Morally, a philosopher who uses his professional competence for anything except a disinterested search for truth is guilty of a kind of treachery.

Unrestricted nationalism is, in the long run, incompatible with world peace.

The search for something permanent is one of the deepest of the instincts leading men to philosophy.

Faith: a firm belief for which there is no evidence.

Fear is the parent of cruelty, and therefore it is no wonder if cruelty and religion go hand in hand.

Mathematics, rightly viewed, possesses not only truth, but supreme beauty-a beauty cold and austere ... yet sublimely pure and capable of stern perfection such as only the greatest art can show.

The Stoic assures us that what is happening now will happen over and over again. [If so, Providende would] ultimately grow weary through despair.