C. J. Ducasse -
A Critical Examination of the Belief in a Life After Death
What is "Mental"?
FROM THE things, events, etc., called "physical" or "material," we now turn to those called "psychical" or "mental." With regard to these, the same two questions arise as did concerning the others. Stated here in their right methodological order, they are: (1) Which events, processes, etc., are the ones named "psychical" or "mental?" and (2) What characteristic does empirical examination discover as peculiar to all of them?
1. Which occurrences are denominated "mental"
The answer to the first of those two questions is that, originally and fundamentally, the events, processes, etc. denoted by the terms "psychical" or "mental" are the inherently private ones each person can, in himself and only in himself, attend to in the direct manner which - whether felicitously or not - is called Introspection. "Mental" or "psychological" events are thus, fundamentally, the immediate experiences, familiar at first hand to each of us, of which the various species are called "thoughts," "ideas," "desires," "emotions," "cravings," "moods," "sensations," "mental images," "volitions," and so on; or comprehensively, "states or modes of consciousness."
What introspection discloses may to some extent be published by the person concerned, but is never itself public. To publish the fact that at a given time one's state of consciousness is of a certain kind consists in performing certain perceptually public acts - vocal, graphic, gestural, facial, or other - that are such as to cause the percipients of them to think of a state of consciousness of that kind and to believe that the state of consciousness of the performer of those acts is of that kind at the time. This is what, for example, utterance of the words "I am anxious," or "I wonder where I parked my car," or "I remember him," etc. ordinarily causes to occur in the person who hears them. But the utterer's state of consciousness, which such words symbolized, is never itself public in the sense in which the sound of those words, or the written words, are public. That state of consciousness is inherently private to the particular person, of whose history alone it is an item - private in the sense that no other person can examine it, whereas each person can examine his own states of consciousness; can, for instance, compare directly the feeling he calls "anxiety" with the feeling he calls "wonder," etc.
2. Introspection, Inspection, Intuition
In the case of sensations, attention directly to them - vs. to what they may be signs of or to what they may be caused by - is termed by some writers Inspection rather than Introspection. Inspection in this technical sense, then, no less than Introspection, is attention directly to experiences that are inherently private; for, evidently, we cannot attend to another person's sensations themselves, but only to his appearance or behavior. Such knowledge as we have concerning his sensations results from our automatically interpreting certain modes of his behavior as signs that, in given situations, he- is experiencing sensations similar to, or as the case may be, different from, those we are experiencing.
For example, we do not and cannot discover that another person is, say, color-blind to red-green, by inspecting the sensations he has when he looks at grass and at a poppy, and comparing them with the sensations we have when we look at the same objects. We discover it by attending to his perceptually public behavior on such occasions, by noticing that in certain ways it is consistently different from our own on the same occasions, and by taking this as signifying that his color-sensations correspondingly differ from ours.
For the direct kind of experience, whether attentive or inattentive, which when attentive is called specifically Introspection, or by some writers in the particular case of sensations, Inspection, a generic name is needed; but no such generic name less cumbersome than "State of consciousness, as such" appears to exist in ordinary language. I have therefore proposed for this elsewhere, in default of a better, the name Intuition - defining Intuition as occurrence of some state of consciousness, as such, i.e., as distinguished from what it may be consciousness of, in the sense of may signify.
Intuition, then, may be attentive (clear) or inattentive (dispersed, dim;) and, in so far as attentive, it is then inspective, or introspective, according as the state of consciousness attended to is a sensation, or is other than a sensation.
3. "Content" vs. "object" of consciousness
The second of the two questions mentioned at the outset, namely, what internal character is peculiar to all the events, processes, etc. that are intuitions as just defined, i.e., are "mental" or "psychical," is more technical than the first. Fortunately, it does not need to be gone into at any length for present purposes. I shall therefore say here, without attempting to argue the point, only that in the case of the events, processes, etc. in view and only in their case, existing consists solely in being experienced and being experienced constitutes the whole of existing. That is, in their case but only in their case, esse est percipi. This is the peculiarity that differentiates them from all other things, events, or processes. The term "Intuition" thus designates the experiencing of such an experience - an intuition standing to the intuiting thereof in the same kind of relation as, for example, a stroke being struck stands to the striking thereof (not, to the object struck;) that is, in both cases equally, as the "connate" or "internal" accusative of the activity concerned, as distinguished from the "alien" or "objective" accusative of it. Similarly, compare tasting a taste with tasting a substance, tasting bitter taste with tasting quinine, thinking a thought with thinking of New York, etc.
Introspection, then, and likewise "Inspection," is intuition attentive to its own modality of the moment, instead of, as normally, inattentive to it. Its particular modality at any moment I term the content of consciousness at the moment, as distinguished from the object of consciousness at the moment.(1)
(1) The contentions and the terminological proposals sketched in this and the preceding two sections are explicated and defended in detail in Chapts. 12, 13, and 14 of my Nature, Mind, and Death Open Court Pub. Co. La Salle, Ill. 1951. See in particular pp. 230-40, 275-80, 293-5, 302.
In connection with the above account of states of consciousness, it will be appropriate to comment here briefly on the fact, of which much is being made these days, that we all possess a vocabulary, understood by our fellows, for mental states or states of consciousness. This, it is alleged, means that mental states cannot, as generally has been assumed and as asserted in the text above, be occurrences unobservable by other persons than the particular one in whom they occur, i.e., be inherently private.
Rather, it is contended, the denotation of the words which denote mental states must have been learned by us in the same manner as that of the words which denote physical objects and events; namely, by our hearing them applied by other persons to public occurrences which they and ourselves were witnessing - these, however, being denominated specifically "mental" when they consisted of modes of behavior of certain special kinds; e.g., anger-behavior, goal-seeking-behavior, listening-behavior, seeing-behavior, etc.
A crucial fact, however, is overlooked by this would-be-inclusive behavioristic account of the manner in which men have acquired a shared vocabulary for mental states notwithstanding the latter's inherent privacy. That crucial fact is that when the behavior, witnessed by another person, which moves him to employ one or another of the "mental" words in characterizing it, is our own behavior - e.g., when he says to us: "Now, don't be so angry," or "Don't you see that bird?" or "What were you dreaming just before I woke you?" or "You are wondering at my appearance today," etc. - then the words italicized do not denote for us our behavior, which the other person is attending to but we are not. Instead and automatically, they denote for us in each case the mental state itself which we are subjectively experiencing - feeling, intuiting, immediately apprehending - and which, irrespective of how in particular it may be connected with our behavior at the moment, is anyway not that behavior itself but something radically different and inherently private. In English, "anger-behavior" denotes one thing, which is public; and "anger" denotes another thing, which is publishable but never itself public. It is only in Behaviorese - the doctrinaire language of the creed of radical behaviorism - that "anger" denotes anger-behavior.
