The Rationality of Witchcraft

We tend to look back at the height of European witch trials and imagine them as a dark aberration, a lapse into pure irrationality. But the truth is more unsettling. The trials were sustained by a rigorous, deeply coherent worldview. When a 17th-century judge or theologian condemned a witch, they were acting within a framework that took the Devil's physical agency entirely seriously, viewing witchcraft as a real, treasonous crime complete with literal pacts and tangible harms.

To stop the witch hunts, you could not simply appeal to humanitarian instincts. You had to dismantle the physics of hell.

This intellectual heavy lifting fell to figures like Balthasar Bekker, a Dutch Cartesian minister who argued a radical proposition: spiritual agency cannot interact with physical matter. Bekker used Cartesian philosophy to drive a wedge between theology and the natural world, insisting that nature simply cannot be explained through scripture, and that demons do not possess the physical payload required to meddle in earthly affairs.

Of course, philosophy rarely acts alone. The decline of the hunts was a messy, contested shift driven just as much by cold courtroom mechanics—such as the eventual refusal to admit spectral evidence—as by grand intellectual revolutions. And historians still debate whether the new mechanical philosophy genuinely cleared the smoke of the trials, given that plenty of early scientists and mechanical philosophers remained enthusiastic supporters of them.

Yet the core transformation remains striking. Long before the modern era banished the supernatural from polite society, thinkers had to fundamentally rewrite the rules of what was physically possible. To save people from being burned as witches, rationalists first had to prove that the universe was running on laws that left no room for magic.