Raskolnikov is best seen as two characters. He sometimes acts in one manner and then suddenly in a manner completely contradictory. These actions compel one to view him as having a split personality or as being a dual character. Perhaps the best description of Raskolnikov occurs in Part Three, Chapter 2 when Razumihkin tries to explain to Raskolnikov's mother, Pulcheria Alexandrovna, and to his sister, Dunya (Avdotya Romanovna) how Raskolnikov has been acting lately: "He is morose, gloomy, proud and haughty, and of late — and perhaps for a long time before — he has been suspicious and fanciful. He has a noble nature and a kind heart; he does not like showing his feelings and would rather do a cruel thing than open his heart freely. . .It's as though he were alternating between two characters." These two characters are best represented as his cold, intellectual detached side, which emphasizes power and self-will, and his warm, humane compassionate side, which suggests self-submissiveness and meekness. The intellectual side is a result of his deliberate and premeditated actions; that is, when he is functioning on this side, he never acts spontaneously, but instead, every action is premeditated. It is this aspect of his personality that enables him to formulate his theories about crime and to commit the crime.
In order to emphasize this dual character in Raskolnikov, Dostoevsky created two other characters in the novel who represent the opposing sides of his character. These characters are Sonya and Svidrigailov.
Svidrigailov represents the cold intellectual side that emphasizes self-will. All of Svidrigailov's acts are performed so as to give him pleasure and to place him above common morality. This is not to imply that Svidrigailov is an intellectual, but rather it implies that he does not allow minor human actions, morality, or law to prevent him from having his own way. Thus, as Raskolnikov could commit a murder because of his theories, so can Svidrigailov rape a 15-year-old mute girl for his own gratification.
Raskolnikov's intellectual side is intricately bound up in his theory of the extraordinary man. If Raskolnikov is to be one of the extraordinary, he must be able to stand alone, without needing human companionship or without being influenced by the actions of others. He must rely on no one and must be completely self-sufficient. When he performs charitable acts, he is temporarily violating this intellectual side of his nature.
The other side of Rodya's character is the warm, compassionate side. It operates without an interceding thought process. His first and immediate reaction to any situation represents this aspect of his personality. Consequently, he will often act in a warm, friendly, charitable, or humane manner, and then when he has had a chance to think over his actions intellectually, he regrets them. For instance, when he spontaneously gives Katerina Marmeladov his last money, he regrets that he has given the Marmeladov family the money shortly afterwards. If left to his immediate reactions, Raskolnikov would always act in a charitable and humane manner; he would always sacrifice himself for his fellow man — incidents galore abound in this manner, including the reports of his risking his life to rescue a child from a fire or his concern over a drugged young girl who is being pursued by a "dandy" with immoral intent.
The actions in the novel that seem to be strange and contradictory are rather the result of the two aspects of Raskolnikov's personality. When he refuses to allow Dunya to marry Luzhin and then a moment later tells her to marry whom she pleases, this reversal is an example of the humane side not wanting his sister to sacrifice herself to help him, and then the intellectual side contending that he must not concern himself with insignificant problems of others.