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.

Simultaneous discovery is utterly commonplace, and it was only the rarity of scientists, not the inherent improbability of the phenomenon, that made it remarkable in the past. Scientists on the same road may be expected to arrive at the same destination, often not far apart.

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.

The art of research [is] the art of making difficult problems soluble by devising means of getting at them.

To deride the hope of progress is the ultimate fatuity, the last word in poverty of spirit and meanness of mind.

All scientists know of colleagues whose minds are so well equipped with the means of refutation that no new idea has the temerity to seek admittance. Their contribution to science is accordingly very small.

If a scientist were to cut his ear off, no one would take it as evidence of a heightened sensibility.