The source of his power lay not in his doctrine, but in his temperament, and the rare quality of his wisdom was due less to his reason than to his imagination. Reality eluded him; he had neither diligence nor constancy enough to master and possess it; but his mind was open to all philosophic influences, from whatever quarter they might blow; the lessons of science and the hints of poetry worked themselves out in him to a free and personal religion. He differed from the plodding many, not in knowing things better, but in having more ways of knowing them. His grasp was not particularly firm, he was far from being, like a Plato or an Aristotle, past master in the art and the science of life. But his mind was endowed with unusual plasticity, with unusual spontaneity and liberty of movement--it was a fairyland of thoughts and fancies. He was like a young god making experiments in creation: he blotched the work, and always began again on a new and better plan. Every day he said, "Let there be light," and every day the light was new. His sun, like that of Heraclitus, was different every morning. What seemed, then, to the more earnest and less critical of his hearers a revelation from above was in truth rather an insurrection from beneath, a shaking loose from convention, a disintegration of the normal categories of reason in favour of various imaginative principles, on which the world might have been built, if it had been built differently. This gift of revolutionary thinking allowed new aspects, hints of wider laws, premonitions of unthought of fundamental unities to spring constantly into view. But such visions were necessarily fleeting, because the human mind had long before settled its grammar, and discovered, after much groping and many defeats, the general forms in which experience will allow itself to be stated. These general forms are the principles of common sense and positive science, no less imaginative in their origin than those notions which we now call transcendental, but grown prosaic, like the metaphors of common speech, by dint of repetition.