To dispose a soul to action we must upset its equilibrium.

One word characterizes the most strenuous of the efforts for the advancement of science that I have made perservereingly during fifty-five years; that word is failure

The aspiration toward freedom is the most essentially human of all human manifestations.

Totalitarianism spells simplification: an enormous reduction in the variety of aims, motives, interests, human types, and, above all, in the categories and units of power.

The search for happiness is one of the chief sources of unhappiness.

When cowardice is made respectable, its followers are without number both from among the weak and the strong; it easily becomes a fashion.

Man's chief goal in life is still to become and stay human, and defend his achievements against the encroachment of nature.