves into melodies1 not by any affinity proper to themselves1 but because the keys of the instrument are struck in the required order4 ,i said a little while ago that parallelism was a perfected materialism4 ,the reason of this will be understood4 ,it is a doctrine which preserves the determinism of physical facts while avoiding the compromising of itself in the difficult explanation of the connection between the soul and the body4 ,it remains scientific without raising a metaphysical heresy4 ,bain is one of those who have most clearly expressed1 not only the advantages1 but also the aspirations of this theory 7,mind and ,body1 p4 #acj73-- ,we have every reason for believing1 he says1 that there is in company with all our mental processes1 an unbroken material succession4 ,from the ingress of a sensation1 to the outgoing responses in action1 the mental succession is not for an instant dissevered from a physical succession4 ,a new prospect bursts upon the view2 there is mental result of sensation1 emotion1 thought--terminating in outward displays of speech or gesture4 ,parallel to this mental series is the physical series of facts1 the successive agitation of the physical organs1 called the eye1 the retina1 the optic nerve1 optic centres1 cerebral hemispheres1 outgoing nerves1 muscles1 c4 ,while we go the round of the mental circle of sensation1 emotion1 and thought1 there is an unbroken physical circle of effects4 ,it would be incompatible with everything we know of the cerebral action1 to suppose that the physical chain ends abruptly in a physical void1 occupied by an immaterial substance2 which immaterial substance1 after working alone1 imparts its results to the other edge of the physical break1 and determines the active response--two shores of the material with an intervening ocean of the immaterial4 ,there is1 in fact1 no rupture of nervous continuity4 ,the only tenable supposition is1 that mental and physical proceed together1 as undivided twins4 ,on reading this passage it is easy to see the idea which forms the basis of the doctrine4 ,it is1 as ,i have already said1 the fetichism of mechanics3 parallelism takes its inspiration from this quite as directly as does materialism1 but with more skill1 inasmuch as it avoids the most dangerous question1 that of the interaction of physics and morals1 and replaces it by an hypothesis much resembling ,leibnitz's hypothesis of the pre-established harmony1 ,on the other hand1 a second merit of this prudent doctrine is the avoiding the question of genesis4 ,it does not seek for the origin of thought1 but places this last in a relation of parallelism with the manifestations of matter2 and in the same way that parallel lines prolonged ad infinitum never meet1 so the partisans of this doctrine announce their resolution not to inquire how the actual state of things has been formed1 nor how it will end if1 for example1 one of the terms should disappear by the death of the bodily organism4 ,notwithstanding so many precautions1 criticisms have not been wanting2 only they would seem not to have touched the weak part of the doctrine and not to be decisive4 ,we will only run through them briefly4 ,it has been said3 there is no logical necessity which forces us to refuse to the consciousness the privilege of acting in complete independence of the nervous mechanism4 ,it has also been said3 it is by no means certain that any nervous mechanism can be invented which imitates and1 if need were1 could replace an intellectual act4 ,for instance1 what association of nerve cells1 what molecular action1 can imitate an act of comparison which enables us to see a resemblance between two objects8 ,let it be supposed1 for example1 that the resemblance of two impressions come from a partial identity1 and that the latter has for material support an identity in the seat or the form of the corresponding nervous influx4 ,but what is identity8 ,how can it be conceived without supposing resemblance1 of which it is but a form8 ,how1 then1 can the one be explained by the other8 ,thus1 for instance1 at the bottom of all our intellectual acts1 there is a certain degree of belief4 ,can any material combination be found which corresponds thereto8 ,there is one last objection1 the most serious of all4 ,parallelism1 by establishing a fixed and invariable relation between the physical and the moral1 ends by denying the rle of this last1 since the physical mechanism is sufficient to draw to itself all the effects which general belief attributes to the moral4 ,the parallelists on this point go very much further than the materialists2 the latter at least concede that the consciousness is of some use1 since they compared it to a function or a secretion1 and1 after all1 a secretion is a useful liquid4 ,the parallelists are so strongly convinced that mechanism is alone efficacious that they come to deny any rle to thought4 ,the consciousness for them has no purpose3 yet it keeps company with its object4 ,the metaphors which serve to define it1 part of which have been imagined by ,huxley1 are all of a passive nature4 ,such is the light1 or the whistling noise which accompanies the working of an engine1 but does not act on its machinery4 ,or1 the shadow which dogs the steps of the traveller4 ,or a phosphorescence lighting up the traces of the movements of the brain4 ,it has also been said that the consciousness is a useless luxury4 ,some have even gone further1 and the fine and significant name of epiphenomenon1 that has been given to thought1 well translates that conception1 according to which semi-realities may exist in nature4 ,all these objections certainly carry great weight1 but they are not capable of killing the doctrine--they only scotch it4 ,i think there is a radical vice in parallelism1 which till now has not been sufficiently indicated1 and ,i ask what can really remain of the whole edifice when this vice has been once exposed8 ,parallelism implies a false idea1 which we have already come across when discussing materialism4 ,it is the idea that a phenomenon of consciousness constitutes one complete whole4 ,the error proceeds from the use of concepts which cause the reality to be lost sight of4 ,the reality shows that every phenomenon of consciousness consists in a mode of activity1 an aggregate of faculties which require an object to fasten on to and so realise themselves1 and that this object is furnished by matter4 ,what we always note in intuition is the union1 the incarnation of consciousness-matter4 ,our thoughts1 our memories1 our reasonings have as object sensations1 images--that is to say1 things which1 strictly speaking1 are as material as our own brains4 ,it is therefore rather childish to put all these workings of the spirit on another plane and in another world than the workings of the brain since they are in great part of the same nature as the last named and they contain so many material elements4 ,now if we re-establish facts as they are1 if we admit a parallelism between physical phenomena1 on the one hand1 and phenomena at once physical and psychical1 on the other1 the parallelist hypothesis loses every sort of meaning4 ,it ceases to present to us the image of two phenomena of an absolutely different order1 which are found coupled together like the two faces of a unity1 the front and back of a page1 the right and wrong side of a stuff4 ,if there is anything material in the psychical part1 the opposition of nature no longer exists between the two terms2 they become identical4 ,very often1 certain parallelists1 after thinking they have discovered the duality of nature1 endeavour to bring it back to unity by supposing that the two faces of the reality are as two effects of one unique reality1 inaccessible to our senses and underlying appearances4 ,why go so far afield to seek unity8 ,it is trouble in vain3 for it is to be found in the phenomenon itself4 ,,footnotes3 ,footnote #df3 ,i can quote two observations in support of this4 ,m4 ,,brieux1 to whom ,i was relating this part of my argument1 stopped me1 saying1 ,you have guessed right2 ,i represent to myself thought issuing from brain in the form of an electric gleam4 ,dr4 ,,simon also informed me1 during the reading of my manuscript1 that he saw thought floating over the brain like an ignis fatuus4 ,,chapter ,,iv ,,modern ,,theories ,it may be thought that the objection taken above to parallelism and materialism is personal to myself1 because ,i have put it forward as the consequence of my analysis of the respective shares of thought and matter in every act of cognition4 ,this is not so4 ,i am here in harmony with other philosophers who arrived at the same conclusions long before me1 and it may be useful to quote them4 ,we will begin with the prince of idealists1 ,berkeley4 ',everything you know or conceive other than spirits1' says ,philonous to ,hylas1 'is but your ideas2 so then when you say that all ideas are occasioned by impressions made in the brain1 either you conceive this brain or you do not4 ,if you conceive it1 you are in that case talking of ideas imprinted in an idea which is the cause of this very idea1 which is absurd4 ,if you do not conceive it1 you are talking unintelligibly1 you are not forming a reasonable hypothesis4' ',how can it be reasonable1' he goes on to say1 'to think that the brain1 which is a sensible thing1 i4e4 which can be apprehended by the senses--an idea consequently which only exists in the mind--is the cause of our other ideas8'#dg ,thus1 in the reasoning of ,berkeley1 the function of the brain cannot explain the production of ideas1 because the brain itself is an idea1 and an idea cannot be the cause of all our other ideas4 ,m4 ,bergson's argument is quite similar1 although he takes a very different standpoint from that of idealism4 ,he takes the word image in the vaguest conceivable sense4 ,to explain the meaning of this word he simply says3 images which are perceived when ,i open my senses1 and unperceived when ,i close them4 ,he also remarks that the external objects are images1 and that the brain and its molecular disturbances are likewise images4 ,and he adds1 ,for this image which ,i call cerebral disturbance to generate the external images1 it would have to contain them in one way or another1 and the representation of the whole material universe would have to be implicated in that of this molecular movement4 ,now1 it is enough to enunciate such a proposition to reveal its absurdity4#dh ,it will be seen that this reasoning is the same as ,berkeley's1 though the two authors are reasoning on objects that are different2 according to ,berkeley1 the brain and the states of conscience are psychical states2 according to ,bergson1 the definition of the nature of these two objects designated by the term image is more comprehensive1 but the essential of his argument is independent of this definition4 ,it is enough that the two terms should be of similar nature for one to be unable to generate the other4 ,my own argument in its turn comes rather near the preceding ones4 ,for the idea of ,berkeley1 and the image of ,bergson1 ,i substitute the term matter4 ,i say that the brain is matter1 and that the perception of any object is perception of matter1 and ,i think it is not easy to explain how from this brain can issue this perception1 since that would be to admit that from one matter may come forth another matter4 ,there is certainly here a great difficulty4 ,m4 ,bergson has thought to overcome it by attacking it in the following way4 ,he has the very ingenious idea of changing the position of the representation in relation to the cerebral movement4 ,the materialist places the representation after this movement and derives it from the movement2 the parallelist places it by the side of the movement and in equivalence to it4 ,m4 ,bergson places it before the movement1 and supposes it to play with regard to it the part of exciting cause1 or simply that of initiator4 ,this cerebral movement becomes an effect of