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.