There is no greater impediment to progress in the sciences than the desire to see it take place too quickly.

The greatest events occur without intention playing any part in them; chance makes good mistakes and undoes the most carefully planned undertaking. The world's greatest events are not produced, they happen.

First we have to believe, and then we believe.

So-called professional mathematicians have, in their reliance on the relative incapacity of the rest of mankind, acquired for themselves a reputation for profundity very similar to the reputation for sanctity possessed by theologians.

One is rarely an impulsive innovator after the age of sixty, but one can still be a very fine orderly and inventive thinker. One rarely procreates children at that age, but one is all the more skilled at educating those who have already been procreated, and education is procreation of another kind.

It is in the gift for employing all the vicissitudes of life to one's own advantage and to that of one's craft that a large part of genius consists.

If all else fails, the character of a man can be recognized by nothing so surely as by a jest which he takes badly. 

To receive applause for works which do not demand all our powers hinders our advance towards a perfecting of our spirit. It usually means that thereafter we stand still.

He who says he hates every kind of flattery, and says it in earnest, certainly does not yet know every kind of flattery.

Man loves company - even if it is only that of a small burning candle.