Let us have Men, Men who will say a word to their souls and keep it — keep it not when it is easy, but keep it when it is hard — keep it when the storm roars and there is a white-streaked sky and blue thunder before, and one's eyes are blinded and one's ears deafened with the war of opposing things; and keep it under the long leaden sky and the gray dreariness that never lifts. Hold unto the last: that is what it means to have a Dominant Idea, which Circumstance cannot break. And such men make and unmake Circumstance.

The Dominant Idea (1910)