Abstract
The great upsurge of witch trials in early modern Europe remains a historical puzzle. Popularly known as the “witch craze”, this eruption of persecution is puzzling because belief in witchcraft had existed for centuries, but large-scale witch-hunting appeared rather abruptly, spread widely, and was remarkably brutal in comparison with the past. We define a theory of ideational diffusion to describe the general process of the emergence and spread of a new idea along with its prescribed behavioral change, in this case the adoption of witch-hunting. Ideational diffusion distinguishes between the adoption of new ideas, which lead social actors to reinterpret the world and thus to change their behavior, and the adoption of behavior alone. We relate how a new theory of witchcraft appeared in the fifteenth century and show that its widespread propagation, owing to the new technology of printing, matches our description of ideational diffusion. We then analyze the diffusion of witch trials in Central Europe by combining data on the publication of demonological treatises alongside climate, state capacity, religious economy, and city network variables. We find that cities adopted persecution after demonological treatises were printed, and that nearby trials induced neighbors to adopt persecution. Tracing the print vectors and social interdependence spurring witch-hunting helps us understand the general mechanisms behind the spread of persecution.