Before we go on to deal with heredity we should note the value for our own lives of our ability to establish habits at all, to inscribe records of action in our instruments of body and brain which shall be capable of an almost automatic repetition. That is the way in which intellectual and bodily skill makes progress. We build a stairway too for our minds and spirits as well as for our bodies, when we lay down step after step of habitual action, handing over to it the carrying-on of what at first we had to think out, and then by degrees learnt to do skilfully and well almost without thought at all. That is the stairway by which the pianist advances towards a perfect execution of his music and the skater mounts towards perfect execution of a figure which at first was beyond his power. Throughout our lives we are handing actions over to be conducted by our bodies and brains as effects of work done consciously before, to be acted over and over again and pass beyond the need of conscious intervention, and in the end to be carried on the better without that aid. A man skates, or plays his violin, or writes a poem, or rides a horse, or walks, or dances, all the better when and if he does not have to think about the appropriate movements of his hands or feet or legs, or the necessary letters of his words, to all of which he once had to give minute attention. Perceptive and creative consciousness is thus set free. His mind, in its originality of creation and perceiving, is enabled to pour itself into the instrumental habit it has laid down and infuse it with his spirit, his poetic, musical, or athletic spirit. He may endow his motor instrument with his graces now that it works without his conscious aid.
We approach the problem of heredity from a new direction and with new eyes. Let us picture to ourselves (as has been suggested), instead of a succession of lives, a single life which goes on like the continuous germ-plasm of some biologists, and never grows old or dies. This one continuous life would pass through every stage of the succession of lives from the jelly-speck onwards. One immortal developing creature would accomplish (in our picture) the whole evolution from the original protoplasm to man. And this development would be effected by forming habits and rising step by step in and through and upon them. Is this in fact what actually has been done along the path of the ascent of species? That is the question which at once springs to our lips. Is heredity akin to the habit-memory which is preserved in our brains and bodies? There are men who tell us that the best conception of heredity they can form is something of this kind. They tell us that they think of individual lives as inscribing on germ-cells, by constant repetition, effects of what they have done. They tell us that the habit-memory of ancestral and thus communicated experience enables the baby to pump food into its mouth with that accurate adjustment of muscular means to exterior conditions and the principles of hydrostatics which it always shows. They go even farther and tell us that the development of any embryo from any egg is on the same lines of unfolding the habit-memories essential to its living as it does. Life in progressing from the single cell learnt, they think, by degrees, and consolidated its lessons into motor-habits graven in living stuff. Sometimes they point to the nucleus of the germ-cell as possibly the instrument for preserving these habits for other members of the race as the brain preserves less established habits for the man; sometimes they say that the cytoplasm acts in the same way. And whether we accept these suggestions or reject them we may recognize with some satisfaction that throughout the whole plan there runs the belief (or assumption—what you will) that function is primary, not structure, though structure once organized is the instrument and condition that contributes to the shaping of specific character.