cells. The rationale of sea-anemones and mud-fish and flying foxes and elephants has to be looked for in man: he alone underlies them. And man is not a vertebrate because his ancestors were vertebrate; but the animals are vertebrate, because or in so far as they are forerunners and offshoots of Man. It has been frequently said that great material changes are succeeded by intellectual and finally by moral revolutions--as the conquests of Alexander passed on into the literary expansion of the Alexandrian schools and thence into the establishment of Christianity, or as the mechanical developments of our own time have been followed by immense literary and scientific activities, and are obviously passing over now into a great social regeneration; but a reconsideration of the matter might, I take it, lead us not so much to look on the later changes as _caused_ by the earlier, as to look on the earlier as the indications and first outward and visible signs of the coming of the later. When a man feels in himself the upheaval of a new moral fact, he sees plainly enough that that fact cannot come into the actual world all at once--not without first a destruction of the existing order of society--such a destruction as makes him feel satanic; then an intellectual revolution; and lastly only, a new order embodying the new impulse. When this new impulse has thoroughly materialised itself, then after a time will come another inward birth, and similar changes will be passed through again. So it might be said that the work of each age is not to build _on_ the past, but to rise _out_ of the past and throw it off; only of course in such matters where all forms of thought are inadequate it is hard to say that one way of looking at the subject is truer than another. As before, we should endeavour to look at the thing from different sides. We are obliged to use images to think by--_e.g._ the opening of a flower or the accretive growth of a coral reef--and possibly it would save a good deal of trouble if we did not disguise by long words the truth that all our theories in science and philosophy are simply metaphors of this kind--but the _fact_ still lies behind and below them.