Under this heading I shall consider comments on what I have written on the nature of the human mind and on the relation between the mental and the bodily aspects of a human being. These topics are the subject of the whole of Mr. Kneale's essay and of parts of the essays of Professor Ducasse and Professor Patterson.

      I will begin by expressing my complete agreement with Mr. Kneale's criticisms of the views which he ascribes to a certain influential group of contemporary philosophers in England and U.S.A. I fully accept his conclusion that "all talk of minds presupposes the occurrence of experiences," in a sense in which statements about experiences are not reducible to statements about behaviour and tendencies to behave.

      As to the persons, mentioned by Mr. Kneale, who profess to be unable to understand what is intended by familiar technical terms, like "experience," "sensation," "event," etc., unless these are used in certain special senses in which they occur in popular speech and writing, I can only say this. I have always given them the credit of not being in fact such fools as they would need to be if their professions of impotence could be taken literally. It is, after all, a very common device, in philosophic and other controversies among well-bred disputants, to use: "I don't understand what Mr. X means" as a polite euphemism for: "I understand quite well what Mr. X means, but I think it such obvious rubbish that I shall not waste time in refuting it." By this device two advantages are gained. One gracefully pretends to take upon oneself the blame for stupidity, whilst in fact imputing it to one's opponent. And one avoids the labour of controverting him in detail.

      There is one other quite minor point in Mr. Kneale's paper which I will dispose of at once. It concerns my use of the word "know."

1. I agree, of course, that this is primarily a dispositional word, though it connotes inter alia a disposition to have certain experiences, and not only to speak, write, or otherwise behave in certain ways.
2. But it certainly is sometimes used in a predominantly occurrent sense. Cf., e.g., the following sentences: -- "When that black thunder-cloud blew up during my afternoon's walk, I knew that I was in for a wetting" and "All the time he was talking to me I knew his thoughts were elsewhere."
3. Certainly the word "know," like many other cognition-words, such as "see," "remember," etc., is not merely descriptive of the experience which the subject is thought to be having at the time or of his supposed disposition. To say that a person "knows" so-and-so, evinces a belief on the part of the speaker that so-and-so is the case. And similar remarks apply mutatis mutandis to the statement that a person is "seeing" soand-so or that he is "remembering" so-and-so. None of this is precisely news to me. I have insisted on it almost ad nauseam in my writings, though probably more in later than in earlier ones.

      Passing now to matters of detail, I will take in turn the following matters: --

1. Professor Patterson's comments on certain points in my account of McTaggart's doctrine of the Self and of Self-knowledge,
2. Mr. Kneale's discussion on Epiphenomenalism, and
3. Professor Ducasse's proposed amendments to my "Compound Theory" of the human individual.

(A) THE SELF AND SELF-KNOWLEDGE ACCORDING TO MCTAGGART.

      On this topic I will make the following comments.

      (1) We must begin by reminding ourselves that McTaggart's doctrine of the self is very peculiar, and that it must be taken together with his doctrine of time. In judging it one has to bear in mind, and try to harmonise, the following facts.

1. For him a self, as it really is, is a timeless existent; and what appears to it and to others as its successive experiences are really timeless existents, ordered in a non-temporal series, by ascertain asymmetrical dyadic relation of "containing" and "contained in." Thus a self and its experiences, though of course not literally extended, have a property which is in important respects formally analogous to spatial extension.
2. On the other hand, his argument to show that every self is directly acquainted with itself is based on alleged facts about our everyday experience, as it appears to us under the partly misleading form of a temporal sequence of dated and fleeting mental events.
3. For McTaggart a self, as it really is, is a non-temporal whole, of which its apparently successive total states are, in reality, parts, in a sense formally analogous to that in which, e.g., the representation of the Queen's head on an English postage-stamp is a part of the whole design on the front of the stamp.
4. According to him there is a certain part of each such whole which stands to that whole in the cognitive relation of prehension to prehended object.

      (2) Since neither Professor Patterson nor I can accept this account of the self, I need say no more about it. But Professor Patterson suggests, as an alternative, that a self may be "present in" the events which make up its history, "as the whole is in the part."

