But our experience does not present us only with objects in space relations; it presents us with a succession of changes in those objects. And if we will reason about those changes as we have reasoned about space relations, many of our difficulties regarding the nature of time may, as it seems, be made to disappear.

Thus we may recognize that we are directly conscious of duration, of succession, and may yet hold that this crude and immediate experience of duration is not what we mean by real time. Every one distinguishes between apparent time and real time now and then. We all know that a sermon may seem long and not be long; that the ten years that we live over in a dream are not ten real years; that the swallowing of certain drugs may be followed by the illusion of the lapse of vast spaces of time, when really very little time has elapsed. What is this real time?

It is nothing else than the order of the changes which take place or may take place in real things. In the last chapter I spoke of space as the "form" of the real world; it would be better to call it a "form" of the real world, and to give the same name also to time.

It is very clear that, when we inquire concerning the real time of any occurrence, or ask how long a series of such lasted, we always look for our answer to something that has happened in the external world. The passage of a star over the meridian, the position of the sun above the horizon, the arc which the moon has described since our last observation, the movement of the hands of a clock, the amount of sand which has fallen in the hourglass, these things and such as these are the indicators of real time. There may be indicators of a different sort; we may decide that it is noon because we are hungry, or midnight because we are tired; we may argue that the preacher must have spoken more than an hour because he quite wore out the patience of the congregation. These are more or less uncertain signs of the lapse of time, but they cannot be regarded as experiences of the passing of time either apparent or real.

Thus, we see that real space and real time are the plan of the world system. They are not things of any sort, and they should not be mistaken for things. They are not known independently of things, though, when we have once had an experience of things and their changes, we can by abstraction from the things themselves fix our attention upon their arrangement and upon the order of their changes. We can divide and subdivide spaces and times without much reference to the things. But we should never forget that it would never have occurred to us to do this, indeed, that the whole procedure would be absolutely meaningless to us, were not a real world revealed in our experience as it is.

He who has attained to this insight into the nature of time is in a position to offer what seem to be satisfactory solutions to the problems which have been brought forward above.

(1) He can see, thus, why it is absurd to speak of any portion of time as becoming nonexistent. Time is nothing else than an order, a great system of relations. One cannot drop out certain of these and leave the rest unchanged, for the latter imply the former. Day-after-to-morrow would not be day-after-to-morrow, if to-morrow did not lie between it and to-day. To speak of dropping out to-morrow and leaving it the time it was conceived to be is mere nonsense.

(2) He can see why it does not indicate a measureless conceit for a man to be willing to say that time is infinite. One who says this need not be supposed to be acquainted with the whole past and future history of the real world, of which time is an aspect. We constantly abstract from things, and consider only the order of their changes, and in this order itself there is no reason why one should set a limit at some point; indeed, to set such a limit seems a gratuitous absurdity. He who says that time is infinite does not say much; he is not affirming the existence of some sort of a thing; he is merely affirming a theoretical possibility, and is it not a theoretical possibility that there may be an endless succession of real changes in a real world?

(3) It is evident, furthermore, that, when one has grasped firmly the significance of the distinction between apparent time and real time, one may with a clear conscience speak of time as infinitely divisible. Of course, the time directly given in any single experience, the minute or the second of which we are conscious as it passes, cannot be regarded as composed of an infinite number of parts. We are not directly conscious of these subdivisions, and it is a monstrous assumption to maintain that they must be present in the minute or second as perceived.

But no such single experience of duration constitutes what we mean by real time. We have seen that real time is the time occupied by the changes in real things, and the question is, How far can one go in the subdivision of this time?

Now, the touch thing which usually is for us in common life the real thing is not the real thing for science; it is the appearance under which the real world of atoms and molecules reveals itself. The atom is not directly perceivable, and we may assign to its motions a space so small that no one could possibly perceive it as space, as a something with part out of part, a something with a here and a there. But, as has been before pointed out (section 26), this does not prevent us from believing the atom and the space in which it moves to be real, and we can represent them to ourselves as we can the things and the spaces with which we have to do in common life.

It is with time just as it is with space. We can perceive an inch to have parts; we cannot perceive a thousandth of an inch to have parts, if we can perceive it at all; but we can represent it to ourselves as extended, that is, we can let an experience which is extended stand for it, and can dwell upon the parts of that. We can perceive a second to have duration; we cannot perceive a thousandth of a second to have duration; but we can conceive it as having duration, i.e. we can let some experience of duration stand for it and serve as its representative.

It is, then, reasonable to speak of the space covered by the vibration of an atom, and it is equally reasonable to speak of the time taken up by its vibration. It is not necessary to believe that the duration that we actually experience as a second must itself be capable of being divided up into the number of parts indicated by the denominator of the fraction that we use in indicating such a time, and that each of these parts must be perceived as duration.

There is, then, a sense in which we may affirm that time is infinitely divisible. But we must remember that apparent time—the time presented in any single experience of duration—is never infinitely divisible; and that real time, in any save a relative sense of the word, is not a single experience of duration at all. It is a recognition of the fact that experiences of duration may be substituted for each other without assignable limit.

(4) But what shall we say to the last problem—to the question how we can be conscious of time at all, when the parts of time are all successive? How can we even have a consciousness of "crude" time, of apparent time, of duration in any sense of the word, when duration must be made up of moments no two of which can exist together and no one of which alone can constitute time? The past is not now, the future is not yet, the present is a mere point, as we are told, and cannot have parts. If we are conscious of time as past, present, and future, must we not be conscious of a series as a series when every member of it save one is nonexistent? Can a man be conscious of the nonexistent?

The difficulty does seem a serious one, and yet I venture to affirm that, if we examine it carefully, we shall see that it is a difficulty of our own devising. The argument quietly makes an assumption—and makes it gratuitously—with which any consciousness of duration is incompatible, and then asks us how there can be such a thing as a consciousness of duration.

The assumption is that we can be conscious only of the existent, and this, written out a little more at length, reads as follows: we can be conscious only of the now existent, or, in other words of the present. Of course, this determines from the outset that we cannot be conscious of the past and the future, of duration.

The past and the future are, to be sure, nonexistent from the point of view of the present; but it should be remarked as well that the present is nonexistent from the point of view of the past or the future. If we are talking of time at all we are talking of that no two parts of which are simultaneous; it would be absurd to speak of a past that existed simultaneously with the present, just as it would be absurd to speak of a present existing simultaneously with the past. But we should not deny to past, present, and future, respectively, their appropriate existence; nor is it by any means self-evident that there cannot be a consciousness of past, present, and future as such.

We fall in with the assumption, it seems, because we know very well that we are not directly conscious of a remote past and a remote future. We represent these to ourselves by means of some proxy—we have present memories of times long past and present anticipations of what will be in the time to come. Moreover, we use the word "present" very loosely; we say the present year, the present day, the present hour, the present minute, or the present second. When we use the word thus loosely, there seems no reason for believing that there should be such a thing as a direct consciousness that extends beyond the present. It appears reasonable to say: No one can be conscious save of the present.

It should be remembered, however, that the generous present of common discourse is by no means identical with the ideal point between past and future dealt with in the argument under discussion. We all say: I now see that the cloud is moving; I now see that the snow is falling. But there can be no moving, no falling, no change, in the timeless "now" with which we have been concerned. Is there any evidence whatever that we are shut up, for all our immediate knowledge, to such a "now"? There is none whatever.

The fact is that this timeless "now" is a product of reflective thought and not a something of which we are directly conscious. It is an ideal point in the real time of which this chapter has treated, the time that is in a certain sense infinitely divisible. It is first cousin to the ideal mathematical point, the mere limit between two lines, a something not perceptible to any sense. We have a tendency to carry over to it what we recognize to be true of the very different present of common discourse, a present which we distinguish from past and future in a somewhat loose way, but a present in which there certainly is the consciousness of change, of duration. And when we do this, we dig for ourselves a pit into which we proceed to fall.

We may, then, conclude that we are directly conscious of more than the present, in the sense in which Augustine used the word. We are conscious of time, of "crude" time, and from this we can pass to a knowledge of real time, and can determine its parts with precision.

[1] Book XI, Chapters 14 and 15.



III. PROBLEMS TOUCHING THE MIND

CHAPTER VIII

WHAT IS THE MIND?

30. PRIMITIVE NOTIONS OF MIND.—The soul or mind, that something to which we refer sensations and ideas of all sorts, is an object that men do not seem to know very clearly and definitely, though they feel so sure of its existence that they regard it as the height of folly to call it in question. That he has a mind, no man doubts; what his mind is, he may be quite unable to say.

We have seen (section 7) that children, when quite young, can hardly be said to recognize that they have minds at all. This does not mean that what is mental is not given in their experience. They know that they must open their eyes to see things, and must lay their hands upon them to feel them; they have had pains and pleasures, memories and fancies. In short, they have within their reach all the materials needed in framing a conception of the mind, and in drawing clearly the distinction between their minds and external things. Nevertheless, they are incapable of using these materials; their attention is engrossed with what is physical,—with their own bodies and the bodies of others, with the things that they can eat, with the toys with which they can play, and the like. It is only later that there emerges even a tolerably clear conception of a self or mind different from the physical and contrasted with it.

