Philosophical Studies

by G. E. Moore

To begin with, there is one answer which is naturally suggested by the reason I have given for saying that, in this case, it is quite obvious that I am not judging, with regard to this presented object, that it is an inkstand, whereas it is not in the same way, quite obvious that, in making such a judgment as "This is a soap-bubble" or "This is a drop of water," I may not be judging, of the object about which my judgment is, that that very object really is a soap-bubble or a drop of water. The reason I gave is that it is quite obvious that I do not take this presented object to be a whole inkstand: that, at most, I only take it to be part of the surface of an inkstand. And this reason naturally suggests that the true answer to our question may be that what I am judging of the presented object is just that it is a part of the surface of an inkstand. This answer seems to me to be obviously on quite a different level from the suggestion that I am judging it really to be an inkstand. It is not childishly obvious that I am not judging it to be part of the surface of an inkstand, as it is that I am not judging it to be an inkstand—a whole one.

On this view, when I say such things as "That is an inkstand," "That is a door," "This is a coin," these expressions would really only be a loose way of saying "That is part of the surface of an inkstand," "That is part of the surface of a door," "This is part of the surface of a coin." And there would, I think, plainly be nothing surprising in the fact that we should use language thus loosely. What, at first sight, appears to be a paradox, namely that, whereas I appear to be asserting of a given thing that it is of a certain kind, I am not really asserting of the thing in question that it is of that kind at all, would be susceptible of an easy explanation. And moreover, if this view were true, it would offer an excellent illustration of the difference between a thing known only by description and a thing not so known, and would show how entirely free from mystery that distinction is. On this view, when I judge "That inkstand is a good big one" I shall in effect be judging: "There is one and only one inkstand of which this is part of the surface, and the inkstand of which this is true is a good big one." It would be quite clear that the part of the surface of the inkstand was given to me in a sense in which the whole was not, just as it is in fact clear that I do now "see" this part of the surface of this inkstand, in a sense in which I do not "see" the whole; and that my judgment, while it is, in fact, about both the whole inkstand, and also about one particular part of its surface, is about them in two entirely different senses.

This view is one, which it is at first sight, I think, very natural to suppose to be true. But before giving the reasons, why, nevertheless, it seems to me extremely doubtful, I think it is desirable to try to explain more precisely what I mean by it. The word "part" is one which is often used extremely vaguely in philosophy; and I can imagine that some people would be willing to assent to the proposition that this sense-datum really is, in some sense or other, a "part" of this inkstand, and that what I am judging with regard to it, when I judge "This is an inkstand," is, in effect, "There is an inkstand, of which this is a part," who would be far from allowing that this can possibly be what I am judging, when once they understand what the sense is in which I am here using the word "part." What this sense is, I am quite unable to define; but I hope I may be able to make my meaning sufficiently clear, by giving instances of things which are undoubtedly "parts" of other things in the sense in question. There is, it seems to me, a sense of the word "part," in which we all constantly use the word with perfect precision, and, which, therefore, we all understand very well, however little we may be able to define it. It is the sense in which the trunk of any tree is undoubtedly a part of that tree; in which this finger of mine is undoubtedly a part of my hand, and my hand a part of my body. This is a sense in which every part of a material thing or physical object is itself a material thing or physical object; and it is, so far as I can see, the only proper sense in which a material thing can be said to have parts. The view which I wish to discuss is the view that I am judging this presented object to be a part of an inkstand, in this sense. And the nature of the view can perhaps be brought out more clearly, by mentioning one important corollary which would follow from it. I am, of course, at this moment, seeing many parts of the surface of this inkstand. But all these parts, except one, are, in fact, themselves parts of that one. That one is the one of which we should naturally speak as "the part of the surface that I am now seeing" or as "this part of the surface of this inkstand." There is only one part of the surface of this inkstand, which does thus contain, as parts, all the other parts that I am now seeing. And, if it were true that I am judging this presented object to be a part of the surface of an inkstand at all, in the sense I mean, it would follow that this presented object must, if my judgment "This is an inkstand" be true (as it certainly is), be identical with this part, which contains all the other parts which I am seeing; since there is plainly no other part with which it could possibly be identified. That is to say, if I am really judging of this presented object that it is part of the surface of an inkstand, in the sense I mean, it must be the case that everything which is true of what I should call "this part of the surface of this inkstand" is, in fact, true of this presented object.

This view, therefore, that what we are judging of the ultimate subject of our judgment, when we judge "This is a so-and-so," is, in general, merely that the subject in question is a part of a thing of the kind in question, can, I think, be most clearly discussed, by asking whether, in this case, this presented object can really be identical with this part of the surface of this inkstand. If it can't, then most certainly I am not judging of it that it is a part of the surface of an inkstand at all. For my judgment, whatever it is, is true. And yet, if this presented object is not identical with this part of the surface of this inkstand, it certainly is not a part of an inkstand at all; since there is no other part, either of this inkstand or of any other, with which it could possibly be supposed to be identical.