the representation and a motor effect4 ,consequently the nervous system passes into the state of motor organ3 the sensory nerves are not1 as supposed1 true sensory nerves1 but they are the commencements of motor nerves1 the aim of which is to lead the motor excitements to the centres which play the part of commutators and direct the current1 sometimes by one set of nerves1 sometimes by others4 ,the nervous system is like a tool held in the hand3 it is a vehicle for action1 we are told1 and not a substratum for cognition4 ,i cannot here say with what ingenuity1 with what powerful logic1 and with what close continuity of ideas ,m4 ,bergson develops his system1 nor with what address he braves its difficulties4 ,his mind is remarkable alike for its power of systematisation and its suppleness of adaptation4 ,before commencing to criticise him1 ,i am anxious to say how much ,i admire him1 how much ,i agree with him throughout the critical part of his work1 and how much ,i owe to the perusal of his book1 ,matire et ,mmoire4 ,though ,i was led into metaphysics by private needs1 though some of the ideas ,i have set forth above were conceptions of my own 7for example1 the criticism of the mechanical theory of matter1 and the definition of sensation71 before ,i had read ,m4 ,bergson's book1 it cannot be denied that its perusal has so strongly modified my ideas that a great part of these are due to him without my feeling capable of exactly discerning which2 for ideas have a much more impersonal character than observations and experiments4 ,it would therefore have been ungrateful to criticise him before having rendered him this tribute4 ,there are1 in ,m4 ,bergson's theory1 a few assertions which surprise us a little1 like everything which runs counter to old habits4 ,it has always been supposed that our body is the receptacle of our psychological phenomena4 ,we store our reminiscences in our nerve centres2 we put the state of our emotions in the perturbations of certain apparatus2 we find the physical basis of our efforts of will and of attention in the sensations of muscular tension born in our limbs or trunk4 ,directly we believe that the nervous system is no longer the depository of these states1 we must change their domicile2 and where are they to be placed8 ,here the theory becomes obscure and vague1 and custom renders it difficult to understand the situation of the mind outside the body4 ,m4 ,bergson places memory in planes of consciousness far removed from action1 and perception he places in the very object we perceive4 ,if ,i look at my bookcase1 my thought is in my books2 if ,i look at the sky1 my thought is in a star4#di ,it is very difficult to criticise ideas such as these1 because one is never certain that one understands them4 ,i will therefore not linger over them1 notwithstanding the mistrust which they inspire in me4 ,but what seems to me to require proof is the function ,m4 ,bergson is led to attribute to the sensory nerves4 ,to his mind1 it is not exact to say that the excitement of a sensory nerve excites sensation4 ,this would be a wrong description1 for1 according to him1 every nerve1 even a sensory one1 serves as a motor2 it conducts the disturbance which1 passing through the central commutator1 flows finally into the muscles4 ,but then1 whence comes it that ,i think ,i feel a sensation when my sensory nerve is touched8 ,whence comes it that a pressure on the epitrochlear nerve gives me a tingling in the hand8 ,whence comes it that a blow on the eyeball gives me a fleeting impression of light8 ,one must read the page where ,m4 ,bergson struggles against what seems to me the evidence of the facts4 ,if1 for one reason or another1 he says1 the excitement no longer passes1 it would be strange if the corresponding perception took place1 since this perception would then put our body in relation with points of space which would no longer invite it to make a choice4 ,divide the optic nerve of any animal2 the disturbance starting from the luminous point is no longer transmitted to the brain1 and thence to the motor nerves4 ,the thread which connected the external object to the motor mechanism of the animal by enveloping the optic nerve1 is severed2 the visual perception has therefore become powerless1 and in this powerlessness consists unconsciousness4 ,this argument is more clever than convincing4 ,it is not convincing1 because it consists in exaggerating beyond all reason a very real fact1 that of the relation which can be discovered between our sensations and our movements4 ,we believe1 with ,m4 ,bergson1 that it is absolutely correct to see in action the end and the raison d'tre of our intelligence and our sensibility4 ,but does it follow that every degree1 every shade1 every detail of sensation1 even the most insignificant1 has any importance for the action8 ,the variations of sensibility are much more numerous than those of movements and of adaptation2 very probably1 as is seen in an attentive study of infancy1 sensibility precedes the power of motion in its differentiations4 ,a child shows an extraordinary acuteness of perception at an age when its hand is still very clumsy4 ,the correlation1 then1 is not absolute4 ,and then even if it were so1 it would not follow that the suppression of any movement would produce by rebound the suppression of the sensation to which this movement habitually corresponds4 ,on this hypothesis1 a sensation which loses its motor effect becomes useless4 ,be it so2 but this does not prove that the uselessness of a sensation is synonymous with insensibility4 ,i can very well imagine the movement being suppressed and the useless sensation continuing to evoke images and to be perceived4 ,does not this occur daily8 ,there are patients who1 after an attack of paralysis remain paralysed in one limb1 which loses the voluntary movement1 but does not necessarily lose its sensibility4 ,many clear cases are observed in which this dissociation takes place4 ,i therefore own that ,i cannot follow ,m4 ,bergson in his deduction4 ,as a physiologist1 ,i am obliged to believe firmly in the existence of the sensory nerves1 and therefore ,i continue to suppose that our conscious sensations are consequent to the excitement of these nerves and subordinate to their integrity4 ,now1 as therein lies1 unless ,i mistake1 the essential postulate1 the heart of ,m4 ,bergson's theory1 by not admitting it ,i must regretfully reject the whole4 ,,footnotes3 ,footnote #dg3 ,i borrow this quotation from ,,renouvier1 ,le ,personnellisme1 p4 #bfc4 ,footnote #dh3 ,matire et ,mmoire1 p4 #c4 ,the author has returned to this point more at length in a communication to the ,congrs de ,philosophie de ,gnve1 in #aijd4 ,see ,revue de ,mtaphysique et de ,morale1 ,nov4 #aijd1 communication from ,h4 ,,bergson entitled ,le ,paralogisme psycho-physiologique4 ,here is a passage from this article which expresses the same idea3 ,to say that the image of the surrounding world issues from this image 7from the cerebral movement71 or that it expresses itself by this image1 or that it arises as soon as this image is suggested1 or that one gives it to one's self by giving one's self this image1 would be to contradict one's self2 since these two images1 the outer world and the intra-cerebral movement1 have been supposed to be of the same nature1 and the second image is1 by the hypothesis1 an infinitesimal part of the field of representation1 while the first fills the whole of it4 ,footnote #di3 ,matire et ,mmoire1 p4 #ca ,,chapter ,v ,,conclusion ,a few convinced materialists and parallelists1 to whom ,i have read the above criticisms on their systems1 have found no answer to them2 my criticisms have appeared to them just1 but nevertheless they have continued to abide by their own systems1 probably because they were bound to have one4 ,we do not destroy an erroneous idea when we do not replace it by another4 ,this has decided me to set forth some personal views which1 provisionally1 and for want of better1 might be substituted for the old doctrines4 ,before doing this1 ,i hasten to explain their character1 and to state openly that they are only hypotheses4 ,i know that metaphysicians rarely make avowals of this kind4 ,they present their systems as a well-connected whole1 and they set forth its different parts1 even the boldest of them1 in the same dogmatic tone1 and without warning that we ought to attach very unequal degrees of confidence to these various parts4 ,this is a deplorable method1 and to it is perhaps due the kind of disdain that observers and experimentalists feel for metaphysics--a disdain often without justification1 for all is not false1 and everything is not hypothetical1 in metaphysics4 ,there are in it demonstrations1 analyses1 and criticisms1 especially the last1 which appear to me as exact and as certain as an observation or experiment4 ,the mistake lies in mixing up together in a statement1 without distinction1 the certain with the probable1 and the probable with the possible4 ,metaphysicians are not wholly responsible for this fault of method2 and ,i am much inclined to think that it is the natural consequence of the abuse of speculation4 ,it is especially by the cultivation of the sciences of observation that we foster in ourselves the precious sense of proof1 because we can check it any minute by experimental verification4 ,when we are working at a distance from the facts1 this sense of proof gets thinner1 and there is lost that feeling of responsibility and fear of seeing one's assertions contradicted by a decisive countervailing observation1 which is felt by every observer4 ,one acquires the unbearable pride which ,i note in ,kant1 and one abandons one's self to the spirit of construction4 ,i am speaking from personal experience4 ,i have several times detected within me this bad spirit of construction1 ,i have been seeking to group several facts of observation under the same idea1 and then ,i have discovered that ,i was belittling and depreciating those facts which did not fit in with the idea4 ,the hypothesis ,i now present on the relations of the mind and the brain has1 for me1 the advantage of bringing to light the precise conditions which a solution of this great problem must satisfy for this solution to be worthy of discussion4 ,these conditions are very numerous4 ,i shall not indicate them all successively2 but here are two which are particularly important4 #a4 ,the manifestations of the consciousness are conditioned by the brain4 ,let us suspend1 by any means1 the activity of the encephalic mass1 by arresting the circulation of the blood for example1 and the psychic function is at once inhibited4 ,compress the carotid1 and you obtain the clouding-over of the intellect4 ,or1 instead of a total abolition1 you can have one in detail2 sever a sensory nerve with the bistoury1 and all the sensations which that nerve transmits to the brain are suppressed4 ,consciousness appears only when the molecular disturbance reaches the nerve centres2 everything takes place in the same way as if this disturbance released the consciousness4 ,consciousness also accompanies or follows certain material states of the nerve centres1 such as the waves which traverse the sensory nerves1 which exercise reflex action in the cells1 and which propagate themselves in the motor nerves4 ,it is to the production1 the distribution1 and the integrity of this nervous influx that the consciousness is closely linked4 ,it there finds one of the conditions of its apparition4 #b4 ,on the other hand1 the consciousness remains in complete ignorance of these intra-cerebral phenomena4 ,it does not perceive the nerve-wave which sets it in motion1 it knows nothing of its peculiarities1 of its trajectory1 or the length of its course4 ,in this sense it may be said that it is in no degree an anatomist2 it has no idea of all the peculiarities of the nerve-wave which form part of its cerebral history from the moment when these peculiarities are out of relation