Thomas Aquinas (1225–1274) was an Italian Dominican friar, philosopher, and theologian who is widely considered the greatest and most influential thinker of the medieval Scholastic tradition. Born into an aristocratic family near Naples, he joined the Dominican order against his family's wishes and studied under Albertus Magnus in Cologne and Paris. His monumental Summa Theologica, though left unfinished at his death, represents the most comprehensive synthesis of Christian theology and Aristotelian philosophy ever attempted. In it he developed his famous Five Ways—five arguments for the existence of God drawn from motion, causation, contingency, degrees of perfection, and the purposiveness of nature. Aquinas argued that faith and reason are complementary rather than contradictory: reason can demonstrate certain truths about God (such as His existence), while revelation provides truths beyond reason's reach (such as the Trinity). His ethical theory, drawing on Aristotle's virtue ethics, identified natural law as a participation of rational creatures in God's eternal law, an idea that profoundly shaped Western legal and moral philosophy. He was canonized in 1323 and declared a Doctor of the Church. In 1879, Pope Leo XIII endorsed Thomism as the official philosophy of the Catholic Church, ensuring its continued centrality in Catholic intellectual life.