The Holy Spirit: Medieval Roman Catholic and Reformation Traditions (Sixth-Sixteenth Centuries) is the third in a series of three volumes devoted to the history of Christian pneumatology.

This concluding volume examines medieval Roman Catholic and Reformation attitudes toward the Holy Spirit beginning with the writings of medieval Catholic theologians from Gregory the Great and Bede to Aquinas and Bonaventure. Subsequent sections describe the contributions of influential women such Hildegard of Bingen, Birgitta of Sweden, and Catherine of Siena; "fringe" figures such as Joachim of Fiore and the Cathars; the magisterial reformers Luther, Zwingli, and Calvin; leading Catholic reformers such as Ignatius of Loyola; and the "radical reformers" Thomas Muntzer and Menno Simons.