Your brother Ivan writes theological articles in joke, for some idiotic, unknown motive of his own, though he’s an atheist, and he admits it’s a fraud himself—that’s your brother Ivan. He’s trying to get Mitya’s betrothed for himself, and I fancy he’ll succeed, too. And what’s more, it’s with Mitya’s consent. For Mitya will surrender his betrothed to him to be rid of her, and escape to Grushenka.