Primitive man is almost as material in his thinking as is the young child. Of this we have traces in many of the words which have come to be applied to the mind. Our word "spirit" is from the Latin spiritus, originally a breeze. The Latin word for the soul, the word used by the great philosophers all through the Middle Ages, anima (Greek, anemos), has the same significance. In the Greek New Testament, the word used for spirit (pneuma) carries a similar suggestion. When we are told in the Book of Genesis that "man became a living soul," we may read the word literally "a breath."

What more natural than that the man who is just awakening to a consciousness of that elusive entity the mind should confuse it with that breath which is the most striking outward and visible sign that distinguishes a living man from a dead one?

That those who first tried to give some scientific account of the soul or mind conceived it as a material thing, and that it was sufficiently common to identify it with the breath, we know from direct evidence. A glance at the Greek philosophy, to which we owe so much that is of value in our intellectual life, is sufficient to disclose how difficult it was for thinking men to attain to a higher conception.

Thus, Anaximenes of Miletus, who lived in the sixth century before Christ, says that "our soul, which is air, rules us." A little later, Heraclitus, a man much admired for the depth of his reflections, maintains that the soul is a fiery vapor, evidently identifying it with the warm breath of the living creature. In the fifth century, B.C., Anaxagoras, who accounts for the ordering of the elements into a system of things by referring to the activity of Mind or Reason, calls mind "the finest of things," and it seems clear that he did not conceive of it as very different in nature from the other elements which enter into the constitution of the world.

Democritus of Abdera (between 460 and 360 B.C.), that great investigator of nature and brilliant writer, developed a materialistic doctrine that admits the existence of nothing save atoms and empty space. He conceived the soul to consist of fine, smooth, round atoms, which are also atoms of fire. These atoms are distributed through the whole body, but function differently in different places—in the brain they give us thought, in the heart, anger, and in the liver, desire. Life lasts just so long as we breathe in and breathe out such atoms.

The doctrine of Democritus was taken up by Epicurus, who founded his school three hundred years before Christ—a school which lived and prospered for a very long time. Those who are interested in seeing how a materialistic psychology can be carried out in detail by an ingenious mind should read the curious account of the mind presented in his great poem, "On Nature," by the Roman poet Lucretius, an ardent Epicurean, who wrote in the first century B.C.

The school which we commonly think of contrasting with the Epicurean, and one which was founded at about the same time, is that of the Stoics. Certainly the Stoics differed in many things from the Epicureans; their view of the world, and of the life of man, was a much nobler one; but they were uncompromising materialists, nevertheless, and identified the soul with the warm breath that animates man.

31. THE MIND AS IMMATERIAL.—It is scarcely too much to say that the Greek philosophy as a whole impresses the modern mind as representing the thought of a people to whom it was not unnatural to think of the mind as being a breath, a fire, a collection of atoms, a something material. To be sure, we cannot accuse those twin stars that must ever remain the glory of literature and science, Plato and Aristotle, of being materialists. Plato (427-347, B.C.) distributes, it is true, the three-fold soul, which he allows man, in various parts of the human body, in a way that at least suggests the Democritean distribution of mind-atoms. The lowest soul is confined beneath the diaphragm; the one next in rank has its seat in the chest; and the highest, the rational soul, is enthroned in the head. However, he has said quite enough about this last to indicate clearly that he conceived it to be free from all taint of materiality.

As for Aristotle (384-322, B.C.), who also distinguished between the lower psychical functions and the higher, we find him sometimes speaking of soul and body in such a way as to lead men to ask themselves whether he is really speaking of two things at all; but when he specifically treats of the nous or reason, he insists upon its complete detachment from everything material. Man's reason is not subjected to the fate of the lower psychical functions, which, as the "form" of the body, perish with the body; it enters from without, and it endures after the body has passed away. It is interesting to note, however, an occasional lapse even in Aristotle. When he comes to speak of the relation to the world of the Divine Mind, the First Cause of Motion, which he conceives as pure Reason, he represents it as touching the world, although it remains itself untouched. We seem to find here just a flavor—an inconsistent one—of the material.

Such reflections as those of Plato and Aristotle bore fruit in later ages. When we come down to Plotinus the Neo-Platonist (204-269, A.D.), we have left the conception of the soul as a warm breath, or as composed of fine round atoms, far behind. It has become curiously abstract and incomprehensible. It is described as an immaterial substance This substance is, in a sense, in the body, or, at least, it is present to the body. But it is not in the body as material things are in this place or in that. It is as a whole in the whole body, and it is as a whole in every part of the body. Thus the soul may be regarded as divisible, since it is distributed throughout the body; but it must also be regarded as indivisible, since it is wholly in every part.

Let the man to whom such sentences as these mean anything rejoice in the meaning that he is able to read into them! If he can go as far as Plotinus, perhaps he can go as far as Cassiodorus (477-570, A.D.), and maintain that the soul is not merely as a whole in every part of the body, but is wholly in each of its own parts.

Upon reading such statements one's first impulse is to exclaim: How is it possible that men of sense should be led to speak in this irresponsible way? and when they do speak thus, is it conceivable that other men should seriously occupy themselves with what they say?

But if one has the historic sense, and knows something of the setting in which such doctrines come to the birth, one cannot regard it as remarkable that men of sense should urge them. No one coins them independently out of his own brain; little by little men are impelled along the path that leads to such conclusions. Plotinus was a careful student of the philosophers that preceded him. He saw that mind must be distinguished from matter, and he saw that what is given a location in space, in the usual sense of the words, is treated like a material thing. On the other hand, he had the common experience that we all have of a relation between mind and body. How do justice to this relation, and yet not materialize mind?

What he tried to do is clear, and it seems equally clear that he had good reason for trying to do it. But it appears to us now that what he actually did was to make of the mind or soul a something very like an inconsistent bit of matter, that is somehow in space, and yet not exactly in space, a something that can be in two places at once, a logical monstrosity. That his doctrine did not meet with instant rejection was due to the fact, already alluded to, that our experience of the mind is something rather dim and elusive. It is not easy for a man to say what it is, and, hence, it is not easy for a man to say what it is not.

The doctrine of Plotinus passed over to Saint Augustine, and from him it passed to the philosophers of the Middle Ages. How extremely difficult it has been for the world to get away from it at all, is made clearly evident in the writings of that remarkable man Descartes.

Descartes wrote in the seventeenth century. The long sleep of the Middle Ages was past, and the several sciences had sprung into a vigorous and independent life. It was not enough for Descartes to describe the relation of mind and body in the loose terms that had prevailed up to his time. He had made a careful study of anatomy, and he realized that the brain is a central organ to which messages are carried by the nerves from all parts of the body. He knew that an injury to the nerve might prevent the receipt of a message, i.e. he knew that a conscious sensation did not come into being until something happened in the brain.

Nor was he content merely to refer the mind to the brain in a general way. He found the "little pineal gland" in the midst of the brain to be in what he regarded as an admirable position to serve as the seat of the soul. To this convenient little central office he relegated it; and he describes in a way that may to-day well provoke a smile the movements that the soul imparts to the pineal gland, making it incline itself in this direction and in that, and making it push the "animal spirits," the fluid contained in the cavities of the brain, towards various "pores."

Thus he writes:[1] "Let us, then, conceive of the soul as having her chief seat in the little gland that is in the middle of the brain, whence she radiates to all the rest of the body by means of the spirits, the nerves, and even the blood, which, participating in the impressions of the spirits, can carry them through the arteries to all the members." And again: "Thus, when the soul wills to call anything to remembrance, this volition brings it about that the gland, inclining itself successively in different directions, pushes the spirits towards divers parts of the brain, until they find the part which has the traces that the object which one wishes to recollect has left there."

We must admit that Descartes' scientific studies led him to make this mind that sits in the little pineal gland something very material. It is spoken of as though it pushed the gland about; it is affected by the motions of the gland, as though it were a bit of matter. It seems to be a less inconsistent thing than the "all in the whole body" soul of Plotinus; but it appears to have purchased its comprehensibility at the expense of its immateriality.

Shall we say that Descartes frankly repudiated the doctrine that had obtained for so many centuries? We cannot say that; he still held to it. But how could he? The reader has perhaps remarked above that he speaks of the soul as having her chief seat in the pineal gland. It seems odd that he should do so, but he still held, even after he had come to his definite conclusions as to the soul's seat, to the ancient doctrine that the soul is united to all the parts of the body "conjointly." He could not wholly repudiate a venerable tradition.

We have seen, thus, that men first conceived of the mind as material and later came to rebel against such a conception. But we have seen, also, that the attempt to conceive it as immaterial was not wholly successful. It resulted in a something that we may describe as inconsistently material rather than as not material at all.

32. MODERN COMMON SENSE NOTIONS OF THE MIND.—Under this heading I mean to sum up the opinions as to the nature of the mind usually held by the intelligent persons about us to-day who make no claim to be regarded as philosophers. Is it not true that a great many of them believe:—

(1) That the mind is in the body?

