“What is not started today is never finished tomorrow.”

“Whether one show one's self a man of genius in science or compose a song, the only point is, whether the thought, the discovery, the deed, is living and can live on.”

“A person hears only what they understand.”

“Duty is the demand of the hour.”

“He who cannot draw on three thousand years is living from hand to mouth.”

“The value of a principle is the number of things it will explain.”

“The simplest and most psychologically satisfying explanation of any observed phenomenon is that it happened that way because someone wanted it to happen that way.”

“Now it seems to me that love of some kind is the only possible explanation of the extraordinary amount of suffering that there is in the world.”