192. Upon this the remark must occur that, if the fact of being unextended constituted immortality, all sounds and smells must be immortal, and that the inseparability of time from the succession of feelings may prove that succession endless, but proves no immortality of a soul unless there be one self-conscious subject of that succession, identical with itself throughout it. To the supposition of there being such a subject, which Berkeley virtually makes, his own mode of disposing of matter suggested ready objections. In Locke, as we have seen, the two opposite ‘things,’ thinking and material, always appear in strict correlativity, each representing (though he was not aware of this) the same logical necessity of substantiation. ‘Sensation convinces us that there are solid extended substances, and reflection that there are thinking ones.’ These are not two convictions, however, but one conviction, representing one and the same essential condition of knowledge. Such logical necessity indeed is misinterpreted when made a ground for believing the real existence either of a multitude of independent things, for everything is a ‘retainer’ to everything else; [1] or of a separation of the thinking from the material substance, since, according to Locke’s own showing, they at least everywhere overlap; [2] or of an absolutely last substance, which because last would be unknowable: but it is evidence of the action of a synthetic principle of self-consciousness without which all reference of feelings to mutually-qualified subjects and objects, and therefore all knowledge, would be impossible. It is idle, however, with Berkeley so to ignore the action of this principle on the one side as to pronounce the material world a mere succession of feelings, and so to take it for granted on the other as to assert that every feeling implies relation to a conscious substance. Upon such a method the latter assertion has nothing to rest on but an appeal to the individual’s consciousness--an appeal which avails as much or as little for material as for thinking substance, and, in face of the apparent fact that with a knock on the head the conscious independent substance may disappear altogether, cannot hold its own against the suggestion that the one substance no less than the other is reducible to a series of feelings, so closely and constantly sequent on each other as to seem to coalesce. We cannot substitute for this illusory appeal the valid method of an analysis of knowledge, without finding that substantiation in matter is just as necessary to knowledge as substantiation in mind. If this method had been Berkeley’s he would have found a better plan for dealing with the ‘materialism’ in vogue. Instead of trying to show that material substance was a fiction, he would have shown that it was really a basis of intelligible relations, and that thus all that was fictitious about it was its supposed sensibility and consequent opposition to the work of thought.