(2) That it acts and reacts with matter?

(3) That it is a substance with attributes?

(4) That it is nonextended and immaterial?

I must remark at the outset that this collection of opinions is by no means something gathered by the plain man from his own experience. These opinions are the echoes of old philosophies. They are a heritage from the past, and have become the common property of all intelligent persons who are even moderately well-educated. Their sources have been indicated in the preceding sections; but most persons who cherish them have no idea of their origin.

Men are apt to suppose that these opinions seem reasonable to them merely for the reason that they find in their own experience evidence of their truth. But this is not so.

Have we not seen above how long it took men to discover that they must not think of the mind as being a breath, or a flame, or a collection of material atoms? The men who erred in this way were abler than most of us can pretend to be, and they gave much thought to the matter. And when at last it came to be realized that mind must not thus be conceived as material, those who endeavored to conceive it as something else gave, after their best efforts, a very queer account of it indeed.

Is it in the face of such facts reasonable to suppose that our friends and acquaintances, who strike us as having reflective powers in nowise remarkable, have independently arrived at the conception that the mind is a nonextended and immaterial substance? Surely they have not thought all this out for themselves. They have taken up and appropriated unconsciously notions which were in the air, so to speak. They have inherited their doctrines, not created them. It is well to remember this, for it may make us the more willing to take up and examine impartially what we have uncritically turned into articles of belief.

The first two articles, namely, that the mind is in the body and that it acts upon, and is acted upon by, material things, I shall discuss at length in the next chapter. Here I pause only to point out that the plain man does not put the mind into the body quite unequivocally. I think it would surprise him to be told that a line might be drawn through two heads in such a way as to transfix two minds. And I remark, further, that he has no clear idea of what it means for mind to act upon body or body to act upon mind. How does an immaterial thing set a material thing in motion? Can it touch it? Can it push it? Then what does it do?

But let us pass on to the last two articles of faith mentioned above.

We all draw the distinction between substance and its attributes or qualities. The distinction was remarked and discussed many centuries ago, and much has been written upon it. I take up the ruler on my desk; it is recognized at once as a bit of wood. How? It has such and such qualities. My paper-knife is of silver. How do I know it? It has certain other qualities. I speak of my mind. How do I know that I have a mind? I have sensations and ideas. If I experienced no mental phenomena of any sort, evidence of the existence of a mind would be lacking.

Now, whether I am concerned with the ruler, with the paper-knife, or with the mind, have I direct evidence of the existence of anything more than the whole group of qualities? Do I ever perceive the substance?

In the older philosophy, the substance (substantia) was conceived to be a something not directly perceived, but only inferred to exist—a something underlying the qualities of things and, as it were, holding them together. It was believed in by philosophers who were quite ready to admit that they could not tell anything about it. For example, John Locke (1632-1704), the English philosopher, holds to it stoutly, and yet describes it as a mere "we know not what," whose function it is to hold together the bundles of qualities that constitute the things we know.

In the modern philosophy men still distinguish between substance and qualities. It is a useful distinction, and we could scarcely get on without it. But an increasing number of thoughtful persons repudiate the old notion of substance altogether.

We may, they say, understand by the word "substance" the whole group of qualities as a group—not merely the qualities that are revealed at a given time, but all those that we have reason to believe a fuller knowledge would reveal. In short, we may understand by it just what is left when the "we know not what" of the Lockian has been discarded.

This notion of substance we may call the more modern one; yet we can hardly say that it is the notion of the plain man. He does not make very clear to himself just what is in his thought, but I think we do him no injustice in maintaining that he is something of a Lockian, even if he has never heard of Locke. The Lockian substance is, as the reader has seen, a sort of "unknowable."

And now for the doctrine that the mind is nonextended and immaterial. With these affirmations we may heartily agree; but we must admit that the plain man enunciates them without having a very definite idea of what the mind is.

He regards as in his mind all his sensations and ideas, all his perceptions and mental images of things. Now, suppose I close my eyes and picture to myself a barber's pole. Where is the image? We say, in the mind. Is it extended? We feel impelled to answer, No. But it certainly seems to be extended; the white and the red upon it appear undeniably side by side. May I assert that this mental image has no extension whatever? Must I deny to it parts, or assert that its parts are not side by side?

It seems odd to maintain that a something as devoid of parts as is a mathematical point should yet appear to have parts and to be extended. On the other hand, if we allow the image to be extended, how can we refer it to a nonextended mind?

To such questions as these, I do not think that the plain man has an answer. That they can be answered, I shall try to show in the last section of this chapter. But one cannot answer them until one has attained to rather a clear conception of what is meant by the mind.

And until one has attained to such a conception, the statement that the mind is immaterial must remain rather vague and indefinite. As we saw above, even the Plotinic soul was inconsistently material rather than immaterial. It was not excluded from space; it was referred to space in an absurd way. The mind as common sense conceives it, is the successor of this Plotinic soul, and seems to keep a flavor of what is material after all. This will come out in the next chapter, where we shall discuss mind and body.

33. THE PSYCHOLOGIST AND THE MIND.—When we ask how the psychologist conceives of the mind, we must not forget that psychologists are many and that they differ more or less from each other in their opinions. When we say "the psychologist" believes this or that, we mean usually no more than that the opinion referred to is prevalent among men of that class, or that it is the opinion of those whom we regard as its more enlightened members.

Taking the words in this somewhat loose sense, I shall ask what the psychologist's opinion is touching the four points set forth in the preceding section. How far does he agree with the plain man?

(1) There can be no doubt that he refers the mind to the body in some way, although he may shake his head over the use of the word "in."

(2) As to whether the mind acts and reacts with matter, in any sense of the words analogous to that in which they are commonly used, there is a division in the camp. Some affirm such interaction; some deny it. The matter will be discussed in the next chapter.

(3) The psychologist—the more modern one—inclines to repudiate any substance or substratum of the sort accepted in the Middle Ages and believed in by many men now. To him the mind is the whole complex of mental phenomena in their interrelations. In other words, the mind is not an unknown and indescribable something that is merely inferred; it is something revealed in consciousness and open to observation.

(4) The psychologist is certainly not inclined to regard the mind or any idea belonging to it as material or as extended. But he does recognize implicitly, if not explicitly, that ideas are composite. To him, as to the plain man, the image held in the memory or imagination seems to be extended, and he can distinguish its parts. He does not do much towards clearing away the difficulty alluded to at the close of the last section. It remains for the metaphysician to do what he can with it, and to him we must turn if we wish light upon this obscure subject.

34. THE METAPHYSICIAN AND THE MIND.—I have reserved for the next chapter the first two points mentioned as belonging to the plain man's doctrine of the mind. In what sense the mind may be said to be in the body, and how it may be conceived to be related to the body, are topics that deserve to be treated by themselves in a chapter on "Mind and Body." Here I shall consider what the metaphysician has to say about the mind as substance, and about the mind as nonextended and immaterial.

It has been said that the Lockian substance is really an "unknowable." No one pretends to have experience of it; it is revealed to no sense; it is, indeed, a name for a mere nothing, for when we abstract from a thing, in thought, every single quality, we find that there is left to us nothing whatever.

We cannot say that the substance, in this sense of the word, is the reality of which the qualities are appearances. In Chapter V we saw just what we may legitimately mean by realities and appearances, and it was made clear that an unknowable of any sort cannot possibly be the reality to which this or that appearance is referred. Appearances and realities are experiences which are observed to be related in certain ways. That which is not open to observation at all, that of which we have, and can have, no experience, we have no reason to call the reality of anything. We have, in truth, no reason to talk about it at all, for we know nothing whatever about it; and when we do talk about it, it is because we are laboring under a delusion.

This is equally true whether we are concerned with the substance of material things or with the substance of minds. An "unknowable" is an "unknowable" in any case, and we may simply discard it. We lose nothing by so doing, for one cannot lose what one has never had, and what, by hypothesis, one can never have. The loss of a mere word should occasion us no regret.

Now, we have seen that we do not lose the world of real material things in rejecting the "Unknowable" (Chapter V). The things are complexes of qualities, of physical phenomena; and the more we know about these, the more do we know about real things.

But we have also seen (Chapter IV) that physical phenomena are not the only phenomena of which we have experience. We are conscious of mental phenomena as well, of the phenomena of the subjective order, of sensations and ideas. Why not admit that these constitute the mind, as physical phenomena constitute the things which belong to the external world?

He who says this says no more than that the mind is known and is knowable. It is what it is perceived to be; and the more we know of mental phenomena, the more do we know of the mind. Shall we call the mind as thus known a substance? That depends on the significance which we give to this word. It is better, perhaps, to avoid it, for it is fatally easy to slip into the old use of the word, and then to say, as men have said, that we do not know the mind as it is, but only as it appears to us to be—that we do not know the reality, but only its appearances.

And if we keep clearly before us the view of the mind which I am advocating, we shall find an easy way out of the difficulties that seem to confront us when we consider it as nonextended and immaterial.

