Happiness is not the portion of man.

The discovery of what is true and the practice of that which is good are the two most important aims of philosophy.

Stand upright, speak thy thoughts, declare The truth thou hast, that all may share; Be bold, proclaim it everywhere: They only live who dare.

The best way to be boring is to include everything.

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.

If you wish to converse with me, define your terms.

This self-love is the instrument of our preservation; it resembles the provision for the perpetuity of mankind: it is necessary, it is dear to us, it gives us pleasure, and we must conceal it.