ABSTRACT
In the 1230s the Dominican preacher and inquisitor, Stephen of Bourbon, came across an oddity while preaching in Valence en Dauphine. He passed a handsome castle that stood empty in the midst of barren lands. When he asked the reason for such a strange thing, he was told that the lord of that castle had stolen both horse and goods from a papal legate. The Tractatus de diversiis materiis praedicabilibus was compiled in Lyon between 1250 and 1261 by Stephen of Bourbon. The issue of appropriate ecclesiastical and secular powers was a perennial topic. Ecclesiastical power and authority were often conflated with supernatural power by both clerics and by popular practices. Yet Stephen's stories make greater claims than the mere reiteration of clerical power, and in doing so reflect the wider contemporary dissension over the practice of excommunication. A final component in this constellation of twelfth and thirteenth-century tensions is the changing concept of the natural world.
