I regret my disbelief in God.

An experiment not worth doing is not worth doing well.

When asked to make the formal declaration that I did not intend to overthrow the Constitution of the United States, I was fool enough to reply that I had no such purpose, but that were I to do it by mistake I should be inexpressibly contrite.

It is the great glory as well as the great threat of science that everything which is in principle possible can be done if the intention to do it is sufficiently resolute.

If a person is A) poorly, B) receives treatment intended to make him better, and C) gets better, then no power of reasoning known to medical science can convince him that it may not have been the treatment that restored his health.

Scientists are people of very dissimilar temperaments doing different things in very different ways. Among scientists are collectors, classifiers and compulsive tidiers-up; many are detectives by temperament and many are explorers; some are artists and others artisans. There are poet-scientists and philosopher-scientists and even a few mystics.

A scientist is no more a collector and classifier of facts than a historian is a man who complies and classifies a chronology of the dates of great battles and major discoveries.