Honest unaffected distrust of human abilities under all circumstances is the surest sign of strength of mind.

I cannot say whether things will get better if we change; what I can say is they must change if they are to get better.

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

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.

In every man there is something of all men.

He swallowed a lot of wisdom, but all of it seems to have gone down the wrong way.

We are obliged to regard many of our original minds as crazy at least until we have become as clever as they are.