In The Idiot Dostoevsky attempts to portray the ideal man—a "positively beautiful individual." Prince Myshkin represents all the qualities Dostoevsky deems the best aspects of a human being. First, he is frank and open; unlike other members of high society such as Ganya and General Yepanchin, Myshkin does not hide his true feelings behind a veneer of friendliness in order to gain something or to merely maintain appearances. The prince always says what is on his mind, regardless of whether it is perfectly appropriate for the social setting. Prince Myshkin is also very meek. In contrast to other characters—Ganya, who considers his self and reputation more important than anything else in life; Nastassya Filippovna, who cares more about her own shame than Myshkin's or Aglaya's happiness; Hippolite, who cannot accept death without making some sort of memorable statement—Myshkin does not think about himself at all. Unlike the other characters, many of whom constantly try to assert themselves, Myshkin is very altruistic. Not only is he humble, but he is also very giving and compassionate. These seemingly perfect traits of man come into headlong collision with a corrupt world.
What happens when the ideal human being comes into the real world? In Dostoevsky's view, the ideal man does not bring good, but rather his own goodness is inverted and manipulated, leading to the destruction of both himself and his ideal. The world that Prince Myshkin enters is one of moral corruption and decay, with money as the object of principal importance. In this world, money not only makes one a better human being (Ganya, for example, believes it can cure his mediocrity), but it can also obtain one a beautiful bride (the various men bid for Nastassya Filippovna). No one deems Prince Myshkin a good husband for Aglaya, while nearly everyone considers Ptitsyn—an emblem of mediocrity who has enriched himself through usury—la most respectable match. Beautiful, intelligent women such as Nastassya Filippovna, are dishonored and consequently destroyed.
The world of the novel is also full of drunks (Lebedev, General Ivolgin, Ferdyshchenko, Rogozhin and his company) and rogues (Lebedev, Doktorenko, Keller, Ferdyshchenko and others). Practically everyone else, such as the Ptitsyns and the Ivolgins, is ordinary. High society is full of superficial nothings along with others—such as General Yepanchin—who have behaved in an obsequious manner to these nothings in order to gain a high position. Though Myshkin is infinitely morally superior to the world he enters, his effect on this world is ultimately zero—a mix of positive and negative. Though Myshkin attempts to help those around him, he drives several of them—General Ivolgin, Nastassya Filippovna, Aglaya—to destruction. The failure of Myshkin's compassion to save those about whom he cares most, especially Nastassya Filippovna, drives him to insanity.
Prince Myshkin is a Christ figure, though Dostoevsky adds what he believes to be a Russian element to this messiah. Myshkin describes religion as an immensely strong feeling similar to the joy God feels for his creation—a feeling he recognizes when he sees a young mother joyously nursing her baby. Much like the idea that religion is a feeling rather than a set of rules that one follows, Myshkin Christ-like character can also be reduced to a feeling: his immense compassion and love for others.
Dostoevsky explores the idea of redemption in a series of characters who are condemned. Myshkin, during his first meeting with the Yepanchins, tries to imagine the feelings of a condemned man prior to his execution. Later on, the novel unravels characters who—much like the man standing near the scaffold and awaiting his execution—stand on the brink of ruin. Such characters include the Swiss woman Marie, Nastassya Filippovna, Hippolite, Rogozhin, General Ivolgin, and even Aglaya. Myshkin offers some sort of hope—if not the complete reversal of the death sentence, then at least the softening of the psychological suffering it inflicts upon the condemned.
The Idiot is also full of sinners, from harmless drunkards like General Ivolgin to habitual liars and rogues like Ferdyshchenko, Lebedev, Keller, Doktorenko and even murderers like Rogozhin. Prince Myshkin spends a considerable amount of time with all of these sinners, even after many of them have committed offenses against him. They need the prince morally and spiritually; his attempts at assisting them even after their affronts represent the ultimate in selfless compassion.