A recent widely discussed work, Gilbert Ryle's The Concept of Mind, appears largely based on its author's overlooking the crucial fact just mentioned. And one contention in it of which much has been made, to wit, that there are no acts of will or volitions, is based merely on failure to notice that although many voluntary acts indeed are not caused by any act of will, nevertheless certain other acts that are voluntary acts are in addition willed acts, i.e., are initiated by deliberate volitions.
4. "Mental," derivatively vs. fundamentally
There now remains to point out that, just as the expression "the material world" denotes not alone whatever events, processes, things, etc. are or can be made perceptually public, but also, derivatively, the imperceptible constituents of them; so likewise the events, processes, etc. denominated "psychical" or "mental" include not only those, such as mentioned above, that are introspectively or "inspectively" scrutinizable, but also, derivatively, certain others which are not accessible to "inspection" or introspection and are therefore termed "subconscious" or "unconsciou" instead of "conscious."
These would comprise such items as the repressed wishes or impulses, the forgotten emotional experiences, the complexes, censors, etc. which psychoanalysts find themselves led to postulate as hidden constituents or activities of the human mind, in order to account for some otherwise inexplicable psychological peculiarities of some persons.
Such hidden constituents can sometimes be brought to consciousness under the direction of the psychoanalyst; but the exploration of these normally unintrospectable psychological factors is still in its infancy as compared with the exploration of the atomic and sub-atomic levels of materiality. The mere fact, however, now definitely known, that there are such things as unconscious, i.e., at the time unintrospectable, psychological processes, is, when taken together with even the limited knowledge of them so far obtained, of vast importance for assessment of the significance of certain of the phenomena alleged to constitute empirical evidence of survival of the personality after death.
Moreover, although the terms "the unconscious," "the subconscious, - are commonly employed in connection with the factors brought to light in therapeutic psychoanalysis, nevertheless factors of the same kinds undoubtedly operate, but ordinarily in a non-pathological manner, in all of us.
Unconscious also, of course, are various assumptions under which a particular person happens to proceed, but which he does not realize he makes because he has never formulated them and nothing in his experience has happened that would have challenged their validity and thus made him conscious of them. Unconscious also at a given time are all those of his memories which he is not then remembering, and all those of his capacities or dispositions which he is not then exercising.
What is "a Mind"?
IN A book cited earlier, Dr. Lamont defines mind as "the power of abstract reasoning," referring to the exercise of it as "the experience of thinking or having ideas," and stating that ideas "are non-material meanings expressing the relations between things and events."(1)
(1) The Illusion of Immortality, pp. 70, 100, 101.
But although the power of abstract reasoning may well be what differentiates human minds from the minds of animals, and developed human minds from the minds of human infants, yet human minds comprise, besides the power of abstract reasoning, various others, wholly or partly independent of it. This power could at most be claimed to constitute the intellectual part of the mind of man; for minds, human as well as animal have also affective and conative capacities, the existence of which Lamont acknowledges but does not include in his definition of mind. His definition is therefore arbitrary and unrealistic.
1. The traits in terms of which one describes particular minds
When we are asked to state the characteristics in which a given person's mind differs from that of another, what we say is, for example, that he is patient whereas the other is irritable; intelligent, and the other stupid; widely informed, and the other ignorant; self-disciplined, and the other self-indulgent; and we add whatever else we happen to know about his particular tastes, opinions, habits, intellectual skills, attitudes, knowledge, personal memories, character, ideals, ambitions, and so on.
It is in terms of such traits that we spontaneously describe the particular nature of a particular mind. Correspondingly, the generic nature of the human mind would be described in terms of traits shared by all normal human minds. Examples of such generic traits would be the capacity to experience sensations - dizziness, thirst, warmth, pain, color, tone, etc.; the capacity to form mental images - visual, auditory, or other - as in dreams, in day-dreams, in memories, and in voluntary imagination; the capacity to experience emotions, moods, cravings, and impulses; the capacity to imagine and desire experiences or situations not at the moment occurring; and so on.
2. What is a power, capacity, or disposition
Lamont's definition of mind, however, although inadequate for the reason stated, is sound to the extent that it conceives minds in terms of "powers."
The term "power" is nowadays out of favor, as is its virtual synonym, "faculty," the utility of which was destroyed by misuse of it as answer to the question "Why?" The classical horrible example of such misuse is the vis dormitiva offered as answer to the question why opium puts people to sleep.
But a power, or faculty, or capacity, or ability, or - to use the term currently in fashion - a disposition, is not an event and therefore never can itself be a cause. A power or disposition is a more or less abiding causal connection between events of particular kinds.(2)
(2) No need arises here to go into the question of the nature of causality itself. I shall therefore say only that a causal connection between events of specified kinds is a causal law, and that a causal law is a law of causation not in virtue of its being a law (since some empirical laws are not laws of causation) but in virtue of the fact that each of the particular sequences, of which the law is an inductive generalization, was, in its own individual right, a causal sequence. For the analysis of the nature of causality this assumes, interested readers are referred to Chs. 7, 8, and 9 of the writer's Nature, Mind, and Death, Open Court Pub. Co. La SalIe, 111. 1951.
More specifically, that something T - whether T be a material thing or a mind - has a power, capacity, or disposition D means that T is such that whenever the state of affairs external or/and internal to T is of a particular kind S, then occurrence of change of a particular kind C in that state of affairs causes occurrence in it of a change of another particular kind E.
For example, solubility in water is a power, faculty, ability, capacity, or disposition of sugar. This means, not that the sugar's solubility causes the sugar to dissolve when it is placed in water; but that sugar is such that (i.e., behaves according to the law that) whenever an event of the kind described as "placing the sugar in water" occurs, then, in ordinary circumstances, that event causes an event of a certain other kind, to wit, the kind described as "sugar's dissolving in water."
This illustration concerns a material thing - sugar. But the mental traits of persons are capacities or dispositions in exactly the same generic sense of these terms, defined above, as are the material traits of sugar and of other material things.
For example, that a person possesses a memory of certain personal experiences, or of some impersonal fact such as that Socrates died in 399 B.C., does not consist simply of occurrences in him, at some particular time, of mental images of those personal experiences, or of word - images formulating that impersonal fact, together with occurrence of what has been termed the feeling of familiarity. Rather, it consists in that person's being such that whenever a question or other "reminder" relating to those personal experiences or to that impersonal fact presents itself to his attention, then, provided that the circumstances in which he is at the time be not abnormal, the advent of the "reminder" causes those images, together with the feeling of familiarity, to arise in him.
Again, that a person is, say, irritable, does not mean that he is at the time experiencing the feeling called Irritation; but that he is such that events of kinds which in most other persons would not in ordinary circumstances cause the feeling of Irritation to arise in them do, in similar circumstances, regularly cause it to arise in him. And so on with the tastes, the skills, the gifts - intellectual, artistic, or other - the habits, etc., which a person possesses. All of them analyze as capacities or dispositions, i.e., as abiding causal connections in him between any event of some particular kind and an event of some other particular kind, under circumstances of some particular kind.
