"The eternal silence of these infinite spaces frightens me."

"We are generally more persuaded by the reasons we have ourselves discovered than by those which have been discovered by others."

"To ridicule philosophy is truly to philosophize."

"To be a man is to be an object of scorn to the angels, and of envy to the devils."

"People are generally better persuaded by the reasons which they have themselves discovered than by those which have come into the mind of others."