On Sameness and Identity: A Psychological Study / Being a Contribution to the Foundations of a Theory of Knowledge

by George Stuart Fullerton

I have already pointed out that several of those who pin their faith to "external" realities seem to apprehend at times but dimly, if at all, that the relation of phenomenon and noumenon, or of idea and "real" thing, is that of representative and thing represented, and that we have here two things and not one. Certainly they sometimes pass from one to the other without rhyme or reason, and apparently in complete unconsciousness of the fact that they have made any change at all. If, for the time being, they really take the two for one, they are not thinking of the seventh kind of sameness, but of another kind. As this is done through mere inadvertence and looseness of reasoning, and cannot be justified on their own assumptions, it is not worth while to dwell upon it farther. Where one really has in mind the seventh kind of sameness, the elements I have mentioned will be found in it.

I. Finally, we come to the perplexing case that I postponed at the outset. What has sameness of the first kind in common with the rest? How can we speak of similarity when strictly one thing is in question? Not one thing in the loose sense in which we call a material object one thing in its successive states, nor one in the sense in which the memory image and its original are one, but one thing as a single element of knowledge is itself at any one instant? How can the idea of likeness hold here? Dundreary's bird flocking all by itself would seem to have found its philosophical prototype.

It may be said that though the thing in question is strictly one, yet we divide it from itself in thought and then affirm it of itself. We give expression to the logical law of identity by saying that x is x. But here the difficulty meets us that, if we are really talking about only the one x, we have said quite all we have to say in merely saying x; while if, to complete our thought, we must add the second x, we have not an identical proposition, in any strict sense of the word, but a synthetic one. It is easy enough in words to divide a "thing" from "itself," since the words "thing" and "itself" are two, and may readily be distinguished. In the same way it is easy in words to affirm a thing to be and not to be at the one time. There is no law to prevent one's stringing sounds together as he may please. But if one is interested not in the mere symbols, but in that which they are supposed to represent, one must see that the expression "x is x," to be a significant proposition, must have a subject and a predicate, and affirm a relation between them. Here we have, by hypothesis, strictly one thing for subject and predicate. The proposition "x is x" must then consist of one thing and a relation between it—which is about as significant as the statement that a door may consist of one side and a relation between it. Between what? One side.[29] Every form of proposition employed to give expression to the law of identity implies this difficulty. Whether we say "x is x," or "whatever is is," or "everything is identical with itself," our proposition, taken literally, is either useless (since we have said all we have to say in mentioning the subject alone), or untrue (since we add a new element in adding the predicate).

It is then sufficiently evident that the forms used to express the logical law of identity do not, taken strictly, express at all the kind of sameness with which we are now concerned, but, on the contrary, something very different. We are considering a sameness in which there is no duality whatever, but our expressions would seem to have no meaning except as indicating a relation between two. They are then significant, not as expressing sameness of the first kind, but as suggesting it, and this they certainly serve to do. The reason for this I shall try to give in a moment.

It has been said that in the other kinds of sameness we always find the notion of similarity. When, however, we distinguish two things as two and yet recognize them as similar, we must have what I may call a mixed experience of likeness and unlikeness. In any two things compared, the degrees of likeness and unlikeness may vary, and we may fix attention upon similarities or differences. In proportion to the attention given to dissimilar elements will the two objects be clearly distinguished from each other and discriminated as two. If the purpose in hand does not require a careful attention to differences, and if what is prominent in mind is the likeness of the two objects, the sense of duality may fall into the background, and the man pass readily from one object to the other with little consciousness that he has made a change. As I now look at the two ink-stands on my desk, I clearly recognize them as two and yet as of the one kind. Here I am as distinctly aware that they are two as I am that they are in some respects the same. But in some of the kinds of sameness I have described this sense of duality falls more into the shade. When I speak of seeing the same ink-stand twice, or when I call up in memory an ink-stand once seen, I am likely, unless I take particular pains to reflect upon my mental operation, to have but a dim realization of the fact that I have two distinct things to deal with. How those who distinguish between the immediate and the mediate objects of knowledge have a tendency to forget their distinction, and to pass unconsciously from one to the other, I have dwelt upon sufficiently.

Suppose, now, that from two objects which we recognize as similar and yet distinct, we abstract one by one the elements which differ. So long as there is any difference left, we still have "identity in diversity"—similarity in the ordinary sense of the term, which implies a recognition of two things as two. When, however, the last difference disappears, all sense of duality must disappear with it, for any division or distinction within what remains is inadmissible. Things which are distinguished are distinguished through some difference. A sense of duality implies a discrimination between two, and where it is impossible to discriminate duality vanishes. Similarity, as we commonly use the word, must then disappear with the disappearance of all dissimilarity between two objects. I say "between two objects" in default of a better expression, for, of course, we have at this point no longer two objects. My meaning is, however, sufficiently plain. A sense of duality implies difference, and similarity, as commonly understood, implies duality. The similarity will then take itself off with the last difference.

