You risk just as much in being credulous as in being suspicious.

A thing is not proved just because no one has ever questioned it. What has never been gone into impartially has never been properly gone into. Hence scepticism is the first step toward truth. It must be applied generally, because it is the touchstone.

The bad gives rise to the good, the good inspires the better, the better produces the excellent, the excellent is followed by the bizarre

When we know to read our own hearts, we acquire wisdom of the heartsof others.

You live as if you were destined to live forever, no thought of your frailty ever enters your head, of how much time has already gone by you take no heed. You squander time as if you drew from a full and abundant supply, so all the while that day which you bestow on some person or thing is perhaps your last. You have all the fears of mortals and all the desires of immortals… What foolish forgetfulness of mortality to defer wise resolutions to the fiftieth or sixtieth year, and to intend to begin life at a point to which few have attained.

There is only one virtue, justice; only one duty, to be happy; only one corollary, not to overvalue life and not to fear death.

It is said that desire is a product of the will, but the converse is in fact true: will is a product of desire.