Philosophy

In this chapter we have to consider the two topics of imagination and memory. The latter has already been considered in Chapter VI, but there we viewed it from outside. We want now to ask ourselves whether there is anything further to be known about it by taking account of what is only perceptible to the person remembering.

As regards the part played by images, I do not think this is essential. Sometimes there are memory-images, sometimes not; sometimes when images come in connection with memory, we may nevertheless know that the images are incorrect, showing that we have also some other and more reliable source of memory. Memory may depend upon images, as in the case mentioned above, of the house where I lived as a child. But it may also be purely verbal. I am a poor visualiser, except for things I saw before I was ten years old; when now I meet a man and wish to remember his appearance, I find that the only way is to describe him in words while I am seeing him, and then remember the words. I say to myself: “This man has blue eyes and a brown beard and a small nose; he is short, with a rounded back and sloping shoulders”. I can remember these words for months, and recognise the man by means of them, unless two men having these characteristics are present at once. In this respect, a visualiser would have the advantage of me. Nevertheless, if I had made my verbal inventory sufficiently extensive and precise, it would have been pretty sure to answer its purpose. I do not think there is anything in memory that absolutely demands images as opposed to words. Whether the words we use in “thought” are themselves sometimes images of words, or are always incipient movements (as Watson contends), is a further question, as to which I offer no opinion, since it ought to be capable of being decided experimentally.

The most important point about memory is one which has nothing to do with images, and is not mentioned in Watson’s brief discussion. I mean the reference to the past. This reference to the past is not involved in mere habit memory, e.g. in skating or in repeating a poem formerly learned. But it is involved in recollection of a past incident. We do not, in this case, merely repeat what we did before: then, we felt the incident as present, but now we feel it as past. This is shown in the use of the past tense. We say to ourselves at the time “I am having a good dinner”, but next day we say “I did have a good dinner”. Thus we do not, like a rat in a maze, repeat our previous performance: we alter the verbal formula. Why do we do so? What constitutes this reference of a recollection to the past?10

Let us take up the question first from the point of view of sensitivity. The stimulus to a recollection is, no doubt, always something in the present, but our reaction (or part of it) is more intimately related to a certain past event than to the present stimulus. This, in itself, can be paralleled in inanimate objects, for example, in a gramophone record. It is not the likeness of our reaction to that called forth on a former occasion that concerns us at the moment; it is its un-likeness, in the fact that now we have the feeling of pastness, which we did not have originally. You cannot sing into a dictaphone “I love you”, and have it say five days hence “I loved you last Wednesday”; yet that is what we do when we remember. I think, however, that this feature of memory is probably connected with a feature of reactions due to association when the association is cerebral: I think also that this is connected with the difference in quality that exists usually, though not always, between images and sensations. It would seem that, in such cases, the reaction aroused through association is usually different from that which would have been aroused directly, in certain definite ways. It is fainter, and has, when attended to, the sort of quality that makes us call it “imaginary”. In a certain class of cases, we come to know that we can make it “real” if we choose; this applies, e.g. to the tactual images produced by visible objects that we can touch. In such cases, the image is attached by us to the object, and its “imaginary” character fails to be noticed. These are the cases in which the association is not due to some accident of our experience, but to a collocation which exists in nature. In other cases, however, we are perfectly aware, if we reflect, that the association depends upon some circumstance in our private lives. We may, for instance, have had a very interesting conversation at a certain spot, and always think of this conversation when we find ourselves in this place. But we know that the conversation does not actually take place again when we go back to where it happened. In such a case, we notice the intrinsic difference between the event as a sensible fact in the present and the event as merely revived by association. I think this difference has to do with our feeling of pastness. The difference which we can directly observe is not, of course, between our present recollection and the past conversation, but between our present recollection and present sensible facts. This difference, combined with the inconsistency of our recollection with present facts if our recollection were placed in the present, is perhaps a cause of our referring memories to the past. But I offer this suggestion with hesitation; and, as we shall find when we have examined imagination, it cannot be the whole truth, though it may be part of it.

