Only in thought is man a God; in action and desire we are the slaves of circumstance.

Zeno was concerned with three problems... These are the problem of the infinitesimal, the infinite, and continuity.

All the time that he can spare from the adornment of his person, he devotes to the neglect of his duties.

There is a possibility in human minds of something mysterious as the night-wind, deep as the sea, calm as the stars, and strong as Death, a mystic contemplation, the “intellectual love of God.” Those who have known it cannot believe in wars any longer, or in any kind of hot struggle. If I could give to others what has come to me in this way, I could make them too feel the futility of fighting. But I do not know how to communicate it: when I speak, they stare, applaud, or smile, but do not understand.

All forms of fear produce fatigue.

Measures of sterilization should, in my opinion, be very definitely confined to persons who are mentally defective

The demand for certainty is one which is natural to man, but is nevertheless an intellectual vice. So long as men are not trained to withhold judgment in the absence of evidence, they will be led astray by cocksure prophets, and it is likely that their leaders will be either ignorant fanatics or dishonest charlatans. To endure uncertainty is difficult, but so are most of the other virtues.