Thus the notion of an independent and permanent world is an ideal term used to mark and as it were to justify the cohesion in space and the recurrence in time of recognisable groups of sensations. This coherence and recurrence force the intellect, if it would master experience at all or understand anything, to frame the idea of such a reality. If we wish to defend the use of such an idea and prove to ourselves its necessity, all we need do is to point to that coherence and recurrence in external phenomena. That brave effort and flight of intelligence which in the beginning raised man to the conception of reality, enabling him to discount and interpret appearance, will, if we retain our trust in reason, raise us continually anew to that same idea, by a no less spontaneous and victorious movement of thought. CHAPTER IV—ON SOME CRITICS OF THIS DISCOVERY [Sidenote: Psychology as a solvent.] The English psychologists who first disintegrated the idea of substance, and whose traces we have in general followed in the above account, did not study the question wholly for its own sake or in the spirit of a science that aims at nothing but a historical analysis of mind. They had a more or less malicious purpose behind their psychology. They thought that if they could once show how metaphysical ideas are made they would discredit those ideas and banish them for ever from the world. If they retained confidence in any notion—as Hobbes in body, Locke in matter and in God, Berkeley in spirits, and Kant, the inheritor of this malicious psychology, in the thing-in-itself and in heaven—it was merely by inadvertence or want of courage. The principle of their reasoning, where they chose to apply it, was always this, that ideas whose materials could all be accounted for in consciousness and referred to sense or to the operations of mind were thereby exhausted and deprived of further validity. Only the unaccountable, or rather the uncriticised, could be true. Consequently the advance of psychology meant, in this school, the retreat of reason; for as one notion after another was clarified and reduced to its elements it was _ipso facto_ deprived of its function.