IT is no easy matter to compose a new preface to a book on metaphysics written twenty years ago. For in twenty years even the most stationary of subjects may make some progress, and even the most case-hardened Of metaphysicians must have had a good deal more experience, and ought to know a good deal better. It happens, moreover, as regards the present book, that the subject has evolved at a revolu tionary rate, and that its author has been carried along in the central whirl of the movement. The discovery in philosophic method, which is generally called Pragmatism, but more truly and significantly Humanism, has rendered more or less out of date every earlier work in metaphysics, in much the same way as the rise of evolutionism rendered out of date every pro-darwinian book on biology, not of course in the sense that nothing of value remained in the work of the earlier era, but because so distinctive a novelty had come into being among philosophic positions that it was imperative that every writer should define his attitude towards it. But this revolu tion has antiquated no work more painfully than that of those who have been most conspicuously sympathetic towards the new method and have most wholeheartedly adopted it. For they must feel most keenly the defectiveness, stupidity and blindness of their earlier gropings.