Alexander of Hales (c.1185–1245)

Alexander’s emphasis on speculative theology initiated the golden age of scholasticism. His philosophy was influenced by that of Aristotle, particularly in the field of ethics, and also by Augustine, Boethius and Peter Lombard. He believed that philosophy, based on natural reason, and theology, based on divine revelation, were two different disciplines and that philosophy ought to be independent of theology. He himself was primarily a theologian, and the colossal Summa Halesiana, most of which was compiled under his direction, constitutes the first complete theological synthesis in the West.