Though they are close friends for most of the novel, seeking out each other's company and placing full trust in one another, Pierre and Andrei also serve as foils for one another. The stark differences in their characters and attitudes are reflected in a conversation they have after the death of Lise and Pierre's separation from Hélène:
“You’ll be seeing my sister, Princess Marya. You’ll get along well with her,” [Prince Bolkonsky] said. “Maybe you’re right for yourself,” he went on after a brief pause, “but each man lives in his own way: you lived for yourself and you say with that you almost ruined your life, and knew happiness only when you began to live for others. But I experienced the opposite. I used to live for glory. (What is glory? The same as love for others, the desire to do something for them, the desire for their praise.) So I lived for others and ruined my life [...]"
Earlier, a disillusioned and world-weary Prince Andrei claimed that helping others through, for example, charity, does not contribute to one's own happiness. The relatively idealistic Pierre, however, is shocked to hear his friend speak with such cynicism. Prince Andrei, in response, acknowledges that they have learned the opposite lessons from their divergent experiences: where Pierre feels that he almost "ruined" his life by living only for himself, Andrei feels, instead, that his attempt to live "for others" has "ruined" his life. Where Andrei tends to be suspicious and critical of others, Pierre throws himself into public work in the wake of his failed marriage. Though this quote underscores how the two men are foils for one another, it also emphasizes their shared search for a settled view of life's meaning, which both pursue throughout the novel.