Philosophy can be compared to some powders that are so corrosive that, after they have eaten away the infected flesh of a wound, they then devour the living flesh, rot the bones, and penetrate to the very marrow. Philosophy at first refutes errors. But if it is not stopped at this point, it goes on to attack truths. And when it is left on its own, it goes so far that it no longer knows where it is and can find no stopping place.

I get up and retire when I wish. I go out if I wish and I do not go out if I do not desire to do so, except for the two days on which I give lectures.

It has been asserted, that a moral Atheist would be a monster beyond the power of nature to create: I reply, that it is not more strange for an Atheist to live virtuously, than for a Christian to abandon himself to crime! If we believe the last kind of monster, why dispute the existence of the first?

One must be stark mad, to believe that mankind can subsist without magistrates.

It is thus tolerance that is the source of peace, and intolerance that is the source of disorder and squabbling.

I am a good Protestant, and in the full sense of the term, for from the bottom of my soul, I protest against everything that is said, and everything that is done.

I know too much to be a sceptic and too little to be a dogmatist.