Peter of Spain (c.1205–77)

For hundreds of years, a number of works in philosophical psychology, medicine and logic have been attributed to a single thirteenth-century author known as Peter of Spain. According to the latest research, however, there were actually two authors of that name. One, who later became Pope John XXI, wrote on medicine and on the soul. In his writings on the soul, this Peter argued for an independent material form that prepared the body for the soul, its substantial form, and he took an Augustinian view of God’s role in illuminating the intellect in ordinary cognition. The second Peter of Spain was a Spanish Dominican who wrote the logical works. He is chiefly known for his Tractatus, an influential textbook of logic written before 1250, expounding both traditional topics and the theory of supposition, concerning reference in sentential contexts.