This quote, from Mary Shelley's Frankenstein, comes from the protagonist, Dr. Frankenstein himself. He is describing the fury that led him to create his monster, how alchemy drove him beyond the normal acceptable limits of human nature. It is a classic example of the "overreacher", as Frankenstein seeks, through science, to transcend the earthly limits of life and death. It must be noted as well that Frankenstein does not attempt this with evil intentions, but almost naively, thinking that he is doing good.
