Porfiry begins by talking about his cigarettes and by apologizing to Raskolnikov for the “ungentlemanly” tone of their last meeting. Porfiry begins, in his characteristically circuitous way, explaining the development of his thoughts regarding Raskolnikov’s guilt. First, he says, he heard rumors of Raskolnikov’s fainting in the police station, then he saw the article Raskolnikov wrote as a student. Porfiry mentions Raskolnikov’s conversation with Zamyotov, which also seemed to lend credence to his boldness and guilt. But all these explanations were only “psychological,” says Porfiry. He was worried that, without physical proof, he would not be able to find the killer.
Porfiry lays out the final case for Raskolnikov’s guilt. He goes through once again the strange circumstances of Raskolnikov’s behavior in recent days: his fainting spells, his incredible agitation and paranoia, his moments of mania followed by moments of extreme depression. Porfiry concludes that, if Raskolnikov is not ill or mad, he must be overcome with an immense amount of guilt. This leads Porfiry to believe that Raskolnikov himself is the murderer of the two women.
Porfiry then explains Nikolai’s confession, which he set about disproving, especially since Nikolai was revealed to be a religious schismatic, or unorthodox believer, and a young man prone to exaggeration. Finally, Raskolnikov asks who killed the two if not Nikolai. Porfiry responds, matter-of-factly: “Why, you did.”
Finally, Porfiry directly acknowledges what Raskolnikov has long feared: that he believes Raskolnikov committed the crime.
Raskolnikov feebly denies Porfiry’s charge and blames it all on the investigator’s psychological games. Porfiry says that, despite the fact that his evidence is only psychological, he knows Raskolnikov is the killer, and he has come beforehand, in a breach of protocol, to announce that he will have Raskolnikov arrested soon. Porfiry wishes also to say that he is not a “monster” but a reasonable man, and that it would be to Raskolnikov’s advantage to confess to the crime at the station.
Porfiry, like Sonya, believes that Raskolnikov should confess to his crime. While Sonya asks that Raskolnikov do this for religious reasons, in order to save his immortal soul, Porfiry desires instead a kind of “mathematical certainty” about the case. Porfiry is not cruel or evil, but he does not care about Raskolnikov's soul. He just wants to definitively close the case. That is how the law operates.
Porfiry says that Raskolnikov will have his sentenced reduced if he confesses. Raskolnikov responds that he doesn’t want a reduction at all. Porfiry tells Raskolnikov not to be a coward, but rather to confess and accept his suffering. Porfiry says he will arrest Raskolnikov in a day or two, and that he knows Raskolnikov will not run away in that time, because it is “impossible for him to do without” his friends and family in Petersburg.
Porfiry’s most important line of the novel. Raskolnikov relies upon the help of others, despite his ardent desire to be independent, a man of his own free will. Porfiry is correct in asserting that Raskolnikov will not leave Petersburg: at this point, Raskolnikov has become too enmeshed in Sonya’s life to do without her.
Raskolnikov listens and then, seeing he is not under arrest at the moment, gets up to take a walk. Porfiry wishes him a fine time in the meanwhile, and Raskolnikov repeats that he has confessed to nothing, which Porfiry acknowledges as Raskolnikov leaves.
Raskolnikov stresses that he has not yet confessed to his crime. Indeed it will take Sonya’s intervention to force him to confess in the police station, after a great deal of hesitation.