“Those who cannot change their minds cannot change anything.”

“Progress is impossible without change; and those who cannot change their minds cannot change anything.”

“He who can, does. He who cannot, teaches. ”

“Those who talk most about the blessings of marriage and the constancy of its vows are the very people who declare that if the chain were broken and the prisoners left free to choose, the whole social fabric would fly asunder. You cannot have the argument both ways. If the prisoner is happy, why lock him in? If he is not, why pretend that he is?”

“Decency cannot be discussed without indecency!”

“What you are to do without me I cannot imagine.”

“The liar's punishment is, not in the least that he is not believed, but that he cannot believe anyone else.”