A dishonest yes is a no to yourself.

- Byron Katie

No man is sane who does not know how to be insane on proper occasions.

- Henry Ward Beecher

The statistics on sanity are that one out of every four Americans is suffering from some form of mental illness. Think of your three best friends. If they're okay, then it's you.

- Rita Mae Brown

Sanity: that which is within the frame of reference of conventional thought.

- Erich Fromm

Madness is rare in individuals - but in groups, political parties, nations, and eras it's the rule.

- Friedrich Nietzsche

A man who is "of sound mind" is one who keeps the inner madman under lock and key.

- Paul Valery

Sanity is madness put to good uses.

- George Santayana

Sanity and happiness are an impossible combination.

- Mark Twain