if there's no immortality of the soul, then there's no virtue, and everything is lawful.
 Fyodor Dostoyevsky, The Brothers Karamazov (1880). copy citation

Context

“His face changed, and his lips twitched. “And the problem's a stupid one. It is no good guessing it. Rack your brains—you'll understand it. His article is absurd and ridiculous. And did you hear his stupid theory just now: if there's no immortality of the soul, then there's no virtue, and everything is lawful. (And by the way, do you remember how your brother Mitya cried out: ‘I will remember!’) An attractive theory for scoundrels!— (I'm being abusive, that's stupid.) Not for scoundrels, but for pedantic poseurs, ‘haunted by profound, unsolved doubts.’ He's showing off, and what it all comes to is, ‘on the one hand we cannot but admit’ and ‘on the other it must be confessed!’ His whole theory is a fraud!” source