After Pavel Petrovich and Bazarov finish their most explosive argument, Nikolai thinks back on a time when he and his mother had a dispute. He said to her, "Of course you cannot understand me; we belong to two different generations" (10.120). In many ways, this line captures the conflict that lies at the heart of the novel: the thwarted attempts of parents and children to understand one another.
Over the course of the novel, we get to peek into a number of different family circles. First, we see the home of the Kirsanovs at Maryino. Later, we get a glimpse into the patchwork family of the Odintsovs. Finally, we see where the conceited young Bazarov grew up, and we are introduced to his proud parents. The title of the novel moves our focus to these family situations, with a specific emphasis on the relations between fathers and their children.
In the character of Bazarov, we find a young man who, above all, wants to be original. When Madame Kukshin asks him if he agrees with the French anarchic thinker Proudhon, he says, "I share no one's ideas: I have my own" (13.50). As the novel goes on, it becomes clear that part of Bazarov's nihilistic philosophy is borne of his own insecurities. He imagines himself destined for greatness and thus does everything he can to define himself separately from his parents and all those who went before him. Ironically, then, the more the old generation tries to understand him, the more he seeks to make himself incomprehensible.
By contrast, Arkady has a great deal of sympathy for his father. The idea of settling down to a farming life at Maryino is attractive to him, and, though he is temporarily under the influence of Bazarov, he will eventually swing back and return to his family circle. Bazarov seems to regard this behavior as a sort of failure; to him it's equivalent to forfeiting in a fight, to giving up one's place in some general revolutionary struggle. Yet everyone else is happy to find middle ground, a place of recognition.
At the end of the novel, it's worth noting that the stories of most characters end happily. Arkady marries Katya; Nikolai marries Fenichka; Anna Sergeyevna finds a husband who might bring her something like love. Yet Bazarov, the central character of the story, spirals downward for the second half of the book. For awhile it seems that he is on top of the world. Yet, the end result of all his renouncing is that he is extremely isolated. Even before he gets typhus, we get the sense that he won't escape from his despair. As in most tragedies, the hero has a fatal flaw that eventually leads to his downfall. In Bazarov's case, the flaw is quite clear: his obscene pride.
Yet the novel is not pessimistic, and, despite its tragic end, the narrator insists on striking a positive chord in the last sentence. No matter how much the force of Bazarov's personality has drawn us in; the narrator feels compelled to offer a commentary on the story he has told and to refute Bazarov's nihilism. He says, "However passionate, sinful and rebellious the heart hidden in the tomb, the flowers growing over it peep at us serenely with their innocent eyes; they speak to us not only of eternal peace, of the vast repose of 'indifferent' nature: they tell us, too, of everlasting reconciliation and of life which has no end" (28.12).