Now what is needed for these problems of primitive existence is something more like a primitive spirit. In calling up this vision of the first things, I would ask the reader to make with me a sort of experiment in simplicity. And by simplicity I do not mean stupidity, but rather the sort of clarity that sees things like life rather than words like evolution. For this purpose it would really be better to turn the handle of the Time Machine a little more quickly and see the grass growing and the trees springing up into the sky, if that experiment could contract and concentrate and make vivid the upshot of the whole affair. What we know, in a sense in which we know nothing else, is that the trees and the grass did grow and that a number of other extraordinary things do in fact happen; that queer creatures support themselves in the empty air by beating it with fans of various fantastic shapes; that other queer creatures steer themselves about alive under a load of mighty waters; that other queer creatures walk about on four legs, and that the queerest creature of all walks about on two. These are things and not theories; and compared with them evolution and the atom and even the solar system are merely theories. The matter here is one of history and not of philosophy; so that it need only be noted that no philosopher denies that a mystery still attaches to the two great transitions: the origin of the universe itself and the origin of the principle of life itself. Most philosophers have the enlightenment to add that a third mystery attaches to the origin of man himself. In other words, a third bridge was built across a third abyss of the unthinkable when there came into the world what we call reason and what we call will. Man is not merely an evolution but rather a revolution. That he has a backbone or other parts upon a similar pattern to birds and fishes is an obvious fact, whatever be the meaning of the fact. But if we attempt to regard him, as it were, as a quadruped standing on his hind legs, we shall find what follows far more fantastic and subversive than if he were standing on his head.