There are some facts that tend to support the above view. In dreams, when our critical faculty is in abeyance, we may live past events over again under the impression that they are actually happening; the reference of recollections to the past must, therefore, be a matter involving a somewhat advanced type of mental activity. Conversely, we sometimes have the impression that what is happening now really happened in the past; this is a well-known and much discussed illusion. It happens especially when we are profoundly absorbed in some inward struggle or emotion, so that outer events only penetrate faintly. I suggest that, in these circumstances, the quality of sensations approximates to that of images, and that this is the source of the illusion.

If this suggestion is right, the feeling of pastness is really complex. Something is suggested by association, but is recognisably different from a present sensible occurrence. We therefore do not suppose that this something is happening now; and we may be confirmed in this by the fact that it is inconsistent with something that is happening now. We may then either refer the something to the past, in which case we have a recollection, though not necessarily a correct one; or we may regard the something as purely imaginary, in which case we have what we regard as pure imagination. It remains to inquire why we do sometimes the one and sometimes the other, which brings us to the discussion of imagination. I think we shall find that memory is more fundamental than imagination, and that the latter consists merely of memories of different dates assembled together. But to support this theory will demand first an analysis of imagination and then, in the light of this analysis, an attempt to give further precision to our theory of memory.

Imagination is not, as the word might suggest, essentially connected with images. No doubt images are often, even usually, present when we imagine, but they need not be. A man can improvise on the piano without first having images of the music he is going to make; a poet might write down a poem without first making it up in his head. In talking, words suggest other words, and a man with sufficient verbal associations may be successfully carried along by them for a considerable time. The art of talking without thinking is particularly necessary to public speakers, who must go on when once they are on their feet, and gradually acquire the habit of behaving in private as they do before an audience. Yet the statements they make must be admitted to be often imaginative. The essence of imagination, therefore, does not lie in images.

The essence of imagination, I should say, is the absence of belief together with a novel combination of known elements. In memory, when it is correct, the combination of elements is not novel; and whether correct or not, there is belief. I say that in imagination there is “a novel combination of known elements”, because, if nothing is novel, we have a case of memory, while if the elements, or any of them, are novel, we have a case of perception. This last I say because I accept Hume’s principle that there is no “idea” without an antecedent “impression”. I do not mean that this is to be applied in a blind and pedantic manner, where abstract ideas are concerned. I should not maintain that no one can have an idea of liberty until he has seen the Statue of Liberty. The principle applies rather to the realm of images. I certainly do not think that, in an image, there can be any element which does not resemble some element in a previous perception, in the distinctive manner of images.

Hume made himself an unnecessary difficulty in regard to the theory that images “copy” impressions. He asked the question: Suppose a man has seen all the different shades of colour that go to make up the spectrum, except just one shade. To put the thing in modern language, suppose he has never seen light of a certain small range of wave-lengths, but has seen light of all other wave-lengths. Will he be able to form an image of the shade he has never seen? Hume thinks he will, although this contradicts the principle. I should say that images are always more or less vague copies of impressions, so that an image might be regarded as a copy of any one of a number of different impressions of slightly different shades. In order to get a test case for Hume’s question, we should have to suppose that there was a broad band of the spectrum that the man had never seen—say the whole of the yellow. He would then, one may suppose, be able to form images which, owing to vagueness, might be applicable to orange-yellow, and others applicable to green-yellow, but none applicable to a yellow midway between orange and green. This is an example of an unreal puzzle manufactured by forgetting vagueness. It is analogous to the following profound problem: A man formerly hairy is now bald; he lost his hairs one by one; therefore there must have been just one hair that made the difference, so that while he had it he was not bald but when he lost it he was. Of course “baldness” is a vague conception; and so is “copying”, when we are speaking of the way in which images copy prototypes.