Certain complexes of mental phenomena—for example, the barber's pole above alluded to—certainly appear to be extended. Are they really extended? If I imagine a tree a hundred feet high, is it really a hundred feet high? Has it any real size at all?

Our problem melts away when we realize what we mean by this "real size." In Chapter V, I have distinguished between apparent space and real space. Real space is, as was pointed out, the "plan" of the real physical world. To occupy any portion of real space, a thing must be a real external thing; that is, the experiences constituting it must belong to the objective order, they must not be of the class called mental. We all recognize this, in a way. We know that a real material foot rule cannot be applied to an imaginary tree. We say, How big did the tree seen in a dream seem; we do not say, How big was it really? If we did ask such a question, we should be puzzled to know where to look for an answer.

And this for a very good reason. He who asks: How big was that imaginary tree really? asks, in effect: How much real space did the unreal tree fill? The question is a foolish one. It assumes that phenomena not in the objective order are in the objective order. As well ask how a color smells or how a sound looks. When we are dealing with the material we are not dealing with the mental, and we must never forget this.

The tree imagined or seen in a dream seems extended. Its extension is apparent extension, and this apparent extension has no place in the external world whatever. But we must not confound this apparent extension with a real mathematical point, and call the tree nonextended in this sense. If we do this we are still in the old error—we have not gotten away from real space, but have substituted position in that space for extension in that space. Nothing mental can have even a position in real space. To do that it would have to be a real thing in the sense indicated.

Let us, then, agree with the plain man in affirming that the mind is nonextended, but let us avoid misconception. The mind is constituted of experiences of the subjective order. None of these are in space—real space. But some of them have apparent extension, and we must not overlook all that this implies.

Now for the mind as immaterial. We need not delay long over this point. If we mean by the mind the phenomena of the subjective order, and by what is material the phenomena of the objective order, surely we may and must say that the mind is immaterial. The two classes of phenomena separate themselves out at once.

[1] "The Passions," Articles 34 and 42.



CHAPTER IX

MIND AND BODY

35. IS THE MIND IN THE BODY?—There was a time, as we have seen in the last chapter (section 30), when it did not seem at all out of the way to think of the mind as in the body, and very literally in the body. He who believes the mind to be a breath, or a something composed of material atoms, can conceive it as being in the body as unequivocally as chairs can be in a room. Breath can be inhaled and exhaled; atoms can be in the head, or in the chest, or the heart, or anywhere else in the animal economy. There is nothing dubious about this sense of the preposition "in."

But we have also seen (section 31) that, as soon as men began to realize that the mind is not material, the question of its presence in the body became a serious problem. If I say that a chair is in a room, I say what is comprehensible to every one. It is assumed that it is in a particular place in the room and is not in some other place. If, however, I say that the chair is, as a whole, in every part of the room at once, I seem to talk nonsense. This is what Plotinus and those who came after him said about the mind. Are their statements any the less nonsensical because they are talking about minds? When one speaks about things mental, one must not take leave of good sense and utter unmeaning phrases.

If minds are enough like material things to be in anything, they must be in things in some intelligible sense of the word. It will not do to say: I use the word "in," but I do not really mean in. If the meaning has disappeared, why continue to use the word? It can only lead to mystification.

Descartes seemed to come back to something like an intelligible meaning when he put the mind in the pineal gland in the brain. Yet, as we have seen, he clung to the old conception. He could not go back to the frank materialization of mind.

And the plain man to-day labors under the same difficulty. He puts the mind in the body, in the brain, but he does not put it there frankly and unequivocally. It is in the brain and yet not exactly in the brain. Let us see if this is not the case.

If we ask him: Does the man who wags his head move his mind about? does he who mounts a step raise his mind some inches? does he who sits down on a chair lower his mind? I think we shall find that he hesitates in his answers. And if we go on to say: Could a line be so drawn as to pass through your image of me and my image of you, and to measure their distance from one another? I think he will say, No. He does not regard minds and their ideas as existing in space in this fashion.

Furthermore, it would not strike the plain man as absurd if we said to him: Were our senses far more acute than they are, it is conceivable that we should be able to perceive every atom in a given human body, and all its motions. But would he be willing to admit that an increase in the sharpness of sense would reveal to us directly the mind connected with such a body? It is not, then, in the body as the atoms are. It cannot be seen or touched under any conceivable circumstances. What can it mean, hence, to say that it is there? Evidently, the word is used in a peculiar sense, and the plain man cannot help us to a clear understanding of it.

His position becomes intelligible to us when we realize that he has inherited the doctrine that the mind is immaterial, and that he struggles, at the same time, with the tendency so natural to man to conceive it after the analogy of things material. He thinks of it as in the body, and, nevertheless, tries to dematerialize this "in." His thought is sufficiently vague, and is inconsistent, as might be expected.

If we will bear in mind what was said in the closing section of the last chapter, we can help him over his difficulty. That mind and body are related there can be no doubt. But should we use the word "in" to express this relation?

The body is a certain group of phenomena in the objective order; that is, it is a part of the external world. The mind consists of experiences in the subjective order. We have seen that no mental phenomenon can occupy space—real space, the space of the external world—and that it cannot even have a position in space (section 34). As mental, it is excluded from the objective order altogether. The mind is not, then, strictly speaking, in the body, although it is related to it. It remains, of course, to ask ourselves how we ought to conceive the relation. This we shall do later in the present chapter.

But, it may be said, it would sound odd to deny that the mind is in the body. Does not every one use the expression? What can we substitute for it? I answer: If it is convenient to use the expression let us continue to do so. Men must talk so as to be understood. But let us not perpetuate error, and, as occasion demands it, let us make clear to ourselves and to others what we have a right to understand by this in when we use it.

36. THE DOCTRINE OF THE INTERACTIONIST.—There is no man who does not know that his mind is related to his body as it is not to other material things. We open our eyes, and we see things; we stretch out our hand, and we feel them; our body receives a blow, and we feel pain; we wish to move, and the muscles are set in motion.

These things are matters of common experience. We all perceive, in other words, that there is an interaction, in some sense of the term, between mind and body.

But it is important to realize that one may be quite well aware of all such facts, and yet may have very vague notions of what one means by body and by mind, and may have no definite theory at all of the sort of relation that obtains between them. The philosopher tries to attain to a clearer conception of these things. His task, be it remembered, is to analyze and explain, not to deny, the experiences which are the common property of mankind.

In the present day the two theories of the relation of mind and body that divide the field between them and stand opposed to each other are interactionism and parallelism. I have used the word "interaction" a little above in a loose sense to indicate our common experience of the fact that we become conscious of certain changes brought about in our body, and that our purposes realize themselves in action. But every one who accepts this fact is not necessarily an interactionist. The latter is a man who holds a certain more or less definite theory as to what is implied by the fact. Let us take a look at his doctrine.

Physical things interact. A billiard ball in motion strikes one which has been at rest; the former loses its motion, the latter begins to roll away. We explain the occurrence by a reference to the laws of mechanics; that is to say, we point out that it is merely an instance of the uniform behavior of matter in motion under such and such circumstances. We distinguish between the state of things at one instant and the state of things at the next, and we call the former cause and the latter effect.

It should be observed that both cause and effect here belong to the one order, the objective order. They have their place in the external world. Both the balls are material things; their motion, and the space in which they move, are aspects of the external world.

If the balls did not exist in the same space, if the motion of the one could not be towards or away from the other, if contact were impossible, we would manifestly have no interaction in the sense of the word employed above. As it is, the interaction of physical things is something that we can describe with a good deal of definiteness. Things interact in that they stand in certain physical relations, and undergo changes of relations according to certain laws.

Now, to one who conceives the mind in a grossly material way, the relation of mind and body can scarcely seem to be a peculiar problem, different from the problem of the relation of one physical thing to another. If my mind consists of atoms disseminated through my body, its presence in the body appears as unequivocal as the presence of a dinner in a man who has just risen from the table. Nor can the interaction of mind and matter present any unusual difficulties, for mind is matter. Atoms may be conceived to approach each other, to clash, to rearrange themselves. Interaction of mind and body is nothing else than an interaction of bodies. One is not forced to give a new meaning to the word.

When, however, one begins to think of the mind as immaterial, the case is very different. How shall we conceive an immaterial thing to be related to a material one?

Descartes placed the mind in the pineal gland, and in so far he seemed to make its relation to the gland similar to that between two material things. When he tells us that the soul brings it about that the gland bends in different directions, we incline to view the occurrence as very natural—is not the soul in the gland?

But, on the other hand, Descartes also taught that the essence of mind is thought and the essence of body is extension. He made the two natures so different from each other that men began to ask themselves how the two things could interact at all. The mind wills, said one philosopher, but that volition does not set matter in motion; when the mind wills, God brings about the appropriate change in material things. The mind perceives things, said another, but that is not because they affect it directly; it sees things in God. Ideas and things, said a third, constitute two independent series; no idea can cause a change in things, and no thing can cause a change in ideas.

