The Astronomer and the Witch: Johannes Kepler's Fight for his Mother by Ulinka Rublack (review)

The Jesuit Friedrich Spee, a fierce opponent of the witch persecutions, wrote in his Cautio Criminalis (1631) that "the only way trials are conducted is so that in the end the truth does not shine brightly throughout Germany, but bonfires."¹ However, Ulinka Rublack's monograph describes a remarkable witch trial in which the truth ultimately did cast its brilliant shine, thanks to the accused woman's stout defendant: the astronomer Johannes Kepler, famed for his discovery of the three laws of planetary motion. As a man of science, Kepler was skilled in defending his astronomical insights and refuting his academic opponents, but upon learning that his aged, illiterate mother, Katharina Kepler, had been accused of witchcraft, he put his telescope aside and used his brilliant analytical and rhetorical skills to conduct her defense, which eventually led to her release.

In this thoroughly researched and beautifully written study, Rublack offers the reader a welcome balanced treatment of the Kepler case, one of the best documented witchcraft trials in Germany, which lasted from 1615 until 1621. Having dusted off the rich archival sources, Rublack atmospherically and vividly paints a picture of Katharina's world and beliefs. Adopting the microhistorical approach, Rublack not only gives voice to Katharina, but also to the rest of her family and the community she lived in, at a time when the witch craze was ravaging early modern Germany. Rublack reconstructs a haunted world in which bad events were explained as the work of the Devil and his band of witches. No one was safe from the Devil's temptation, and paranoia reigned. The reader thus gains an in-depth understanding of how the witch craze impacted ordinary people in a small Lutheran community in the Duchy of Württemberg. Most originally, Rublack presents Katharina's trial as the hitherto untold story of how witchcraft accusations transformed family dynamics. Subsequently, her monograph does not just focus on Kepler, his mother, and their relationship, but also on the witch trial as a family tragedy.

Rublack sets the scene by guiding the reader through early modern Leonberg, Katharina's hometown. She explains in rich detail how communal life was governed by daily patterns and seasonal rhythms. Thanks to Rublack's engaging and vivid writing style, the reader gets a real sense of what life must have been like for Katharina in this bustling market town. Despite her middling wealth, Katharina faced much hardship because her husband—unwilling to settle down—had left her to raise their four children, and was never heard of again. Katharina nevertheless managed to fend for herself, thereby showing great resilience and resourcefulness. At the beginning of the seventeenth century, she finally seemed to have entered calm water.

However, Katharina's life took a dramatic turn in August 1615 when, at the age of 68, she was accused of being a witch. She had allegedly given the local glazier's wife a poisonous brew which had made her ill. All of a sudden, the illiterate aged widow was caught up in the machinations of the witch persecutions, instigated by an overzealous ducal governor. What follows is a gripping account of a six-year legal battle in which Katharina narrowly escapes physical torture, which most likely would have resulted in a confession, and consequently, the death sentence.

In great detail and with painstaking effort, Rublack reconstructs the six-year-long case and the anxiety it causes among Katharina and her children. Throughout those years Johannes tirelessly confronts the judicial system, exposing some of the causes of the German witch craze in the process, such as the deeply embedded cultural fear of old women. However, although the trial unfolds against the backdrop of the scientific revolution with Kepler himself being a man of science, Rublack rightly does not describe...