The Summa Theologiæ (written 1265–1274 and also known as the Summa Theologica or simply the Summa) 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 was intended as an instructional guide for theology students, including seminarians and the literate laity. It was 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's topics follow a cycle: the existence of God; Creation, Man; Man's purpose; Christ; the Sacraments; and back to God.