I believe, indeed, that overemphasis on the purely intellectual attitude, often directed solely to the practical and factual, in our education, has led directly to the impairment of ethical values. I am not thinking so much of the dangers with which technical progress has directly confronted mankind, as of the stifling of mutual human considerations by a 'matter-of-fact' habit of thought which has come to lie like a killing frost upon human relations. Without 'ethical culture' there is no salvation for humanity.

[Max Planck] was one of the finest people I have ever known... but he really didn't understand physics, [because] during the eclipse of 1919 he stayed up all night to see if it would confirm the bending of light by the gravitational field. If he had really understood [general relativity], he would have gone to bed the way I did

[There is] a duty in refusing to cooperate in any undertaking that violates the Constitutional rights of the individual. This holds in particular for all inquisitions that are concerned with the private life and the political affiliations of the citizens.

The mathematician knows some things, no doubt, but not those things one usually wants to get from him.

If you want to find out anything from the theoretical physicists about the methods they use, I advise you to stick closely to one principle: don't listen to their words, fix your attention on their deeds. To him who is a discoverer in this field the products of his imagination appear so necessary and natural that he regards them, and would like to have them regarded by others, not as creations of thought but as given realities.

I believe that a simple and unassuming manner of life is best for everyone, best both for the body and the mind.

The question that drives me hazy is whether it is I or others who is crazy.