Neo-Scholastic metaphysics plays an outstanding role in 17th century philosophy. The beginnings of the modern scientific view of the world originate from precisely the same time. With reference to the anatomist Francis Glisson (ca. 1597-1677), this study investigates the significance of school metaphysics for the inception of a new form of natural philosophy. It shows that Glisson developed a retrospective theory of substance from his identity as a scientist. In so doing, it casts a surprising light on the formative intellectual conditions governing the emergence of the sciences in the modern age.

The soul-body problem was among the most controversial issues discussed in thirteenth-century Europe, and it continues to capture much attention today as the quest to understand human identity becomes more and more urgent. What made the discussion about this problem particularly interesting in the scholastic period was the tension between the traditional dualist doctrines and a growing need to affirm the unity of the human being. This debate is frequently interpreted as a conflict between the "new" philosophy, conveyed by the rediscovered works of Aristotle and his followers, and doctrinal requirements, especially the belief in the soul's immortality. However, a thorough examination of Parisian texts, written between approximately 1150 and 1260, leads to surprising conclusions. In The Soul-Body Problem at Paris, ca. 1200–1250, the study and edition of some little-known texts of Hugh of St-Cher and his contemporaries, ranging from Gilbert of Poitiers to Thomas Aquinas, reveals an extremely rich and colorful picture of the Parisian anthropological debate of the time. This book also offers an opportunity to reconsider some received views concerning medieval philosophy, such as the conviction that the notion of "person" did not play any major role in the anthropological controversies.