And if ever you need encouragement, remember at least two sober facts which nobody can rationally deny: that you are a new and unique living force in nature, and that you can, by taking thought and pursuing it, become more and more intensely alive.

Readers of Darwin's life, for instance, and particularly of the published correspondence of Darwin, are henceforth naturalists in the making. Ever afterwards they are Darwins on a small scale, seeing animals and plants in an entirely different light and with a correspondingly keener interest.