Wisdom alone is true ambition's aim, wisdom is the source of virtue and of fame; obtained with labour, for mankind employed, and then, when most you share it, best enjoyed.
True courage is not the brutal force of vulgar heroes, but the firm resolve of virtue and reason.
Periods of tranquility are seldom prolific of creative achievement. Mankind has to be stirred up.
It is the business of the future to be dangerous; and it is among the merits of science that it equips the future for its duties.
If a dog jumps in your lap, it is because he is fond of you; but if a cat does the same thing, it is because your lap is warmer.
Ideas won't keep; something must be done about them.
Fundamental progress has to do with the reinterpretation of basic ideas.
Every really new idea looks crazy at first.
Common sense is genius in homespun.
Civilization advances by extending the number of important operations which we can perform without thinking.