The Devil can so completely assume the human form, when he wants to deceive us, that we may well lie with what seems to be a woman, of real flesh and blood, and yet all the while 'tis only the Devil in the shape of a woman. 'Tis the same with women, who may think that a man is in bed with them, yet 'tis only the Devil; and...the result of this connection is oftentimes an imp of darkness, half mortal, half devil...
The Life of Luther (ed. 1846)