Every man can educate himself. It's shameful to put one's mind into the hands of those whom you wouldn't entrust with your money. Dare to think for yourself.

A circumstance which has always appeared wonderful to me, is that such sublime discoveries should have been made by the sole assistance of a quadrant and a little arithmetic.

It would be very singular that all nature, all the planets, should obey eternal laws, and that there should be a little animal five feet high, who, in contempt of these laws, could act as he pleased, solely according to his caprice.

It is better to risk saving a guilty man than to condemn an innocent one.

Of all religions, Christianity is without a doubt the one that should inspire tolerance most

Constant happiness is the philosopher's stone of the soul.

I know of nothing more laughable than a doctor who does not die of old age.