Next to worry probably one of the most potent causes of unhappiness is envy.

I once saw a photograph of a large herd of wild elephants in Central Africa Seeing an airplane for the first time, and all in a state of wild collective terror... As, however, there were no journalists among them, the terror died down when the airplane was out of sight.

To a mind of sufficient intellectual power, the whole of mathematics would appear trivial, as trivial as the statement that a four-footed animal is an animal.

Whenever you find yourself getting angry about a difference of opinion, be on your guard; you will probably find, on examination, that your belief is going beyond what the evidence warrants.

An individual human existence should be like a river

The qualities most needed are charity and tolerance, not some form of fanatical faith such as is offered to us by the various rampant isms

Be isolated, be ignored, be attacked, be in doubt, be frightened, but do not be silenced.