The wise man will be as happy as circumstances permit, and if he finds the contemplation of the universe painful beyond a point, he will contemplate something else instead.

If you wish to be happy yourself, you must resign yourself to seeing others also happy.

Even if the open windows of science at first make us shiver after the cozy indoor warmth of traditional humanizing myths, in the end the fresh air brings vigor, and the great spaces have a splendor of their own.

The Ten Commandments should be headed like an examination paper: No more than six to be attempted.

If you had the power to destroy the world, would you do so?

A priori Logical propositions are such as can be known a priori without study of the actual world.

Man is the product of causes which had no prevision of the end they were achieving; his origin, his growth, his hopes and fears, his loves and beliefs, are but the outcome of accidental collocations of atoms; no fire, no heroism, no intensity of though and feeling, can preserve an individual life beyond the grave.