In the great depression, things could only be set right by causing the idle plant to work again . . . Roosevelt . . . spent billions of public money and created a huge public debt, but by so doing he revived production and brought his country out of the depression. Businessmen, who in spite of such a sharp lesson continued to believe in old-fashioned economics, were infinitely shocked, and although Roosevelt saved them from ruin, they continued to curse him and to speak of him as 'the madman in the White House.' . . . [It's one more] striking example of inability to learn from experience.

I think that there is far too much work done in the world, that immense harm is caused by the belief that work is virtuous, and that what needs to be preached in modern industrial countries is quite different from what always has been preached.

I would never die for my beliefs because I might be wrong.

Ordinary language is totally unsuited for expressing what physics really asserts, since the words of everyday life are not sufficiently abstract. Only mathematics and mathematical logic can say as little as the physicist means to say.

Men have physical needs, and they have emotions. While physical needs are unsatisfied, they take first place; but when they are satisfied, emotions unconnected with them become important in deciding whether a man is to be happy or unhappy.

As for earthquakes, though they were still formidable, they were so interesting that men of science could hardly regret them.

Affection cannot be created; it can only be liberated.