Yet, if we could think our way anywhere near to that point in regard to man, I doubt not that we should eventually succeed in forging a fresh instrument for controlling the destinies of our species, an instrument perhaps more powerful than education itself--I mean, eugenics, the art of improving the human breed.
To see what race means when considered apart, let us first of all take your individual self, and ask how you would proceed to separate your inherited nature from the nature which you have acquired in the course of living your life.

It is not easy.

Suppose, however, that you had a twin brother born, if indeed that were possible, as like you as one pea is like another.

An accident in childhood, however, has caused him to lose a leg.

So he becomes a clerk, living a sedentary life in an office.