The term "dispositions", however, although currently in greater favor than "powers" or "capacities," is really less felicitous than these since it suffers from a certain ambiguity of which they are free and which easily leads to serious misconceptions. For, besides the sense of "disposition" in which the word is synonymous with "capacity" or with "power," it has another sense, in which "a disposition" and the verb "being disposed to ..." designate an event, to wit, occurrence of an impulse or inclination to act in some particular manner.
For example, that a given person is at the moment disposed to forgive a certain injury that was done him means no more than that, at the moment, an impulse or inclination to forgive is present in him. This does not mean that he has, or is acquiring, "a forgiving disposition," i.e., that similar situations regularly cause, or henceforth will regularly cause, the impulse to forgive to arise in him.
3. What a mind is
The distinction essential in connection with the immediately preceding paragraph is between the nature of a given mind, and the history of that mind.
The history consists of events. Occurrence of some impulse, occurrence of awareness of some situation, acquisition or loss of some habit or capacity, etc., are events; each of them results from exercise of some capacity, and each is an item in the history of a mind. On the other hand, an account of the nature of a given mind is an account of the particular sort of mind it is at the time, i.e., of the particular set of dispositions, capacities, powers, or abilities which are what as a matter of course we list when called upon to describe that particular mind. The events that constitute a mind's history doubtless are in large part responsible for that mind's having come to be the particular sort of mind it is now. But recital of them is no part of an account of what it now is.
The capacities that together constitute the nature of a mind are of three comprehensive kinds. These may be denominated psycho-psychical, psycho-physical, and physico-psychical, according, respectively, as the cause-event and the effect-event entering in the description of a given capacity are, both of them, psychical events; or, the cause-event psychical but the effect-event physical; or the cause-event physical but the effect-event psychical.
In all three cases the state of affairs, in which the cause-event and the effect-event are changes, is normally in part somatic and more specifically cerebral; and in part psychical. Whether this is the case not only normally, but also invariably and necessarily, is another question. Evidently, the possibility or impossibility of survival after death depends in part on the answer to it.
However, if a mind continues to function after the death of its body, its functioning would not then normally include exercise either of its physico-psychical or of its psycho-physical capacities. That is, such awareness, if any, as a discarnate mind had of physical events would be paranormal and more specifically, "clairvoyant", i.e., without the intermediary of the bodily sense organs; and such action, if any, as a discarnate mind exerted on physical objects would likewise be paranormal and more specifically "psychokinetic," i.e., without the intermediary of muscular apparatus.
It should be noticed that the various dispositions or capacities that enter into the nature of a mind constitute together a system rather than simply an aggregate. For one thing, as Professor Broad has pointed out, some dispositions are of a higher order than some others, in the sense that the former consist of capacities to acquire the latter(3). An aptitude, as distinguished from e.g., a skill, is a capacity to acquire a capacity. Again, possession of certain capacities at a certain time is in some cases dependent on possession of certain other capacities at that time.
(3) Examination of McTaggart's Philosophy, Vol. 1: 264-278.
A mind, then, is a set of capacities of the three generic kinds mentioned, qua interrelated in the systematic manner which constitutes them a more or less thoroughly integrated personality; and the mind, of which we say that it "has" those capacities, is not something existentially independent of them, but "has" them in the sense in which a week has days or an automobile has a motor. That a mind exists during a certain period means that, during that period, ones or others of the capacities, which together define the particular sort of mind it is, function. That is, the existing of a mind of a particular description is the series of actual occurrences which, as causally related one to another, constitute exercisings of that mind's capacities. A mind's existing thus consists not just of its having a particular nature, but of its having in addition a history.
But further, just as a material object consists of various parts interrelated in some particular manner, each of which is itself a material object whose nature is analyzable into a set of capacities, though to a greater or less extent ones different from those of the whole; so likewise a mind has parts, normally connected with one another in a certain manner, each of which, like the whole, analyzes into some particular complex of capacities, though capacities to some extent different from those of the whole.
Moreover, in a mind as in a material object, some part of it may on occasion become dissociated from the rest and perhaps function independently, although then in a manner more or less different from that in which it functioned while integrated with and censored by the rest. As Professor H. H. Price has remarked somewhere, the unity of a mind is not a matter of all or none, but rather of more or less. Each of the parts of a mind is itself a mind, or mindkin, of sorts.
The foregoing account of what a mind is has revealed that a mind, and a physical substance such as sugar or a physical object such as a tree, ultimately analyze equally as complexes of systematically interrelated capacities. Had not the word "substance" so chequered a philosophical history, we could say that a mind is as truly a psychical substance as any material object is a physical substance. Let us, however, avoid the misunderstandings this might lead to, and say that a mind, no less than a tree or sugar, is a substantive - using this word as does W. E. Johnson for the kind of entity to which the part of speech called a "noun" corresponds.(4)
(4) Logic, Cambridge Univ. Press, 1921 Vol I:9. For a more elaborate account of the conception of what a mind is, outlined above, the interested reader is referred to Ch. 17 of the author's already cited Nature, Mind, and Death.
Evidently, the preceding analysis of the nature of a mind in terms of capacities or dispositions applies not only to the intellectual or cognitive powers sometimes specifically meant by the term "Mind," but also to the emotional, affective, and conative capacities sometimes more particularly in view when the terms "soul" or "spirit," instead of "mind," are used. In these pages, therefore, the term "mind" will be used in the broad sense comprehensive of "soul" and of "spirit," as well as of "intellect." That is, it will include whatever constituents of the human personality are other than material in the sense of this term defined in Chapt. V.
What Would Establish the Possibility of Survival?
THE INQUIRY we undertook in Part II, as to what exactly the pivotal terms "material," "mental", "mind," and "life" denote, was unavoidably somewhat lengthy and technical. It may therefore be well to summarize its findings before we proceed, with their aid, to an exposition of the case for the possibility of survival.
1. Summary of the findings of Part II
The first question considered in Part II was: Which things - i.e., which objects, characteristics, events, processes, relations, etc., - are denominated "material" or "physical." The answer reached was that, fundamentally, they are the things that are or can be made perceptually public; and in addition, derivatively, the minute or otherwise unperceivable existential constituents of those.
The next question was: Which things are denominated alive" or "living." The answer was that the marks by which we distinguish them from the things called "dead," or "inorganic," are in general metabolism, growth, respiration, reproduction, and adaptation to environment; and that, more particularly in the case of human bodies, the minimal marks of their being "alive" not "dead" are breathing, heart beat, and maintenance of body temperature above a certain level.
