You need not wonder whether you should have an unreliable person as a friend. An unreliable person is nobody's friend.

Worry is a cloud which rains destruction.

From time to time ponder whether you are unconsciously saying: 'Truth is what I happen to be thinking at this moment.

Better to be safe than to be sorry' is a remark of value only when these are the actual alternatives.

Learn to be as analytical about things of which you are credulous as you are of those which you criticise.

A real secret is something which only one person knows.

Anyone can see that an ass laden with books remains a donkey. A human being laden with the undigested results of a tussle with thoughts and books, however, still passes for wise.