What causes us, in imagination, to put elements together in a new way? Let us think first of concrete instances. You read that a ship has gone down on a route by which you have lately travelled; very little imagination is needed to generate the thought “I might have gone down”. What happens here is obvious: the route is associated both with yourself and with shipwreck, and you merely eliminate the middle term. Literary ability is largely an extension of the practice of which the above is a very humble example. Take, say:

I do not pretend to explain all the associations which led Shakespeare to think of these lines, but some few are obvious. “Dusty death” is suggested by Genesis iii. 19: “Dust thou art, and unto dust shalt thou return”. Having spoken of “lighting fools the way”, it is natural to think of a “candle”, and thence of a “walking shadow” being lighted by the candle along the way. From shadows to players was a well-established association in Shakespeare’s mind; thus in Midsummer Night’s Dream he says of players: “The best in this kind are but shadows, and the worst are no worse, if imagination amend them”. From a “poor player” to a “tale told by an idiot” is no very difficult transition for a theatre-manager; and “sound and fury” no doubt often formed part of the tales to which he had to listen in spite of their “signifying nothing”. If we knew more about Shakespeare, we could explain more of him in this sort of way.

Thus exceptional imaginative gifts appear to depend mainly upon associations that are unusual and have an emotional value owing to the fact that there is a certain uniform emotional tone about them. Many adjectives are suitable to death: in a mood quite different from Macbeth’s, it may be called “noble, puissant and mighty”. A Chancellor of the Exchequer, thinking of the Death Duties, might feel inclined to speak of “lucrative death”; nevertheless he would not, like Vaughan, speak of “dear, beauteous death”. Shakespeare also would not have spoken of death in such terms, for his view of it was pagan; he speaks of “that churl death”. So a man’s verbal associations may afford a key to his emotional reactions, for often what connects two words in his mind is the fact that they rouse similar emotions.

The absence of belief that accompanies imagination is a somewhat sophisticated product; it fails in sleep and in strong and emotional excitement. Children invent terrors for fun, and then begin to believe in them. The state of entertaining an idea without believing it is one involving some tension, which demands a certain level of intellectual development. It may be assumed that imagination, at first, always involved belief, as it still does in dreams. I am not concerned at the moment to define “belief”, but a criterion is influence on action. If I say “suppose there were a tiger outside your front door”, you will remain calm; but if I say, with such a manner as to command belief, “there is a tiger outside your front door”, you will stay at home, even if it involves missing your train to the office. This illustrates what I mean when I say that imagination, in its developed form, involves absence of belief. But this is not true of its primitive forms. And even a civilised adult, passing through a churchyard on a dark night, may feel fear if his imagination turns in the direction of ghosts.

When imagination passes into belief, it does not, as a rule, become a belief about the past. Generally we place the imagined object in the present, but not where it would be perceptible to our senses. If we place it in the past, it is because the past has some great emotional significance for us. If a person we love has been in great danger, and we do not know whether he has come through safely, imagination of his death may lead us to believe that he has been killed. And often imagination leads us to believe that something is going to happen. What is common to all such cases is the emotional interest: this first causes us to imagine an event, and then leads us to think that it has happened, is happening, or will happen, according to the circumstances. Hope and fear have this effect equally; wish-fulfilment and dread-fulfilment are equally sources of dreams and day-dreams. A great many beliefs have a source of this kind. But, in spite of psycho-analysis, there are a great many that have a more rational foundation. I believe that Columbus first crossed the ocean in 1492, though 1491 or 1493 would have suited me just as well. I cannot discover that there is any emotional element in this belief, or in the belief that Semipalatinsk is in Central Asia. The view that all our beliefs are irrational is perhaps somewhat overdone nowadays, though it is far more nearly true than the views that it has displaced.

We must now return to the subject of memory. Memory proper does not, like imagination, involve a re-arrangement of elements derived from past experience; on the contrary, it should restore such elements in the pattern in which they occurred. This is the vital difference between memory and imagination; belief, even belief involving reference to the past, may, as we have seen, be present in what is really imagination though it may not seem to be so to the person concerned. That being so, we still have to consider what constitutes the reference to the past, since the view tentatively suggested before we had considered imagination turns out to be inadequate.

