Any useful logic must concern itself with Ideas with a fringe of vagueness and a Truth that is a matter of degree.

The world of the future will be an even more demanding struggle against the limitations of our intelligence, not a comfortable hammock in which we can lie down to be waited upon by our robot slaves.

A painter like Picasso, who runs through many periods and phases, ends up by saying all those things which are on the tip of the tongue of the age to say, and finally sterilizes the originality of his contemporaries and juniors.

The modern physicist is a quantum theorist on Monday, Wednesday, and Friday, and a student of gravitational relativity on Tuesday, Thursday, and Saturday. On Sunday, he is praying... that someone will find the reconciliation between the two views.

The advantage is that mathematics is a field in which one's blunders tend to show very clearly and can be corrected or erased with a stroke of the pencil.

the science of control and communication in the animal and the machine

There is one quality more important than know-how.... This is know-how by which we determine not only how to accomplish our purposes, but what our purposes are to be.