As a Romantic, Mary Shelley believed in the "natural man" who was pure and untouched by science and the corruption of society. This corruption came from the false pride that arose from the ownership of property and scientific inventions. According to Rousseau, this pride is an artifical one that promotes comparison of oneself with others in society, and creates an "unwarranted fear" in the individual that causes him to take pleasure in the pain or weakness of others.
Shelley's creature that Victor Frankenstein creates is a virtuous innocent until he is exposed to society. Of him, the renowned Harold Bloom writes,
The greatest paradox and most astonishing achievement of Mary Shelley's novel is the the monster is more human that his creator.
Before the creature is rejected by the Delaceys and before he is attacked by a father whose daughter he was trying to save from drowning, the creature is possessive of a loving heart and a compassion for others. Even when he is attacked by Felix and rejected by the Delaceys, the creature yet harbors no malice in his heart. It is not until he meets again his creator, Victor Frankenstein, that the creature, having been exposed to the dangers of science and the comparison of himself with others, does he develop the fear that drives him to his cruel acts. He tells Victor,
“Of what a strange nature is knowledge! It clings to the mind, when it has once seized on it, like a lichen on the rock. I wished sometimes to shake off all thought and feeling; but I learned that there was but one means to overcome the sensation of pain, and that was death—a state which I feared yet did not understand. I admired virtue and good feelings, and loved the gentle manners and amiable qualities of my cottagers; but I was shut out from intercourse with them, except through means which I obtained by stealth, when I was unseen and unknown, and which rather increased than satisfied the desire I had of becoming one among my fellows."
Fearing to be alone and so rejected, the creature asks Victor to create a mate for him. However, after commencing this creation, Victor changes his mind and destroys his nascent creation. Vowing revenge upon Victor, the creature kills Henry Clerval and Elizabeth, having told Victor, "I shall be with you on your wedding-nights."
Out of his "unwarranted fear" of others and of being rejected by all, the creature takes pleasure in the pain of others. In Chapter 20, he tells Victor,
“Shall each man,” cried he, “find a wife for his bosom, and each beast have his mate, and I be alone? I had feelings of affection, and they were requited by detestation and scorn. Man! you may hate; but beware! your hours will pass in dread and misery, and soon the bolt will fall which must ravish from you your happiness forever. Are you to be happy while I grovel in the intensity of my wretchedness? You can blast my other passions; but revenge remains—revenge, henceforth dearer than light or food! I may die; but first you, my tyrant and tormentor, shall curse the sun that gazes on your misery. Beware; for I am fearless, and therefore powerful. I will watch with the wiliness of a snake, that I may sting with its venom. Man, you shall repent of the injuries you inflict.”
The poor creature's words come back to haunt him as he, too, repents of the injuries that he has inflicted upon Victor Frankenstein, his creator. He vows to kill himself by fire so that all his evil will be purged.