Mary Shelley subtitled her novel "The Modern Prometheus." According to the Greeks, Prometheus stole fire from the gods. As punishment, he was chained to a rock, where an eagle each day plucked at his liver. Haughty Prometheus sought fire for human betterment--to make tools and warm hearts. Similarly, Mary Shelley's arrogant scientist, Victor Frankenstein, claimed "benevolent intentions, and thirsted for the moment when I should put them in practice." Frankenstein endures not only because of its infamous horrors but also for the richness of the ideas it asks us to confront--human accountability, social alienation, and the nature of life itself. These passages illuminate some of them.

In Frankenstein, the intelligent and sensitive monster created by Victor Frankenstein reads a copy of Milton's Paradise Lost, which profoundly stirs his emotions. The monster compares his situation to that of Adam. Unlike the first man who had "come forth from the hands of God a perfect creature," Frankenstein's creature is hideously formed. Abandoned by Victor Frankenstein, the monster finds him "wretched, helpless, and alone."

Frankenstein opens with a series of letters written by Arctic explorer Robert Walton engaged in a personal quest to expand the boundaries of the known world. It is Walton who first encounters Victor Frankenstein in the Arctic desperately searching for the monster he has created. The explorer becomes the only person to hear Victor Frankenstein's strange and tragic tale.

A sledge . . . had drifted towards us in the night, on a large fragment of ice. Only one dog remained alive; but there was a human being within it . . .. His limbs were nearly frozen, and his body dreadfully emaciated by fatigue and suffering. I never saw a man in so wretched a condition. 

I beheld a stream of fire issue from an old and beautiful oak . . . and so soon as the dazzling light vanished the oak had disappeared, and nothing remained but a blasted stump . . .. I eagerly inquired of my father the nature and origin of thunder and lightning. He replied, "Electricity." 

  By the early nineteenth century, philosophers like physician Erasmus Darwin and chemist Humphry Davy, both well known to Mary Shelley, pointed the way to mastery of the physical universe. Discoveries about the human body and the natural world promised the dawn of a new age of medical power, when such things as reanimation of dead tissue and the end of death and disease seemed within reach.

The modern masters promise very little . . .. But these philosophers . . . have indeed performed miracles . . .. They have discovered how the blood circulates, and the nature of the air we breathe. They have acquired new and almost unlimited powers; they can command the thunders of heaven, mimic the earthquake, and even mock the invisible world with its own shadows. 

With feverish excitement, Victor Frankenstein pursues nature to her hiding places. By moonlight, he gathers the body parts he needs by visits to the graveyard, to the charnel house, to the hospital dissecting room and the slaughterhouse. Although he finds his solitary preoccupation repulsive, he is not deterred from his quest to restore life.

Overcome by the horror of what he has done, Victor Frankenstein abandons the "miserable monster" he fathered in his laboratory. That evening a nightmare disturbs his sleep; Elizabeth, his fiancée, becomes in his arms the decaying corpse of his own dead mother. The next morning when he returns to his "workshop of filthy creation," the monster has escaped.

  Abandoned by his creator, the monster takes his revenge on Victor Frankenstein by killing his younger brother, William. Frankenstein's silence, in the face of the monster's murderous actions, exacts a terrible price. His self-imposed isolation from society mirrors the social isolation the monster experiences from all that see him. Frankenstein's decision to remain silent about the monster leads to further tragedy.

 Victor Frankenstein initially agrees to create a mate for his monster. But as Frankenstein begins to assemble an Eve for his Adam, he grows terrified by the prospect that this female creature will be "ten thousand times more malignant" than her companion, and that the two might themselves produce "a race of devils." Breaking his promise to the monster, Frankenstein disposes of the body parts he gathered to produce the female creature. Inflamed with hatred, the monster sets outs to destroy in Frankenstein's life all that he coveted for his own. After killing Clerval, Frankenstein's best friend, the monster murders Elizabeth, Frankenstein's bride, on their wedding night.

As he lies dying aboard Walton's ship, Frankenstein offers an ambivalent assessment of his own conduct. In both the subtitle (The Modern Prometheus) of her novel and through Frankenstein's dying words, Mary Shelley suggests that Frankenstein's misfortune did not arise from his Promethean ambition of creating life, but in the mistreatment of his creature. Frankenstein's failure to assume responsibility for the miserable wretch he fathered in his workshop is his real tragedy.

  Encountering Robert Walton aboard his ship, the monster expresses overwhelming remorse for his frightful catalogue of misdeeds, the deaths of William, Clerval, Elizabeth, and his creator. The creature informs the explorer that he will destroy himself in the frozen north, and disappears in the icy waves. The tragedy of Frankenstein and his monster is complete.

From: http://www.nlm.nih.gov/frankenstein/frank_modern_1.html