      I find two difficulties in this.

1. In what sense is any whole ever present in any part of it? In what sense, e.g., is the whole design on the front of a penny stamp present in the representation of the Queen's head, which forms a part of it?
2. I understand that Professor Patterson agrees with me in denying that a self's experiences are parts of it. In that case a self cannot stand to its experiences in exactly that relation (whatever it may be) which is described by saying that a whole is "present in" each part of it. At best there might be some kind of important analogy between the two relations. But what exactly is the analogy?

      (3) I drew a distinction between "perception" and "prehension," and substituted the latter term throughout for the former as used by McTaggart. Professor Patterson objects to this.

      Now there is no doubt about the following facts.

1. McTaggart intended to use "perception" for what Lord Russell called "acquaintance with particulars."
2. He held that, whenever a person is acquainted with a particular, it presents itself to him as characterised in certain ways, e.g., as red, as squeaky, as having the emotional tone of anger, and so on.
3. He regarded it as an almost intolerable paradox to suppose that a particular could present itself, to a person who is acquainted with it, as having any character which does not in fact characterise it at the time.
4. "Perception" is commonly used as a general name for such experiences as "seeing," "touching," "hearing," etc.; and what we ostensibly see, touch, hear, etc., is either of the nature of bodies (e.g., tables or bells or lamps) or of the nature of physical events (e.g., flashes of lightning, peals of thunder, etc.).

      Now, everyone admits that the experience of ostensibly seeing, e.g., a cow, involves as an essential factor being acquainted with a particular which sensibly presents itself as having a certain characteristic shape, size, arrangement of colours, and so on. And this holds mutatis mutandis of the other species of perception. So "perception," in the ordinary sense, certainly involves "perception" in McTaggart's sense. But it seems equally Rlain that it involves something more and something different. In the first place, a person would not claim to be "seeing a cow" unless he took himself to be in the presence of something which has many specific characteristics, e.g., being an animal that gives milk, which the particular which he is acquainted with at the moment is certainly not sensibly presenting itself to him as having. Secondly, no one finds any difficulty or paradox in a perceived object being perceived as having a characteristic which it does not in fact have at the time. There is, e.g., no paradox in the fact that a stick, which is in fact straight, is seen as bent when half in air and half in water.

      For these reasons I hold to my view that McTaggart used "perception" in an unusual sense; that this usage is liable to mislead through the associations of the ordinary usage; and that it is best therefore to substitute some technical term, such as "prehension" for what he obviously had in mind.

      Professor Patterson says that what I call "perception" is "an unholy amalgam of prehension and judgment." As to "unholy," hard words break no bones. As to "judgment," a rather similar point is raised by Professor Blanshard in his essay, and I may as well deal with it here Professor Blanshard is inclined to assert that a rudimentary kind of non-demonstrative inference is involved in sense-perception. The reason that he gives is that there certainly are data, e.g., the visual appearance of the object; that there certainly is a kind of transition from them; and that what is reached by that transition must be a judgment, since it can significantly be said to be "true" or "false."

      Now I think that this question largely turns on the usage of certain words. I should not talk of "judgment" unless a person had before his mind a proposition with a subject and a predicate. I should not talk of "inference" unless that person

1. saw or thought he saw a certain logical relation of entailment or of probabilification between that proposition and another proposition, and
2. in virtue of this, and of his full or partial conviction of the truth of the former proposition, took up an attitude of full or partial belief in the latter.

      Before leaving this topic, I wish to emphasise that the reasons stated above for distinguishing prehension from perception are quite independent of whether or not the object prehended is ever identical with, or a part of, the object perceived.

      (4) In terms of this distinction it seems to me that a person's awareness of himself must be much more like "perception," in my sense of the word, than like "perception" in McTaggart's sense, i.e., prehension. For, assuming the reality of time, a self is something with a long history, consisting of its successive experiences, and it is something with an elaborately organised system of dispositions. That being so, I should suppose that self-consciousness would resemble perception

1. in involving non-discursive awareness of certain particulars as having certain psychological qualities and standing in certain psychological relations to each other, and
2. in including another kind of cognition (based on the former) which so far resembles judgment as to be significantly describable as "true" or "false," "veridical" or "delusive."

