“An idea that is not dangerous is unworthy of being called an idea at all.”

“All great ideas are dangerous.”

“I want to be good. I can't bear the idea of my soul being hideous.”

“We have quite the same ideas. No; I think our ideas are quite different. But he has been most pleasant.”

“The value of an idea has nothing to do with the honesty of the man expressing it.”

“Any preoccupation with ideas of what is right or wrong in conduct shows an arrested intellectual development.”

“One knows so well the popular idea of health: the English country gentleman galloping after a fox - the unspeakable in full pursuit of the unbeatable.”