There is one possible view, suggested, though not definitely adopted, by Dr. Broad in his chapter on “Memory” already referred to. According to this view, we have to start from temporal succession as perceived within what is called the “specious present”, i.e. a short period of time such that the events that occur throughout it can be perceived together. (I shall return to this subject presently.) For example, you can see a quick movement as a whole; you are not merely aware that the object was first in one place and then in another. You can see the movement of the second-hand of a watch, but not of the hour-hand or minute-hand. When you see a movement in this sense, you are aware that one part of it is earlier than another. Thus you acquire the idea “earlier”, and you can mean by “past” “earlier than this”, where “this” is what is actually happening. This is a logically possible theory, but it seems nevertheless somewhat difficult to believe. I do not know, however, of any easier theory, and I shall therefore adopt it provisionally while waiting for something better.

For the understanding of memory, it is a help to consider the links connecting its most developed forms with other occurrences of a less complex kind. True recollection comes at the end of a series of stages. I shall distinguish five stages on the way, so that recollection becomes the sixth in gradual progress. The stages are as follows:

1. Images.—As we have seen, images, at any rate in their simpler parts, in fact copy past sensations more or less vaguely, even when they are not known to do so. Images are “mnemic” phenomena, in the sense that they are called up by stimuli formerly associated with their prototypes, so that their occurrence is a result of past experience according to the law of association. But obviously an image which in fact copies a past occurrence does not constitute a recollection unless it is felt to be a copy.

2. Familiarity.—Images and perceptions may come to us, and so may words or other bodily movements, with more or less of the feeling we call “familiarity”. When you recall a tune that you have heard before, either by images or by actually singing it, part of what comes to you may feel familiar, part unfamiliar. This may lead you to judge that you have remembered the familiar part rightly and the unfamiliar part wrongly, but this judgment belongs to a later stage.

3. Habit-Memory.—We have already discussed this in Chapter VI. People say they remember a poem if they can repeat it correctly. But this does not necessarily involve any recollection of a past occurrence; you may have quite forgotten when and where you read the poem. This sort of memory is mere habit, and is essentially like knowing how to walk although you cannot remember learning to walk. This does not deserve to be called memory in the strict sense.

4. Recognition.—This has two forms. (a) When you see a dog, you can say to yourself “there is a dog”, without recalling any case in which you have seen a dog before, and even without reflecting that there have been such cases. This involves no knowledge about the past; essentially it is only an associative habit. (b) You may know “I saw this before”, though you do not know when or where, and cannot recollect the previous occurrence in any way. In such a case there is knowledge about the past, but it is very slight. When you judge: “I saw this before”, the word “this” must be used vaguely, because you did not see exactly what you see now, but only something very like this. Thus all that you are really knowing is that, on some past occasion, you saw something very like what you are seeing now. This is about the minimum of knowledge about the past that actually occurs.

5. Immediate Memory.—I come now to a region intermediate between sensation and true memory, the region of what is sometimes called “immediate memory”. When a sense-organ is stimulated, it does not, on the cessation of the stimulus, return at once to its unstimulated condition: it goes on (so to speak) vibrating, like a piano-string, for a short time. For example, when you see a flash of lightning, your sensation, brief as it is, lasts much longer than the lightning as a physical occurrence. There is a period during which a sensation is fading: it is then called an “acoleuthic” sensation. It is owing to this fact that you can see a movement as a whole. As observed before, you cannot see the minute-hand of a watch moving, but you can see the second-hand moving. That is because it is in several appreciably different places within the short time that is required for one visual sensation to fade, so that you do actually, at one moment, see it in several places. The fading sensations, however, feel different from those that are fresh, and thus the various positions which are all sensibly present are placed in a series by the degree of fading, and you acquire the perception of movement as a process. Exactly the same considerations apply to hearing a spoken sentence.

Thus not only an instant, but a short finite time is sensibly present to you at any moment. This short finite time is called the “specious present”. By the felt degree of fading, you can distinguish earlier and later in the specious present, and thus experience temporal succession without the need of true memory. If you see me quickly move my arm from left to right, you have an experience which is quite different from what you would have if you now saw it at the right and remembered that a little while ago you saw it at the left. The difference is that, in the quick movement, the whole falls within the specious present, so that the entire process is sensible. The knowledge of something as in the immediate past, though still sensible, is called “immediate memory”. It has great importance in connection with our apprehension of temporal processes, but cannot count as a form of true memory.

