Friedrich Spee von Langenfeld

Spee's authority comes from where he stood. As a Jesuit priest in the German prosecutions he was assigned to the condemned: he heard their last confessions and walked with them to the place of execution. A confession in that setting is made by someone with nothing left to gain by lying, and Spee wrote afterwards that he did not believe he had ever accompanied a guilty person.

That is not a theological claim and he was careful to keep it from becoming one. The Cautio Criminalis of 1631 does not argue that witches do not exist. It sets that question aside as one the book does not need, and attacks the procedure instead, question by question, in the dry manner of a legal treatise.

The core of it is a trap with no exit. Torture makes a person say what stops the torture, and what stops it is agreement. Once she has agreed there was a gathering she must say who else was there, so she names neighbours, and the neighbours are arrested. A defendant who denies is tortured for denying. One who confesses is executed. One who retracts is tortured again for retracting. Innocence has no available move.

Spee then makes the point that the judges could not answer: if the procedure would convict an innocent woman with the same certainty that it convicts a guilty one, then the convictions carry no information at all. Whatever the truth about witches, this court cannot find it.

The book was published without its author's name, at Rinteln in 1631, and the precaution was sensible. It accused named practices, and by clear implication the princes, judges and clergy who ran them, of killing innocent people in numbers. Spee's authorship was known in his lifetime nonetheless, and Leibniz affirmed it later in the century.

What it achieved is honestly uncertain. Historians credit the Cautio with contributing to the ending of prosecutions in several German territories, and some contemporaries said so directly. It is also true that the decline in the Holy Roman Empire had several causes running together: the exhaustion of the Thirty Years War, reform of criminal procedure, higher courts reasserting review over local ones, and a slow change in what educated men were prepared to believe. A book does not stop a persecution on its own, and nobody has isolated its effect.

Spee saw none of it. He was seriously injured in an attack in 1629, and in 1635 he died at Trier of plague caught while nursing wounded soldiers, in his mid forties. His other surviving work is devotional poetry, published after his death, some of which is still sung in German hymnals at Christmas.

It is worth holding those two things together. The sharpest procedural critique of the seventeenth century and a set of tender Christmas carols were written by the same man, out of the same conviction, in the same short life.