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