Life is a language in which certain truths are conveyed to us; if we could learn them in some other way, we should not live.

Thus also every keen pleasure is an error and an illusion, for no attained wish can give lasting satisfaction.

That arithmetic is the basest of all mental activities is proved by the fact that it is the only one that can be accomplished by a machine.

You can do what you will, but in any given moment of your life you can will only one definite thing and absolutely nothing other than that one thing.

Mensch kann tun was er will; er kann aber nicht wollen was er will. (One can choose what to do, but not what to want.)

Style is what gives value and currency to thoughts.

The principle of contradiction establishes merely the agreement of concepts, but does not itself produce concepts.