To burn always with this hard, gemlike flame, to maintain this ecstasy, is success in life.

I imagine that one of the first forms of behavior, like one of the first signals, may be reduced to this: “Keep me warm.”

If there is a word in the dictionary under any letter from A to Z that I abominate, it is energy.

A first-class man subsists on the matter he destroys.

Will and energy sometimes prove greater than either genius or talent or temperament.

Fire is a natural symbol of life and passion, though it is the one element in which nothing can actually live.

The transition from tenseness, self-responsibility, and worry to equanimity, receptivity, and peace is the most wonderful of all those shiftings of inner equilibrium, those changes of personal center of energy.

Where it is a duty to worship the sun, it is pretty sure to be a crime to examine the laws of heat.