To be content with life or to live merrily, rather all that is required is that we bestow on all things only a fleeting, superficial glance; the more thoughtful we become the more earnest we grow.

To err is human also in so far as animals seldom or never err, or at least only the cleverest of them do so.

Man is to be found in reason, God in the passions.

He marvelled at the fact that the cats had two holes cut in their fur at precisely the spot where their eyes were.

A good method of discovery is to imagine certain members of a system removed and then see how what is left would behave: for example, where would we be if iron were absent from the world: this is an old example.

Non cogitant, ergo non sunt.

He who is enamored of himself will at least have the advantage of being inconvenienced by few rivals.