The third question was: Which things - still taking this word in the comprehensive sense - are denominated "mental" or "psychical." We found the answer to be that, fundamentally, they are the ones capable of being introspectively observed; and in addition, derivatively, whatever unintrospectable processes, events, etc., are existentially implicit in those that are introspectable.
The fourth question was: What is "a mind." Distinguishing between the history of a mind, which consists of a series of events, and the nature of a mind at a given time in its history, we found that its nature analyzes as a set of systematically interconnected "dispositions," i.e., capacities, powers, abilities; and that each of these consists in the more or less abiding sufficiency, or as the case may be, insufficiency, of change of some particular kind C in a state of affairs of a kind S, to cause change of another particular kind E in S immediately thereafter. For example, that a person is of a patient disposition means that kinds of occurrences that would in similar situations be sufficient to cause most other persons to feel irritation are in his case insufficient to cause this.
The dispositions, which together constitute the nature of a mind are, we further found, of three comprehensive kinds: psycho-psychical, physico-psychical, and psycho-physical, according as, respectively, the cause-event and the effect-event are both psychical, or the cause-event physical and the effect-event psychical, or the cause-event psychical and the effect event physical.
Lastly, we noticed that existence of a mind having a given nature consists, not in existence of something distinct from and "having" the set of dispositions that define that mind's nature, but in the series of actual occurrences which constitute exercise of ones or others of those dispositions; that is, constitute the historical individuation of a mind having that particular nature.
2. Theoretical possibility, empirical possibility, and factuality
In Chapt Ill, we set forth the considerations that constitute the basis - in common knowledge, in the knowledge possessed by the Natural Sciences, and in certain theoretical reflections - for the contention that survival of the individual's consciousness after the death of his body is impossible. The clarification of key concepts we achieved in Part II now puts us in position to judge whether or how far the items of the case against the possibility of survival are strong and cogent, or on the contrary weak or inept.
If and in so far as they turn out to have either of these defects, then and in so far they fail to establish the impossibility they are alleged to establish, and they therefore leave open the possibility of a life after death. That is, the case for the possibility (not automatically the reality) of survival consists of the case against the adequacy of the grounds on which survival is asserted to be impossible: That a life after death remains a theoretical possibility would mean that the theoretical grounds alleged to entail its impossibility are unsound; or, if sound in themselves, nevertheless do not really but only seemingly entail it. And, that survival remains an empirical possibility would mean that survival, notwithstanding possible appearances to the contrary, really is compatible with all the facts and laws of Nature so far truly ascertained by the sciences.
If critical examination of the merits of the case against the possibility of survival reveals that, notwithstanding the negative "verdict of science", a life after death remains both a theoretical and an empirical possibility, then certain questions will confront us.
The first will be as to what prima facie positive empirical evidence, if any, is available that survival is a fact. Next, we shall have to ask whether such evidence for it as our inquiry may turn up is really sufficient to establish survival or the probability of it. And, if this itself should be dubious, then the methodologically prior question will force itself upon us, as to what kind and quantity of evidence, if it should be or become available, would conclusively prove, or make conclusively more probable than not, that survival is a fact. Overarching of course these various problems, there is the question as to what forms survival, if it be a fact, can plausibly be conceived to take.
3. The tacit theoretical premise of the empirical arguments against the possibility of survival
One of the facts listed in Chapt. III as allegedly proving that consciousness cannot survive the body's death was that a severe blow on the head permanently or temporarily terminates all the evidences of consciousness which the body had until then been giving. This, it is alleged, and likewise the other empirical facts cited in that chapter, shows that a person's states of consciousness are direct products of the neural processes that normally take place in his brain; and hence that when, at death, these terminate, then consciousness necessarily lapses also.
This conclusion, however, is based not simply on the observed facts, but also on a certain theoretical premise, tacitly and in most cases unconsciously employed. The nature of it becomes evident if one considers the prima facie analogous empirical fact that smashing the receiver of a radio brings to an end all the evidences the instrument had until then been giving that a program was on the air, but that this does not in the least warrant concluding that the program was a product of the radio and therefore had automatically lapsed when the latter was smashed.
The hidden premise of the contention that the cessation at death of all evidences of consciousness entails that consciousness itself then necessarily ceases is, evidently, that the relation of brain activity to consciousness is always that of cause to effect, never that of effect to cause. But this hidden premise is not known to be true, and is not the only imaginable one consistent with the empirical facts listed in Chapt. III. Quite as consistent with them is the supposition, which was brought forth by William James, that the brain's function is that of intermediary between psychological states or activities, and the body's sense organs. muscles, and glands. That is, that the brain's function is that of receiver-transmitter - sometimes from body to mind and sometimes from mind to body.
These remarks are not intended to answer or to hint at a particular answer to the question of the nature of the relation between brain or body and mind; but only to make evident that the validity or invalidity of the conclusion, from the various empirical facts cited in Chapt. III, that man's consciousness cannot survive the death of his body, is wholly dependent on what really is the relation between body and mind.
Our task in the remaining chapters of Part III must therefore be to consider the various hypotheses which, in the history of thought, have been offered concerning the nature of that relation, and to decide which one among them best seems to accord with all the definitely known facts.
Mind Conceived as Bodily Processes, Matter Conceived as Set of Ideas
AMONG THE hypotheses concerning the relation between mind and body, one of the most ancient is the radically materialistic one. Let us consider it first; and then its polar opposite, the radically idealistic hypothesis.
1. The contention that thought is a physical process
The materialistic conception of mind is that "thoughts," "feelings," ideals," "mental processes," or, comprehensively, "states of consciousness," are but other names for material occurences of certain kinds - more specifically, for molecular processes in the tissues of the brain; or for speech, vocal or sub-vocal; or for discriminative and adaptive behavior. This, if true, would entail that the supposition that consciousness persists after death has terminated these material activities is absurd because then obviously self-contradictory.
But as Friedrich Paulsen long ago and others since have made quite clear, no evidence really ever has been or can be offered to support that materialistic conception of mind, for it constitutes in fact only an attempt unawares to force upon the words ',thoughts," "ideas," "feelings," "desires," and so on, a denotation radically other than that which they actually have.
Paulsen writes: "The proposition, Thoughts are in reality nothing but movements in the brain, feelings are nothing but bodily processes in the vaso-motor system, is absolutely irrefutable"; not, however, because it is true but because it is absurd. "The absurd has this advantage in common with truth, that it cannot be refuted. To say that thought is at bottom but a movement is to say that iron is at bottom made of wood. No argument avails here. All that can be said is this: I understand by a thought a thought and not a movement of brain molecules; and similarly, I designate with the words anger and fear, anger and fear themselves and not a contraction or dilation of blood vessels. Suppose the latter processes also occur, and suppose they always occur when the former occur, still they are not thoughts and feelings."(1)
(1) Introduction to Philosophy, transl. F. Thilly, Henry Holt and Co. N.Y. 1895, pp. 82-3.
