People who have read a good deal rarely make great discoveries. I do not say this in excuse of laziness, but because invention presupposes an extensive independent contemplation of things.

It is a great shame; most of our words are misused tools / which often still smell of the mud in which previous owners / desecrated them.

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.

Libraries can in general be too narrow or too wide for the soul.

Whenever he composes a critical review, I have been told, he gets an enormous erection.

The great trick of regarding small departures from the truth as the truth itself - on which is founded the entire integral calculus - is also the basis of our witty speculations, where the whole thing would often collapse if we considered the departures with philosophical rigour.

There are people who think that everything one does with a serious face is sensible.