with the properties of external objects4 ,one sometimes wonders that our consciousness is not aware that the objects we perceive with our two eyes correspond to a double undulation1 namely1 that of the right and that of the left1 and that the image is reversed on the retina1 so that it is the rods of the right which are impressed by objects on our left1 and the rods of the upper part by objects below our eyes4 ,these are1 it has been very justly said1 factitious problems1 imaginary difficulties which do not exist4 ,there is no need to explain1 for instance1 direct vision by a reversed image1 because our consciousness is not aware that the image on the retina is reversed4 ,in order to take account of this1 we should require another eye to see this image4 ,this answer appears particularly to the point4 ,it will be found that it is absolutely correct if we reflect that this case of the unfelt inversion of the image on the retina is but one example of the anatomical ignorance of the consciousness4 ,it might also be declared1 in the same order of ideas1 that our consciousness is ignorant1 that excitements of the eye cross each other at the level of the chiasma1 and pass through the internal capsule1 and that the majority of the visual excitements of an eye are received by the opposite hemisphere4 ,a rather confused notion of these facts has formed itself in the minds of several critics1 and ,i can discern the proof of this in the language they use4 ,it will be said1 for example1 that the idea exists in the consciousness or in the mind1 and phrases like the following will be avoided3 ,i think with my brain--the suggestion consists in introducing an idea in the brain--,the nerve cell perceives and reasons1 c4 ,ordinarily these forms of speech are criticised because they appear to have the defect of establishing a confusion between two irreducible elements1 the physical and the mental4 ,i think the error of language proceeds from another cause1 since ,i do not admit this distinction between the physical and the mental4 ,i think that the error consists in supposing vaguely that the consciousness comprehends intra-cerebral phenomena1 whereas it ignores them4 ,let me repeat that there is no such thing as intra-cerebral sensibility4 ,the consciousness is absolutely insensitive with regard to the dispositions of the cerebral substance and its mode of work4 ,it is not the nervous undulation which our consciousness perceives1 but the exciting cause of this wave--that is1 the external object4 ,the consciousness does not feel that which is quite close to it1 but is informed of that which passes much further off4 ,nothing that is produced inside the cranium interests it2 it is solely occupied with objects of which the situation is extra-cranial4 ,it does not penetrate into the brain1 we might say1 but spreads itself like a sheet over the periphery of the body1 and thence springs into the midst of the external objects4 ,there is1 therefore1 ,i do not say a contradiction1 but a very striking contrast between these two facts4 ,the consciousness is conditioned1 kept up1 and nourished by the working of the cerebral substance1 but knows nothing of what passes in the interior of that substance4 ,this consciousness might itself be compared to a parasitical organism which plunges its tap roots into the nerve centres1 and of which the organs of perception1 borne on long stalks1 emerge from the cranium and perceive everything outside that cranium4 ,but this is1 of course1 only a rough image4 ,strictly1 it is possible to explain this distribution of the conscience1 singular as it is at first sight1 by those reasons of practical utility which are so powerful in the history of evolution4 ,a living being has to know the world external to himself in order to adapt and preadapt himself to it1 for it is in this outer world that he finds food1 shelter1 beings of his own species1 and the means of work1 and it is on this world of objects that he acts in every possible way by the contractions of his muscles4 ,but with regard to intracephalic actions1 they are outside the ordinary sphere of our actions4 ,there is no daily need to know them1 and we can understand that the consciousness has not found very pressing utilitarian motives for development in that direction4 ,one must be an histologist or a surgeon to find an appreciable interest in studying the structure of the nerve cell or the topography of the cerebral centres4 ,we can therefore explain well enough1 by the general laws of adaptation1 the reason of the absence of what might be called cerebral sensibility1 but1 here as elsewhere1 the question of the ,why is much easier to solve than that of the ,how4 ,the question of the ,how consists in explaining that the consciousness1 directly aroused by a nerve-wave1 does not perceive this undulation1 but in its stead the external object4 ,let us first note that between the external object and the nervous influx there is the relation of cause to effect4 ,it is only the effect which reaches us1 our nerve cells1 and our consciousness4 ,what must be explained is how a cognition 7if such a word may be employed here7 of the effect can excite the consciousness of the cause4 ,it is clear that the effect does not resemble the cause1 as quality3 the orange ,i am looking at has no resemblance with the brain wave which at this moment is traversing my optic nerve2 but this effect contains everything which was in the cause1 or1 more exactly1 all that part of the cause of which we have perception4 ,since it is only by the intermediary of our nervous system that we perceive the object1 all the properties capable of being perceived are communicated to our nervous system and inscribed in the nerve wave4 ,the effect produced therefore is the measure of our perception of the cause4 ,this is absolutely certain4 ,all bodies possess an infinity of properties which escape our cognitions2 because1 as excitants of our organism1 these properties are wanting in the intensity or the quality necessary to make it vibrate2 they have not been tuned in unison with our nervous chords4 ,and1 inversely1 all we perceive of the mechanical1 physical1 and chemical properties of a body is contained in the vibration this body succeeds in propagating through our cerebral atmosphere4 ,there is in this a phenomenon of transmission analogous to that which is produced when an air of music is sent along a wire2 the whole concert heard at the other extremity of the wire has travelled in the form of delicate vibrations4 ,there must therefore exist1 though unperceived by our senses1 a sort of kinship between the qualities of the external objects and the vibrations of our nerves4 ,this is sometimes forgotten4 ,the theory of the specific energy of the nerves causes it to be overlooked4 ,as we see that the quality of the sensation depends on the nerve that is excited1 one is inclined to minimise the importance of the excitant4 ,it is relegated to the position of a proximate cause with regard to the vibration of the nerve1 as the striking of a key on the piano is the proximate cause of the vibration of a string1 which always gives the same degree of sound whether struck by the forefinger or third finger1 or by a pencil or any other body4 ,it will be seen at once that this comparison is inexact4 ,the specific property of our nerves does not prevent our knowing the form of the excitant1 and our nerves are only comparable to piano strings if we grant to these the property of vibrating differently according to the nature of the bodies which strike them4 ,how is it that the nerve wave1 if it be the depository of the whole of the physical properties perceived in the object1 resembles it so little8 ,it is because--this is my hypothesis--these properties1 if they are in the undulation1 are not there alone4 ,the undulation is the work of two collaborators3 it expresses both the nature of the object which provokes it and that of the nervous apparatus which is its vehicle4 ,it is like the furrow traced in the wax of the phonograph which expresses the collaboration of an arial vibration with a stylus1 a cylinder1 and a clock-work movement4 ,this engraved line resembles1 in short1 neither the phonographic apparatus nor the arial vibration1 although it results from the combination of the two4 ,similarly1 ,i suppose that if the nervous vibration resembles so little the excitant which gives it birth1 it is because the factor nervous system adds its effect to the factor external object4 ,each of these factors represents a different property3 the external object represents a cognition and the nervous system an excitement4 ,let us imagine that we succeed in separating these two effects4 ,it will be conceived1 theoretically1 that a separation of this kind will lay bare the hidden resemblances1 giving to each collaborator the part which belongs to it4 ,the excitement1 for instance1 will be suppressed1 and the cognition will be retained4 ,is it possible to make1 or at least to imagine1 such an analysis8 ,perhaps3 for1 of these two competing activities1 one is variable1 since it depends on the constantly changing nature of the objects which come into relation with us2 the other1 on the contrary1 is a constant1 since it expresses the contribution of our nerve substance1 and1 though this last is of very unstable composition1 it necessarily varies much less than the series of excitants4 ,we consequently see faintly that these two elements differ sufficiently in character for us to be able to suppose that they are separable by analysis4 ,but how could this analysis be made8 ,evidently not by chemical or physical means3 we have no need here of reagents1 prisms1 centrifugal apparatus1 permeable membranes1 or anything of that kind4 ,it will suffice to suppose that it is the consciousness itself that is the dialyser4 ,it acts by virtue of its own laws--that is to say1 by changes in intensity4 ,supposing that sensibility increases for the variable elements of the undulation1 and becomes insensible for the constant elements4 ,the effect will be the same as a material dissociation by chemical analysis3 there will be an elimination of certain elements and the retention of others4 ,now1 all we know of the consciousness authorises us to entrust this rle to it1 for it is within the range of its habits4 ,we know that change is the law of consciousness1 that it is effaced when the excitements are uniform1 and is renewed by their differences or their novelty4 ,a continued or too often repeated excitement ceases in time to be perceived4 ,it is to condense these facts into a formula that ,bain speaks of the law of relativity of cognition1 and1 in spite of a few ambiguities on the part of ,spencer and of ,bain himself in the definition of this law1#ej the formula with the sense ,i have just indicated is worth preserving4 ,let us see what becomes of it1 when my hypothesis is adopted4 ,it explains how certain excitements proceeding from the objects--that is to say1 forming part of the variable element--cease to be perceived when they are repeated and tend to become constant4 ,a fortiori1 it seems to me1 should the same law explain how the constant element par excellence1 the one which never varies from the first hour1 is never perceived4 ,there is1 in the concert of the sounds of nature1 an accompaniment so monotonous that it is no longer perceived2 and the melody alone continues to be heard4 ,it is in this precisely that my hypothesis consists4 ,we will suppose a nerve current starting from one of the organs of the senses1 when it is excited by some object or other1 and arriving at the centre of the brain4 ,this current contains all the properties of the object1 its colour1 its form1 its size1 its thousand details of structure1 its weight1 its sonorous qualities1 c41 c41 properties combined with and connected by the properties of the nerve-organ in which the current is propagated4 ,the consciousness remains insensible to those nervous properties of the