      (5) Lastly, I think it is misleading to say, as Professor Patterson does, that to hold a "bundle-theory" of the self is equivalent to "denying that there is any self at all." A bundle-theory would claim to admit all the facts which we summarise by saying that certain simultaneous and successive experiences "belong to a certain self," and that certain others "belong to a certain other self." What it then professes to do is to give a satisfactory account of these facts wholly in terms of direct interrelations between experiences. Ordinary language does undoubtedly suggest a quite different view, viz., that the experiences which "belong to a certain self" derive their characteristic inter-relations from a common relationship in which they all stand to something which is not an experience or a group of experiences. Let us call this a "Pure Ego." Then a bundle-theory does "deny that there is any self at all," in the sense of a Pure Ego; and in so doing it does go against the suggestions of ordinary language. But, if it does not ignore any relevant introspectable fact, and if it does give a satisfactory account of all the relevant introspectable facts, it cannot fairly be charged with "denying that there is a self at all." At worst it denies a certain theory of the self, which is so embodied in the language in which we speak of mental facts that we have a difficulty in separating it from them and in realising that it is a theory.

(B) EPIPHENOMENALISM.

      I think that Epiphenomenalism, (in the sense in whichvMr. Kneale takes it, is equivalent to what T. H. Huxley called the "conscious automaton theory." It may be summed up in the following three propositions: --

1. An experience is not a state or modification of any substance, if "substance" be understood to mean a particular existent of a peculiar kind, other than a set of intimately inter-related events, which has qualities, states, and dispositions, but is not a quality or a state or a disposition of anything.
2. The complete immediate cause of any experience is a simultaneous bodily event in the brain or nervous system of some one living organism.
3. No experience is a cause-factor in the total cause of any bodily event. (It is unnecessary to add that no experience is a cause-factor in the total cause of any mental event, for that follows immediately from Proposition (2) above.)

      This is not the place for me to consider at length the arguments which might be adduced for and against these propositions. As regards the second and the third of them, I will content myself with the following remarks. Both are in prima facie conflict with notorious facts. This is admitted by all intelligent epiphenomenalists, and there are certain well known opening moves in the game of trying to reconcile these propositions with the facts. I would summarise my impression of the whole controversy as follows. I do not think that there is any adequate empirical evidence for either of these two propositions. As to Proposition (2) the utmost that can be said is this. There is fair, but far from conclusive, empirical evidence for holding that a necessary condition for the occurrence of any experience is a simultaneous event in the brain or nervous system of some living organism. And there is no strong empirical evidence against this, though some fairly well established phenomena of trance-mediumship seem difficult to reconcile with it. Proposition (3) is in a still weaker position. There is such strong prima facie evidence against it that it is an extreme paradox. It could be accepted only on a priori grounds. And it can be defended empirically only by making liberal drafts on the unobserved and the unobservable; by drawing a distinction between de facto invariable accompaniment and causal conditioning; and by holding that only the former relation holds between a brain-event and its mental correlate, whilst the latter holds between certain bodily events.

      As to Proposition (1) and its logical relationship to the other two propositions, I would make the following remarks. So far as I can see, Proposition (2) is quite consistent with there being non-causal relations of the most intimate and peculiar kind, which hold between all or some of the mental correlates of events in one and the same brain, and do not hold between any of the mental correlates of events in different brains.

      Suppose we grant that it is intelligible to talk of a mental event which is not a modification or state of any kind of substratum. Then Proposition (2) is compatible with the view that the mental correlates of events in a single highly organised brain constitute a single mental system, highly organised in its own characteristic way. That is what a mind would be, on such a view. It might fairly be described as an "empirical substance," except for the following important defect. An essential part of the notion of an empirical substance is that dispositional properties of specific kinds can be ascribed to it. Now, if Proposition (2) be assumed, dispositional properties could be ascribed to a mind only by courtesy. Strictly speaking, they would all belong to the brain, with which that mind is correlated in the way described.

