"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."

“Our poor bodies have strength and resources that we learn to know only when we are in the gravest situations.”

“The art of resting is a part of the art of working. A man who is tired and greatly in need of rest cannot do any good work. We are all familiar with those terrible mornings after sleepless nights when our brains refuse to function. It would be useless then to attempt to apply the principles of the art of working. Those principles presuppose mind and body to be in good condition. The human organism cannot live without alternating work and rest.”

“Almost all of our fellow-beings deceive us, but a few of us have known the joy of meeting a woman or a man whose sincerity and frankness were genuine, who in almost every situation has behaved according to our wishes, and who in our most difficult moments has not forsaken us. Those few are familiar with that marvelous feeling: confidence. With at least one person they are able for a little while each day to lift the heavy visor of their helmets, breathe freely, and show their faces and their hearts without fear.”

“Marriage makes a man more vulnerable by doubling the expanse of sail exposed to the tempests of social life.”

“To amuse is not to teach. The object of teaching is to erect a framework of knowledge in a child's mind and gradually to bring the child as near as may be to the average level of intelligence. Later in life the facts taught by experience and new discoveries will add themselves to this framework. It is wrong to attempt to upset this natural order and to appeal to a child's mind by diverting it with the spectacle of modern life. Teaching by means of pictures, radio, and the cinema is in itself ineffective; these methods must not be used unless they involve some effort or special enthusiasm. That which is learned without difficulty is soon forgotten, and for the same reason, oral instruction which does not require the pupil's personal participation is almost always rather useless. Eloquence slides in and out of young minds. To listen is not to work.”

“The aspiring author, whether genius or not, should never let a day pass without writing at least a few lines.”