In fact, in considering this question of life, it is about as difficult for the unscientific mind to get along without postulating a vital principle or force--which, Huxley says, is analogous to the idea of a principle of aquosity in water--as it is to walk upon the air, or to hang one's coat upon a sunbeam. It seems as if something must breathe upon the dead matter, as at the first, to make it live. Yet if there is a distinct vital force it must be correlated with physical force, it must be related causally to the rest. The idea of a vital force as something new and distinct and injected into matter from without at a given time and place in the earth's history, must undoubtedly be given up. Instead of escaping from mechanism, this notion surrenders one into the hands of mechanism, since to supplement or reinforce a principle with some other principle from without, is strictly a mechanical procedure. But the conception of vitality as potential in matter, or of the whole universe as permeated with spirit, which to me is the same thing, is a conception that takes life out of the categories of the fortuitous and the automatic. No doubt but that all things in the material world are causally related, no doubt of the constancy of matter and force, no doubt but that all phenomena are the result of natural principles, no doubt that the living arose from the non-living, no doubt that the evolution process was inherent in the constitution of the world; and yet there is a mystery about it all that is insoluble. The miracle of vitality takes place behind a veil that we cannot penetrate, in the inmost sanctuary of the molecules of matter, in that invisible, imaginary world on the borderland between the material and the immaterial. We may fancy that it is here that the psychical effects its entrance into the physical--that spirit weds matter--that the creative energy kindles the spark we call vitality. At any rate, vitality evidently begins in that inner world of atoms and molecules; but whether as the result of their peculiar and very complex compounding or as the cause of the compounding--how are we ever to know? Is it not just as scientific to postulate a new principle, the principle of vitality, as to postulate a new process, or a new behavior of an old principle? In either case, we are in the world of the unverifiable; we take a step in the dark. Most of us, I fancy, will sympathize with George Eliot, who says in one of her letters: "To me the Development Theory, and all other explanations of processes by which things came to be, produce a feeble impression compared with the mystery that lies under the processes." V SCIENTIFIC VITALISM I