The art of thinking is also the art of believing, because no human being at the present stage of civilization could safely call all his individual and social beliefs into question again or submit them to his conscience. To change all one's opinions is a mental diversion which requires leisure for its indulgence. In order to live a life of action, man must accept most of the moral, social, and religious laws which have been recognized as necessary by his predecessors.

Un Art de Vivre (The Art of Living) (1939) - The Art of Thinking