This brings us to the recognition of a _competition among determinants_ which is an important, indeed a cardinal, feature in Weismann’s theory of evolution. He makes, as I am forced to believe, an illegitimate and extravagant use of it, but the principle may really exist and be operative without furnishing the master-word to the riddle of organized being. The master-word, as I shall try to show, is nature’s will to live. But before going fully into this argument, let us fix in our minds the _rationale_ of those processes of elementary organic life which have been described in this chapter. Protoplasmic life may be supposed to have originated, and perhaps to be still originating, in certain molecular combinations of matter. In other words, the combination, when it took place, developed certain peculiar forces through which it was enabled to maintain itself and to grow, by the processes called assimilation and nutrition. These forces, then, were potentially present in nature before the molecules combined to evoke them. They are among the latent powers of life. They waited, ready to be called into action when the required external form should be arrived at in the play of molecular energy. Life first originated, no doubt, in unconnected and inconceivably small units of protoplasm. Between the units thus formed and their combination into the elaborate structure which we now know a cell to be—packed as full of varied energies, it has been said, as an ironclad is of machinery—there is evidently a very wide gap. All we know is that when we have got the cell, we find it in possession of a complex apparatus for subdivision, which, taken together with the faculties of nutrition and growth, enable any one cell to multiply indefinitely by producing replicas of itself. To _life_ and _growth_, then, has been added the faculty for _multiplication_. Here we strike on a veritable mystery. Why should any new movement ever take place? Why should a cell ever divide in two? We can only say that it is its property to do so.[51] It does so because it is alive. Did this property first arise as one of a multitude of aimless movements—the only one which ensured permanence and multiplicity to the organisms which exhibited it? If so, then Nature, at the time when life began on the earth, behaved in a manner most unlike that in which she behaves at present. If we are to interpret the processes hidden in the remote past by the light of what we see at present, we shall conclude that, at bottom, the will to live made molecular action—and the same force incorporated itself in the combinations which originated protoplasmic life, ordered the structure of the cell, and gave it the need and the power to multiply. Nature is for ever changing, for ever straining after new life, after more life.