We find that the statements of science are not of what is true and what is not true, but statements of what is known with different degrees of certainty: "It is very much more likely that so and so is true than that it is not true".

One of the ways of stopping science would be only to do experiments in the region where you know the law. But experimenters search most diligently, and with the greatest effort, in exactly those places where it seems most likely that we can prove our theories wrong. In other words, we are trying to prove ourselves wrong as quickly as possible, because only in that way can we find progress.

There are thousands of years in the past, and there is an unknown amount of time in the future. There are all kinds of opportunities, and there are all kinds of dangers.

Scientific views end in awe and mystery, lost at the edge in uncertainty, but they appear to be so deep and so impressive that the theory that it is all arranged as a stage for God to watch man's struggle for good and evil seems inadequate.

Work as hard and as much as you want to on the things you like to do the best.

Teach principles not formulas.

The real problem in speech is not precise language. The problem is clear language.