Words such as "thought," "feeling," etc., have two possible functions. One is to predicate of something certain characters which the word connotes; the other is to indicate - point at, denote, tag, direct attention to - certain occurrences or entities. And the fact is that, just as our finger does point at whatever we point it at, or just as a tag does tag and identify whatever we tag with it, so do our words denote - name, tag, direct attention to - whatever we use them to denote. And what we use the words "thought," "feelings," etc., to denote are occurrences with which we are directly familiar, and which are patently quite different from those we denote by the words "molecular motions in the brain" or "modes of bodily behavior."
Hence, however much there may be that we do not know about states of consciousness or about bodily processes, however close and intimate may turn out to be the relation between them, and whatever the particular nature of that relation may be, it is at all events not identity.
2. Connection to be distinguished from identity
The point just made, although elementary, is crucial. Hence, even at the risk of laboring it, a few words will be added in order to render it unmistakable.
Let us consider the case, say, of the moon and the earth. They are connected and influence one another, but the moon and the earth are not one and the same thing. Hence it is possible to know much about one of them and little about the other. On the other hand, the thing which the words "the moon" denote is identically the same thing as that which the words "la lune," or the words "the earth's largest satellite," denote; and the identity entails that, although one might not know all three of these names of that single thing, nevertheless, whatever (other than some of its names) one happened to know, or to be ignorant of, about the thing denoted by one of them, one would necessarily know it, or be ignorant of it, about the thing denoted by either of the other two names. For one thing only is concerned, not three.
Now, a parallel conclusion follows in the case of, say, the word "pain" and the words "a certain motion of the molecules of the nerve cells of the brain." If these two sets of words both denoted - i.e., were but two different names for - one single event, then any person who at a given moment knows pain, i.e., experiences the particular feeling which the word "pain" denotes, would necessarily know which particular motion of which particular things the words "a certain motion of molecules in the brain" denote at that moment; for, under the supposition, one event only would be occurring, but denoted equally by each of those two different names. But the patent fact is on the contrary that all men know directly and only too well the event itself which the word "pain" denotes. They know it in the sense of experiencing it, whether or not they happen to know also that it is called "pain"; whereas no man knows what particular molecular motion is occurring in the nerve cells of his brain at the time he feels pain; and only a few men know even that molecular motions occur there. Moreover, even this they know not empirically and directly as on the contrary every man knows pain, but know it only indirectly through theoretical inferences.
How one comes to learn that "pain" is the English name of the feeling he or someone else has on a given occasion is one question; but what that feeling itself is (and no matter what, if anything, it is called at the time) is another question. One learns what pain is by having pins stuck into him, and in various other manners that likewise cause it to occur. "Pain" is the name of the feeling caused in these various ways.
The concrete occurrences which the word "pain," and the words "thought," "ideas" "desires" "sensations," "mental states," etc., denote in English, are quite familiar at first hand to all of us, for they are directly experienced by us and open to our introspective attention; and what introspection reveals is, for example, that the event we denote by the word "pain" when we say "I have a pain" does not in the least resemble - to say nothing of being identically - what attention to perceptually public facts reveals when directed perhaps to the cutting or burning of the skin, or to the writhing or shrinking behavior or to the groans on such an occasion; or to the words "I have a pain," or to the (postulated, not observed) molecular motions in the brain.
All these are material events, and no doubt are connected with the mental event called "pain," which occurs when they occur. But connection is one thing and identity is wholly another.
This simple fact, which becomes patent if only one attends strictly to the denotation of the "material" and of the "mental" terms, strangely eludes some of. the writers who express themselves on the subject of the mind-body relation. Dr. C. S. Myers, for example, in his L. T. Hobhouse Memorial Lecture for 1932 entitled "The Absurdity of any Mind-Body Relation," writes:
"The conclusion which I have at length reached is that the notion of any relation between mind and body is absurd - because mental activity and living bodily activity are identical. The most highly specialized forms of these two activities are, respectively, conscious processes and the processes of living brain matter." (p.6)
But obviously what is absurd is to do, as these statements do, both of the following things: On the one hand. to mention two activities, to wit, the activity called "mental" and the activity called "living bodily activity" - both of which are observable and when observed are found to be each patently unlike the other; and yet, on the other hand, to assert that these two utterly dissimilar activities are identically one and the same!
Farther on, we shall consider specifically another contention which is often confused with this and which-however otherwise open to criticism - is anyway not absurd; namely, the contention that mental activity and living bodily activity are two aspects of one same process.
In conclusion, then, since connection is one thing and identity wholly another, the fact that the events which the expression "mental events" denotes, and certain of the events which the expression "material events" denotes (specifically, certain neural or behavioral events) are perhaps so connected as to form a "psychophysical unity" - this fact does not entail, as Lamont and others have alleged, that the unity is indissoluble; but only that, so long as the connection remains what it has been, the two series of quite dissimilar events-the mental and the bodily-continue ... to form "a psychophysical unity"!
What cessation of the connection may entail as regards continuance, or not, either of the bodily series or of the mental one, depends on the specific nature of the connection, and cannot be inferred simply from the fact that during the life of the body, the two were in some way united, i.e., closely connected.
3. Disguised assertions about the word "thought" mistaken for assertions about thought
Some additional remarks are called for at this point in order to account for the fact that such statements as that thought is really a motion of molecules in the brain, or is really a particular mode of bodily behavior, have been made by some intelligent persons and have been considered by them penetrating instead of absurd as in fact they are.
The first thing to note is that of course anybody can devise and use language that differs from the common language in that certain words of the common language-for example, the words "thoughts," "ideas," "feelings," "desires," "mental states" - are employed in the devised language to denote certain things - for example, brain states of certain kinds - which are radically other than the things they denote in the common language.
Moreover, a person who is using such a subverted language may be unaware that he is doing so and may assume, as naturally will his hearers, that when, for instance, he makes the statement that "thought is really a motion of molecules in the brain," he is using the common language.
That statement, however, when taken as made in the common language, is so paradoxical that hearers of it are likely to assume - humbly though in fact gratuitously - that somehow it must express a truth which the utterer of it perceives, but which the hearer is as yet unable to apprehend. And the utterer too but proudly instead of humbly - is likely to assume this.
On the other hand, if one allows neither humility nor pride to becloud one's judgment, then what one perceives is that the statement "thought is really a motion of molecules in the brain" is in fact not worded in the common language; and that to make that statement is on the contrary to perform an act of subversion of the common language.
That is, one perceives that the statement is in fact not an assertion about thought itself and molecular motion itself, but only about the words "thought" and "molecular motion;" and that, in that assertion, the word, "really," expresses not at all an insight, but only the utterer's naive preference for language as in so far subverted!
