Page:Ferrier's Works Volume 3 "Philosophical Remains" (1883 ed.).djvu/337

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