Johann Weyer

Weyer studied as a young man with Heinrich Cornelius Agrippa, which matters for reading him: he came out of a learned magical culture, not out of hostility to it, and he never doubted that spirits act in the world. His medical training gave him something else, an eye for what a body and a mind under strain will produce.

The argument he built in 1563 runs like this. Demons exist and deceive. Old, poor, isolated women, often unwell and often in the grip of melancholy, are precisely the people a deceiver would find easiest to work on. When such a woman says she flew to a gathering and killed a neighbour's cow, the sane reading is that she believes it and it did not happen. She has neither the power nor the capacity. Punishing her is punishing an illness.

He wrote from cases. Weyer described patients he had attended, including people convinced of things that could not be so, and the descriptions are close, particular and unsentimental. He also insisted on a distinction his critics found intolerable: the learned man who sits down with a grimoire to summon a spirit acts knowingly and deserves what he gets, while the woman who confesses under questioning to a crime nobody could commit deserves a physician.

For a court, that was the usable part. It did not require a magistrate to abandon his theology, only to notice who was in front of him.

Jean Bodin answered Weyer in 1580 with an argument that tells you what the risk was. A man who defends witches this warmly, Bodin suggested, is not merely mistaken; his sympathy is itself evidence about him. That move, treating opposition to the trials as a symptom of complicity, was available to anyone at any time, and it is the reason so few argued in print. Weyer had a patron, the Duke of Cleves, and a position at his court. Without that protection the book would very likely not have been publishable, and its author would have been vulnerable to exactly the inference Bodin drew. It was placed on the Index of Prohibited Books.

Later readers have consistently enlarged him, and the enlargement should be resisted. Weyer did not say that there is no Devil. He did not say that magic is empty. He did not say that the whole category was a fiction, which is what Reginald Scot would argue in English twenty one years later. His case was narrow by design, and its narrowness is what gave it a chance of landing.

In the nineteenth century, psychiatry adopted him. Editions appeared presenting De Praestigiis Daemonum as an early textbook of mental illness and Weyer as a founder of the discipline. Historians of medicine treat that claim cautiously: the language of melancholy in 1563 is not the language of clinical diagnosis in 1860, and reading it as such takes the book out of the argument it was actually in. Which does not diminish what he did. He looked at a condemned woman and asked what was wrong with her.