great success which has attended his endeavours. He has not duly attended or done justice to the pertinacity with which Berkeley adheres to the facts of vision cut off from all the other knowledge of which our other senses are the inlets. In studying the science of vision, the eye of his mind has not been "single;" and hence his mind has not been "full of light." He does not himself appear to have experimentally verified the pure facts of the virgin eye as yet unwedded to the touch. He has not formed to himself a clear conception of the absolute distinction between these two senses and their respective objects—a distinction upon the clear apprehension of which the whole intelligibility of Berkeley's assertions and reasonings depends.
In proof of what we aver, let us turn to the consideration of one fact which Berkeley has largely insisted on as the fundamental fact of the science. Colour, says the Bishop, is the proper and only object of vision, and the outness of this object (i.e., its outness from the eye) is not perceived by sight. Upon which Mr Bailey, disputing the truth of the latter fact, remarks, "on turning to Berkeley's essay, we find literally no arguments which specifically apply to this question; nothing but bare assertion repeated in various phrases." This is undoubtedly too true—and perhaps Berkeley is to be condemned for having left his assertion so destitute of the support of reasoning. But he saw that he had stated a fact which he himself had verified, and perhaps he did not think it necessary to prove it to those who had eyes to see it for themselves; perhaps he was unable to prove it. But, at any rate, Mr Bailey's complaint shows that he is deficient in that speculative sense which enables a man to see that to be a fact which is a fact, and to explicate its reason, even when no rationale of it has been given by him who originally promulgated it. This reason we shall now endeavour to supply. Let us ask, then—what do we mean when we say that a colour is seen to be external? We mean that it is seen to be external to some other colour which is before us. Thus we say that white is external to black, because we see it to be so. It is only when we can make a comparison between two or more colours that we can say that they are seen to be external—i.e., external to each other. But if there were no colour but one before us, not being able to make any comparison, we should be unable by sight to form any judgment at all about its outness, or to say that we saw it to be out of anything. For what would it be seen to be out of? Out of the eye or the mind, you say. But you do not see the colour of the eye or of the mind—and therefore you have no ground whatever afforded you on which, instructed by the sense of sight, you can form your judgment. You have no other colour with which to compare it, and therefore, as a comparison with other colours is necessary before you can say that any one of them is seen to be external, you cannot predicate visible outness of it at all. Nor does it make any difference how numerous soever the colours before you may be. You can predicate outness of them all in relation to each other; but you can predicate nothing of the sort with regard to any of them in relation to your eye or to your mind, for you have no colour of your eye or mind before you with which you can compare them, and aid of which, in virtue of that comparison, you can say that they visibly exist. Doubtless, if you saw the colour of your own eye, you could then say that other visible objects, that is, other colours, were seen to be external to it. But, as you never see this, you have nothing left for it but even now to accept the fact as Berkeley laid it down, coupled with the reasoning by which we have endeavoured to explain and expiscate it. But the touch! Does not the touch enable us to form a judgment with respect to the outness of objects from the eye? Undoubtedly it does—as Berkeley everywhere contends. But the only question at present at issue is: does the sight?—and the fact established beyond all question by the foregoing reasoning is, that it does not.
What makes people so reluctant and unwilling to accept this fact is, that they suppose we are requiring them to believe that visible objects, that is, colours, are not seen to be external to their own visible bodies; that, for instance, a colour, at the other end of the room, is not seen to be external to their hand, or the point of their own nose. They think that when such a colour is said not to be seen to be external to the eye, that we are maintaining that they must see it to be in close proximity to their own visible nose or eyebrows. But, in truth, we are maintaining no position so completely at variance with the fact, and
