In 1563 Johan Wier’s protest against the criminal prosecution of presumed witches, caused much upheaval. He attempted to exonerate these defendants by arguing that human beings are incapable of doing the things they were accused of. It was demons and not humans who were the real offenders. Until now, Wier’s religious convictions have remained indistinct. It is argued here that he refused to choose sides in the religious conflicts of the sixteenth century. His correspondence and other writings show that he was a spiritualist who felt inspired by men like David Joris, Hendrick Niclaes, his brother Matthias Wier, and Sebastian Castellio. It is also argued here that he did not really believe that demons had any real power to influence the course of nature, but that he had to furnish the judges with other possible suspects in order to exculpate the people who were accused of witchcraft.