The guiding motto in the life of every natural philosopher should be, seek simplicity and distrust it.

Some of the finest moral intuitions come to quite humble people. The visiting of lofty ideas doesn't depend on formal schooling.

The defense of morals is the battle-cry which best rallies stupidity against change.

Faith in the possibility of science, generated antecedently to the development of modern scientific theory, is an unconscious derivative from medieval theology.

Inventive genius requires pleasurable mental activity as a condition for its vigorous exercise

The only use of a knowledge of the past is to equip us for the present. The present contains all that there is. It is holy ground; for it is the past, and it is the future.

Learning is often spoken of as if we are watching the open pages of all the books which we have ever read, and then, when occasion arises, we select the right page to read aloud to the universe.