Alyosha is said to be the hero of the story by the narrator, and he represents the position of "faith," along with his teacher and spiritual father, Zosima. He can easily read people and understand complex emotions. Alyosha is about 20 years old, and he wants to be a monk because he has been inspired by the teachings of Zosima. He is loved by everyone because he has no trace of self-importance and does not judge others. He always thinks the best of them, even though he is not blind to human shortcomings. Alyosha is also known as Alyoshka, Alyoshenka, Alyoshechka, Alexeichik, Lyosha, and Lyoshenka.
If Alyosha is the hero of the story, Ivan is the antihero. He is a 24-year-old intellectual and avowed atheist. Ivan has a brilliant mind and has already made a name for himself as a writer and critic. He arrives in town at the request of his half-brother, Dmitri, whom he both loves and despises. Ivan is struggling with the meaning of life and searching for an alternative way to live that does not involve God or religion. In truth, he is torn between faith and doubt. Ivan is occasionally called Vanya, Vanka, and Vanechka.
Dmitri "Mitya" Karamazov is a wild and irresponsible ex-military officer who comes to town to claim the remains of his inheritance from his equally wild and irresponsible father. He is 28 years old and engaged to Katerina, a proud woman whom he helped out of a financial difficulty. Dmitri falls in love with Grushenka, however, and then wants to break it off with Katerina. Dmitri has a difficult time containing his emotions, which often results in eruptions of violence. Dmitri is also referred to as Mitka, Mitenka, and Mitri Fyodorovich.
Fyodor Karamazov is the comic villain of the novel. He is a casebook study in antisocial personality disorder (sociopathy), an amoral individual with no remorse. Fyodor Karamazov is sexually voracious and perverse—a rapist, drunkard, and shady businessman who has become rich because of his wily intelligence and knack for taking advantage of others. He is an abusive parent who abandoned his children early in their lives. What makes him comical is his spiteful and perverse behavior. He is comically transgressive in social situations and has a comic's sense of the absurd when he pokes fun of other people's deeply held beliefs.
Smerdyakov is the most evil character in the novel and can be equated with the devil. He is the product of the rape of his mother, who was a mentally handicapped and mute vagrant, and his father is almost certainly Fyodor Pavlovich. Smerdyakov is full of hatred and resentment because of his background and upbringing. From early childhood, Smerdyakov exhibited the psychopathic tendencies of a serial killer—by torturing and killing cats and then praying over them using a mock ritual. He murders his unacknowledged parent, implicating Ivan and Dmitri in the crime. Smerdyakov is highly intelligent, the same age as Ivan, and underestimated by everybody.
Grushenka is about 22 years old and the daughter of a deacon. She is seduced and abandoned at 17 by a Polish officer, then rescued by an old merchant, who takes her as his mistress. Grushenka, warped by this experience, has become a spiteful and heartless seductress. Both Dmitri and his father are courting her, but Dmitri is desperately in love with her. Through Alyosha's compassion and Dmitri's love, Grushenka reverts to her true nature, which is large-hearted and generous. She is well matched with Dmitri, because both of them are highly emotional and addicted to melodrama. Grushenka is also referred to as Grusha, Grushka, and Grush.
Katerina is the aristocratic, well-educated, and intelligent daughter of Dmitri's commanding officer. The proud Katerina scorns Dmitri's advances, but later offers herself to him for money to save her father from court-martial, after he makes that suggestion to her half-sister. Dmitri has a change of heart and simply gives her the money, and later, when she comes into an inheritance, she becomes his fiancée. Katerina is a study in ressentiment, a literary term for a specific type of resentment. On the surface she seems to be self-sacrificing, but she performs good deeds to feel morally superior. Katerina is enraged by Dmitri's betrayal of her, and she makes him pay by disguising her revenge as selfless love. She humiliates herself for the ultimate purpose of gaining power over others or making them feel small. Katerina loves Ivan, not Dmitri. Katerina is sometimes referred to as Katya, Katka, and Katenka.