current which are so often repeated that they are annulled2 it perceives1 on the contrary1 its variable and accidental properties which express the nature of the excitant4 ,by this partial sensibility1 the consciousness lays bare that which1 in the nerve current1 represents the object--that is to say1 a cognition2 and this operation is equivalent to a transformation of the current into a perception1 image1 or idea4 ,there is not1 strictly speaking1 a transformation1 but an analysis2 only1 the practical result is the same as that of a transformation1 and is obtained without its being necessary to suppose the transmutation of a physical into a mental phenomenon4 ,let us place ourselves now at the moment when the analysis ,i am supposing to be possible has just been effected4 ,our consciousness then assists at the unrolling of representations which correspond to the outer world4 ,these representations are not1 or do not appear to be1 lodged in the brain2 and it is not necessary to suppose a special operation which1 taking them in the brain1 should project them to the periphery of our nerves4 ,this transport would be useless1 since for the consciousness the brain does not exist3 the brain1 with its fibres and cells1 is not felt2 it therefore supplies no datum to enable us to judge whether the representation is external or internal with regard to it4 ,in other words1 the representation is only localised in relation to itself2 there is no determinate position other than that of one representation in relation to another4 ,we may therefore reject as inexact the pretended law of eccentricity of the physiologists1 who suppose that sensation is first perceived as it were centrally1 and then1 by an added act1 is localised at the peripheric extremity of the nerve4 ,this argument would only be correct if we admitted that the brain is perceived by the consciousness of the brain4 ,i have already said that the consciousness is not an anatomist1 and that therefore this problem does not present itself4 ,such as it is1 this hypothesis appears to me to present the advantage of explaining the reason why our consciousness coincides1 in certain circumstances1 with the actions of the brain1 and1 in others1 does not come near them4 ,in other words1 it contains an explanation of the unconscious4 ,i can show this by quoting certain exact facts1 of which the explanation has been hitherto thought to present difficulties1 but which become very easy to understand on the present hypothesis4 ,the first of these facts relates to the psychology of the motor current4 ,this current has been a great feature in the studies which have been made on the feeling of effort and on the physical basis of the will4 ,the motor current is that which1 starting from the cerebral cells of the motor region1 travels by way of the fibres of the pyramidal tract into the muscles of the body2 and it is centrifugal in direction4 ,researches have been made as to whether we are or may be conscious of this current2 or rather1 the question has been put in somewhat different terms4 ,it has been asked whether a psychological state can be the counterpart of this motor current1--if1 for example1 the feeling of mental effort produced in us at the moment of executing a difficult act or of taking a grave resolution1 might not have this motor current for a basis4 ,the opinion which has prevailed is in the negative4 ,we have recognised--a good deal on the faith of experiment1 and a little also for theoretical reasons--that no sensation is awakened by the centrifugal current4 ,as to the sensation of effort1 it has been agreed to place it elsewhere4 ,we put it among the centripetal sensations which1 are produced as the movement outlines itself1 and which proceed from the contracted muscles1 the stretched ligaments1 and the frictional movements of the articulations4 ,effort would therefore form part of all the psychical phenomenology1 which is the duplicate of those sensory currents which are centripetal in direction4 ,in the long run1 ,i can see no sort of theoretical reason for subordinating the consciousness to the direction of the nerve current1 and for supposing that the consciousness is aroused when this current is centripetal1 and that it cannot follow the centrifugal current4 ,but this point matters little4 ,my hypothesis would fairly well explain why the motor current remains unconscious2 it explains the affair by taking into consideration the nature of this current and not its direction4 ,this current is a motor one because it is born in the central cells1 because it is a discharge from these cells1 and is of entirely nervous origin4 ,since it does not correspond with the perception of an object--the ever varying object--it is always the same by nature4 ,it does not carry with it in its monotonous course the dbris of an object1 as does the sensory current4 ,thus it can flow without consciousness4 ,this same kind of hypothesis supplies us with the reasons why a given sensory current may be1 according to circumstances1 either conscious or unconscious4 ,the consciousness resulting from the analysis of the molecular wave is1 as it were1 a supplementary work which may be subsequently added to the realised wave4 ,the propagation of the wave is the essential fact--there is always time to become conscious of it afterwards4 ,it is thus that we happen1 in moments of abstraction1 to remain insensible to certain even very powerful excitements4 ,our nervous system registers them1 nevertheless1 and we can find them again1 later on1 within the memory4 ,this is the effect of a belated analysis4 ,the converse phenomenon occurs much more frequently4 ,we remark many actions and perceptions which occur the first time with consciousness1 emotion1 and effort4 ,then1 when they are repeated1 as coordination becomes stronger and easier1 the reflex consciousness of the operation becomes feebler4 ,this is the law of habit1 which slowly carries us towards automatism4 ,these observations have even been extended1 and the endeavour made to apply them to the explanation of the origin of reflex actions and of instincts which have all started with consciousness4 ,this is a rather bold attempt1 for it meets with many serious difficulties in execution2 but the idea seems fairly correct1 and is acceptable if we may limit it4 ,it is certain that the consciousness accompanies the effort towards the untried1 and perishes as soon as it is realised4 ,whence comes this singular dilemma propounded to it by nature3 to create something new or perish8 ,it really seems that my hypothesis explains this4 ,every new act is produced by nerve currents1 which contain many of those variable elements which the consciousness perceives2 but1 in proportion as the action of the brain repeats itself and becomes more precise and more exact1 this variable element becomes attenuated1 falls to its lowest pitch1 and may even disappear in the fixation of habit and instinct4 ,my hypothesis much resembles the system of parallelism4 ,it perfects it1 as it seems to me1 as much as the latter has perfected materialism4 ,we indeed admit a kind of parallelism between the consciousness and the object of cognition2 but these two series are not independent1 not simply placed in juxtaposition as is possible in ordinary parallelism2 they are united and fused together so as to complete each other4 ,this new theory appears to me to represent a better form of the series of attempts which have been inspired by the common necessity of making the phenomena of consciousness accord with the determinism of physical facts4 ,i hold fast to this physical determinism1 and accept a strictly mechanical conception of the functions of the nervous system4 ,in my idea1 the currents which pass through the cerebral mass follow each other without interruption1 from the sensorial periphery to the motor periphery2 it is they1 and they alone1 which excite the movements of the body by acting on the muscles4 ,parallelism recognises all these things1 and ,i do likewise4 ,let us now see the advantages of this new system4 ,first1 it contains no paralogism1 no logical or psychological error1 since it does not advance the supposition that the mental differs by its nature from the physical phenomenon4 ,we have discussed above the consequences of this error1 ,they are here avoided4 ,in the second place1 it is explanatory1 at least in a certain measure1 since the formula we employ allows us to understand1 better than by the principle of a simple juxtaposition1 why certain nerve currents flow in the light of consciousness1 while others are plunged into the darkness of unconsciousness4 ,this law of consciousness1 which ,bain called the law of relativity1 becomes1 when embodied with my theory of the relations of the physical to the moral1 an explanation of the distribution of consciousness through the actions of the brain4 ,i ask myself whether the explanation ,i have devised ought to be literally preserved4 ,perhaps not4 ,i have endeavoured less to present a ready-made solution than to indicate the direction in which we ought to look for one4 ,the law of consciousness which ,i have used to explain the transformation of a nerve current into perception and images is only an empirical law produced by the generalisation of particular observations4 ,until now there has been1 so far as ,i know1 no attempt to ascertain whether this law of consciousness1 notwithstanding the general nature which some authors incline to ascribe to it1 might not explain itself by some more general facts1 and might not fit1 as a particular case1 into a more comprehensive frame4 ,to be brief1 this is very possible4 ,i have not troubled myself about it1 and ,i have made a transcendental use of this empirical law2 for ,i have impliedly supposed it to be a first principle1 capable of accounting for the development of the consciousness1 but itself incapable of explanation4 ,if other observers discover that that which to me has appeared inexplicable1 may be explained by quite peculiar causes1 it is clear that my theory must be abandoned or modified4 ,new theories must then be sought for1 which will probably consist in recognising different properties in the consciousness4 ,a little thought will discover several1 ,i have no doubt4 ,by way of suggestion1 ,i will indicate one of these hypothetical possibilities3 ,the consciousness has the faculty of reading in the effect that which existed in the cause4 ,it is not rash to believe that by working out this idea1 a certain solution would be discovered4 ,moreover1 the essential is1 ,i repeat1 less to find a solution than to take account of the point which requires one2 and metaphysics seem to me especially useful when it shows us where the gap in our knowledge exists and what are the conditions required to fill this gap4 ,above all1 ,i adhere to this idea1 which has been one of the guiding forces of this book3 there exists at the bottom of all the phenomena of the intelligence1 a duality4 ,to form a true phenomenon1 there must be at once a consciousness and an object4 ,according to passing tendencies1 either of temperament or of fashion1 preponderance has been given sometimes to one of the terms of this couple1 sometimes to the other4 ,the idealist declares3 ,thought creates the world4 ,the materialist answers3 ,the matter of the brain creates thought4 ,between these two extreme opinions1 the one as unjustifiable as the other in the excesses they commit1 we take up an intermediate position4 ,looking at the balance1 we see no argument capable of being placed in the scale of the consciousness which may not be neutralised by an argument placed in the scale of the object2 and if we had to give our final verdict we should say3 ,the consciousness and matter have equal rights1 thus leaving to every one the power to place1 in this conception of an equality of rights1 the hopes of survival of which his heart has need4 ,,footnotes3 ,footnote #ej3 ,the quivoque perpetrated by ,,bain and ,,spencer