To know one thing thoroughly would be to know the universe.

A man may not achieve everything he has dreamed, but he will never achieve anything great without having dreamed it first.

Fatalism, whose solving word in all crises of behavior is All striving is vain, will never reign supreme, for the impulse to take life strivingly is indestructible in the race. Moral creeds which speak to that impulse will be widely successful in spite of inconsistency, vagueness, and shadowy determination of expectancy. Man needs a rule for his will, and will invent one if one be not given him.

Science must constantly be reminded that her purposes are not the only purposes and that the order of uniform causation which she has use for, and is therefore right in postulating, may be enveloped in a wider order, on which she has no claim at all.

Religion, whatever it is, is a man's total reaction upon life.

The work that leads to a doctor's degree is a constant temptation to sacrifice one's growth as a man to one's growth as a specialist.

When a thing is new, people say: ‘It is not true.’ Later, when its truth becomes obvious, they say: ‘It is not important.’ Finally, when its importance cannot be denied, they say: ‘Anyway, it is not new.