We hunger for nobility: the rare words and acts that harmonize simplicity and truth.

Sometimes the answer to fear does not lie in trying to explain away the causes, sometimes the answer lies in courage.

No man should escape our universities without knowing how little he knows.

We may anticipate a state of affairs in which two Great Powers will each be in a position to put an end to the civilization and life of the other, though not without risking its own. We may be likened to two scorpions in a bottle, each capable of killing the other, but only at the risk of his own life.

Both the man of science and the man of action live always at the edge of mystery, surrounded by it.

I can't think that it would be terrible of me to say - and it is occasionally true - that I need physics more than friends.

Things which stimulate my curiosity are pretty far removed from the practical and therefore from classification.