consists in supposing that the consciousness bears solely on differences4 ,this is going too far4 ,i confine myself to admitting that1 if sensation is not changed from time to time1 the consciousness becomes weaker and disappears4 ,,chapter ,,vi ,,recapitulation ,i ask permission to reproduce here a communication made by me in ,december #aijd to the ,socit ,franaise de ,philosophie4 ,i there set forth briefly the ideas which ,i have just developed in this book4 ,this succinct expos may be useful as a recapitulation of the argument4 ,description of ,matter4--,the physicists who are seeking for a conception of the ,inmost structure of matter in order to explain the very numerous phenomena they perceive1 fancy they can connect them with other phenomena1 less numerous1 but of the same order4 ,they thus consider matter in itself4 ,we psychologists add to matter something more1 viz4 the observer4 ,we consider matter and define it by its relations to our modes of knowledge--that is to say1 by bearing in mind that it is conditioned by our external perception4 ,these are two different points of view4 ,in developing our own standpoint1 we note that of the outer world we are acquainted with nothing but our sensations3 if we propound this limit1 it is because many observations and experiments show that1 between the external object and ourselves1 there is but one intermediary1 the nervous system1 and that we only perceive the modifications which the external object1 acting as an excitant1 provokes in this system4 ,let us provisionally apply to these modifications the term sensations1 without settling the question of their physical or mental nature4 ,other experiments1 again1 prove to us that our sensations are not necessarily similar to the objects which excite them2 for the quality of each sensation depends on what is called the specific energy of the nerve excited4 ,thus1 whether the optic nerve be appealed to by a ray of light1 an electric current1 or a mechanical shock1 it always gives the same answer1 and this answer is the sensation of light4 ,it follows that our nervous system itself is only known to us as regards its structure by the intermediary of sensations1 and we are not otherwise more informed upon its nature than upon that of any other object whatever4 ,in the second place1 a much more serious consequence is that all our sensations being equally false1 so far as they are copies of the excitants which provoke them1 one has no right to use any of these sensations to represent to ourselves the inmost structure of matter4 ,the theories to which many physicists still cling1 which consist in explaining all the modalities of matter by different combinations of movement1 start from false premises4 ,their error consists in explaining the whole body of our sensations by certain particular sensations of the eye1 of the touch1 and of the muscular sense1 in which analysis discovers the elements and the source of the representation of motion4 ,now these particular sensations have no more objective value than those of the tongue1 of the nose1 and of the ear2 in so far as they are related to the external excitant of which it is sought to penetrate the inmost nature1 one of them is as radically false as the other4 ,it is true that a certain number of persons will think to escape from our conclusion1 because they do not accept our starting point4 ,there exist1 in fact1 several systems which propound that the outer world is known to us directly without the intermediary of a tertium quid1 that is1 of sensation4 ,in the first place1 the spiritists are convinced that disembodied souls can remain spectators of terrestrial life1 and1 consequently1 can perceive it without the interposition of organs4 ,on the other hand1 some ,german authors have recently maintained1 by rather curious reasoning1 that the specific energy of our nervous system does not transform the excitants1 and that our sensations are the faithful copies of that which causes them4 ,finally1 various philosophers1 ,reid1 ,hamilton1 and1 in our own days1 the deep and subtle mind of ,m4 ,bergson1 have proposed to admit that by direct comprehension we have cognisance of the objects without mystery and as they are4 ,let this be admitted4 ,it will change nothing in our conclusions1 and for the following reasons4 ,we have said that no kind of our sensations--neither the visual1 the tactile1 nor the muscular--permits us to represent to ourselves the inmost structure of matter1 because all sensations1 without exception1 are false1 as copies of material objects4 ,we are now assured that we are mistaken1 and that our sensations are all true--that is to say1 are faithful copies of the objects4 ,if all are true1 it comes to the same thing as if all are false4 ,if all are true1 it is impossible to make any choice among them1 to retain only the sensations of sight and touch1 and to use them in the construction of a mechanical theory1 to the exclusion of the others4 ,for it is impossible for us to explain some by the others4 ,if all are equally true1 they all have the same right to represent the structure of matter1 and1 as they are irreconcilable1 no theory can be formed from their synthesis4 ,let us1 consequently1 conclude this3 whatever hypothesis may be built up on the relations possibly existing between matter and our sensations1 we are forbidden to make a theory of matter in the terms of our sensations4 ,that is what ,i think of matter1 understood as the inmost structure of bodies--of unknowable and metaphysical matter4 ,i shall not speak of it again2 and henceforth when ,i use the word matter1 it will be in quite a different acceptation--it will be empirical and physical matter1 such as it appears to us in our sensations4 ,it must therefore be understood that from this moment we change our ground4 ,we leave the world of noumena and enter that of phenomena4 ,definition of ,mind4--,generally1 to define the mind1 we oppose the concept of mind to the concept of matter1 with the result that we get extremely vague images in our thoughts4 ,it is preferable to replace the concepts by facts1 and to proceed to an inventory of all mental phenomena4 ,now1 in the course of this inventory1 we perceive that we have continually to do with two orders of elements1 which are united in reality1 but which our thought may consider as isolated4 ,one of these elements is represented by those states which we designate by the name of sensations1 images1 emotions1 c42 the other element is the consciousness of these sensations1 the cognition of these images1 the fact of experiencing these emotions4 ,it is1 in other words1 a special activity of which these states are the object and1 as it were1 the point of application--an activity which consists in perceiving1 judging1 comparing1 understanding1 and willing4 ,to make our inventory orderly1 let us deal with these two elements separately and begin with the first4 ,we will first examine sensation3 let us put aside that which is the fact of feeling1 and retain that which is felt4 ,thus defined and slightly condensed1 what is sensation8 ,until now we have employed the word in the very vague sense of a tertium quid interposed between the object and ourselves4 ,now we have to be more precise1 and to inquire whether sensation is a physical or a mental thing4 ,i need not tell you that on this point every possible opinion has been held4 ,my own opinion is that sensation should be considered as a physical phenomenon2 sensation1 be it understood1 in the sense of impression felt1 and not in that of capacity to feel4 ,here are the arguments ,i invoke for the support of my thesis3 in the first place1 popular opinion1 which identifies matter with what we see1 and with what we touch--that is to say1 with sensation4 ,this popular opinion represents a primitive attitude1 a family possession which we have the right to retain1 so long as it is not proved to us to be false3 next1 this remark1 that by its mode of apparition at once unexpected1 the revealer of new cognitions1 and independent of our will1 as well as by its content1 sensation sums up for us all we understand by matter1 physical state1 outer world4 ,colour1 form1 extent1 position in space1 are known to us as sensations only4 ,sensation is not a means of knowing these properties of matter1 it is these properties themselves4 ,what objections can be raised against my conclusion8 ,one has evidently the right to apply the term psychological to the whole sensation1 taken en bloc1 and comprising in itself both impression and consciousness4 ,the result of this terminology will be that1 as we know nothing except sensations1 the physical will remain unknowable1 and the distinction between the physical and the mental will vanish4 ,but it will eventually be re-established under other names by utilising the distinction ,i have made between objects of cognition and acts of cognition2--a distinction which is not verbal1 and results from observation4 ,what is not permissible is to declare that sensation is a psychological phenomenon1 and to oppose this phenomenon to physical reality1 as if this latter could be known to us by any other method than sensation4 ,if the opinion ,i uphold be accepted1 if we agree to see in sensation1 understood in a certain way1 a physical state1 it will be easy to extend this interpretation to a whole series of different phenomena4 ,to the images1 first1 which proceed from sensations1 since they are recurring sensations2 to the emotions also1 which1 according to recent theories1 result from the perception of the movements which are produced in the heart1 the vessels1 and the muscles2 and finally1 to effort1 whether of will or of attention1 which is constituted by the muscular sensations perceived1 and consequently also results from corporeal states4 ,the consequences must be clearly remarked4 ,to admit that sensation is a physical state1 is to admit1 by that very fact1 that the image1 idea1 emotion1 and effort--all those manifestations generally ascribed to the mind alone--are also physical states4 ,what1 then1 is the mind8 ,and what share remains to it in all these phenomena1 from which it seems we are endeavouring to oust it8 ,the mind is in that special activity which is engaged in sensation1 image1 idea1 emotion1 and effort4 ,for a sensation to be produced2 there must be1 as ,i said a little time ago1 two elements3 the something felt--a tree1 a house1 an animal1 a titillation1 an odour1--and also the fact of feeling this something1 the consciousness of it1 the judgment passed on it1 the reasoning applied to it--in other terms1 the categories which comprehend it4 ,from this point of view1 the dualism contained in sensation is clearly expressed4 ,sensation as a thing felt1 that is1 the physical part1 or matter2 sensation as the fact of feeling or of judging1 that is1 the mind4 ,mark the language ,i use4 ,we say that matter is the something felt2 but we do not say for the sake of symmetry1 that the mind is the something which feels4 ,i have used a more cautious1 and1 ,i think1 a more just formula1 which places the mind in the fact of feeling4 ,let me repeat again1 at the risk of appearing too subtle3 the mind is the act of consciousness2 it is not a subject which has consciousness4 ,for a subject1 let it be noted1 a subject which feels1 is an object of cognition--it forms part of the other group of elements1 the group of sensations4 ,in practice we represent by mind a fragment of our own biography1 and by dint of pains we attribute to this fragment the faculty of having a consciousness2 we make it the subject of the relation subject-object4 ,but this fragment1 being constituted of memories and sensations1 does not exactly represent the mind1 and does not correspond to our definition2 it would rather represent the mind sensationalised or materialised4 ,from this follows the curious consequence that the mind is endowed with an incomplete existence2 it is like form1 which can only be realised by its application