The business of the philosopher is well done if he succeeds in raising genuine doubt.

Conservatism clings to what has been established, fearing that, once we begin to question the beliefs that we have inherited, all the values of life will be destroyed.

Wisdom is not to be obtained from textbooks, but must be coined out of human experience in the flame of life.

Inertia is the first law of history, as it is of physics.

Let philosophy resolutely aim to be as scientific as possible, but let her not forget her strong kinship with literature.

It is not impossible to think that the minds of philosophers sometimes act like those of other mortals, and that, having once been determined by diverse circumstances to adopt certain views, they then look for and naturally find reasons to justify these views.

The picture which the philosopher draws of the world is surely not one in which every stroke is necessitated by pure logic.