The central theme of Crime and Punishment explores the motivations behind immoral actions and examines both the consequences of these actions and the thought processes leading to them. Unlike Dostoevsky's later works, which often incorporate a murder mystery plot, this novel presents a straightforward narrative. It is a psychological study focused on a murderer, his family (whom he genuinely cares for despite his personal struggles), and his acquaintances. Some of the most gripping scenes involve the interactions between the examining magistrate, Porfiry Petrovich, and Raskolnikov. As Raskolnikov becomes increasingly anxious, it becomes apparent early on that Porfiry suspects him. When Raskolnikov's loyal friend, Razumikhin, attempts to justify the crime—"Nothing is admitted . . . I'm not wrong! I can show you their books [those of the socialists who claim that crime is simply the protest against 'bad and abnormal social conditions']"—Porfiry counters that he is entirely mistaken and soon references an article recently written by Raskolnikov.

In this essay, published in a local journal, Raskolnikov (who claims to be unaware of its publication) examines "the psychology of a criminal during the entire course of the crime." Porfiry uses this essay in his subtle and unsettling psychological examination of Raskolnikov. Initially, Raskolnikov denies the extreme claim of the article—that "extraordinary" individuals (unlike "ordinary" ones, who "must lead a life of strict obedience and have no right to transgress the law") "have a perfect right to commit all sorts of enormities and crimes and . . . they are, as it were, above the law." However, he soon defends this idea, arguing that the "extraordinary" person "has a right—not an officially sanctioned right, of course—to allow his conscience to overcome certain barriers." Raskolnikov supports his argument with historical examples, most notably Napoleon, but also includes Lycurgus, Solon, and Mahomet, who would all be considered criminals by legal and societal standards.

Even towards the novel's conclusion, Raskolnikov insists (mostly to himself) that he did not truly commit a "crime." Within eight pages of the ending, after already spending time in prison, he still reflects that he would be content "if he really could have regarded himself as guilty of a crime!" A page later, he expresses his fundamental reasoning about "guilt": "How . . . was my idea more stupid than any other ideas or theories that have swarmed and clashed in the world since the world existed? . . . Why does my action strike them as so hideous?. . . Is it because it was a crime? What does 'crime' mean? My conscience is clear." He concludes by thinking that his only "real" crime was his failure to succeed and in having confessed to the act.