to matter of some kind4 ,one may fancy a sensation continuing to exist1 to live and to provoke movements1 even after ceasing to be perceived4 ,those who are not uncompromising idealists readily admit this independence of the objects with regard to our consciousness1 but the converse is not true4 ,it is impossible to understand a consciousness existing without an object1 a perception without a sensation to be perceived1 an attention without a point of application1 an empty wish which should have nothing to wish for2 in a word1 a spiritual activity acting without matter on which to act1 or more briefly still--mind without matter4 ,mind and matter are correlative terms2 and1 on this point1 ,i firmly believe that ,aristotle was much closer to the truth than many modern thinkers4 ,i have convinced myself that the definition of mind at which we have just arrived is1 in its exactness and soberness1 the only one which permits psychology to be distinguished from the sciences nearest to it4 ,you know that it has been discovered in our days that there exists a great difficulty in effecting this delimitation4 ,the definitions of psychology hitherto proposed nearly all have the defect of not agreeing with the one thing defined4 ,time fails us to review them all1 but ,i shall point out one at least1 because our discussion on this particular formula will serve as a preparation for taking in hand the last question that remains to be examined--the relation of the mind to the body4 ,according to the definition ,i am aiming at1 psychology would be the science of internal facts1 while the other sciences deal with the external4 ,psychology1 it has also been said1 has as its instrument introspection1 while the natural sciences work with the eye1 the touch1 the ear--that is to say1 with the senses of extrospection4 ,to this distinction1 ,i reply that in all sciences there exist but two things3 sensations and the consciousness which accompanies them4 ,a sensation may belong to the inner or the outer world through accidental reasons1 without any change in its nature2 the sensation of the outer world is the social sensation which we share with our fellows4 ,if the excitant which provokes it is included in our nervous system1 it is the sensation which becomes individual1 hidden to all except ourselves1 and constituting a microcosm by the side of a macrocosm4 ,what importance can this have1 since all the difference depends on the position occupied by the excitant8 ,but we are persistently told3 there are in reality two ways of arriving at the cognition of objects--from within and from without4 ,these two ways are as opposite as the right and wrong side of a stuff4 ,it is in this sense that psychology is the science of the within and looks at the wrong side1 while the natural sciences reckon1 weigh1 and measure the right side4 ,and this is so true1 they add1 that the same phenomenon absolutely appears under two forms radically different from each other according as they are looked at from one or the other of the two points of view4 ,every one of our thoughts1 they point out to us1 is in correlation with a particular state of our cerebral matter2 our thought is the subjective and mental face1 the corresponding cerebral process is the objective and material face4 ,though this dualism is frequently presented as an observed truth1 ,i think it is possible to show its error4 ,take an example3 ,i look at the plain before me1 and see a flock of sheep pass through it4 ,at the same time an observer1 armed with a microscope la ,jules ,verne1 looks into my brain and observes there a certain molecular dance which accompanies my visual perception4 ,thus1 on the one hand1 is my representation2 on the other1 a dynamic state of the nerve cells4 ,this is what constitutes the right and the wrong sides of the stuff4 ,we are told1 ,see how little resemblance there is in this2 a representation is a psychical1 and a movement of molecules a material1 thing4 ,but ,i1 on the contrary1 think there is a great resemblance4 ,when ,i see the flock passing1 ,i have a visual perception4 ,the observer who1 by the hypothesis1 is at that moment looking into my brain1 also experiences a visual perception4 ,granted1 they are not the same perception4 ,how could they be the same8 ,i am looking at the sheep1 he is looking at the interior of my brain2 it is not astonishing that1 looking at objects so different1 we should receive images also very different4 ,but1 notwithstanding their difference of object--that is1 of content--there are here two visual perceptions composed in the same way2 and ,i do not see by what right it can be said that one represents a material1 the other a physical1 phenomenon4 ,in reality1 each of these perceptions has a two-fold and psycho-physical value--physical in regard to the object to which it applies1 and psychical inasmuch as it is an act of perception1 that is to say1 of consciousness4 ,for one is just as much psychical as the other1 and as much material1 for a flock of sheep is as material a thing as is my brain4 ,if we keep this conclusion in our minds1 when we come to make a critical examination of certain philosophical systems1 we shall easily see the mistake they make4 ,spiritualism#ea rests on the conception that the mind can subsist and work in total independence of any tie to matter4 ,it is true that1 in details1 spiritualists make some modification in this absolute principle in order to explain the perceptions of the senses and the execution of the orders of the will2 but the duality1 the independence1 and the autonomy of the soul and the body remain1 in any case1 the peculiar dogma of the system4 ,this dogma appears to me utterly false2 the mind cannot exist without matter to which it is applied2 and to the principle of heterogeneity1 so often invoked to forbid all commerce between the two substances1 ,i reply by appealing to intuition1 which shows us the consciousness and its different forms1 comparison1 judgment1 and reasoning1 so closely connected with sensation that they cannot be imagined as existing with an isolated life4 ,materialism1 we know1 argues quite differently2 it imagines that a particular state of the nerve centres has the virtue of generating a psychical phenomenon1 which represents1 according to various metaphors1 property1 function1 effect1 and even secretion4 ,critics have often asked how1 with matter in motion1 a phenomenon of thought could be explained or fabricated4 ,it is very probable that those who admit this material genesis of thought1 represent it to themselves under the form of something subtle1 like an electric spark1 a puff of wind1 a will-of-the-wisp1 or an alcoholic flame4 ,materialists are not alone responsible for these inadequate metaphors1 which proceed from a metaphysics constructed of concepts4 ,let us recollect exactly what a psychical phenomenon is4 ,let us banish the will-o'-the-wisps1 replace them by a precise instance1 and return to the visual perception we took as an example a little while back3 without intending a pun1 revenons nos moutons4 ,these sheep which ,i see in the plain are as material1 as real1 as the cerebral movement which accompanies my perception4 ,how1 then1 is it possible that this cerebral movement1 a primary material fact1 should engender this secondary material fact1 this collection of complicated beings which form a flock8 ,before going any further1 let us invite another philosophical system to take a place within the circle of our discussion2 for the same answer will suffice for it as well as for the preceding one1 and it will be as well to deal with both at once4 ,this new system1 parallelism1 in great favour at the present day1 appears to me to be a materialism perfected especially in the direction of caution4 ,to escape the mystery of the genesis of the mind from matter1 this new system places them parallel to each other and side by side1 we might almost say experimentally1 so much do parallelists try to avoid talking metaphysics4 ,but their position is untenable1 and they likewise are the victims of the mirage of concepts2 for they consider the mental as capable of being parallel to the physical without mingling with it1 and of subsisting by itself and with a life of its own4 ,such a hypothesis is only possible by reason of the insufficient definition given to the mind4 ,if it be recognised that the mind has an incomplete existence and is only realised by its incarnation in matter1 the figure which is the basis of parallelism becomes indefensible4 ,there is no longer on the one hand the physical1 and on the other the mental1 but on one side the physical and the mental combined1 and on the other the same combination2 which amounts to saying that the two faces to a reality1 which it was thought had been made out to be so distinct1 are identical4 ,there are not two faces1 but one face2 and the monism1 which certain metaphysicians struggle to arrive at by a mysterious reconciliation of the phenomenal duality within the unity of the noumenon1 need not be sought so far afield1 since we already discover it in the phenomenon itself4 ,the criticisms ,i have just pointed out to you1 only too briefly1 are to be found in several philosophers1 confusedly in ,berkeley1 and with more precision in ,m4 ,bergson's book on ,matire et ,mmoire4 ,the latter author1 remarking that our brain and the outer world are to us images of the same order1 refuses to admit that the brain1 which is only a very small part of these images1 can explain and contain the other and much larger part1 which comprises the vast universe4 ,this would amount to saying that the whole is comprised in the part4 ,i believe that this objection is analogous to the one just stated with less ingenuity4 ,it is interesting to see how ,m4 ,bergson gets out of the difficulty which he himself raised4 ,being unwilling to bring forth from the molecular movement of the brain the representation of the world1 or to superpose the representation on this movement as in the parallelist hypothesis1 he has arrived at a theory1 very ingenious but rather obscure1 which consists in placing the image of the world outside the brain1 this latter being reduced to a motor organ which executes the orders of the mind4 ,we thus have four philosophical theories1 which1 while trying to reconcile mind with matter1 give to the representation a different position in regard to cerebral action4 ,the spiritualist asserts the complete independence of the representation in relation to cerebral movement2 the materialist places it after1 the parallelist by the side of1 the cerebral movement2 ,m4 ,bergson puts it in front4 ,i must confess that the last of these systems1 that of ,m4 ,bergson1 presents many difficulties4 ,as he does not localise the mind in the body1 he is obliged to place our perception--that is to say1 a part of ourselves--in the objects perceived2 for example1 in the stars when we are looking at them4 ,the memory is lodged in distant planes of consciousness which are not otherwise defined4 ,we understand with difficulty these emigrations1 these crumblings into morsels of our mind4 ,this would not matter if our author did not go so far as to maintain that the sensory nerves of the brain are not sensory nerves1 and that the severance of them does not suppress sensations1 but simply the motor efforts of these sensations4 ,all the physiologist in me protests against the rashness of these interpretations4 ,the principal difficulties of the problem of the union between the mind and the body proceed from the two following facts1 which seem incompatible4 ,on the one hand1 our thought is conditioned by a certain intra-cerebral movement of molecules and atoms2 and1 on the other hand1 this same thought has no consciousness of this molecular movement4 ,it does not know the path of the wave in our nerves2 it does not suspect1 for example1 that the image of the objects is reversed in the retina1 or that the excitements of the right eye for the most part go into