The interactionist is a man who refuses to take any such turn as these philosophers. His doctrine is much nearer to that of Descartes than it is to any of theirs. He uses the one word "interaction" to describe the relation between material things and also the relation between mind and body, nor does he dwell upon the difference between the two. He insists that mind and matter stand in the one causal nexus; that a change in the outside world may be the cause of a perception coming into being in a mind, and that a volition may be the cause of changes in matter.

What shall we call the plain man? I think we may call him an interactionist in embryo. The stick in his hand knocks an apple off of the tree; his hand seems to him to be set in motion because he wills it. The relation between his volition and the motion of his hand appears to him to be of much the same sort as that between the motion of the stick and the fall of the apple. In each case he thinks he has to do with the relation of cause and effect.

The opponent of the interactionist insists, however, that the plain man is satisfied with this view of the matter only because he has not completely stripped off the tendency to conceive the mind as a material thing. And he accuses the interactionist of having fallen a prey to the same weakness.

Certainly, it is not difficult to show that the interactionists write as though the mind were material, and could be somewhere in space. The late Dr. McCosh fairly represents the thought of many, and he was capable of expressing himself as follows;[1] "It may be difficult to ascertain the exact point or surface at which the mind and body come together and influence each other, in particular, how far into the body (Descartes without proof thought it to be in the pineal gland), but it is certain, that when they do meet mind knows body as having its essential properties of extension and resisting energy."

How can an immaterial thing be located at some point or surface within the body? How can a material thing and an immaterial thing "come together" at a point or surface? And if they cannot come together, what have we in mind when we say they interact?

The parallelist, for it is he who opposes interactionism, insists that we must not forget that mental phenomena do not belong to the same order as physical phenomena. He points out that, when we make the word "interaction" cover the relations of mental phenomena to physical phenomena as well as the relations of the latter to each other, we are assimilating heedlessly facts of two different kinds and are obliterating an important distinction. He makes the same objection to calling the relations between mental phenomena and physical phenomena causal. If the relation of a volition to the movement of the arm is not the same as that of a physical cause to its physical effect, why, he argues, do you disguise the difference by calling them by the same name?

37. THE DOCTRINE OF THE PARALLELIST.—Thus, the parallelist is a man who is so impressed by the gulf between physical facts and mental facts that he refuses to regard them as parts of the one order of causes and effects. You cannot, he claims, make a single chain out of links so diverse.

Some part of a human body receives a blow; a message is carried along a sensory nerve and reaches the brain; from the brain a message is sent out along a motor nerve to a group of muscles; the muscles contract, and a limb is set in motion. The immediate effects of the blow, the ingoing message, the changes in the brain, the outgoing message, the contraction of the muscles—all these are physical facts. One and all may be described as motions in matter.

But the man who received the blow becomes conscious that he was struck, and both interactionist and parallelist regard him as becoming conscious of it when the incoming message reaches some part of the brain. What shall be done with this consciousness? The interactionist insists that it must be regarded as a link in the physical chain of causes and effects—he breaks the chain to insert it. The parallelist maintains that it is inconceivable that such an insertion should be made. He regards the physical series as complete in itself, and he places the consciousness, as it were, on a parallel line.

It must not be supposed that he takes this figure literally. It is his effort to avoid materializing the mind that forces him to hold the position which he does. To put the mind in the brain is to make of it a material thing; to make it parallel to the brain, in the literal sense of the word, would be just as bad. All that we may understand him to mean is that mental phenomena and physical, although they are related, cannot be built into the one series of causes and effects. He is apt to speak of them as concomitant.

We must not forget that neither parallelist nor interactionist ever dreams of repudiating our common experiences of the relations of mental phenomena and physical. Neither one will, if he is a man of sense, abandon the usual ways of describing such experiences. Whatever his theory, he will still say: I am suffering because I struck my hand against that table; I sat down because I chose to do so. His doctrine is not supposed to deny the truth contained in such statements; it is supposed only to give a fuller understanding of it. Hence, we cannot condemn either doctrine simply by an uncritical appeal to such statements and to the experiences they represent. We must look much deeper.

Now, what can the parallelist mean by referring sensations and ideas to the brain and yet denying that they are in the brain? What is this reference?

Let us come back to the experiences of the physical and the mental as they present themselves to the plain man. They have been discussed at length in Chapter IV. It was there pointed out that every one distinguishes without difficulty between sensations and things, and that every one recognizes explicitly or implicitly that a sensation is an experience referred in a certain way to the body.

When the eyes are open, we see; when the ears are open, we hear; when the hand is laid on things, we feel. How do we know that we are experiencing sensations? The setting tells us that. The experience in question is given together with an experience of the body. This is concomitance of the mental and the physical as it appears in the experience of us all; and from such experiences as these the philosopher who speaks of the concomitance of physical and mental phenomena must draw the whole meaning of the word.

Let us here sharpen a little the distinction between sensations and things. Standing at some distance from the tree, I see an apple fall to the ground. Were I only half as far away, my experience would not be exactly the same—I should have somewhat different sensations. As we have seen (section 17), the apparent sizes of things vary as we move, and this means that the quantity of sensation, when I observe the apple from a nearer point, is greater. The man of science tells me that the image which the object looked at projects upon the retina of the eye grows larger as we approach objects. The thing, then, may remain unchanged; our sensations will vary according to the impression which is made upon our body.

Again. When I have learned something of physics, I am ready to admit that, although light travels with almost inconceivable rapidity, still, its journey through space does take time. Hence the impression made upon my eye by the falling apple is not simultaneous with the fall itself; and if I stand far away it is made a little later than when I am near. In the case in point the difference is so slight as to pass unnoticed, but there are cases in which it seems apparent even to the unlearned that sensations arise later than the occurrences of which we take them to be the report.

Thus, I stand on a hill and watch a laborer striking with his sledge upon the distant railway. I hear the sound of the blow while I see his tool raised above his head. I account for this by saying that it has taken some time for the sound-waves to reach my ear, and I regard my sensation as arising only when this has been accomplished.

But this conclusion is not judged sufficiently accurate by the man of science. The investigations of the physiologist and the psychologist have revealed that the brain holds a peculiar place in the economy of the body. If the nerve which connects the sense organ with the brain be severed, the sensation does not arise. Injuries to the brain affect the mental life as injuries to other parts of the body do not. Hence, it is concluded that, to get the real time of the emergence of a sensation, we must not inquire merely when an impression was made upon the organ of sense, but must determine when the message sent along the nerve has reached some part of the brain. The resulting brain change is regarded as the true concomitant of the sensation. If there is a brain change of a certain kind, there is the corresponding sensation. It need hardly be said that no one knows as yet much about the brain motions which are supposed to be concomitants of sensations, although a good deal is said about them.

It is very important to remark that in all this no new meaning has been given to the word "concomitance." The plain man remarks that sensations and their changes must be referred to the body. With the body disposed in a certain way, he has sensations of a certain kind; with changes in the body, the sensations change. He does not perceive the sensations to be in the body. As I recede from a house I have a whole series of visual experiences differing from each other and ending in a faint speck which bears little resemblance to the experience with which I started. I have had, as we say, a series of sensations, or groups of such. Did any single group, did the experience which I had at any single moment, seem to me to be in my body? Surely not. Its relation to my body is other than that.

And when the man of science, instead of referring sensations vaguely to the body, refers them to the brain, the reference is of precisely the same nature. From our common experience of the relation of the physical and the mental he starts out. He has no other ground on which to stand. He can only mark the reference with greater exactitude.

I have been speaking of the relation of sensations to the brain. It is scarcely necessary for me to show that all other mental phenomena must be referred to the brain as well, and that the reference must be of the same nature. The considerations which lead us to refer ideas to the brain are set forth in our physiologies and psychologies. The effects of cerebral disease, injuries to the brain, etc., are too well known to need mention; and it is palpably as absurd to put ideas in the brain as it is to put sensations there.

Now, the parallelist, if he be a wise man, will not attempt to explain the reference of mental phenomena to the brain—to explain the relation between mind and matter. The relation appears to be unique. Certainly it is not identical with the relation between two material things. We explain things, in the common acceptation of the word, when we show that a case under consideration is an exemplification of some general law—when we show, in other words, that it does not stand alone. But this does stand alone, and is admitted to stand alone. We admit as much when we say that the mind is immaterial, and yet hold that it is related to the body. We cannot, then, ask for an explanation of the relation.

But this does not mean that the reference of mental phenomena to the body is a meaningless expression. We can point to those experiences of concomitance that we all have, distinguish them carefully from relations of another kind, and say: This is what the word means, whether it be used by the plain man or by the man of science.

I have said above: "If there is a brain change of a certain kind, there is the corresponding sensation." Perhaps the reader will feel inclined to say here: If you can say as much as this, why can you not go a little farther and call the brain change the cause of the sensation?

But he who speaks thus, forgets what has been said above about the uniqueness of the relation. In the objective order of our experiences, in the external world, we can distinguish between antecedents and consequents, between causes and their effects. The causes and their effects belong to the one order, they stand in the same series. The relation of the physical to the mental is, as we have seen, a different relation. Hence, the parallelist seems justified in objecting to the assimilation of the two. He prefers the word "concomitance," just because it marks the difference. He does not mean to indicate that the relation is any the less uniform or dependable when he denies that it is causal.

