§ 14.

Of course it may very well be that many a man would disclaim any such conception, who is yet constantly acting upon the distinction between what he believes to be mere appearance and what he believes to be reality. But want of familiarity with the abstract expression of a conception, want of ability to analyse it, is no evidence that the conception is inoperative upon the experience of the person who, from this want of familiarity or ability, would say, if he were asked, that he had it not or knew not what it meant. The proof of the necessity of certain ideas has never been supposed, by any one who knew what he was about, to rest upon the fact that every one was aware of having them. Such a proof, to say nothing of the well-worked appeal to savages or the uneducated, would be at the mercy of every lively gentleman who was pleased to say that he searched his breast for such ideas in vain. The necessity of a conception, as distinct from the logical (or rather rhetorical) necessity of a conclusion contained in premises already conceded, means that it is necessary to the experience without which there would not for us be a world at all; and there can be neither proof nor disproof of such necessity as is claimed for any conception, but through analysis of the conditions which render this experience possible. Unless the accuracy or sufficiency of the analysis can be disputed, the necessary character of the ideas which it exhibits as operative in the formation of experience, is unaffected by the inability of any one to recognise them in that abstract form to which the analysis reduces them, but which, just because they are operative in concrete experience, is not the form of their familiar use. (§ 14 ¶ 1)

Thus a man who is quite at home with the distinction between facts and fancies may think it strange to be told that the distinction implies a conception of the world as a single system of relations; that this is the conception on the strength of which he constantly sets aside as fancy what he had taken to be fact, because he finds that the supposed relations, which for him formed the nature of the fact, are not such as can be combined with others that he recognises in one intelligible system. Such language may convey no meaning to him, but the question will still remain whether upon reflection the distinction can be otherwise accounted for. When we analyse our idea of matter of fact, can we express it except as an idea of a relation which is always the same between the same objects; or our idea of an object except as that which is always the same in the same relations? And does not each expression imply the idea of a world as a single and eternal system of related elements, which may be related with endless diversity but must be related still? If we may properly call the consciousness which yields this idea understanding, are we not entitled to say that understanding is the source of there being for us an objective world, that it is the principle of objectivity? (§ 14 ¶ 2)