- "Why do you not judge for yourselves what is right?"
- "I do not believe in the immortality of the individual, and I consider ethics to be an exclusively human concern without any superhuman authority behind it."
- "The Christian religion has been and still is the principal enemy of moral progress in the world."
- "I call Christianity the one great curse, the one great intrinsic depravity, the one great instinct of revenge, for which no means are venomous enough, or secret, subterranean and small enough -- I call it the one immortal blemish upon the human race."
See also: Ethics