We assume a common sense as the necessary condition of the universal communicability of our knowledge, which is presupposed in every logic and every principle of knowledge that is not one of skepticism.

All human knowledge begins with intuitions, proceeds from thence to concepts, and ends with ideas.

All trades, arts, and handiworks have gained by division of labor... Where the different kinds of work are not distinguished and divided, where everyone is a jack-of-all-trades, there manufactures remain still in the greatest barbarism.

Act in such a way that you will be worthy of being happy.

Sincerity is the indispensable ground of all conscientiousness, and by consequence of all heartfelt religion.

The greatest human quest is to know what one must do in order to become a human being.

The wise man can change his mind; the stubborn one, never.