The Kreutzer Sonata is and was Lev Tolstoy's most controversial work, which is saying a lot. Its protagonist reflects on how he came to kill his wife in a jealous rage, and concludes that sex is evil, there is no such thing as Christian marriage, and that everyone should aspire to be chaste even at the expense of the species. "Let it die out", said Tolstoy in defence of his story. "I am no more sorry for the two legged animal than I am for the ichthyosaurs etc. What I care about is that the true life should not die out, the love of creatures that are able to love."

- Independent