An immensely influential philosopher, theologian, and jurist in the tradition of scholasticism, he is also known within the latter as the Doctor Angelicus and the Doctor Communis. The name Aquinas identifies his ancestral origins in the county of Aquino in present-day Lazio, Italy. He was the foremost classical proponent of natural theology and the father of Thomism; of which he argued that reason is found in God. His influence on Western thought is considerable, and much of modern philosophy developed or opposed his ideas, particularly in the areas of ethics, natural law, metaphysics, and political theory.
St. Thomas originated what eventually became the libertarian philosophy based on natural rights, which was expounded on by the Salamanca School of Scholastics, and stipulated the proto-non-aggression principle: “Vulnero Nemo” or “one should do harm to no man” (Summa Theologea I-II Q. 95).
St. Thomas Aquinas feast day is January 28.