Can we, then, hold that this sense-datum really is identical with this part of the surface of this inkstand? That everything which is true of the one is true of the other?

An enormous number of very familiar arguments have been used by various philosophers, which, if they were sound, would show that we can not. Some of these arguments seem to me to be quite clearly not sound—all, for instance, which rest either on the assumption that this sense-datum can only exist so long as it is perceived, or on the assumption that it can only exist so long as it is perceived by me. Of others I suspect that they may have some force, though I am quite unable to see that they have any. Such, for instance, are all those which assume either that this sense-datum is a sensation or feeling of mine, in a sense which includes the assertion that it is dependent on my mind in the very same sense in which my perception of it obviously is so; or that it is causally dependent on my body in the sense in which my perception of it admittedly is so. But others do seem to me to have great force. I will, however, confine myself to trying to state one, which seems to me to have as much as any. It will be found that this one involves an assumption, which does seem to me to have great force, but which yet seems to me to be doubtful. So far as I know, all good arguments against the view that this sense-datum really is identical with this part of the surface of the inkstand, do involve this same assumption, and have no more force than it has. But in this, of course, I may be wrong. Perhaps some one will be able to point out an argument, which is obviously quite independent of it, and which yet has force.

The argument I mean involves considerations which are exceedingly familiar, so familiar that I am afraid every one may be sick of hearing them alluded to. But, in spite of this fact, it seems to me not quite easy to put it quite precisely, in a way which will distinguish it clearly from other arguments involving the same familiar considerations, but which do not seem to me to be equally cogent. I want, therefore, to try to put it with a degree of precision, which will prevent irrelevant objections from being made to it—objections which would, I think, be relevant against some of these other arguments, but are not, I think, relevant against it.

The fact is that we all, exceedingly commonly, when, at each of two times, separated by a longer or shorter interval, we see a part of the surface of a material thing, in the sense in which I am now seeing this part of the surface of this inkstand, or when at one time we see such a surface and at another perceive one by touch, make, on the second occasion, the judgment "This part of a surface is the same part of the surface of the same thing, as that which I was seeing (or perceiving by touch) just now." How commonly we all do this can scarcely be exaggerated. I look at this inkstand, and then I look again, and on the second occasion I judge "This part of the surface of this inkstand is the same as, or at least contains a part which is the same as a part of, the part of its surface which I was seeing just now." Or I look at this finger and then I touch it, and I judge, on the second occasion, "This part of the surface of this finger is the same as one of those I was seeing just now." We all thus constantly identify a part of a surface of a material thing which we are perceiving at one time with a part which we were perceiving at another.

Now, when we do this—when we judge "This is the same part of the same thing as I was seeing or touching just now," we, of course, do not mean to exclude the possibility that the part in question may have changed during the interval; that it is really different, on the second occasion, either in shape or size or quality, or in all three, from what it was on the first. That is to say, the sense of sameness which we are here concerned with is one which clearly does not exclude change. We may even be prepared to assert, on general grounds, in all such cases, that the surface in question certainly must have changed. But nevertheless there is a great difference in one respect, between two kinds of such cases, both of which occur exceedingly commonly. If I watch somebody blowing air into a child's balloon, it constantly happens, at certain stages in the process, that I judge with regard to the part of the surface which I am seeing at that stage, not only that it is larger than it was at an earlier stage, but that it is perceptibly larger. Or, if I pull the face of an india-rubber doll, I may judge at a certain stage in the process that the patch of red colour on its cheek not only is different in shape from what it was at the beginning, but is perceptibly so; it may, for instance, be a perceptibly flatter ellipse than it was to start with. Or, if I watch a person blushing, I may judge at a certain stage that a certain part of the surface of his face not only is different in colour from what it was, when I saw it before he began to blush, but is perceptibly so—perceptibly redder. In enormous numbers of cases we do thus judge of a surface seen at a given time that it is thus perceptibly different in size, or in shape, or in colour, from what it was when we saw it before. But cases are at least equally numerous in which, though we might, on general grounds be prepared to assert that it must have changed in some respect, we should not be prepared to assert that it had, in any respect whatever, changed perceptibly. Of this part of this surface of this inkstand, for instance, I am certainly not prepared to assert that it is now perceptibly different in any respect from what it was when I saw it just now. And similar cases are so numerous that I need not give further instances. We can, therefore, divide cases, in which we judge, of a part of a surface which we are seeing, "This is the same part of the surface of the same material thing as the one I saw just now," into cases where we should also judge "But it is perceptibly different from what it was then," and cases in which, even though we might assert "It must be different," we are certainly not prepared to assert that it is perceptibly so.