Pushkin begins the chapter by condemning the cold, manipulative game of love, one which Onegin had once been so adept at but now intensely despises. With this thought in mind, Onegin delivers a curt, didactic rejection to Tatyana, citing her naivety and the unpleasantness of marriage, which he considers restrictive and boring. Nevertheless, he does acknowledge that Tatyana has stirred a long dormant feeling within him but also says that he is not worthy of her goodness. Beset by unhappiness, Tatyana begins to waste away.
Pushkin then turns to Lensky's rosy love for Olga and the many poems he writes in her album. Although, as Pushkin relates, the album is a social convention with all the attendant disingenuousness, Lensky nevertheless writes with true feeling and unusual poetic ardor. Olga, however, does not read what her impassioned lover writes.
At his estate, Onegin whiles away his days in idleness. Though it is summer, it is still the far north and snow begins to fall, turning the landscape even more featureless and boring for Onegin. To his delight, Lensky visits one night, and the two drink. Lensky mentions that Onegin has been invited to Tatyana's name-day celebration and assuages his friend's concern that there will be a large local crowd, telling him that it will only be a family gathering.
The chapter ends with a foreboding reflection on Lensky's youthful ignorance of marriage's boredom and the shallowness or lack of Olga's love for him.
The chapter's epigraph, "Morality is in the nature of things," seems to refer to Onegin's moralizing speech ("Again he'd done his moral duty") to Tatyana in the beginning of the chapter (IV.18). As though in the mind of Onegin while recollecting his past, Pushkin once again criticizes the crafty and dissembling ladies of high society, just as he had done in the chapter before to illuminate Tatyana's simplicity and honesty in contrast.
That done, Pushkin returns to the scene where he left off, in which Onegin gives his reply to Tatyana's letter, rejecting her love for three reasons: the undesirability of married life, his own unworthy position, and the ease with which young girls find new love.
The first reason is one which Pushkin mentions again at the end of the chapter in Lensky's case; both Tatyana and Lensky love with the complacency of youth and without the disaffectedness of the older Onegin. It seems a fair point to make, but, as Onegin himself had noted while thinking of Lensky, it is not kind to force such practicalities upon the inexperienced.
In describing himself as "A coldly jealous, selfish brute" for his second reason, Onegin is actually quite accurate, though especially because, as he does not realize, his own self-deprecation only takes himself into account and ignores the feelings of Tatyana (IV.15). As Pushkin will later call her, Onegin thinks he may someday call her "my ideal," but considers himself unworthy of her due to his own unhappiness and lack of empathy (IV.13). Onegin's line, "Can Fate indeed be so unkind?" will later be recalled in Tatyana's own speech to him at the end of the novel when their positions are reverse, in which she submits herself to Fate (IV. 15).
Onegin also draws a contrast between himself, past his days of youth as he sees it, and the still young Tatyana, thinking that by taking "restraint and reason" as he now possesses that she will find happiness, albeit with some other man (IV.16). Here there is a clear clash between the emotionalism of Tatyana and the rationalism of Onegin, parallel the poetry-vs-prose conflict between Lensky and Onegin. As in the overall structure of the novel-in-verse, it is not that one side triumphs and the other loses; each has its virtues and faults, and in the end they will come together in some way. Although Lensky dies before he can change and Onegin is left off abruptly at the end, Tatyana has clearly gained the kind of mature control over her emotions that Onegin advised, though hers is not as melancholic and disparaging of her past as Onegin's.
Deeply hurt by this rejection, Tatyana loses sleep, and her health begins to decline, just as Onegin later will when Tatyana does not respond to his letters and advances. Pushkin himself can't "help but care / And feel a deep commiseration" for Tatyana, and even says "I love my dear Tatyana so!" (IV.24). Interestingly, the "my" the Pushkin uses could have the meaning of Pushkin the character loving Tatyana, but in this case it seems much more likely that it is Pushkin the narrator loving the character he has created, as he mentions thinking up Tatyana and Onegin in the last stanza of the novel.
With this, one of his many authorial interventions, Pushkin deftly turns the focus of the narrative to the happier couple, Lensky and Olga. Once again, the empty practices of the aristocrats are brought up and criticized by Pushkin in order to show the honesty of feeling of his characters; in this case, Lensky writes true verses of true love in Olga's album, despite the ossified convention of the album itself.
In the lines, "No madrigals of pure convention /Does Olga's Lensky thus compose; /His pen breathes love, not pure invention /Or sparkling wit as clear as prose," Pushkin the approach to poetry that he himself took in his youth (IV.31). Lensky's honest poetic style is one and the same in his heart with his honest love and generally honest way of living, a connection between literature and life.
Olga, however, does not show as much ardor as Lensky does, whether in poetry or love. Pushkin mentions that Lensky would have written odes, "But Olga didn't read the things" (IV.34). Indeed, it seems that Onegin's initial judgment in the last chapter was correct, and Lensky himself comes to realize the simplemindedness of his lover when he visits her the day before his duel. Nevertheless, Lensky himself is a simple person, and so he does not despair that Olga lacks the emotional depth of his sister.
Perhaps one of the most delightful lines in the novel is "The frost already cracks and crunches; /The fields are silver where they froze… /(And you, good reader, with your hunches, / Expect the rhyme, so take it -- Rose!)" (IV.42). Here, much more clearly than anywhere else, Pushkin shows his awareness of, and parodies, the reader's presence and literary precedents. Such frequent and lighthearted interruptions by the author make the novel quite unlike any other, one that is constantly aware of its position as a work of fiction.
In the last stanza, Pushkin returns once again to the contrast between Lensky and Onegin: simple love and experienced disaffection. As he says in several other such reflections, Pushkin praises the blitheness of the young and pities the torments of the mature.