There are two lives, the natural and the spiritual, and we must lose the one before we can participate in the other.

'Pure experience' is the name I gave to the immediate flux of life which furnishes the material to our later reflection with its conceptual categories.

A good hypothesis in science must have other properties than those of the phenomenon it is immediately invoked to explain, otherwise it is not prolific enough.

It is only in the lonely emergencies of life that our creed is tested: then routine maxims fail, and we fall back on our gods.

Democracy is still upon its trial. The civic genius of our people is its only bulwark.

A man has as many social selves as there are individuals who recognize him.

Round about the accredited and orderly facts of every science there ever floats a sort of dust-cloud of exceptional observations, of occurrences minute and irregular and seldom met with, which it always proves more easy to ignore than to attend to... Anyone will renovate his science who will steadily look after the irregular phenomena, and when science is renewed, its new formulas often have more of the voice of the exceptions in them than of what were supposed to be the rules.