Intolerance is the most socially acceptable form of egotism, for it permits us to assume superiority without personal boasting.

A famously wise old man in a village was once asked how he came by his wisdom. "I got it from my good judgment," he answered. And where did his good judgment come from? "I got it from my bad judgment."

The pessimist sees only the tunnel; the optimist sees the light at the end of the tunnel; the realist sees the tunnel and the light - and the next tunnel.

An idealist believes the short run doesn't count. A cynic believes the long run doesn't matter. A realist believes that what is done or left undone in the short run determines the long run.

It's surprising how many persons go through life without ever recognizing that their feelings toward other people are largely determined by their feelings toward themselves, and if you're not comfortable within yourself, you can't be comfortable with others.

Isolation always perverts; when a man lives only among his own sort, he soon begins to believe that his sort are the best sort. This attitude breeds both the arrogance of the conservative and the bitterness of the radical.

Ignorance per se is not nearly as dangerous as ignorance of ignorance.