To gain anything we have longed for is only to discover how vain and empty it is; and even though we are always living in expectation of better things, at the same time we often repent and long to have the past back again.

Whoever wants his judgment to be believed, should express it coolly and dispassionately; for all vehemence springs from the will. And so the judgment might be attributed to the will and not to knowledge, which by its nature is cold.

We seldom speak of what we have but often of what we lack.

The fourfold root of the principle of sufficent reason is "Anything perceived has a cause. All conclusions have premises. All effects have causes. All actions have motives.

Opinion is like a pendulum and obeys the same law.

The brain may be regarded as a kind of parasite of the organism, a pensioner, as it were, who dwells with the body.

The truth can wait, for it lives a long life.