      I will now consider two closely inter-connected objections which Mr. Kneale puts forward. They concern, not so much the possibility of a view of minds which takes the notion of an experience or mental event as primary and self-sufficient, as the consistency of that view with certain statements which I have made about

1. what I call "prehension" or acquaintance with particulars, and
2. introspection.

      (1) The first seems to come to this. I talk in many places as if the statement that X is prehending so-and-so (e.g., is aware of a squeaky noise) consists in a subject S_x (X's "ego") standing in a certain asymmetrical dyadic relation of "prehending" (in this case auditorily sensing) to a certain particular (in this case an auditory sensible of a squeaky kind). Now, it is said, Proposition (1) explicitly rules out such an entity as S_x, and therefore is incompatible with this account of prehension.

      No doubt that it is true. But the following modification of the above account of prehension would remove the inconsistency. Let us say that the asymmetrical dyadic relation is not that of prehending but that of being-a-prehension-of; and let us say that this relation relates not a "subject" but a mental event, to a certain particular. The proposition that X is prehending so-and-so, now consists of a conjunction of the following two propositions: --

1. In that system of organised experiences which is X's mind there is a certain experience e, and
2. e has to so-and-so the relation of prehension to prehensum.

      (2) The point about introspection seems to be this. I alleged that introspection is comparable, not to sensation (which I regard as a species of prehension), but to sense-perception (which I consider to involve sensation, but to involve also something fundamentally different). But the appropriate object of sense-perception is a body. Now, according to epiphenomenalism, a mind differs from a body in the absolutely fundamental respect that it is not a substance, whilst a body is.

      To this objection I would answer as follows.

      (i) The only analogy which I wanted to draw between introspection and sense-perception was this. In both there is prima facie a prehensive factor. In the former this is an immediate non-sensuous awareness of some contemporary experience or complex of experiences; in the latter it is an immediate awareness of some sensibile. In both there is certainly another factor, based upon the former, but carrying the mind beyond what is being prehended at the moment. The "something more," which is "accepted" introspectively in the one case and perceptually in the other, is of extremely different character in the two cases. But that is irrelevant for the present purpose.

      (ii) The prehensive factor in introspection could be treated, consistently with a "bundle-theory" of the mind, on the lines indicated above for sensation in my answer to Mr. Kneale's first objection

      (iii) Epiphenomenalists do no doubt regard a body as a "substance" in the empirical sense; but they are not, as such, committed to holding that it involves a "substance" in the metaphysical sense of a substratum. Now, as I have argued above, they are not precluded from holding that a human mind is at any rate a "half-blown" substance in the empirical sense. (It could not be a "full-blown" empirical substance for them, because they deny it to have any dispositional properties.) So I do not think that the statement that for epiphenomalists the objects of sense-perception are substances, whilst the objects of self-awareness are not, will bear the weight which Mr. Kneale attaches to it.

(C) THE "COMPOUND" THEORY.

      I fully agree with Professor Ducasse as to the four defects which he enumerates in the theory of a "psychogenic" factor, as put forward by me on various occasions. I welcome his attempt to substitute something on the same lines, but more definite and therefore more susceptible to experimental confirmation or invalidation. I will confine myself to the following comments on his proposals.

      (1) The theory is a form of substantival dualism. As that type of theory is unfashionable at the moment, and as it has been held in forms which are almost certainly untenable and can easily be made to appear ridiculous by anyone who has a happy turn for phrase-making, I would like to say explicitly that I see no objection in principle to substantival dualism.

      According to Professor Ducasse's form of the theory, a living human being from his conception to his death is composed of two substances intimately interconnected. One of these is purely physical, viz., a brain; the other is purely psychical, but it is not at first a mind. It is provided from the first with certain aptitudes, i.e., dispositions to acquire certain dispositions; and it is not unless and until it has acquired a number of these dispositions, and they have become organised, that it becomes a mind. Until then it can be called only a "psychical germ."

