One could count on one's fingers the number of scientists throughout the world with a general idea of the history and development of their particular science: there is none who is really competent as regards sciences other than his own. As science forms an indivisible whole, one may say that there are no longer, strictly speaking, scientists, but only drudges doing scientific work.

All the tragedies which we can imagine return in the end to the one and only tragedy: the passage of time.

In struggling against anguish one never produces serenity; the struggle against anguish only produces new forms of anguish.

Patriotism is idolatry of the self.

Two forces rule the universe: light and gravity.

The joy of learning is as indispensable in study as breathing is in running. Where it is lacking there are no real students, but only poor caricatures of apprentices who, at the end of their apprenticeship, will not even have a trade.

Men owe us what we imagine they will give us. We must forgive them this debt.