This introduction examines the distinction between natural cause and free cause. First, it shows that the modern view of the opposition between natural (efficient) causes and free (rational) causes has its roots in J. Duns Scotus's thought. Second, it considers the continuity of Scotus thought and Modern Philosophy via the mediation of Baroque Scholasticism. Lastly, it presents an examination of Suarez's views on the same themes. To sum up: the articles contained in this volume deal mainly with three topics: Scotus's theory of will and freedom, the transmission of Scotistic ideas between the 14th and 17th centuries, and Suarez's doctrine of will, freedom and nature.