Optimism leads to success; pessimism leads to defeat.

A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty.

A pessimist is a man who thinks everybody is as nasty as himself, and hates them for it.

Every man should ask himself each day whether he is not too readily accepting negative solutions.

Let me declare expressly that in the days when mankind was not yet ashamed of its cruelty, life on earth was more cheerful than it is now that pessimists exist.

A pessimist is a well-informed optimist.