A man is as much affected pleasurably or painfully by the image of a thing past or future as by the image of a thing present.

All laws which can be broken without any injury to another, are counted but a laughing-stock, and are so far from bridling the desires and lusts of men, that on the contrary they stimulate them.

Many errors, of a truth, consist merely in the application of the wrong names of things. For if a man says that the lines which are drawn from the centre of the circle to the circumference are not equal, he understands by the circle, at all events for the time, something else than mathematicians understand by it.

True piety for the universe but no time for religions made for man's convenience.

The safest way for a state is to lay down the rule that religion is comprised solely in the exercise of charity and justice, and that the rights of rulers in sacred, no less than in secular matters, should merely have to do with actions, but that every man should think what he likes and say what he thinks.

Man can, indeed, act contrarily to the decrees of God, as far as they have been written like laws in the minds of ourselves or the prophets, but against that eternal decree of God, which is written in universal nature, and has regard to the course of nature as a whole, he can do nothing.

Men will find that they can ... avoid far more easily the perils which beset them on all sides by united action.

Desire is the essence of a man.

The proper study of a wise man is not how to die but how to live.