38. IN WHAT SENSE MENTAL PHENOMENA HAVE A TIME AND PLACE.—We have seen in Chapters VI and VII what space and time—real space and time—are. They are the plan of the real external world and its changes; they are aspects of the objective order of experience.

To this order no mental phenomenon can belong. It cannot, as we have seen (section 35), occupy any portion of space or even have a location in space. It is equally true that no series of mental changes can occupy any portion of time, real time, or even fill a single moment in the stream of time. There are many persons to whom this latter statement will seem difficult of acceptance; but the relation of mental phenomena to space and to time is of the same sort, and we can consider the two together.

Psychologists speak unhesitatingly of the localization of sensations in the brain, and they talk as readily of the moment at which a sensation arises and of the duration of the sensation. What can they mean by such expressions?

We have seen that sensations are not in the brain, and their localization means only the determination of their concomitant physical phenomena, of the corresponding brain-change. And it ought to be clear even from what has been said above that, in determining the moment at which a sensation arises, we are determining only the time of the concomitant brain process. Why do we say that a sensation arises later than the moment at which an impression is made upon the organ of sense and earlier than the resulting movement of some group of muscles? Because the change in the brain, to which we refer the sensation, occurs later than the one and earlier than the other. This has a place in real time, it belongs to that series of world changes whose succession constitutes real time. If we ask when anything happened, we always refer to this series of changes. We try to determine its place in the world order.

Thus, we ask: When was Julius Caesar born? We are given a year and a day. How is the time which has elapsed since measured? By changes in the physical world, by revolutions of the earth about the sun. We ask: When did he conceive the plan of writing his Commentaries? If we get an answer at all, it must be an answer of the same kind—some point in the series of physical changes which occur in real time must be indicated. Where else should we look for an answer? In point of fact, we never do look elsewhere.

Again. We have distinguished between apparent space and real space (section 34). We have seen that, when we deny that a mental image can occupy any portion of space, we need not think of it as losing its parts and shrivelling to a point. We may still attribute to it apparent space; may affirm that it seems extended. Let us mark the same distinction when we consider time. The psychologist speaks of the duration of a sensation. Has it real duration? It is not in time at all, and, of course, it cannot, strictly speaking, occupy a portion of time. But we can try to measure the duration of the physical concomitant, and call this the real duration of the sensation.

We all distinguish between the real time of mental phenomena, in the sense indicated just above, and the apparent time. We know very well that the one may give us no true measure of the other. A sermon seems long; was it really long? There is only one way of measuring its real length. We must refer to the clock, to the sun, to some change in the physical world. We seem to live years in a dream; was the dream really a long one? The real length can only be determined, if at all, by a physical reference. Those apparent years of the dream have no place in the real time which is measured by the clock. We do not have to cut it and insert them somewhere. They belong to a different order, and cannot be inserted any more than the thought of a patch can be inserted in a rent in a real coat.

We see, thus, when we reflect upon the matter, that mental phenomena cannot, strictly speaking, be said to have a time and place. He who attributes these to them materializes them. But their physical concomitants have a time and place, and mental phenomena can be ordered by a reference to these. They can be assigned a time and place of existing in a special sense of the words not to be confounded with the sense in which we use them when we speak of the time and place of material things. This makes it possible to relate every mental phenomenon to the world system in a definite way, and to distinguish it clearly from every other, however similar.

We need not, when we come to understand this, change our usual modes of speech. We may still say: The pain I had two years ago is like the pain I have to-day; my sensation came into being at such a moment; my regret lasted two days. We speak that we may be understood; and such phrases express a truth, even if they are rather loose and inaccurate. But we must not be deceived by such phrases, and assume that they mean what they have no right to mean.

39. OBJECTIONS TO PARALLELISM.—What objections can be brought against parallelism? It is sometimes objected by the interactionist that it abandons the plain man's notion of the mind as a substance with its attributes, and makes of it a mere collection of mental phenomena. It must be admitted that the parallelist usually holds a view which differs rather widely from that of the unlearned.

But even supposing this objection well taken, it can no longer be regarded as an objection specifically to the doctrine of parallelism, for the view of the mind in question is becoming increasingly popular, and it is now held by influential interactionists as well as by parallelists. One may believe that the mind consists of ideas, and may still hold that ideas can cause motions in matter.

There is, however, another objection that predisposes many thoughtful persons to reject parallelism uncompromisingly. It is this. If we admit that the chain of physical causes and effects, from a blow given to the body to the resulting muscular movements made in self-defense, is an unbroken one, what part can we assign to the mind in the whole transaction? Has it done anything? Is it not reduced to the position of a passive spectator? Must we not regard man as "a physical automaton with parallel psychical states"?

Such an account of man cannot fail to strike one as repugnant; and yet it is the parallelist himself whom we must thank for introducing us to it. The account is not a caricature from the pen of an opponent. "An automaton," writes Professor Clifford,[2] "is a thing that goes by itself when it is wound up, and we go by ourselves when we have had food. Excepting the fact that other men are conscious, there is no reason why we should not regard the human body as merely an exceedingly complicated machine which is wound up by putting food into the mouth. But it is not merely a machine, because consciousness goes with it. The mind, then, is to be regarded as a stream of feelings which runs parallel to, and simultaneous with, a certain part of the action of the body, that is to say, that particular part of the action of the brain in which the cerebrum and the sensory tracts are excited."

The saving statement that the body is not merely a machine, because consciousness goes with it, does not impress one as being sufficient to redeem the illustration. Who wants to be an automaton with an accompanying consciousness? Who cares to regard his mind as an "epiphenomenon"—a thing that exists, but whose existence or nonexistence makes no difference to the course of affairs?

The plain man's objection to such an account of himself seems to be abundantly justified. As I have said earlier in this chapter, neither interactionist nor parallelist has the intention of repudiating the experience of world and mind common to us all. We surely have evidence enough to prove that minds count for something. No house was ever built, no book was ever written, by a creature without a mind; and the better the house or book, the better the mind. That there is a fixed and absolutely dependable relation between the planning mind and the thing accomplished, no man of any school has the right to deny. The only legitimate question is: What is the nature of the relation? Is it causal, or should it be conceived to be something else?

The whole matter will be more fully discussed in Chapter XI. This chapter I shall close with a brief summary of the points which the reader will do well to bear in mind when he occupies himself with parallelism.

(1) Parallelism is a protest against the interactionist's tendency to materialize the mind.

(2) The name is a figurative expression, and must not be taken literally. The true relation between mental phenomena and physical is given in certain common experiences that have been indicated, and it is a unique relation.

(3) It is a fixed and absolutely dependable relation. It is impossible that there should be a particular mental fact without its corresponding physical fact; and it is impossible that this physical fact should occur without its corresponding mental fact.

(4) The parallelist objects to calling this relation causal, because this obscures the distinction between it and the relation between facts both of which are physical. He prefers the word "concomitance."

(5) Such objections to parallelism as that cited above assume that the concomitance of which the parallelist speaks is analogous to physical concomitance. The chemist puts together a volume of hydrogen gas and a volume of chlorine gas, and the result is two volumes of hydrochloric acid gas. We regard it as essential to the result that there should be the two gases and that they should be brought together. But the fact that the chemist has red hair we rightly look upon as a concomitant phenomenon of no importance. The result would be the same if he had black hair or were bald. But this is not the concomitance that interests the parallelist. The two sorts of concomitance are alike only in the one point. Some phenomenon is regarded as excluded from the series of causes and effects under discussion. On the other hand, the difference between the two is all-important; in the one case, the concomitant phenomenon is an accidental circumstance that might just as well be absent; in the other, it is nothing of the sort; it cannot be absent—the mental fact must exist if the brain-change in question exists.

It is quite possible that, on reading this list of points, one may be inclined to make two protests.

First: Is a parallelism so carefully guarded as this properly called parallelism at all? To this I answer: The name matters little. I have used it because I have no better term. Certainly, it is not the parallelism which is sometimes brought forward, and which peeps out from the citation from Clifford. It is nothing more than an insistence upon the truth that we should not treat the mind as though it were a material thing. If any one wishes to take the doctrine and discard the name, I have no objection. As so guarded, the doctrine is, I think, true.

Second: If it is desirable to avoid the word "cause," in speaking of the relation of the mental and the physical, on the ground that otherwise we give the word a double sense, why is it not desirable to avoid the word "concomitance"? Have we not seen that the word is ambiguous? I admit the inconsistency and plead in excuse only that I have chosen the lesser of two evils. It is fatally easy to slip into the error of thinking of the mind as though it were material and had a place in the physical world. In using the word "concomitance" I enter a protest against this. But I have, of course, no right to use it without showing just what kind of concomitance I mean.

[1] "First and Fundamental Truths," Book I, Part II, Chapter II. New York, 1889.

[2] "Lectures and Essays," Vol. II, p. 57. London, 1879.



