This ebook is the best-known work of Thomas Aquinas (c.1225–1274). Although unfinished, the Summa is “one of the classics of the history of philosophy and one of the most influential works of Western literature.” It is intended as an instructional guide for moderate theologians, and a compendium of all of the main theological teachings of the Catholic Church. It presents the reasoning for almost all points of Christian theology in the West. The Summa Theologica is divided into three parts, and each of these three parts contains numerous subdivisions. Part 1 deals primarily with God and comprises discussions of 119 questions concerning the existence and nature of God, the Creation, angels, the work of the six days of Creation, the essence and nature of man, and divine government. Part 2 deals with man and includes discussions of 303 questions concerning the purpose of man, habits, types of law, vices and virtues, prudence and justice, fortitude and temperance, graces, and the religious versus the secular life. Part 3 deals with Christ and comprises discussions of 90 questions concerning the Incarnation, the Sacraments, and the Resurrection. Some editions of the Summa Theologica include a Supplement comprising discussions of an additional 99 questions concerning a wide variety of loosely related issues such as excommunication, indulgences, confession, marriage, purgatory, and the relations of the saints toward the damned. Scholars believe that Rainaldo da Piperno, a friend of Aquinas, probably gathered the material in this supplement from a work that Aquinas had completed before he began working on the Summa Theologica.