I saw—with shut eyes, but acute mental vision—I saw the pale student of unhallowed arts kneeling beside the thing he had put together. I saw the hideous phantasm of a man stretched out, and then, on the working of some powerful engine, show signs of life and stir with an uneasy, half-vital motion. Frightful must it be, for supremely frightful would be the effect of any human endeavor to mock the stupendous mechanism of the Creator of the world.

Taken from Mary Shelley’s Author’s Introduction to the 1831 edition of Frankenstein, this quote describes the vision that inspired the novel and the prototypes for Victor and the monster. Shelley’s image evokes some of the key themes, such as the utter unnaturalness of the monster (“an uneasy, half-vital motion”), the relationship between creator and created (“kneeling beside the thing he had put together”), and the dangerous consequences of misused knowledge (“supremely frightful would be the effect of . . . mock[ing] . . . the Creator”).