6. True Recollection.—We will suppose, for the sake of definiteness, that I am remembering what I had for breakfast this morning. There are two questions which we must ask about this occurrence: (a) What is happening now when I recollect? (b) What is the relation of the present happening to the event remembered? As to what is happening now, my recollection may involve either images or words; in the latter case, the words themselves may be merely imagined. I will take the case in which there are images without words, which must be the more primitive, since we cannot suppose that memory would be impossible without words.

The first point is one which seems so obvious that I should be ashamed to mention it, but for the fact that many distinguished philosophers think otherwise. The point is this: whatever may be happening now, the event remembered is not happening. Memory is often spoken of as if it involved the actual persistence of the past which is remembered; Bergson, e.g. speaks of the interpenetration of the present by the past. This is mere mythology; the event which occurs when I remember is quite different from the event remembered. People who are starving can remember their last meal, but the recollection does not appease their hunger. There is no mystic survival of the past when we remember; merely a new event having a certain relation to the old one. What this relation is, we shall consider presently.

It is quite clear that images are not enough to constitute recollection, even when they are accurate copies of a past occurrence. One may, in a dream, live over again a past experience; while one is dreaming, one does not seem to be recalling a previous occurrence, but living through a fresh experience. We cannot be said to be remembering, in the strict sense, unless we have a belief referring to the past. Images which, like those in dreams, feel as if they were sensations, do not constitute recollection. There must be some feeling which makes us refer the images to a past prototype. Perhaps familiarity is enough to cause us to do so. And perhaps this also explains the experience of trying to remember something and feeling that we are not remembering it right. Parts of a complex image may feel more familiar than other parts, and we then feel more confidence in the correctness of the familiar parts than in that of the others. The conviction that the image we are forming of a past event is wrong might seem to imply that we must be knowing the past otherwise than by images, but I do not think this conclusion is really warranted, since degrees of familiarity in images suffice to explain this experience.

(b) What is the relation of the present happening to the event remembered? If we recollect correctly, the several images will have that kind of resemblance of quality which images can have to their prototypes, and their structure and relations will be identical with those of their prototypes. Suppose, for instance, you want to remember whether, in a certain room, the window is to the right or left of the door as viewed from the fireplace. You can observe your image of the room, consisting (inter alia) of an image of the door and an image of the window standing (if your recollection is correct) in the same relation as when you are actually seeing the room. Memory will consist in attaching to this complex image the sort of belief that refers to the past; and the correctness of memory consists of similarity of quality and identity of structure between the complex image and a previous perception.

As for the trustworthiness of memory, there are two things to be said. Taken as a whole, memory is one of the independent sources of our knowledge; that is to say, there is no way of arriving at the things we know through memory by any argument wholly derived from things known otherwise. But no single memory is obliged to stand alone, because it fits, or does not fit, into a system of knowledge about the past based upon the sum-total of memories. When what is remembered is a perception by one or more of the public senses, other people may corroborate it. Even when it is private, it may be confirmed by other evidence. You may remember that you had a toothache yesterday, and that you saw the dentist to-day; the latter fact may be confirmed by an entry in your diary. All these make a consistent whole, and each increases the likelihood of the other. Thus we can test the truth of any particular recollection, though not of memory as a whole. To say that we cannot test the truth of memory as a whole is not to give a reason for doubting it, but merely to say that it is an independent source of knowledge, not wholly replaceable by other sources. We know that our memory is fallible, but we have no reason to distrust it on the whole after sufficient care in verification has been taken.

The causation of particular acts of recollection seems to be wholly associative. Something in the present is very like something in the past, and calls up the context of the past occurrence in the shape of images or words; when attention falls upon this context, we believe that it occurred in the past, not as mere images, and we then have an act of recollection.

There are many difficult problems connected with memory which I have not discussed, because they have an interest which is more purely psychological than philosophical. It is memory as a source of knowledge that specially concerns the philosopher.