Medieval speculation about the nature of monsters ran the gamut from a simple identification of them as accomplices of Satan to somewhat more sophisticated speculation about their place in relation to humanity and the larger divine design. Medieval scholars' mental maps of the world featured monstrous races of giants, wild apes, and dog-headed men. Christian scholars sometimes speculated that these creatures represented the progeny of Cain, cursed by God for slaying his brother (Grendel, Beowulf's monstrous opponent in the Anglo-Saxon epic, is said to be of the lineage of Cain). Occasionally, glimpses of a more nuanced view of monstrosity can be seen. One minor tradition in the middle ages portrayed St. Christopher as a Cynocephalus or "dog-headed." Scholars in the medieval world debated whether or not monsters had souls, and thus whether, hypothetically, they could receive baptism.9

Most of the monsters that rose from the grave in modern America have their distant origins in this context of medieval folklore, legend, and literature. Europeans had portrayed the witch, the vampire, and the werewolf, unlike many of the fantastical creatures located in other climes, as accomplices of Satan. The witch had a clear relationship with the devil, drawing her power from a pact she had made with him. The vampire in eastern Europe and parts of Germany had some relationship with Satan but also drew on beliefs about revenants and the consequences of a "bad death." Werewolves, and shapeshifters of all kinds, have a more complicated history, at times being portrayed as guiltless figures who labor under a curse (much like Larry Talbot in Universal pictures 1941 The Wolfman). Other versions of the werewolf mythos represent them as satanic creatures whose power, like that of the witch, comes from hell. Belief in these creatures assumed that no strict separation of "nature" and "supernature" existed, and that a world of shadows periodically and terrifyingly haunted humanity.10

The sixteenth and seventeenth centuries saw the birth of a new worldview. The "scientific revolution" introduced the notion of the universe as a mechanism rather than a playground for divine and demonic spirits. Kepler, Copernicus, and Galileo challenged the domination of Aristotelian cosmology that placed the earth at the center of the known universe. A new mechanical conception of nature began to shape thinking about the world, suggesting that observable, repeatable laws governed everything from the behavior of heavenly bodies to the phenomenon of human bodies. Neither miracles nor monsters would seem to have much of a foothold in this reimagined cosmos.

Ironically, the dawning age of science also became an age obsessed with the work of Satan on earth, specifically his use of witches and other evil accomplices. Witchcraft trials during the early modern period took the lives of perhaps as many as sixty thousand people. Trials of people suspected of being "loupe garou," or werewolves, became common in sixteenth and seventeenth-century France. Seldom imagined as forlorn beings travelling under a curse, magistrates and churchmen described the werewolf instead as a human being who willfully transformed into a monster with the help of the devil.11

The long history of humanity's monstrous fascinations, and the mythologies and theologies that supported them, would seem to have little to do with the early American republic or its citizens. The American Revolution grew in part out the Enlightenment goal of applying rationality to politics. While it is too simplistic to view the creation of the United States as merely the fulfillment of the Enlightenment project, many of America's founders did imagine a new nation reared on the foundations of human reason. Patriots forged the United States, it has often been explained to us, out of a wedding of Enlightenment political ideology and a growing sense of national destiny. Adams, Franklin, and Jefferson admired the political philosophy of John Locke, who favored the creation of rational republics where the superstitions of statecraft and "priestcraft" had no purchase. The new republic, seemingly, would live in a sunlit world without shadows, a place where no monster could hide.12