      (2) If we ask what exactly is meant by calling such a germ a "psychical" substance, we are told that such a substance may be defined as one that has some "psycho-psychical" dispositions, and no "physico-physical" dispositions. If we consider Professor Ducasse's definitions of these terms, and of their congeners "psycho-physical" and "physico-psychical" dispositions, we are referred back finally to "psychical" and "physical" as applied to what may be called "stimulus-events" and "reaction-events." I think that Professor Ducasse might fairly say that the meaning of "psychical" and of "physical," as applied to events, can be made quite plain (except to the hopelessly stupid or the artfully naive) by instances and counter-instances. E.g., a twinge of toothache, as actually felt, is certainly a psychical event (whether or not it be in some sense also physical). And an electrical disturbance in a certain part of the brain is certainly a physical event (whether or not it be in some sense also psychical). A general, and perfectly well understood, name for a psychical event is an "experience," as that word is used in books by psychologists and epistemologists. And physical events may be quite satisfactorily indicated for the present purpose by saying that they are the kind of events which are discussed in books on physics and chemistry and physiology.

      That being understood, we can define a "purely psychical substance" as follows. It would be a substance which

1. has some dispositions which both need an experience to stimulate them, and when thus stimulated react (if at all) by producing an experience; and
2. has no dispositions which both need a physical event to stimulate them, and when thus stimulated react (if at all) by producing a physical event.

      (3) I think that there are some obscurities in Professor Ducasse's general account of dispositions, on which the above definitions depend. We are told that to say S has a disposition D is to say:

"In circumstances of the kind C the occurrence of an event of the kind E causes S to respond in the manner R."

      Suppose, e.g., that there is telepathic interaction between embodied human minds, and that this is not mediated by their brains. Then it would involve psycho-psychical dispositions, for which the stimulus-event is in one psychical substance and the reaction-event in another. In view of all this, one is inclined to ask: What is the criterion for attributing a disposition D to a certain one substance S? Suppose that a stimulus-event E in S, under the kind of circumstances C, gives rise to a reaction-event of the kind R in a different substance S'. Are we to assign the disposition always to S (the seat of the stimulus-event), or always to S' (the seat of the reaction-event), or in some cases to one and in others to the other? Or are we to assign two complementary dispositions, D and D', one to S and the other to S'?

      (4) Lastly, I am not altogether happy about Professor Ducasse's attempt to explain in terms of his theory the case of a man, hitherto of an amiable and benevolent disposition, who becomes violent and morose after an injury to his brain.

      As I understand it, the explanation proposed comes to this. A man, who predominantly often responds in a friendly way to external stimuli which might be responded to either in a friendly or an unfriendly manner, may, when certain transitory internal conditions are fulfilled (e.g., when he is very tired or in a state of great anxiety), respond in an unfriendly way to similar stimuli. This shows that he has a disposition to respond in a predominantly unfriendly way, in addition to his disposition to respond in a predominantly friendly way, to such stimuli. The prevailing internal condition of a benevolent man is such that his disposition to a friendly response generally passes into action, whilst his co-existing disposition to an unfriendly response generally fails to do so. In the case of a morose man we have only to substitute "unfriendly" for "friendly" and conversely, in the last sentence.

      Suppose now that a man, who has hitherto been benevolent, becomes morose after suffering a brain-injury; or that one, who has hitherto been morose, becomes benevolent after an operation on his frontal lobes. Then, according to Professor Ducasse, we must say, not that the dispositions of his mind have been changed, but that the internal conditions necessary for the functioning of a certain one disposition have been suspended, whilst those necessary for the functioning of a co-existent disposition of the opposite kind have been fulfilled.

      Now my original difficulty with ordinary dualism was that the facts about changes of character and temperament, after brain-injuries or operations, made it very difficult in principle to know what dispositions to ascribe to a man's mind, as such. I do not find this difficulty much lightened by being told that we may and must ascribe to a man's mind all kinds of opposite dispositions, and ascribe the predominance of some over others in his habitual reaction to his fellows to the prevalence of this or that background condition of his body or his mind or both.