It may be objected that a consciousness of duality and a consciousness of similarity are only possible on the ground that I mention, but that duality and similarity themselves may really obtain when no difference between two is perceptible. But a moment's reflection will make it plain that one who speaks thus is simply supplying in himself the elements that he is supposing absent in the case of another. If he uses the words "duality" and "similarity," and they really mean anything to him, they imply all that I have said. He cannot represent to himself two things at all without distinguishing them from each other, and he can not distinguish them from each other unless they differ in some way. If, then, he speak of two things as being two and yet completely indistinguishable, he is, taken literally, talking nonsense. He may, of course, mean the misleading phrase to be understood as indicating something not actually expressed by the words. He may mean to point out that, under certain circumstances, in which he has an experience which he calls a recognition of two objects as two and as similar, he has reason to think another mind has an experience partly like and partly unlike his own—like in as much as it contains what corresponds to that which is common to the two objects he has in mind; unlike in as much as it contains nothing which corresponds to the elements which make it possible for him to recognize two objects. It is this that is in his mind when he speaks of thinking of two objects as really two and yet indistinguishable to this man or that. If, however, the expression "two things may be indistinguishable" is used to indicate this experience, it should be carefully borne in mind that the proposition must not be taken literally, for the good reason that the subject and predicate are not in the one consciousness. The "two objects" are in the mind of Smith, and the "indistinguishable" element in the mind of Jones. When we speak of two men as seeing the same thing, I have shown that we are using the word same in a looser sense which should never be confounded with the stricter sense. Strictly speaking, then, the "two things" are never indistinguishable, but that which corresponds to the two things in a consciousness from which all recognition of duality is absent. That one man may have a consciousness of duality while another man has not, and that these two experiences may be related as the experiences of different minds are related when we say they are experiencing the same thing, no one would care to dispute. Should a man say that he can think of himself as unable to distinguish two things which are nevertheless two, the case, would not be materially different. The man cannot, of course, think of the two things as indistinguishable, but he may think of two things and connect with this thought the thought of himself as having an experience in which there is no consciousness of duality.

But, it may be insisted, we are still only talking about consciousness; let us come to "real" things. Suppose no one able to distinguish between them, abstract all consciousness of difference, would not two "real" things remain two, however we might confound them? Can a thing in one place be a thing in another place, however closely it may resemble it, or however ignorant we may be?

To this I answer that when one speaks of two "real" things the words only mean something to him because he has present in mind what I have said must be present if one is to have a consciousness of duality. A "thing in one place" and a "thing in another place" are to him two simply because he thinks them as differing—in place. When one has come to the conclusion that he must duplicate his experience, distinguish between the world of immediate and the world of mediate objects, and place the latter in a region "outside," there is nothing to prevent him from thinking of two "real" things as two, although all distinctions within the field of immediate objects have been obliterated. Still, in thinking these "real" things as two, he does just what he does in thinking two immediate objects as two—he recognizes difference. The twoness depends upon difference as much in the one case as in the other, and to speak of two objects in a "real" world as two and yet having no differing element would be to use words without meaning. In talking about a "real" world, if we are really to talk and not merely to utter a series of sounds, our words must be significant. To say "this or that may be in a 'real' world, though we may not be able to conceive it," would, if "this" or "that" implies a contradiction, be to say nothing. The fact is that this "external" world, as we think it, implies the notions of before and after, in this place and that, all the distinctions and differences which make it to us a world of distinct objects. Of course it follows that things in the "external" world are thought as distinct from each other, but this does not affect my statement that distinction is impossible without difference.

We may, then, have a series of experiences, beginning with one in which two objects are recognized as similar and yet are very clearly distinguished as two objects, continued in others in which the sense of duality falls more and more into the background, and ending in one in which there is no consciousness of duality at all. The last of these experiences is not wholly different from the others. There is in it no experience of similarity in so far as this word is used to express identity in difference, or a relation between two. There can be no such relation unless there are two, and here there are not two. But it should be marked that this experience differs from the others, not in the element which has led us to declare two objects similar—the element which they have in common—but in that which has led us to declare them two and different. It is by adding to this last experience, so to speak, that we get the others. They contain it and more. Usage will not allow us to apply the term similarity in speaking of an experience in which two things are not distinguished, and this is proper enough; but it should never be forgotten that this experience is at the bottom of all our experiences of similarity—is, so to speak, their common core. When, therefore, I said some pages back that all the kinds of sameness under discussion contain the idea of similarity, I was using the word in a certain broad sense to indicate that which is the ground of all our experiences of similarity, and is also found in the first kind of sameness on the list. I preferred to use there the word similarity, because it was easy to show that this notion is really contained in six of the seven uses of the word same, and it was convenient afterward to show the connection between the first kind of sameness and the notion of similarity.