Freedom is absolutely necessary for the progress in science and the liberal arts.

If a man had begun to hate an object of his love, so that love is thoroughly destroyed, he will, causes being equal, regard it with more hatred than if he had never loved it, and his hatred will be in proportion to the strength of his former love.

All happiness or unhappiness solely depends upon the quality of the object to which we are attached by love.

True knowledge of good and evil as we possess is merely abstract or general, and the judgment which we pass on the order of things and the connection of causes, with a view to determining what is good or bad for us in the present, is rather imaginary than real.

Those who wish to seek out the cause of miracles and to understand the things of nature as philosophers, and not to stare at them in astonishment like fools, are soon considered heretical and impious, and proclaimed as such by those whom the mob adores as the interpreters of nature and the gods.

Surely human affairs would be far happier if the power in men to be silent were the same as that to speak.

Schisms do not originate in a love of truth, which is a source of courtesy and gentleness, but rather in an inordinate desire for supremacy.