Beauty surfaces in various forms in the novel. Everyone marvels at Nastassya Filippovna's beauty. Aglaya is renowned for her beauty. The Yepanchin girls mention that beauty is power. Myshkin remarks that beauty is an enigma. During the engagement party at the Yepanchins the Prince exclaims that beauty can be found in all of God's creation. Pervading the novel is a sort of spiritual beauty to the character of Prince Myshkin and to the love he displays toward all the other characters. Indeed, such beauty is an enigma because it is a feeling and, therefore, impossible to define. Significantly, by the end of The Idiot, all the examples of beauty in the novel, including Nastassya Filippovna, Aglaya, and Myshkin, are ruined.
Dostoevsky strikes a contrast between light and dark from the outset, juxtaposing descriptions of Rogozhin's dark hair and eyes with Myshkin's light hair. Practically everything that involves Rogozhin is dark—his appearance, his house, the hall in which he tries to kill Myshkin, and the study in which he kills Nastassya Filippovna. Darkness is also frequently associated with Nastassya Filippovna: she wears a dark dress at the evening party, and thinking of her makes Myshkin think of darkness. Myshkin, on the other hand, writes the letter to Aglaya as to his "light." Aglaya's name itself also means "light." The contrast between light and dark emphasizes the contrast between the goodness of the prince and the corruption of the world around him. This contrast also underlines the different effects Nastassya Filippovna and Aglaya have on Myshkin: while the former fills his soul with darkness, the latter fills it with light.
Dostoevsky gives examples of many types of love: love out of vanity, passion, romantic love, and pity. Ganya's affection for Aglaya is vain love; he is not willing to sacrifice all for it, as we see in Part I when he asks Aglaya for some kind of insurance before he is willing to break off his engagement with Nastassya Filippovna. Rogozhin's feelings toward Nastassya Filippovna exemplify all-devouring passion; this kind of love approaches hate and is very destructive, both to the lover and the object of love. Both Nastassya Filippovna and Aglaya exemplify romantic love in their feelings toward Prince Myshkin, who in return loves Aglaya with romantic love. Finally, the strongest love of all in the novel is compassionate love, or pity, embodied in Myshkin and directed particularly strongly toward Nastassya Filippovna.
Money is one of the greatest temptations for man; in the corrupted world of The Idiot, virtually everyone aside from the Prince and Nastassya Filippovna has succumbed to greed. Ganya is willing to do almost anything in his passion for money—even marry someone he despises and of whom his family strongly disapproves. General Ivolgin desires money to support his drinking habit and also because it is the only way for him to spend time with his mistress, Madame Terentyev. Lebedev is willing to put his hands into the fireplace in order to retrieve the package with 100,000 rubles that Nastassya Filippovna discards. No one at Nastassya Filippovna's pays any attention to Myshkin until the moment he announces his inheritance; after he does so, he is surrounded by claimants who desire his money. Those like Burdovsky and his gang even go so far as to lie to try to get some of the prince's money. In the society of The Idiot, money not only creates one's fortune—Ptitsyn's, for example—it also obtains one a bride. "Bids" for Nastassya Filippovna range from 75,000 rubles to 100,000 to over a million. Money, then, is a clear symbol of the perversion of human values in the novel.
The dark and stifling dwelling of the Rogozhin family symbolizes the Rogozhin's lifestyle. Its darkness is symbolic of the man himself: both his physical appearance and his inner world are filled with jealousy, obsession, and aggression. Much like the iron bars on the windows of the house, Rogozhin's passion is stifling. His love for Nastassya Filippovna is oppressing.
In the course of reading his "Essential Statement," Hippolite describes a dream that features a horrific monster about to devour him. This ugly monster fills him with terrible fear. On a psychological level, the monster represents nature as Hippolite sees it—a force that is about to devour him through a death from consumption. On a broader scale, however, the monster represents the ugliness and corruption within the society Dostoevsky portrays in The Idiot. The moral decay we see everywhere threatens to devour the characters in within the novel much as the monster threatens to destroy Hippolite in his dream.