these terms? It will still be said that such doubt implies a new criterium. But the implication is of another sort. It may be that the sceptic must as a matter of fact go on exercising his faculty of thought, and it may be that to think is to apply such categories as Being, Substance, Space, and the rest. But this implies no Archimedean point of certainty. All the categories available may prove useless. The organism inevitably reacts on its environment, with the hope of using it; but its environment may be rock walls, and it may perish of hunger. We go on thinking, but it is claiming a great deal to say that this involves of necessity our reaching truth. It does not even imply an ineradicable assurance in our own minds that the world is thinkable. Lotze, when discussing scepticism, argues that scepticism presupposes truth. The question whether after all our ideas agree with the reality is, he considers, a barren one. Then he comes to the conclusion that it is unanswerable, and the supposition of an intelligence that should know that its ideas and the facts agree is, he says, an absurd and impossible one. Now it is surely possible to conceive an intelligence for which the facts of the whole infinite universe are known, for which there is no beyond, by whose activity these facts are constituted; and recognizing this possibility, we may yet humbly admit that that intelligence is not ours, and if we be forced to say that we cannot determine whether our ideas and the actual world are in consonance, the conclusion may not be barren, but may prove most instructive.
The nature of knowledge may now in some important respects be clearer. All thought is the effort of the mind to explain the world. Within the mind the categories are born; they come to light as explanations of the world. Not, however, as infallible; they are, from the thought of Being to the ‘laws’ of science, gained by induction; and thus they are tentative and hypothetical; and as in the political life of nations there have been so many revolutions that men become chary of accepting any constitution as final, there may in the structure of knowledge be acknowledged a similar want of finality. What was regarded as truth has to be contradicted,
