Mary Shelley vision that inspired Frankenstein characters

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 endeavour to mock the stupendous mechanism of the Creator of the world.

– Mary Shelley

Frankenstein, author Mary Shelley’s Introduction to 1831 edition. She writes of the vision that inspired the novel and characters of Victor Frankenstein and his creation the monster.