When intuition and logic agree, you are always right.

We need not have the loftiest mind to understand that here is no lasting and real satisfaction, that our pleasures are only vanity, that our evils are infinite, and, lastly, that death, which threatens us every moment, must infallibly place us within a few years under the dreadful necessity of being forever either annihilated or unhappy.

Not to be mad is another form of madness

If you want to be a real seeker of truth, you need to, at least once in your lifetime, doubt in, as much as it's possible, in everything.

Man is obviously made for thinking. Therein lies all his dignity and his merit; and his whole duty is to think as he ought.

The property of power is to protect.

Vanity of science. Knowledge of physical science will not console me for ignorance of morality in time of affliction, but knowledge of morality will always console me for ignorance of physical science.