CHAPTER X

HOW WE KNOW THERE ARE OTHER MINDS

40. IS IT CERTAIN THAT WE KNOW IT?—I suppose there is no man in his sober senses who seriously believes that no other mind than his own exists. There is, to be sure, an imaginary being more or less discussed by those interested in philosophy, a creature called the Solipsist, who is credited with this doctrine. But men do not become solipsists, though they certainly say things now and then that other men think logically lead to some such unnatural view of things; and more rarely they say things that sound as if the speaker, in some moods, at least, might actually harbor such a view.

Thus the philosopher Fichte (1762-1814) talks in certain of his writings as though he believed himself to be the universe, and his words cause Jean Paul Richter, the inimitable, to break out in his characteristic way: "The very worst of it all is the lazy, aimless, aristocratic, insular life that a god must lead; he has no one to go with. If I am not to sit still for all time and eternity, if I let myself down as well as I can and make myself finite, that I may have something in the way of society, still I have, like petty princes, only my own creatures to echo my words. . . . Every being, even the highest Being, wishes something to love and to honor. But the Fichtean doctrine that I am my own body-maker leaves me with nothing whatever—with not so much as the beggar's dog or the prisoner's spider. . . . Truly I wish that there were men, and that I were one of them. . . . If there exists, as I very much fear, no one but myself, unlucky dog that I am, then there is no one at such a pass as I."

Just how much Fichte's words meant to the man who wrote them may be a matter for dispute. Certainly no one has shown a greater moral earnestness or a greater regard for his fellowmen than this philosopher, and we must not hastily accuse any one of being a solipsist. But that to certain men, and, indeed, to many men, there have come thoughts that have seemed to point in this direction—that not a few have had doubts as to their ability to prove the existence of other minds—this we must admit.

It appears somewhat easier for a man to have doubts upon this subject when he has fallen into the idealistic error of regarding the material world, which seems to be revealed to him, as nothing else than his "ideas" or "sensations" or "impressions." If we will draw the whole "telephone exchange" into the clerk, there seems little reason for not including all the subscribers as well. If other men's bodies are my sensations, may not other men's minds be my imaginings? But doubts may be felt also by those who are willing to admit a real external world. How do we know that our inference to the existence of other minds is a justifiable inference? Can there be such a thing as verification in this field?

For we must remember that no man is directly conscious of any mind except his own. Men cannot exhibit their minds to their neighbors as they exhibit their wigs. However close may seem to us to be our intercourse with those about us, do we ever attain to anything more than our ideas of the contents of their minds? We do not experience these contents; we picture them, we represent them by certain proxies. To be sure, we believe that the originals exist, but can we be quite sure of it? Can there be a proof of this right to make the leap from one consciousness to another? We seem to assume that we can make it, and then we make it again and again; but suppose, after all, that there were nothing there. Could we ever find out our error? And in a field where it is impossible to prove error, must it not be equally impossible to prove truth?

The doubt has seemed by no means a gratuitous one to certain very sensible practical men. "It is wholly impossible," writes Professor Huxley,[1] "absolutely to prove the presence or absence of consciousness in anything but one's own brain, though by analogy, we are justified in assuming its existence in other men." "The existence of my conception of you in my consciousness," says Clifford,[2] "carries with it a belief in the existence of you outside of my consciousness. . . . How this inference is justified, how consciousness can testify to the existence of anything outside of itself, I do not pretend to say: I need not untie a knot which the world has cut for me long ago. It may very well be that I myself am the only existence, but it is simply ridiculous to suppose that anybody else is. The position of absolute idealism may, therefore, be left out of count, although each individual may be unable to justify his dissent from it."

These are writers belonging to our own modern age, and they are men of science. Both of them deny that the existence of other minds is a thing that can be proved; but the one tells us that we are "justified in assuming" their existence, and the other informs us that, although "it may very well be" that no other mind exists, we may leave that possibility out of count.

Neither position seems a sensible one. Are we justified in assuming what cannot be proved? or is the argument "from analogy" really a proof of some sort? Is it right to close our eyes to what "may very well be," just because we choose to do so? The fact is that both of these writers had the conviction, shared by us all, that there are other minds, and that we know something about them; and yet neither of them could see that the conviction rested upon an unshakable foundation.

Now, I have no desire to awake in the mind of any one a doubt of the existence of other minds. But I think we must all admit that the man who recognizes that such minds are not directly perceived, and who harbors doubts as to the nature of the inference which leads to their assumption, may, perhaps, be able to say that he feels certain that there are other minds; but must we not at the same time admit that he is scarcely in a position to say: it is certain that there are other minds? The question will keep coming back again: May there not, after all, be a legitimate doubt on the subject?

To set this question at rest there seems to be only one way, and that is this: to ascertain the nature of the inference which is made, and to see clearly what can be meant by proof when one is concerned with such matters as these. If it turns out that we have proof, in the only sense of the word in which it is reasonable to ask for proof, our doubt falls away of itself.

41. THE ARGUMENT FOR OTHER MINDS.—I have said early in this volume (section 7) that the plain man perceives that other men act very much as he does, and that he attributes to them minds more or less like his own. He reasons from like to like—other bodies present phenomena which, in the case of his own body, he perceives to be indicative of mind, and he accepts them as indicative of mind there also. The psychologist makes constant use of this inference; indeed, he could not develop his science without it.

John Stuart Mill (1806-1873), whom it is always a pleasure to read because he is so clear and straightforward, presents this argument in the following form:[3]—

"By what evidence do I know, or by what considerations am I led to believe, that there exist other sentient creatures; that the walking and speaking figures which I see and hear, have sensations and thoughts, or, in other words, possess Minds? The most strenuous Intuitionist does not include this among the things that I know by direct intuition. I conclude it from certain things, which my experience of my own states of feeling proves to me to be marks of it. These marks are of two kinds, antecedent and subsequent; the previous conditions requisite for feeling, and the effects or consequences of it. I conclude that other human beings have feelings like me, because, first, they have bodies like me, which I know, in my own case, to be the antecedent condition of feelings; and because, secondly, they exhibit the acts, and other outward signs, which in my own case I know by experience to be caused by feelings. I am conscious in myself of a series of facts connected by a uniform sequence, of which the beginning is modifications of my body, the middle is feelings, the end is outward demeanor. In the case of other human beings I have the evidence of my senses for the first and last links of the series, but not for the intermediate link. I find, however, that the sequence between the first and last is as regular and constant in those other cases as it is in mine. In my own case I know that the first link produces the last through the intermediate link, and could not produce it without. Experience, therefore, obliges me to conclude that there must be an intermediate link; which must either be the same in others as in myself, or a different one. I must either believe them to be alive, or to be automatons; and by believing them to be alive, that is, by supposing the link to be of the same nature as in the case of which I have experience, and which is in all respects similar, I bring other human beings, as phenomena, under the same generalizations which I know by experience to be the true theory of my own existence. And in doing so I conform to the legitimate rules of experimental inquiry. The process is exactly parallel to that by which Newton proved that the force which keeps the planets in their orbits is identical with that by which an apple falls to the ground. It was not incumbent on Newton to prove the impossibility of its being any other force; he was thought to have made out his point when he had simply shown that no other force need be supposed. We know the existence of other beings by generalization from the knowledge of our own; the generalization merely postulates that what experience shows to be a mark of the existence of something within the sphere of our consciousness, may be concluded to be a mark of the same thing beyond that sphere."

Now, the plain man accepts the argument from analogy, here insisted upon, every day of his life. He is continually forming an opinion as to the contents of other minds on a basis of the bodily manifestations presented to his view. The process of inference is so natural and instinctive that we are tempted to say that it hardly deserves to be called an inference. Certainly the man is not conscious of distinct steps in the process; he perceives certain phenomena, and they are at once illuminated by their interpretation. He reads other men as we read a book—the signs on the paper are scarcely attended to, our whole thought is absorbed in that for which they stand. As I have said above, the psychologist accepts the argument, and founds his conclusions upon it.

Upon what ground can one urge that this inference to other minds is a doubtful one? It is made universally. We have seen that even those who have theoretic objections against it, do not hesitate to draw it, as a matter of fact. It appears unnatural in the extreme to reject it. What can induce men to regard it with suspicion?

I think the answer to this question is rather clearly suggested in the sentence already quoted from Professor Huxley: "It is wholly impossible absolutely to prove the presence or absence of consciousness in anything but one's own brain, though, by analogy, we are justified in assuming its existence in other men."

Here Professor Huxley admits that we have something like a proof, for he regards the inference as justified. But he does not think that we have absolute proof—the best that we can attain to appears to be a degree of probability falling short of the certainty which we should like to have.

Now, it should be remarked that the discredit cast upon the argument for other minds has its source in the fact that it does not satisfy a certain assumed standard. What is that standard? It is the standard of proof which we may look for and do look for where we are concerned to establish the existence of material things with the highest degree of certainty.

There are all sorts of indirect ways of proving the existence of material things. We may read about them in a newspaper, and regard them as highly doubtful; we may have the word of a man whom, on the whole, we regard as veracious; we may infer their existence, because we perceive that certain other things exist, and are to be accounted for. Under certain circumstances, however, we may have proof of a different kind: we may see and touch the things themselves. Material things are open to direct inspection. Such a direct inspection constitutes absolute proof, so far as material things are concerned.

