Sure, there’s a Halloween sound to our second hour today — a conversation with historian John Demos about his new book, “The Enemy Within: 2,000 Years of Witch-Hunting in the Western World.” But it strikes a more profound theme than trick-or-treating, one that still resonates.

Demos himself puts it this way in the book’s prologue:

Witch-hunting, large as it is, belongs to a still more capacious terrain that also includes racism, sexism, and anti-Semitism, as well as pogroms, lynchings, genocide, and ethnic cleansing. To such patently downside matters, witch-hunting bears an obvious similarity-and even perhaps some dynamic connection. But one crucial element divides them. While the goal for all is separation from a despised “other,” witch-hunting alone finds the other within its own ranks. The Jew, the black, and the ethnic opposite exist, in some fundamental sense, “on the outside”; the point of actions against them is to enforce difference and distance, and sometimes to eliminate them altogether. The witch, by contrast, is discovered (and “discovery” is key to the process) inside the host community; typically he or she is a former member in good standing of that community who has chosen not only to reject but also to subvert it. Thus, the idea of witchcraft holds at its center the theme of betrayal. Thus, too, witch-hunting has an intensely countersubversive, anti-conspiratorial tone. Always and everywhere, its goal is to root out the hidden enemy within.

You can read the rest of the prologue here — and you can listen to the show here.