"The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt."

"The desire for safety stands against every great and noble enterprise."

"I believe that when I die I shall rot, and nothing of my ego will survive."

"The child thus comes to the conclusion that parents are apt to lie to him. If they lie in one matter, they may lie in another, so that their moral and intellectual authority is destroyed."

"There are three ways of securing a society that shall be stable as regards population. The first is that of birth control, the second that of infanticide or really destructive wars, and the third that…"