We are ready to die for an opinion but not for a fact

A great man's greatest good luck is to die at the right time.

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

Language was invented to ask questions. Answers may be given by grunts and gestures, but questions must be spoken. Humanness came of age when man asked the first question. Social stagnation results not from a lack of answers but from the absence of the impulse to ask questions.

It would be difficult to exaggerate the degree to which we are influenced by those we influence.

There is no loneliness greater than the loneliness of a failure. The failure is a stranger in his own house.

The remarkable thing is that it is the crowded life that is most easily remembered. A life full of turns, achievements, disappointments, surprises, and crises is a life full of landmarks. The empty life has even its few details blurred, and cannot be remembered with certainty.