With her repulsive face and head full of living, venomous snakes, Medusa is petrifying--quite literally, since looking directly at her turned people to stone. Ever since Perseus cut off her head and presented it to Athena, she has been a woman of many forms: a dangerous female monster that had to be destroyed, an erotic power that could annihilate men, and, thanks to Freud, a woman whose hair was a nest of terrifying penises that signaled castration. She has been immortalized by artists from Leonardo da Vinci to Salvador Dali and was the emblem of the Jacobins after the French Revolution....