The case is thus exactly parallel, except in one irrelevant respect, to a case where a Frenchman who, using English but holding with naive pride that French is the one "real" language, were to say: "A dog is really un chien." He would appear to himself and to others to be talking about dogs, but he would in fact be talking only about the word "dog" and claiming that it would be preferable to use instead the word "chien." The minor and only difference between the two cases is that "dog" and "chien" belong to two independent languages but have the same denotation in each; whereas both the word "thought" and the words "molecular motion in brain cells" belong to the same language, to wit, English, but, in it, do not have the same denotation. They would have it only in (materialistically) subverted English.
The statement that thought is really a motion of molecules in the brain thus operates as do the statements in which communists - sometimes perhaps equally sincerely but then naively - use "liberation" to denote enslavement and "democracy" to denote tyranny: Such statements only befuddle both the persons who make them honestly and the persons who accept them uncritically.
4. The radically idealistic conception of material objects
Only a few words will now be needed to make evident that the radically idealistic conception of material objects is invalidated by the same kind of absurdity which we have seen invalidates the radically materialistic conception of mind.
Paulsen, it will be remembered. rightly insists that feelings, sensations, or thoughts themselves, which are introspectively known to all of us, are what the words "feelings," "sensations," or "thoughts" denote, and not the very different things denoted on the contrary by such expressions as "motions of molecules in in the brain" or "modes of bodily behavior."
Now, conversely here, we must insist that when we use the latter expressions, or the broader expression "material events and objects," we denote by them material events and objects themselves, or motions of molecules or modes of behavior themselves and not, as Berkeley would have it, certain groups of systematically associated sensations; for these are something very different indeed. They are elements in the process of perceiving material objects, but not in the material objects themselves, which exist independently of whether they are or are not being perceived.
The contention of a radical idealism would be on the contrary that what the words "material objects" denote is, identically, the same as what the words "perceivings of material objects" denote; namely the particular kind of state of consciousness which such perceiving constitutes. As in the case of the analogous radical materialistic claim, this radical idealistic claim too cannot be refuted; and this, again not because it is true but because it is absurd. It can and need be met only by flat denial: The words "the object perceived” do not, in English as distinguished from Idealese, denote the same thing as the words "the perceiving of an object;" and words do denote what we employ them to denote. To assert that the two expressions denote one and the same thing, instead of each something different, is not to set forth a novel truth but only here again to subvert the English language and thereby to muddle oneself and possibly one's hearers or readers. What specifically the relation is between the material object perceived and the psychological events - sensations and others - that enter into the process of perceiving the object is a most interesting but intricate question, into which fortunately we do not need to go for present purposes. What need be said is only that, whatever may be the relation between the two it is anyway not identity.
Two Versions of Psycho-Physical Parallelism
IN THE present chapter, we turn from the radically materialistic and radically idealistic conceptions of the body-mind relation, which we have now seen to be untenable, and pass to an examination of two versions of the conception of it termed Psycho-physical Parallelism.
1. Mind and body as in "pre-established harmony"
The "pre-established harmony" conception of the connection between the series of mental events and the series of bodily events goes back to Leibnitz. According to him, only "monads" exist-simple, unextended "substances" whose essence consists in the power of action and whose exercise of this power consists in having ideas. A substance, however, is conceived by him as well as by others in his day as something wholly self-dependent and therefore as incapable of influencing or of being influenced by the activities of other substances. Hence the monads "have no windows" through which anything might come in or go out. The sequence of their ideas proceeds solely out of their own internal, i.e., psychological activity. The material world consists of masses of monads, whose aggregations, separations, and motions are determined, not like the internal states of each monad by mental causes, but solely by mechanical ones. Yet, harmony obtains between the succession of ideas in a given monad, and the motions of it and of the other monads associated with it in what we call its body. On this view, the correlations which obtain between a man's mental states and his bodily states - for example, that a pin prick and pain, or that volition to move the arm and motion of the arm regularly go together notwithstanding that neither causes the other - is analogous to the correlation which obtains between the motions of the hands of two clocks notwithstanding that neither clock causes the other to behave as it does.
The explanation of the harmony between the behavior of the two is of course that it was preestablished by the maker of the clocks, who so constructed and so set them that they would keep time to each other. Similarly, on the Leibnitzian view, the harmony which obtains between the series of a man's bodily states and the series of his mental states is due to its having been preestablished by man's maker, God.
It is perhaps unnecessary to comment on this quaint conception beyond saying that no evidence at all exists that body and mind are each inherently incapable of influencing the other; nor is there any evidence that the harmony which obtains between them was preestablished by a cosmic clock maker.
But even if this should somehow happen to be the case, nothing at all could be inferred from it as to whether or not mental life continues after the body dies. For inferences as to this could be drawn only if one knew-whereas in fact one does not first that such a divine "clockmaker" as postulated by the preestablished harmony conception exists; and only if one knew in addition what his will is as to survival, or not, of man's or of some men's minds after death.
On the other hand, if one supposes the connection - or more properly then simply the correlation - between the bodily and the mental series of events to be a purely de facto parallelism; that is, one neither due to causation of the events of either series by those of the other, nor due to causation of both series by some one same cause distinct from both as in the preestablished harmony conception; then, ex hypothesi, termination of either series would have no effect at all on the other. Termination of the bodily series might, or might not, de facto, be paralleled by termination also of the mental series. From purely de facto parallelism in the past and present, nothing at all can be inferred as to the future.
2. Mind and body as two aspects of one same thing
Still another conception of the connection between mind and body is of the type envisaged by Spinoza, but divorced in the writings of contemporary biologists and psychologists that accept it from the theological hypothesis in terms of which Spinoza phrased it.
The connection in view is of the so-called "double aspect" kind, analogous to that which obtains, for example, between the two sides of a sheet of paper. There, a creasing of the sheet appears as a ridge on one side, and automatically and simultaneously as a valley on the other side, although the ridge does not cause the valley nor the valley the ridge.
If the paper analogy is used at all, however, its additional features also must be considered; for example, the fact that a spot of color on one side is not necessarily matched by a difference of any kind on the other side. The implication of the paper analogy as regards the "double aspect" conception of the connection between body and mind is then that one cannot tell whether the difference on the material side, which cessation of the body's life constitutes, is or is not automatically matched on the other side by cessation of consciousness, unless one knows independently what the entity or substance is, of which body and mind are alleged to be two "aspects;" and knows what properties it, as distinguished from either of its aspects, has. For only such knowledge would enable one to judge whether the body's death is analogous to, say, the ridging of one side of the paper - which, because of the properties of the paper sheet, is automatically matched by a valleying of the other side - or is analogous on the contrary to the staining of one side - which, again because of the properties of the paper sheet, is not automatically matched by any change on the other side.
In short, the supposition that body and mind are two "aspects" of one same thing is wholly metaphorical; and unless and until the metaphor has been translated into literal terms identifying for us the entity or substance itself, of which brain and mind are supposed to be two "aspects," nothing can be inferred as to whether the material change - death of the brain - is or is not automatically matched by death of the mind.
