“Dare to think for yourself.”

“Think for yourself and let others enjoy the privilege of doing so too.”

“No problem can stand the assault of sustained thinking.”

“The greatest consolation in life is to say what one thinks.”

“Men will always be mad, and those who think they can cure them are the maddest of all.”

“Divert yourself, and ask each passenger to tell his story, and if there is one of them all who has not cursed his existence many times, and said to himself over and over again that he was the most miserable of men, I give you permission to throw me head-first into the sea.”

“Madness is to think of too many things in succession too fast, or of one thing too exclusively.”