Karenin gives up his son

Oblonsky enters the study with an unaccustomed timidity he refuses to recognise as conscience. Karenin, pacing, hands him an unfinished letter: he sees his presence is distasteful, does not blame her, does not repent of what he did, and submits entirely to her wishes. Oblonsky, choked, argues that Anna is crushed by his generosity and cannot judge her own position, and that the way out is divorce. Karenin has considered it a thousand times and finds it impossible — he will not plead guilty to a fictitious adultery nor let the wife he has forgiven be disgraced; the boy cannot go to an illegitimate household and keeping him would be revenge; and consenting would, as Dolly said, ruin Anna outright, since a church marriage to Vronsky is barred while he lives. He believes none of Oblonsky's arguments and has refutations ready, and still feels the coarse mighty power in them. Then he cries out that he will take the disgrace and give up his son — and feels, under the shame, a joy at the greatness of his own humility.

Karenin's reasons against divorce are the best in the novel and he surrenders anyway — Tolstoy's demonstration that argument does not decide anything here, pressure does. The joy in his own humility is the flaw planted in the forgiveness, and it is what Lydia Ivanovna will feed on. Oblonsky leaves composing a riddle about chemists, which measures what the scene cost him.