The true meaning of a term is to be found by observing what a man does with it, not by what he says about it.

I can see no justification whatever for the attitude which refuses on purely a priori grounds to accept action at a distance ... Such an attitude bespeaks an unimaginativeness, a mental obtuseness and obstinacy.

It is the merest truism, evident at once to unsophisticated observation, that mathematics is a human invention.

Coincidence is what you have left over when you apply a bad theory.

It seems to me that there is a good deal of ballyhoo about scientific method. I venture to think that the people who talk most about it are the people who do least about it. Scientific method is what working scientists do, not what other people or even they themselves may say about it. No working scientist, when he plans an experiment in the laboratory, asks himself whether he is being properly scientific, nor is he interested in whatever method he may be using as method.

The result is that a generation of physicists is growing up who have never exercised any particular degree of individual initiative, who have had no opportunity to experience its satisfactions or its possibilities, and who regard cooperative work in large teams as the normal thing. It is a natural corollary for them to feel that the objectives of these large teams must be something of large social significance.

There is no adequate defense, except stupidity, against the impact of a new idea.