St. Thomas Aquinas’ Just War Theory

Abstract

St. Thomas Aquinas’ thought on just war is the theme of this paper. It begins with a brief outline of the historical development of the just war theory from its Christian roots in Antiquity, through the Middle Ages, to the Modern Age and contemporary secular versions. Furthermore, a survey of the principles of the modern just war theory is presented in order to clarify Aquinas’ role in the development of his thought on just war. The final and most important section contains an analysis of his deliberation on just war with a special emphasis on the four articles in S. th. II, 2, 40. In conclusion, the author offers his own opinion on the relevance of Thomas’ thought for the contemporary just war theory given the rising number of international and internal conflicts motivated by religion, especially in the Near East. In view of these conflicts, we may consider Aquinas to be as relevant today as he was in the 13th century.