Fyodor Dostoyevsky quote cannibalism
“If you were to destroy in mankind the belief in immortality, not only love but every living force maintaining the life of the world would at once be dried up. Moreover, nothing then would be immoral, everything would be permissible, even cannibalism.”
Pyotr Miusov, summarizing an argument made by Ivan at a social gathering
The Brothers Karamazov (1879–1880)
https://www.goodreads.com/quotes/326870-ivan-hold-your-tongue-or-i-ll-kill-you-the-devil
As soon as men have all of them denied God — and I believe that period, analogous with geological periods, will come to pass — the old conception of the universe will fall of itself without cannibalism, and, what’s more, the old morality, and everything will begin anew. Men will unite to take from life all it can give, but only for joy and happiness in the present world. Man will be lifted up with a spirit of divine Titanic pride and the man-god will appear.
…
But as, owing to man’s inveterate stupidity, this cannot come about for at least a thousand years, everyone who recognises the truth even now may legitimately order his life as he pleases, on the new principles. In that sense, ‘all things are lawful’ for him. What’s more, even if this period never comes to pass, since there is anyway no God and no immortality, the new man may well become the man-god, even if he is the only one in the whole world, and promoted to his new position, he may lightheartedly overstep all the barriers of the old morality of the old slaveman, if necessary. There is no law for God. Where God stands, the place is holy. Where I stand will be at once the foremost place… ‘all things are lawful’ and that’s the end of it!
Fyodor Dostoyevsky, The Brothers Karamazov