Thomas Aquinas Quotes
It would seem that the ingratitude, whereby a subsequent sin causes the return of sins previously forgiven, is a special sin. For, the giving of thanks belongs to counter passion, which is a necessary condition of justice. But justice is a special virtue. Therefore this ingratitude is a special sin. Thanksgiving is a special virtue. But ingratitude is opposed to thanksgiving. Therefore ingratitude is a special sin.
Aquinas, Thomas. Summa Theologica. Translated by Fathers of the English Dominican Province, vol. 2, Benziger Brothers, 1947, p. 2568 (Part III, Question 88, Article 3, Objection 1).
Thomas Aquinas was an Italian Dominican friar, philosopher, Catholic priest, and Doctor of the Church. An immensely influential philosopher, theologian, and jurist in the tradition of scholasticism, he is also known within the latter as the Doctor Angelicus, the Doctor Communis, and the Doctor Universalis. The name Aquinas identifies his ancestral origins in the county of Aquino in present-day Lazio, Italy. Among other things, he was a prominent proponent of natural theology and the father of a school of thought (encompassing both theology and philosophy) known as Thomism. He argued that God is the source of both the light of natural reason and the light of faith. 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.