We have no organ at all for knowledge, for truth: we know (or believe or imagine) precisely as much as may be useful in the interest of the human herd, the species: and even what is here called usefulness is in the end only a belief, something imagined and perhaps precisely that most fatal piece of stupidity by which we shall one day perish.

Many brief follies-that is what you call love. And your marriage puts an end to many brief follies, with a single long stupidity.

The bite of conscience, like the bite of a dog into a stone, is a stupidity.

To forget one's purpose is the commonest form of stupidity.

Every virtue inclines to stupidity, every stupidity to virtue; "stupid to the point of sanctity," they say in Russia.

It is in the nature of things that joy arises in a person free from remorse.