History is only a value of relation.

Nature, to be commanded, must be obeyed. The imagination must be given not wings but weights.

At best, the renewal of broken relations is a nervous matter.

One does every day and without a second thought, what at another time would be the event of a year, perhaps of a life.

Absolute liberty is absence of restraint; responsibility is restraint; therefore, the ideally free individual is responsible to himself.

Analogies are figures intended to serve as fatal weapons if they succeed, and as innocent toys if they fail.

Mathematicians practice absolute freedom.