But no substance or thing having body and mind as two aspects has ever yet been exhibited, both aspects of which could be so experimented upon that one might discover what kinds of changes, if any, and of which aspect, are or are not automatically paralleled by changes of the other aspect.
Moreover, if it were suggested, as occasionally it is, that the body itself or the brain is that substance, and that mental activity is brain activity, but "viewed from within" - from the inside instead of the outside - then the appropriate comment would obviously be that the word "inside" as so used really means nothing at all. For, if one wishes to observe what goes on literally inside the brain, what one must do is simply to open it up and look. Such an operation might, in a then facetiously etymological sense of the word, be termed "Introspection," but would anyway be something radically different from what in fact is denominated Introspection.
Thus, although the "double-aspect" description of the connection between mind and brain or mind and body has found favor with a number of biologists and psychologists, it turns out on examination to be nothing but a vacuous metaphor, from which nothing at all follows as to whether or not mental life can continue after death.
3. Mental activity as a function of cerebral activity
A statement currently much in vogue is that mental activity is a function of the activity of the brain and nervous system.
The word "function," (from L. fungere, to perform) has a variety of meanings, some of which are not wholly distinct from certain of the others. Most broadly, when two things, A and B, each of which admits of variations, vary concomitantly, i.e., in such manner that variation of kind or/and magnitude V (a) of A, and variation of kind or/and magnitude V (b) of B, occur regularly together, then the two sets of variations are said to be functionally related; and either can be said to be a function of the other.
If, however, the variations given, or instituted, are, say, those of A, and the variations then observed those of B, then B is termed the dependent variable and A the independent variable.
If the variations of one of the two functionally related variables, say, those of B, occur after the variations of A of which they are functions, then ordinarily the dependence of the variations of B upon those of A is causal dependence, direct or indirect. This, apparently, is the meaning which "dependent upon" is intended to have in Webster's definition of one of the senses of "function of" as: "any quality, trait or fact so related to another that it is dependent upon and varies with that other." This sense is usually the one in which thought, or mental activity, is said to be a function of brain activity; and in which it is said that the specific function of the brain is to "perform" the various mental activities - thinking, perceiving, remembering, etc.
In the light of these remarks, it is evident that to speak of mental activity as a function of brain activity is not to offer a new description of the connection between the two, different from all those already mentioned; for each of these asserts that brain states and mental states are functionally related: If the functional dependence is causal, and of mental activity on brain activity, then this is the type of connection, i.e., of function. which epiphenomenalism describes. If the dependence is causal, but is of brain activity on mental activity, then this type of functional relation would be describable as hypophenomenalism - the exact converse of epiphenomenalism. If the functional dependence is causal, but not exclusively either of mental upon cerebral states, or of cerebral upon mental states, then what we have is psycho-physical interactionism. Lastly, if the functional dependence is not causal, then it constitutes parallelism of one or another of the types described in what precedes, from which, as we have seen, nothing can be inferred as to whether survival of the mind after death is or is not possible.
We shall now consider in turn epiphenomenalism, hypophenomenalism, and interactionism.
Mind as "Halo Over the Saint"
WHEN A person who has leaned to the purely physicalistic conception of mind sees that it presupposes the absurdity that certain of our words do not denote what we do denote by them, he is likely to adopt in its place the less radically materialist conception which the late ]Professor G. S. Fullerton picturesquely termed the "halo over the saint" theory of the mind's relation to the body.
That theory asserts that mental events have to brain events much the same sort of relation which the saint's traditional halo supposedly has to him: the halo is an automatic effect of his saintliness, but does not itself cause or contribute at all to it. This is the relation which, as between brain events and mental events, is technically termed epiphenomenalism (from the Greek epi = beside, above + phainomai = to appear): the mental events are conceived to be an epiphenomenon of, i.e., a phenomenon beside or above certain of the physical events occurring in the brain; and to be a by-product, and hence an automatic accompaniment, of cerebral activity; but never themselves to cause or affect the latter.
This conception is not, like the radically physicalistic one, open to the charge of absurdity since, unlike the latter, it admits that the term "mental events" denotes events that are other than those denominated "physical" and more specifically "cerebral." Epiphenomenalism is thus not strictly a physicalistic monism. But virtually, i.e., for all practical purposes, it is both a monism. and a physicalistic one, for it holds that the only occurences that ultimately count in determining behavior are bodily ones and therefore physical. And this means that if it were possible to do away altogether with a person's mental states without in any way altering his brain and nervous system, he would go on behaving exactly as usual, and nobody could tell that he no longer had a mind.
Now, obviously, if it is true as epiphenomenalism. asserts that all mental states actually are effects of cerebral states, and also that no mental states could be caused otherwise than directly by cerebral states, then it follows that mental states and activities cannot possibly continue after the life of the brain has ceased.
2. Metaphorical character of the epiphenomenalistic thesis
Let us, however, now examine critically the epiphenomenalistic conception of the body-mind relation.
It is associated chiefly with the names of T. H. Huxley and of Shadworth Hodgson. As defined by the latter, it is the doctrine that "the states of consciousness, the feelings, are effects of the nature, sequence, and combination, of the nerve states, without being themselves causes either of one another or of changes in the nerve states which support them."(1) Huxley, similarly, writes: "It seems to me that in men, as in brutes, there is no proof that any state of consciousness is the cause of change in the motion of the matter of the organism ... our mental conditions are simply the symbols in consciousness of the changes which take place automatically in the organism; and that ... the feeling we call volition is not the cause of a voluntary act, but the symbol of that state of the brain which is the immediate cause of that act."(2)
(1) Theory of Practice, London, Longmans, Green, 1870 Vol. 1:336.
(2) Collected Essays, Appleton, New York, 1893, Vol. 1:244.
In so stating, however, Huxley ignores the fact that symbolizing is not a physical but a psychological relation: That S is a symbol of something T means that consciousness of S in a mind M that is in a state of kind K, regularly causes M to think of T.(3) Other metaphors used by epiphenomenalists to characterize the relation between brain states and states of consciousness are that consciousness is but "a spark thrown off by an engine," or (by Hodgson) "the foam thrown up by and floating on a wave .... a mere foam, aura, or melody arising from the brain, but without reaction upon it."(4)
(3) Cf. the writer's Symbols, Signs, and Signals, Jl. of Symbolic Logic, Vol. 4:41-43, No. 2, June 1939.
(4) Time and Space, London, Longmans Green, 1865, P. 279. The wave-and-foam metaphor is used by Hodgson in this book to characterize a theory of the mind-body relation which he there attacks. But in his Theory of Practice, published five years later, he embraces the (epiphenomenalistic) theory he had attacked in the earlier book, and declares entirely erroneous the "double aspect" theory he had opposed to it there (p. 283). The "wave-and-foam" metaphor is therefore true to the radically epiphenomenalistic conception of the mind-body relation formulated in the passage quoted previously from the later book.
