But if we are to adopt the view that something of this sort is what we are judging, there occurs at once the pressing question: What on earth can the relation be with regard to which we are judging, that one and only one thing stands in it to this presented object? And this is a question to which, so far as I know, none of those philosophers, who _both_ hold (as many do) that this presented object is _not_ identical with this part of the surface of this inkstand, _and_ also that there really is something of which it could be truly predicated that it is this part of the surface of this inkstand (that is to say, who reject all views of the Mill-Russell type), have given anything like a clear answer. It does not seem to have occurred to them that it requires an answer, chiefly, I think, because it has not occurred to them to ask what we can be judging when we make judgments of this sort. There are only two answers, that I can think of, which might be suggested with any plausibility.
Many philosophers, who take the view that the presented objects about which we make these judgments are sensations of ours, and some even who do not, are in the habit of talking of _"the_ causes" of these objects as if we knew, in the case of each, that it had one and only one cause; and many of them seem to think that this part of the surface of this inkstand could be correctly described as _the_ cause of this presented object. They suggest, therefore, the view that what I am judging in this case might be: "This presented object has one and only one cause, and that cause is part of the surface of an inkstand." It seems to me quite obvious that _this_ view, at all events, is utterly untenable. I do not believe for a moment, nor does any one, and certainly therefore do not judge, that this presented object has _only_ one cause: I believe that it has a whole series of different causes. I do, in fact, believe that this part of the surface of this inkstand is _one_ among the causes of my perception of this presented object: that seems to me to be a very well established scientific proposition. And I am prepared to admit that there _may_ be good reasons for thinking that it is one among the causes of this presented object itself, though I cannot myself see that there are any. But that it is the _only_ cause of this presented object I certainly do not believe, nor, I think, does anybody, and hence my judgment certainly cannot be "_The_ cause of this is part of the surface of an inkstand." It might no doubt, be possible to define some _kind_ of causal relation, such that it might be plausibly held that it and it alone causes this presented object _in that particular way._ But any such definition would, so far as I can see, be necessarily very complicated. And, even when we have got it, it seems to me it would be highly improbable we could truly say that what we are judging in these cases is: "This presented object has one and only one cause, of this special kind." Still, I do not wish to deny that some such view may _possibly_ be true.