the left hemisphere4 ,in a word1 it is no anatomist4 ,it is a very curious thing that our consciousness enters into relation only with the extra-cerebral1 the external objects1 and the superficies of our bodies4 ,from this1 this exact question suggests itself3 a molecular wave must come as far as our visual cerebral centre for us to have the perception of the object before our eyes2 how is it that our consciousness is unaware of this physiological event from which it depends1 and is borne towards the distant object as if it sprang forth outside our nervous system8 ,let us first remark1 that if we do not perceive this wave1 yet it must contain all we know of the external object1 for it is evident that we only know of it that part of its properties which it transmits to our nerves and our nerve centres4 ,all the known substance of the external object is1 then1 implied in this vibration2 it is there1 but it is not there by itself4 ,the vibration is the work of two collaborators2 it expresses at once the nature of the object which provokes it1 and the nature of the nerve apparatus which transports it1 as the furrow traced in the wax of the phonograph implies the joint action of an arial vibration with a stylus1 a cylinder1 and1 a clock-work apparatus4 ,i therefore suppose--and this is1 ,i say it plainly1 but an hypothesis--that if the nervous vibration so little resembles the external excitant which generates it1 it is because the factor nervous system superadds its effect to the factor excitant4 ,let us imagine1 now1 that we have managed to separate these two effects1 and we shall understand that then the nervous event so analysed might resemble only the object1 or only the nervous system4 ,now1 of these two effects1 one is constant1 that one which represents the action of the nervous system2 there is another which varies with each new perception1 and even with every moment of the same perception--that is to say1 the object4 ,it is not impossible to understand that the consciousness remains deaf to the constant and sensitive to the variable element4 ,there is a law of consciousness which has often been described1 and fresh applications of which are met with daily3 this is1 that the consciousness only maintains itself by change1 whether this change results from the exterior by impressions received1 or is produced from the interior by movements of the attention4 ,let us here apply this empirical law1 and admit that it contains a first principle4 ,it will then be possible for us to understand that the consciousness formed into a dialyser of the undulation may reject that constant element which expresses the contribution of the nervous system1 and may lay bare the variable element which corresponds to the object3 so that an intestinal movement of the cerebral substance1 brought to light by this analytical consciousness1 may become the perception of an object4 ,by accepting this hypothesis1 we restore to the sensory nerves and to the encephalic centres their property of being the substrata of representation1 and avoid the objection made above against materialism and parallelism1 that they did not explain how a cerebral movement1 which is material1 can engender the perception of an object which differs greatly from it and is yet as material as the movement itself4 ,there is not here1 properly speaking1 either generation1 transformation1 or metamorphosis4 ,the object to be perceived is contained in the nerve current4 ,it is1 as it were1 rolled up in it2 and it must be made to go forth from the wave to be seen4 ,this last is the work of the consciousness4 ,,footnotes3 ,footnote #ea3 ,see ,note #dc on p4 #aia4 ,,index ,,abstractions1 character of1 #h ,archives de ,psychologie1 #aih ,aristotle1 #ajf1 #abi1 #afi1 #ahf-aij1 #bja1 #bfe ,association1 inseparable1 #aaf ,automatism1 #bej ,,bain1 #c1 #aba1 #ahf1 #ahi1 #bai1 #bde1 #beb ,belfast1 congress at1 #bjg ,bergson1 #dg1 #hf2 theory of images and brain1 #bbf-bcj2 refutation of1 #bcj-bcc2 #bei1 #bga1 #bgb ,berkeley1 #dg1 #aji1 #bbe1 #bbf1 #bbg1 #bga ,berthelot1 #adg ,binet1 #c1 #aia2 theory of mind and brain1 #bcf1 #bee ,body1 union with mind1 #agi2 ,aristotle on body and soul1 #ahh ,brain1 #bbe1 #bbf1 #bbg2 and consciousness1 #bcf1 #bcg1 #bdg ,brieux1 #bji ,brillouin1 #aj ,,categories1 #ajf1 #ajg1 #aad1 #aij1 #bfc ,change1 law of consciousness1 #bde ,cognition1 #ae1 #cc1 #eh1 #ih1 #aje1 #ajg1 #aag1 #abc1 #adj1 #ada1 #ade1 #aec1 #aee1 #aeg1 #afb1 #ahd1 #aij1 #aie1 #bjh1 #bbe1 #bbh1 #bda1 #bdc1 #bdf1 #bea1 #bfj1 #bfb1 #bfd1 #bff ,comte1 ,auguste1 #bac ,concepts1 method of1 #f1 #g2 metaphysics of1 #h1 #bbc ,conclusion1 #bcd-bee ,condillac1 #ih ,condition1 normal1 #hj ,consciousness1 #eh1 #aie2 anatomical ignorance of1 #bcg1 #bch2 definition of3 relation subject-object1 categories of the understanding1 separability of the consciousness from its object1 idealism1 #if-acd2 as dialyser1 #bdd2 law of1 #bge1 #bgf2 and nerve current1 #bdg-bee2 manifestations of1 #bcf2 of a state1 #fc2 origin of1 #ahj2 phenomena of1 #ag1 #hh1 #aij1 #baj1 #bbc2 useless luxury1 #bbb ,contiguity1 law of1 #afi1 #agj1 #agc ,current1 motor1 psychology of1 #bdh1 #bdi2 nerve1 #bdf1 #bdi1 #bej1 #bea1 #beb1 #bgf2 sensory1 #bej ,,dantec1 ,les ,lois ,naturelles1 #aj ,dastre1 ,la ,vie et la ,mort1 #aj1 #ade ,democritus1 #aeh ,descartes1 #fd1 #gg1 #gh1 #ig1 #aeb1 #aic ,discours de la ,mthode1 #gg ,dreams1 #hb1 #hg ,dualism1 of mind and matter1 #fi1 #ga1 #ahb1 #adj1 #aee1 #ahb1 #bed1 #bfc ,duality1 of sensation1 #gh2 of ideation1 #gh2 of consciousness and object1 #aii2 of nature1 #bbd2 of soul and body1 #bfi ,duhem1 evolution of mechanics1 #aj ,ebbinghaus1 #afj1 #afa ,eccentricity1 law of1 #bdg ,effort1 psychological nature of1 #id2 sensation of1 #bdi1 #bfc ,ego1 #ge1 #hf1 #hh1 #hi1 #ii1 #aeb2 and non-ego1 #if1 #ajj1 #aja ,emotions1 definitions of the1 #hh-ie1 #bfc ,energy1 #cj1 #ca ,enumeration1 method of1 #f ,epiphenomenon1 #bbb tude ,exprimentale de l',intelligence 7,binet71 #h ,excitant1 the1 #ah1 #ba1 #bb1 #hc1 #bdd1 #beg1 #beh1 #bff ,existence or reality1 #hd1 #he ,externospection1 #adj-adf ,fathers of the ,church1 #bja ,fechner1 #adi ,ferrier1 #gc ,finality1 definition of1 #afc ,flournoy1 #gj1 #gc1 #ahb1 #aia1 #aih ,geneva1 congress of1 philosophy at1 #bbf ,goblot1 ,e41 ,la ,finalit sans ,intelligence1 #afd ,habit1 law of1 #bej ,hallucinations1 #ha1 #hb1 #hg ,hamilton1 ,william1 #dg1 #fe1 #bef2 ,philosophy of1 #dg ,herbart1 #ij1 #ia ,herrick1 ,c4 ,l41 #hf ,heterogeneity1 axiom of1 #ahb1 #ahc2 principle of1 #h1 #gc1 #gd1 #ahb1 #ahc1 #aid1 #bje1 #bjf1 #bjh1 #bae1 #bfi ,histoire du ,matrialisme 7,lange71 #acg ,hume1 #fd1 #aji ,huxley1 #aah1 #bbb ,idealism1 principle of1 #fd1 #gc1 #aai-abe2 refutation of1 #ie-bjj ,ideation1 duality of1 #gh1 #hj ,identity1 #bba ,image1 definition of the1 #gf-hg1 #bfc ,intellectualism1 definition of1 #aff ,intelligence1 only inactive consciousness1 #aag2 materialist explanation of1 #bjd ,inter-actionism1 #ahe ,introspection1 #adj-adf ,intuition1 #bfi ,james1 ,william1 theory of emotion1 #ia-id2 #ajj1 #afc ,journal of ,philosophy1 #ajj ,kant1 #cd1 #ajf1 #ajg1 #ajh1 #aha1 #aij1 #bce ,kelvin1 ,lord1 #aa ,knowable1 the1 #d1 #e1 #g ,knowledge and its object1 #ee-ei2 two groups of1 #ih ,klpe1 #afj ,l',ame et le ,corps1 #c ,la ,finalit sans ,intelligence 7,goblot71 #afd ,la ,nouvelle ,monadologie 7,renouvier et ,prat71 #fd ,la ,philosophie de ,hamilton1 #dg ,la ,vie et la ,mort 7,dastre71 #aj ,ladd1 #eh note#ad ,lange1 theory of emotion1 #ia2 ,histoire du ,matrialisme1 #acg ,law of contiguity1 #afb note#cg1 #afi1 #agj1 #agc ,law of eccentricity1 #bdg ,law of mental expression rejected1 #afb note#cg2 mental distinguished from physical1 #afc ,law1 psychological compared with natural1 #afg1 #afh ,law of relativity of cognition1 #bde ,law of similarity1 #afb note#cg1 #afi1 #agj ,le ,bon1 ,gustave 7l',evolution de la ,matire71 #bg ,le ,paralogisme psycho-physiologique 7,bergson71 #bbf ,le ,personnellisme 7,renouvier71 #bbf ,leons de ,philosophie 7,rabier71 #adh ,leibnitz1 #abi1 #aie1 #bbj ,littr1 #bjg ,locke1 #aci ,logical and ,psychological ,distinction between the ,true and the ,real 7,herrick71 #hf ,lotze1 #gc1 #adh ,lyons1 #ff ,mach1 #afj ,materialism1 origin and definition of1 #bja-bjc2 refutation of1 #bjc-bad2 #bfi1 #bge ,matire et ,mmoire 7,bergson71 #hf1 #bbf1 #bbi1 #bcj1 #bga ,matter1 definition of1 #c-ea2 description of1 #bef-bfj2 distinct from mind1 #c2 domain of physics1 #f2 mechanical theories of1 #bg-dc2 non-significant properties of1 #agb1 #agc2 ,x of2 #ah1 #ba1 #be1 #di ,mechanics1 fetichism of1 #bbj ,mechanism1 nervous1 to imitate intellectual act1 #bba ,metaphysics1 #abh note#ca1 #bcd1 #bce ,mtaphysique et ,psychologie 7,flournoy71 #ahb ,method1 rule of1 #e2 of concepts and enumeration1 #f ,meudon1 #aeb ,mill1 ,john ,stuart1 #ac1 #ai1 #dg1 #fd1 #aaf1 #aba ,mind1 definition of1 #ee-age2 #bfj-bff2 distinction between1 and matter1 #c2 domain of psychology1 #f2 incomplete life of1 #agi-aij2 inseparability of1 and matter1 #ahe2 inventory of #ef2 ,mind and ,body 7,bain71 #c1 #bai ,monadism1 #aie ,monism1 #fi1 #bga ,motion1 #ce ,movement1 molecular1 #gc2 vibratory1 #ca ,mller1 #ba ,mnsterberg1 #afj ,nerves1 motor1 #bbh1 #bcj2 power of distinction1 #bb2 specific energy of1 #ba1 #df1 #bdb2 sensory1 #bbh1 #bcj1 #bcb1 #bgc1 #bge2 vibrations of1 #bdb1 #bdc2 nervous system1 #af1 #ag1 #bd1 #be1 #dd1 #de1 #dh1 #aae1 #bbh1 #bda1 #beg1 #beh1 #bgd1 #bge ,noumena1 #cd1 #ce1 #dc1 #aji1 #adb note#cd1 #bfj1 #bga ,object4 ,see ,subject ,observation1 #bce ,organ1 function of1 material1 #bjf ,ostwald1 #aj ,panmaterialism1 #gj ,panpsychism1 #gj1 #aie1 #aih ,parallelism1 definition of1 #bad-bbj2 refutation of1 #bba-bbd2 #bea2 #beb1 #bgj-bgb2 #bge ,parallelist theory1 #acb ,perceptible1 the1 #hd1 #he ,perception1 intermediate character of1 #ae2 of a child1 #bcb ,personality1 formation of1 #ajj ,phenomena1 auditory1 #cg2 physical1 #cj1 #ca2 visual1 #cg ,phenomenism of ,berkeley1 #aji note#bf ,philosophical ,review1 #gj ,philosophy1 history of1 #bjj ,philosophy of ,hamilton 7,j4 ,s4 ,mill71 #dg ,pilon1 #aac ,plato1 #bja ,preadaptation1 process of1 #afd-age ,prince1 ,morton1 #gj ,probabilism forced upon us1 #agd ,psychical ,review1 #hf ,psychologie1 #aab ,psychologie du ,raisonnement 7,binet71 #aac ,psychology1 definitions of1 #ace-age1 #bfe1 #bff ,rabier1 ,e41 #ih1 #aab1 #adh ,radio-activity1 #bg ,reason developed according to law1 #afi ,recapitulation1 #bef-bgf ,reid1 ,thomas1 #dg1 #fe1 #bei ,relativity1 principle of1 #ajd1 #aji1 #beb ,renouvier1 #fd1 #ig1 #ajf1 #bje1 #bbf ,revue ,gnrale des ,sciences1 #aj ,revue de ,mtaphysique et de ,morale1 #afd1 #bbf ,revue de ,philosophie1 #aj ,raymond1 ,du ,bois1 #gc ,ribot1 #acg ,search1 direction of1 #e1 #f ,sensation1 #aj1 #ad1 #ce1 #dd1 #ej1 #ea1 #ee2 definition of1 #fj-ge2 mistrusted by physicists1 #bh-cj2 only means of acquaintance with outer world1 #aj-bf1 #ej1 #bef-bei2 physical or mental1 #bfa-bff2 visual1 #gc ,sensibility1 cerebral1 #bci1 #bdj2 employment in physiology1 #fa ,separation of consciousness from its object1 #abf-acd ,similarity4 ,see ,law ,simon1 ,dr41 #bji ,socit ,franaise de ,philosophie1 #bef ,soul1 distinct from body1 #gg2 union of body and1 #agi-bgf ,souls1 disembodied1 #de ,specificity of ,nerves4 ,see ,nerves ,spencer1 ,herbert1 #bde ,spiritualism1 refutation of1 #aib1 #aie1 #bfh1 #bfi ,strong1 ,m41 #aie ,subject1 defined and distinguished from object1 #if ,substance1 definition of1 #ajb ,substantialism1 #acd ,symbols1 mechanical theories of matter1 #bg-dc ,system1 nervous1 #af1 #ag1 #bd1 #be1 #dd1 #de1 #dh1 #aae1 #bbh1 #bda1 #beg1 #beh1 #bgd1 #bge ,taine1 #gi ,theories1 modern1 #bbe-bcc ,thought1 not a movement1 #g1 #h2 characteristics of1 #gf ,truth1 #hd1 #he ,tyndall1 #hi1 #bjg ,unconsciousness1 #abg-acc ,understanding1 categories of the1 #ajc-aah ,unknowable1 the1 #be1 #bf ,union of mind and body1 problem of1 #bgc2 of soul and body1 #agi-bgf ,verne1 ,jules1 #bfg ,vogt1 ,karl1 #bjd ,wave1 molecular1 #bgc1 #bgd1 #bgf2 nerve1 #bdc ,will1 