The spark and the foam in these metaphors are indeed by-products in the sense that they do not react - or more strictly, only to a negligibly minute extent - upon their producers. But - and this is the crucial point - they are themselves, like their producers, purely physical; whereas states of consciousness, as we have seen and indeed as maintained by epiphenomenalists, are non-physical events, irreducible to terms of matter and motion. The analogy those metaphors postulate is therefore lacking in the very respect that is essential: If states of consciousness are effects of brain activity, they are not so in the sense in which occurrence of the spark or the foam is an effect of the activity of the machine or of the water under the then existing conditions; for the spark and the foam are fragments of the machine and of the wave, but states of consciousness are not fragments of cerebral tissue.
Hence, if mental events are effects of cerebral events, they are so in the quite different sense that changes in the state of the brain cause changes - modifications, modulations, alterations - in the state of the mind; the mind thus being conceived in as substantive a manner as is the brain itself, i.e., as something likewise capable of a variety of states, and of changes from one to another in response to the action of certain causes.
3. Arbitrariness of the epiphenomenalistic contention as to causality between cerebral and mental events
This brings us to another respect in which the epiphenomenalistic account of the mind-body relation is indefensible, namely, its arbitrariness in asserting that although cerebral events cause mental events, mental events on the contrary never cause cerebral events nor even other mental events.
That assertion is arbitrary because if, as epiphenomenalism contends, causation can occur between events as radically different in kind as, on the one hand, motions of molecules or of other physical particles in the brain and, on the other, mental events, then no theoretical reason remains at all why causation should not be equally possible and should not actually occur in the converse direction; that is, causation of brain events by mental events.
The paradoxical character of the contention that states of consciousness never determine or in the least direct the activities of the body is perhaps most glaring when, as Ruyer points out, one considers on the one hand painful states of consciousness and desire to prevent them and, on the other, man's invention and employment of anaesthetics: "The invention of anaesthetics by man supposes that disagreeable states of consciousness have incited man to seek means to suppress such states of consciousness. If, according to the (epiphenomenalistic) hypothesis, disagreeable consciousness is inefficacious, how, on the one hand, can it originate an action? On the other hand, how can a chain of pure causality (as between brain events) so manage as not to 'become' such as to get accompanied by disagreeable consciousness?'(5)
(5) Raymond Ruyer: Neofinalisme, Presses Universitaires de France, Paris 1952, p. 24.
As a matter of fact, the empirical evidence one has for concluding that occurrence, for example, of the mental event consisting of decision to raise one's arm causes the physical rising of the arm, is of exactly the same form as the empirical evidence one has for concluding - as the epiphenomenalist so readily does - that the physical event consisting of burning the skin, - or, more directly, the brain event thereby induced - causes the mental event called pain. If either the conception of causality which the so-called "method" of Single Difference defines, or the regularity-of-sequence conception of causality, warrants the latter conclusion, then, since the one or the other is likewise the conception of causality through which the former conclusion is reached, that conclusion is equally warranted.
On the other hand. if the supposition that a volition or idea or other mental event can push or pull or somehow otherwise move a physical molecule were rejected, either on the ground of its being absurd or on the ground that it would constitute a violation of the principle of the conservation of energy, then the supposition that motion of a physical molecule in the brain can cause a mental, i.e., a non-physical event, would have to be rejected also, since it would involve the converse absurdity or would involve violation of that same principle.
Again, if it is argued that mutilations of the brain, whether experimental or accidental, are known to cause alterations of specific kinds in the mental states and activities connected with that brain, it must then be pointed out that, as psychosomatic medicine now recognizes, mental states of certain kinds generate corresponding somatic defects; so that here too causation is sometimes from mind to body, as well as sometimes from body to mind.
The preceding considerations, then, make amply evident that the epiphenomenalistic theory of the relation between body and mind is altogether arbitrary in holding that causation as between brain and mind is always from brain to mind and never from mind to brain.
Furthermore, it is arbitrary also in holding that all mental states are effects of brain states; for this is not known, but only that some mental states - of which sensations are the most obvious examples - are so. Moreover, observation, as distinguished from epiphenomenalistic dogma, testifies that, in any case of association of ideas, occurrence of the first is what causes occurrence of the second. Nor do we know that mental states of certain kinds, which normally have physical causes, might not - although perhaps with more or less different specific content - be caused otherwise than physically. This possibility is suggested by the occurrence of visions, apparitions, dreams, and other forms of hallucination; for in all such cases mental states indistinguishable at the time from sensations are caused somehow otherwise than, as normally, by stimulation of the sense organs.(6) That even then those states are always and wholly effects of cerebral states is not a matter of knowledge but only of faithfully epiphenomenalistic speculative extrapolation.
(6) See, for instance, the remarkable case of a waking hallucination reported in Vol. XVIII of the Proc. of the Society for Psychical Research, pp. 308-322.
Moreover, if the capacity of mescalin or of lysergic acid diethylamide to induce hallucinations by physical means should be cited, the comment would then have to be that what needs to be accounted for is not only that hallucinations then occur, but also what specifically their content - which in fact varies greatly - happens to be. That is, do these drugs cause what they cause one to see in a sense comparable to that in which a painter's action causes the picture he paints and sees; or, on the contrary, do they cause one only to see what one then sees, in a manner analogous to that in which the raising of the blind of a window on a train causes a passenger in the train to see the landscape which happens to be outside at the time?
These remarks are not offered as an argument that, since we do not know that the specific content of hallucinations has cerebral causes, therefore probably its causes are non-cerebral; for so to argue would be to become guilty of the fallacy argumentum ad ignorantiam. They are offered only to underline that this very fallacy infects the contention that, if, as in fact is the case we do not know that only some mental states are cerebrally caused, then probably all of them are so caused.
That all mental states have exclusively cerebral causes is thus only postulated; and - notwithstanding the contrary empirical evidence we cited - postulated only out of pious wish to have an at least virtual physicalistic monism, since a strict physicalistic one is ruled out by the absurdity pointed out in Ch. VIII, which it involves. What the epiphenomenalist does is to erect tacitly into a creed as to the nature of all reality what in fact is only the program of the sciences dedicated to the study of the material world - the program, namely, of explaining in terms of physical causes everything that happens to be capable of being so explained.
The upshot is then that the epiphenomenalistic conception of the relation between brain and mind not only is not known to be true, but even arbitrarily disregards positive empirical facts which appear to invalidate it. Hence the consequence that would follow if that conception were true - namely that no mental activities or experiences can occur after the brain has died - is itself not known to be true. That is, so far as goes anything that epiphenomenalists have shown to the contrary, after-death mental life - at least of certain kinds - remains both a theoretical and an empirical possibility.