But we have no right to set this up as our standard of absolute proof, when we are talking about other minds. In this field it is not proof at all. Anything that can be directly inspected is not another mind. We cannot cast a doubt upon the existence of colors by pointing to the fact that we cannot smell them. If they could be smelt, they would not be colors. We must in each case seek a proof of the appropriate kind.

What have we a right to regard as absolute proof of the existence of another mind? Only this: the analogy upon which we depend in making our inference must be a very close one. As we shall see in the next section, the analogy is sometimes very remote, and we draw the inference with much hesitation, or, perhaps, refuse to draw it at all. It is not, however, the kind of inference that makes the trouble; it is the lack of detailed information that may serve as a basis for inference. Our inference to other minds is unsatisfactory only in so far as we are ignorant of our own minds and bodies and of other bodies. Were our knowledge in these fields complete, we should know without fail the signs of mind, and should know whether an inference were or were not justified.

And justified here means proved—proved in the only sense in which we have a right to ask for proof. No single fact is known that can discredit such a proof. Our doubt is, then, gratuitous and can be dismissed. We may claim that we have verification of the existence of other minds. Such verification, however, must consist in showing that, in any given instance, the signs of mind really are present. It cannot consist in presenting minds for inspection as though they were material things.

One more matter remains to be touched upon in this section. It has doubtless been observed that Mill, in the extract given above, seems to place "feelings," in other words, mental phenomena, between one set of bodily motions and another. He makes them the middle link in a chain whose first and third links are material. The parallelist cannot treat mind in this way. He claims that to make mental phenomena effects or causes of bodily motions is to make them material.

Must, then, the parallelist abandon the argument for other minds? Not at all. The force of the argument lies in interpreting the phenomena presented by other bodies as one knows by experience the phenomena of one's own body must be interpreted. He who concludes that the relation between his own mind and his own body can best be described as a "parallelism," must judge that other men's minds are related to their bodies in the same way. He must treat his neighbor as he treats himself. The argument from analogy remains the same.

42. WHAT OTHER MINDS ARE THERE?—That other men have minds nobody really doubts, as we have seen above. They resemble us so closely, their actions are so analogous to our own, that, although we sometimes give ourselves a good deal of trouble to ascertain what sort of minds they have, we never think of asking ourselves whether they have minds.

Nor does it ever occur to the man who owns a dog, or who drives a horse, to ask himself whether the creature has a mind. He may complain that it has not much of a mind, or he may marvel at its intelligence—his attitude will depend upon the expectations which he has been led to form. But regard the animal as he would regard a bicycle or an automobile, he will not. The brute is not precisely like us, but its actions bear an unmistakable analogy to our own; pleasure and pain, hope and fear, desire and aversion, are so plainly to be read into them that we feel that a man must be "high gravel blind" not to see their significance.

Nevertheless, it has been possible for man, under the prepossession of a mistaken philosophical theory, to assume the whole brute creation to be without consciousness. When Descartes had learned something of the mechanism of the human body, and had placed the human soul—hospes comesque corporis—in the little pineal gland in the midst of the brain, the conception in his mind was not unlike that which we have when we picture to ourselves a locomotive engine with an engineer in its cab. The man gives intelligent direction; but, under some circumstances, the machine can do a good deal in the absence of the man; if it is started, it can run of itself, and to do this, it must go through a series of complicated motions.

Descartes knew that many of the actions performed by the human body are not the result of conscious choice, and that some of them are in direct contravention of the will's commands. The eye protects itself by dropping its lid, when the hand is brought suddenly before it; the foot jerks away from the heated object which it has accidentally touched. The body was seen to be a mechanism relatively independent of the mind, and one rather complete in itself. Joined with a soul, the circle of its functions was conceived to be widened; but even without the assistance of the soul, it was thought that it could keep itself busy, and could do many things that the unreflective might be inclined to attribute to the efficiency of the mind.

The bodies of the brutes Descartes regarded as mechanisms of the same general nature as the human body. He was unwilling to allow a soul to any creature below man, so nothing seemed left to him save to maintain that the brutes are machines without consciousness, and that their apparently purposive actions are to be classed with such human movements as the sudden closing of the eye when it is threatened with the hand. The melancholy results of this doctrine made themselves evident among his followers. Even the mild and pious Malebranche could be brutal to a dog which fawned upon him, under the mistaken notion that it did not really hurt a dog to kick it.

All this reasoning men have long ago set aside. For one thing, it has come to be recognized that there may be consciousness, perhaps rather dim, blind, and fugitive, but still consciousness, which does not get itself recognized as do our clearly conscious purposes and volitions. Many of the actions of man which Descartes was inclined to regard as unaccompanied by consciousness may not, in fact, be really unconscious. And, in the second place, it has come to be realized that we have no right to class all the actions of the brutes with those reflex actions in man which we are accustomed to regard as automatic.

The belief in animal automatism has passed away, it is to be hoped, never to return. That lower animals have minds we must believe. But what sort of minds have they?

It is hard enough to gain an accurate notion of what is going on in a human mind. Men resemble each other more or less closely, but no two are precisely alike, and no two have had exactly the same training. I may misunderstand even the man who lives in the same house with me and is nearly related to me. Does he really suffer and enjoy as acutely as he seems to? or must his words and actions be accepted with a discount? The greater the difference between us, the more danger that I shall misjudge him. It is to be expected that men should misunderstand women; that men and women should misunderstand children; that those who differ in social station, in education, in traditions and habits of life, should be in danger of reading each other as one reads a book in a tongue imperfectly mastered. When these differences are very great, the task is an extremely difficult one. What are the emotions, if he has any, of the Chinaman in the laundry near by? His face seems as difficult of interpretation as are the hieroglyphics that he has pasted up on his window.

When we come to the brutes, the case is distinctly worse. We think that we can attain to some notion of the minds to be attributed to such animals as the ape, the dog, the cat, the horse, and it is not nonsense to speak of an animal psychology. But who will undertake to tell us anything definite of the mind of a fly, a grasshopper, a snail, or a cuttlefish? That they have minds, or something like minds, we must believe; what their minds are like, a prudent man scarcely even attempts to say. In our distribution of minds may we stop short of even the very lowest animal organisms? It seems arbitrary to do so.

More than that; some thoughtful men have been led by the analogy between plant life and animal life to believe that something more or less remotely like the consciousness which we attribute to animals must be attributed also to plants. Upon this belief I shall not dwell, for here we are evidently at the limit of our knowledge, and are making the vaguest of guesses. No one pretends that we have even the beginnings of a plant psychology. At the same time, we must admit that organisms of all sorts do bear some analogy to each other, even if it be a remote one; and we must admit also that we cannot prove plants to be wholly devoid of a rudimentary consciousness of some sort.

As we begin with man and descend the scale of beings, we seem, in the upper part of the series, to be in no doubt that minds exist. Our only question is as to the precise contents of those minds. Further down we begin to ask ourselves whether anything like mind is revealed at all. That this should be so is to be expected. Our argument for other minds is the argument from analogy, and as we move down the scale our analogy grows more and more remote until it seems to fade out altogether. He who harbors doubts as to whether the plants enjoy some sort of psychic life, may well find those doubts intensified when he turns to study the crystal; and when he contemplates inorganic matter he should admit that the thread of his argument has become so attenuated that he cannot find it at all.

43. THE DOCTRINE OF MIND-STUFF.—Nevertheless, there have been those who have attributed something like consciousness even to inorganic matter. If the doctrine of evolution be true, argues Professor Clifford,[4] "we shall have along the line of the human pedigree a series of imperceptible steps connecting inorganic matter with ourselves. To the later members of that series we must undoubtedly ascribe consciousness, although it must, of course, have been simpler than our own. But where are we to stop? In the case of organisms of a certain complexity, consciousness is inferred. As we go back along the line, the complexity of the organism and of its nerve-action insensibly diminishes; and for the first part of our course we see reason to think that the complexity of consciousness insensibly diminishes also. But if we make a jump, say to the tunicate mollusks, we see no reason there to infer the existence of consciousness at all. Yet not only is it impossible to point out a place where any sudden break takes place, but it is contrary to all the natural training of our minds to suppose a breach of continuity so great."

We must not, says Clifford, admit any breach of continuity. We must assume that consciousness is a complex of elementary feelings, "or rather of those remoter elements which cannot even be felt, but of which the simplest feeling is built up." We must assume that such elementary facts go along with the action of every organism, however simple; but we must assume also that it is only when the organism has reached a certain complexity of nervous structure that the complex of psychic facts reaches the degree of complication that we call Consciousness.

So much for the assumption of something like mind in the mollusk, where Clifford cannot find direct evidence of mind. But the argument does not stop here: "As the line of ascent is unbroken, and must end at last in inorganic matter, we have no choice but to admit that every motion of matter is simultaneous with some . . . fact or event which might be part of a consciousness."