the most characteristic psychical function1 #aff1 #afg ,world1 assembly of sensations1 #bf2 our ideas1 #fe2 external known only by our sensations1 #aj-bf2 #ej1 #bef-bei ,x of matter1 #ah1 #ba1 #be1 #di ,zoologist1 visual sensations of1 #ac 99 99 99 99 99 ,,the ,,international ,,scientific ,,series4 ,each ,book ,complete in ,one ,volume4 ,crown #hvo4 cloth1 #es4 unless otherwise described4 ,i4 ,,forms of ,,water3 in ,clouds and ,rivers1 ,ice and ,glaciers4 ,by ,j4 ,,tyndall1 ,,ll4,d41 ,f4,r4,s4 ,with #be ,illustrations4 ,twelfth ,edition4 ,,ii4 ,,physics and ,,politics2 or1 ,thoughts on the ,application of the ,principles of ',natural ,selection' and ',inheritance' to ,political ,society4 ,by ,,walter ,,bagehot4 ,tenth ,edition4 ,,iii4 ,,foods4 ,by ,,edward ,,smith1 ,m4,d41 ,,ll4,b41 ,f4,r4,s4 ,with #aef ,illustrations4 ,tenth ,edition4 ,,iv4 ,,mind and ,,body3 the ,theories of their ,relation4 ,by ,,alexander ,,bain1 ,,ll4,d4 ,with ,four ,illustrations4 ,ninth ,edition4 ,v4 ,the ,,study of ,,sociology4 ,by ,,herbert ,,spencer4 ,eighteenth ,edition4 ,,vi4 ,the ,,conservation of ,,energy4 ,by ,,balfour ,,stewart1 ,m4,a41 ,,ll4,d41 ,f4,r4,s4 ,with #ad ,illustrations4 ,eighth ,edition4 ,,vii4 ,,animal ,,locomotion2 or1 ,walking1 ,swimming1 and ,flying4 ,by ,j4 ,b4 ,,pettigrew1 ,m4,d41 ,f4,r4,s41 c4 ,with #acj ,illustrations4 ,fourth ,edition4 ,,viii4 ,,responsibility in ,,mental ,,disease4 ,by ,,henry ,,maudsley1 ,m4,d4 ,fifth ,edition4 ,,ix4 ,the ,,new ,,chemistry4 ,by ,professor ,j4 ,p4 ,,cooke1 of the ,harvard ,university4 ,with #ca ,illustrations4 ,eleventh ,edition4 ,x4 ,the ,,science of ,,law4 ,by ,professor ,,sheldon ,,amos4 ,eighth ,edition4 ,,xi4 ,,animal ,,mechanism3 a ,treatise on ,terrestrial and ,arial ,locomotion4 ,by ,professor ,e4 ,j4 ,,mahey4 ,with #aag ,illustrations4 ,fourth ,edition4 ,,xii4 ,the ,,doctrine of ,,descent and ,,darwinism4 ,by ,professor ,,oscar ,,schmidt 7,strasburg ,university74 ,with #bf ,illustrations4 ,eighth ,edition4 ,,xiii4 ,the ,,history of the ,,conflict between ,,religion and ,,science4 ,by ,j4 ,w4 ,,draper1 ,m4,d41 ,,ll4,d4 ,twenty-second ,edition4 ,,xiv4 ,,fungi3 their ,nature1 ,influences1 ,uses1 c4 ,by ,m4 ,c4 ,,cooke1 ,m4,a41 ,,ll4,d4 ,edited by the ,rev4 ,m4 ,j4 ,,berkeley1 ,m4,a41 ,f4,l4,s4 ,with ,illustrations1 ,fifth ,edition4 ,,xv4 ,the ,,chemistry of ,,light and ,,photography4 ,by ,dr4 ,,herman ,,vogel4 ,with #ajj ,illustrations4 ,sixth ,edition4 ,,xvi4 ,the ,,life and ,,growth of ,,language4 ,by ,,william ,,dwight ,,whitney4 ,sixth ,edition4 ,,xvii4 ,,money and the ,,mechanism1 of ,,exchange4 ,by ,w4 ,,stanley ,,jevons1 ,m4,a41 ,f4,r4,s4 ,eleventh ,edition4 ,,xviii4 ,the ,,nature of ,,light1 with a ,general ,account of ,,physical ,,optics4 ,by ,dr4 ,,eugene ,,lommel4 ,with #ahh ,illustrations and a ,table of ,spectra in ,chromo-lithography4 ,sixth ,edition4 ,,xix4 ,,animal ,,parasites and ,,messmates4 ,by ,monsieur ,,van ,,beneden4 ,with #hc ,illustrations4 ,fourth ,edition4 ,,xx4 ,,fermentation4 ,by ,professor ,,sch,,tzenberger4 ,with #bh ,illustrations4 ,fourth ,edition4 ,,xxi4 ,the ,,five ,,senses of ,,man4 ,by ,professor ,,bernstein4 ,with #ia ,illustrations4 ,seventh ,edition4 ,,xxii4 ,the ,,theory of ,,sound in its ,,relation to ,,music4 ,by ,professor ,,pietro ,,blaserna4 ,with numerous ,illustrations4 ,sixth ,edition4 ,,xxiii4 ,,studies in ,,spectrum ,,analysis4 ,by ,j4 ,,norman ,,lockyer1 ,f4,r4,s4 ,with ,six ,photographic ,illustrations of ,spectra1 and numerous ,engravings on ,wood4 ,fifth ,edition4 #fs4 #f;d4 ,,xxiv4 ,a ,,history of the ,,growth of the ,,steam ,,engine4 ,by ,professor ,r4 ,h4 ,,thurston4 ,with numerous illustrations4 ,fifth ,edition4 ,,xxv4 ,,education as a ,,science4 ,by ,,alexander ,,bain1 ,,ll4,d4 ,ninth ,edition4 ,,xxvi4 ,the ,,human ,,species4 ,by ,professor ,a4 ,,de ,,quatrefages1 ,membre de l',institut4 ,fifth ,edition4 ,,xxvii4 ,,modern ,,chromatics4 ,with ,application to ,art and ,industry4 ,by ,,ogden ,n4 ,,rood4 ,third ,edition4 ,with #acj original ,illustrations4 ,,xxviii4 ,the ,,crayfish3 an ,introduction to the ,study of ,zoology4 ,by ,t4 ,h4 ,,huxley1 ,f4,r4,s4 ,sixth ,edition4 ,with #hb ,illustrations4 ,,xxix4 ,the ,brain ,as an ,organ of ,mind4 ,by ,h4 ,,charlton ,,bastian1 ,m4,d4 ,fourth ,edition4 ,with #ahd ,illustrations4 ,,xxx4 ,the ,,atomic ,,theory4 ,by ,professor ,a4 ,,wurtz4 ,translated by ,e4 ,,cleminshaw1 ,f4,c4,s4 ,seventh ,edition4 ,,xxxi4 ,the ,,natural ,,conditions of ,,existence as they affect ,animal ,life4 ,by ,,karl ,,semper1 ,fifth ,edition4 ,with #b ,maps and #ajf ,woodcuts4 ,,xxxii4 ,,general ,,physiology of ,,muscles and ,,nerves4 ,by ,prof4 ,j4 ,,rosenthal4 ,fourth ,edition4 ,with #ge ,illustrations4 ,,xxxiii4 ,,sight3 an ,exposition of the ,principles of ,monocular and ,binocular ,vision4 ,by ,,joseph ,,le ,,conte1 ,,ll4,d4 ,third ,edition4 ,with #acb ,illustrations4 ,,xxxiv4 ,,illusions3 a ,psychological ,study4 ,by ,,james ,,sully4 ,fourth ,edition4 ,,xxxv4 ,,volcanoes3 what they are and what they teach4 ,by ,,john ,w4 ,,judd1 ,f4,r4,s4 ,fifth ,edition4 ,with #if ,illustrations4 ,,xxxvi4 ,,suicide3 an ,essay on ,comparative ,moral ,statistics4 ,by ,professor ,h4 ,,morselli4 ,third ,edition4 ,,xxxvii4 ,the ,,brain and its ,,functions4 ,by ,j4 ,,luys1 ,physician to the ,hospice de la ,salptrire4 ,with numerous ,illustrations4 ,third ,edition4 ,,xxxviii4 ,,myth and ,,science3 an ,essay4 ,by ,,tito ,,vignoli4 ,fourth ,edition4 ,,xxxix4 ,the ,,sun4 ,by ,c4 ,a4 ,,young1 ,ph4,d41 ,,ll4,d4 ,fifth ,edition4 ,with numerous ,illustrations4 ,,xl4 ,,ants1 ,,bees1 and ,,wasps4 ,a ,record of ,observations on the ,habits of the ,social ,hymenoptera4 ,by ,lord ,,avebury4 ,fourteenth ,edition4 ,with #e ,chromo-lithographic ,plates4 ,,xli4 ,,animal ,,intelligence4 ,by ,,george ,j4 ,,romanes1 ,,ll4,d41 ,f4,r4,s4 ,sixth ,edition4 ,,xlii4 ,the ,,concepts and ,,theories of ,,modern ,,physics4 ,by ,j4 ,b4 ,,stallo4 ,third ,edition4 ,,xliii4 ,,diseases of ,,memory4 ,an ,essay in the ,positive ,psychology4 ,by ,,th4 ,,ribot4 ,fourth ,edition4 ,,xliv4 ,,man ,,before ,,metals4 ,by ,n4 ,,joly1 ,correspondent del',institut de ,france4 ,fifth ,edition4 ,with #adh ,illustrations4 ,,xlv4 ,the ,,science of ,,politics4 ,by ,prof4 ,,sheldon ,,amos4 ,third ,edition4 ,,xlvi4 ,,elementary ,,meteorology4 ,by ,,robert ,h4 ,,scott4 ,with #aa ,plates and #dj ,figures in ,text4 ,seventh ,edition4 ,,xlvii4 ,the ,,organs of ,,speech4 ,by ,,georg ,,hermann ,,von ,,meyer4 ,with #dg ,illustrations4 ,,xlviii4 ,,fallacies3 a ,view of ,logic from the ,practical ,side4 ,by ,,alfred ,,sidgwick4 ,second ,edition4 ,,xlix4 ,the ,,origin of ,,cultivated ,,plants4 ,by ,,alphonse ,,de ,,candolle4 ,second ,edition4 ,l4 ,,jelly ,,fish1 ,,star ,,fish1 and ,,sea ,,urchins4 ,being a ,research on ,primitive ,nervous ,systems4 ,by ,g4 ,j4 ,,romanes1 ,,ll4,d41 ,f4,r4,s4 ,second ,edition4 ,,li4 ,the ,,common ,,sense of the ,,exact ,,sciences4 ,by the late ,,william ,,kingdon ,,clifford4 ,third ,edition4 ,with #ajj ,figures4 ,,lii4 ,,physical ,,expression3 its ,modes and ,principles4 ,by ,,francis ,,warner1 ,m4,d41 ,f4,r4,c4,p4 ,second ,edition4 ,with #ej ,illustrations4 ,,liii4 ,,anthropoid ,,apes4 ,by ,,robert ,,hartmann4 ,with #fc ,illustrations4 ,second ,edition4 ,,liv4 ,the ,,mammalia in their ,,relation to ,,primeval ,,times4 ,by ,,oscar ,,schmidt4 ,second ,edition4 ,with #ea ,woodcuts4 ,,lv4 ,,comparative ,,literature4 ,by ,h4 ,,macaulay ,,posnett1 ,,ll4,d4 ,,lvi4 ,,earthquakes ,,and ,,other ,,earth ,,movements4 ,by ,prof4 ,,john ,,milne4 ,with #ch ,figures4 ,fourth ,edition1 revised4 ,,lvii4 ,,microbes1 ,,ferments1 and ,,moulds4 ,by ,e4 ,l4 ,,trouessart4 ,with #ajg ,illustrations4 ,third ,edition4 ,,lviii4 ,,geographical1 and ,,geological ,,distribution of ,,animals4 ,by ,prof4 ,a4 ,,heilprin4 ,second ,edition4 ,,lix4 ,,weather3 a ,popular ,exposition of the ,nature of ,weather ,changes from ,day to ,day4 ,by the ,hon4 ,,ralph ,,abercromby4 ,with #if ,figures4 ,fourth ,edition4 ,,lx4 ,,animal ,,magnetism4 ,by ,,alfred ,,binet and ,,charles ,f,,re4 ,fourth ,edition4 ,,lxi4 ,,manual of ,,british ,,discomycetes1 with descriptions of all the ,species of ,fungi hitherto found in ,britain included in the ,family1 and ,illustrations of the ,genera4 ,by ,,william ,,phillips1 ,f4,l4,s4 ,second ,edition4 ,,lxii4 ,,international ,,law4 ,with ,materials for a ,code of ,international ,law4 ,by ,professor ,,leone ,,levi4 ,,lxiii4 ,the ,,geological ,,history of ,,plants4 ,by ,sir ,j4 ,,william ,,dawson4 ,with #hj ,illustrations4 ,,lxiv4 ,the ,,origin of ,,floral ,,structures ,,through ,,insect and other ,,agencies4 ,by ,prof4 ,g4 ,,henslow4 ,second ,edition4 ,,lxv4 ,on the ,,senses1 ,,instincts1 and ,,intelligence of ,,animals1 ,with special reference to ,,insects4 ,by ,lord ,,avebury4 ,with #aah ,illustrations4 ,third ,edition4 ,,lxvi4 ,the ,,primitive ,,family in its ,,origin and ,,development4 ,by ,c4 ,n4 ,,starcke4 ,second ,edition4 ,,lxvii4 ,,physiology of ,,bodily ,,exercise4 ,by ,,fernand ,,lagrange1 ,m4,d4 ,second ,edition4 ,,lxviii4 ,the ,,colours of ,,animals3 their ,meaning and ,use1 especially considered in the case of ,insects4 ,by ,e4 ,b4 ,,poulton1 ,f4,r4,s4 ,with ,chromo-lithographic ,frontispiece and upwards of #fj figures in ,text1 ,second ,edition4 ,,lxix4 ,,introduction to ,,fresh-,,water ,,alg4 ,with an ,enumeration of all the ,british ,species4 ,by ,m4 ,c4 ,,cooke1 ,,ll4,d4 ,with #ac ,plates ,illustrating all the ,genera4 ,,lxx4 ,,socialism3 ,,new and ,,old4 ,by ,,william ,,graham1 ,m4,a44 ,professor of ,political ,economy and ,jurisprudence1 ,queen's ,college1 ,belfast4 ,second ,edition4 ,,lxxi4 ,,colour-,,blindness and ,,colour-,,perception4 ,by ,f4 ,w4 ,,edridge-,,green1 ,m4,d4 ,with #c ,coloured ,plates4 ,,lxxii4 ,,man and the ,,glacial ,,period4 ,by ,g4 ,f4 ,,wright1 ,d4,d4 ,with #aaa ,illustrations and ,maps4 ,second ,edition4 ,,lxxiii4 ,,handbook of ,,greek and ,,latin ,,pal,,ography4 ,by ,sir ,e4 ,,maunde ,,thompson1 ,k4,c4,b4 ,with ,tables of ,alphabets and ,facsimiles4 ,second ,edition4 ,,lxxiv4 ,a ,,history of ,,crustacea3 ,recent ,malacoatraca4 ,by ,,thomas ,r4 ,r4 ,,stebbing1 ,m4,a4 ,with #ai ,plates and #cb ,figures in ,text4 ,,lxxv4 ,the ,,dispersal of ,,shells3 an ,inquiry into the means of ,dispersal possessed by ,fresh ,water and ,land ,mollusca4 ,by ,h4 ,,wallis ,,kew1 ,f4,z4,s4 ,with ,preface by ,a4 ,r4 ,,wallace1 ,f4,r4,s41 and ,illustrations4 ,,lxxvi4 ,,race and ,,language4 ,by ,,andr ,,lef,,vre1 ,professor in the ,anthropological ,school1 ,paris4 ,,lxxvii4 ,the ,,origin of ,,plant ,,structures by ,,self-,,adaptation ,,to ,,the ,,environment4 ,by ,rev4 ,g4 ,,henslow1 ,m4,a41 ,f4,l4,s41 ,f4,c4,s41 c41 author of ',the ,origin of ,floral ,structures1' c4 ,,lxxviii4 ,,ice-,,work ,,present and ,,past4 ,by ,rev4 ,t4 ,g4 ,,bonney1 ,d4,sc4 ,,ll4,d41 ,f4,r4,s41 c41 ,professor of ,geology at ,university ,college1 ,london2 ,fellow of ,st4 ,john's ,college1 ,cambridge4 ,,lxxix4 ,a ,,contribution to our ,,knowledge of ,,seedlings4 ,by ,lord ,,avebury4 ,,lxxx4 ,the ,,art of ,,music4 ,by ,sir ,c4 ,,hubert ,h4 ,,parry1 ,mus4 ,doc4 ,,lxxxi4 ,the ,,polar ,,aurora4 ,by ,,alfred ,,angot4 ,illustrated4 ,,lxxxii4 ,,what is ,,electricity8 ,by ,j4 ,,trowbridge4 ,illustrated4 ,,lxxxiii4 ,,memory4 ,by ,f4 ,w4 ,,edridge-,,green1 ,m4,d4 ,with ,frontispiece4 ,,lxxxiv4 ,the ,,elements of ,,hypnotism4 ,by ,r4 ,,harry ,,vincent4 ,with ,diagrams4 ,second ,edition4 ,,lxxxv4 ,,seismology4 ,by ,,john ,,milne1 ,f4,r4,s41 ,f4,g4,s41 c1 ,author of ',earthquakes4' ,with #ec ,figures4 ,,lxxxvi4 ,on ,,buds and ,,stipules4 ,by ,lord ,,avebury1 ,f4,r4,s41 ,d4,c4,l41 ,,ll4,d4 ,with #d ,coloured ,plates and #cdj ,figures in the ,text4 ,,lxxxvii4 ,,evolution by ,,atrophy1 in ,biology and ,sociology4 ,by ,,jean ,,demoor1 ,,jean ,,massart1 and ,,emile ,,vandervelde4 ,translated by ,mrs4 ,,chalmers ,,mitchell4 ,with #hd ,figures4 ,,lxxxviii4 ,,variation in ,,animals and ,,plants4 ,by ,h4 ,m4 ,,vernon1 ,m4,a41 ,m4,d4 ,london3 ,,kegan ,,paul1 ,,trench1 ,,tr,,bner1 ,,co41 ,,ltd4