"The secret of realizing the greatest fruitfulness and the greatest enjoyment of existence is to live dangerously!"

"The demand to be loved is the greatest of all arrogant presumptions."

"A man who wants to do great things must know how to suffer."

"The strongest and most evil spirits have so far advanced humanity the most: they have always rekindled the slumbering passions."

"Man's maturity: to have reacquired the seriousness that one had as a child at play."