"I know more of the world than you do," [Anna] said. "I know how men like Stiva look at it. You speak of his talking of you with her. That never happened. Such men are unfaithful, but their home and wife are sacred to them. Somehow or other these women are still looked on with contempt by them, and do not touch on their feeling for their family. They draw a sort of line that can't be crossed between them and their families. I don't understand it, but it is so." (1.19.47)
He was so far from conceiving of love for woman apart from marriage that he positively pictured to himself first the family, and only secondarily the woman who would give him a family. His ideas of marriage were, consequently, quite unlike those of the great majority of his acquaintances, for whom getting married was one of the numerous facts of social life. For Levin it was the chief affair of life, on which its whole happiness turned. And now he had to give up that. (1.27.3)
Vronsky heard with pleasure this light-hearted prattle of a pretty woman, agreed with her, gave her half-joking counsel, and altogether dropped at once into the tone habitual to him in talking to such women. In his Petersburg world all people were divided into utterly opposed classes. One, the lower class, vulgar, stupid, and, above all, ridiculous people, who believe that one husband ought to live with the one wife whom he has lawfully married; that a girl should be innocent, a woman modest, and a man manly, self-controlled, and strong; that one ought to bring up one's children, earn one's bread, and pay one's debts; and various similar absurdities. This was the class of old-fashioned and ridiculous people. But there was another class of people, the real people. To this class they all belonged, and in it the great thing was to be elegant, generous, plucky, gay, to abandon oneself without a blush to every passion, and to laugh at everything else.
For the first moment only, Vronsky was startled after the impression of a quite different world that he had brought with him from Moscow. But immediately as though slipping his feet into old slippers, he dropped back into the light-hearted, pleasant world he had always lived in. (1.34.16-17)