Unity, Charity, and Fraternity as Foundations for International Law in Francisco Suárez

Abstract

The Jesuit philosopher and theologian, Francisco Suárez (1548–1617), believed the common rational nature of all human beings provides the foundation for both the natural law and international law. He also believed that the human race has a certain unity supported by the principles of mutual love and mercy. This article shows how the unity of the human race and the theological virtue of charity provide a basis for Suárez’s notion of international law. The article situates Suárez within the Catholic tradition of Aquinas and Vitoria, and it distinguishes between the natural law and the law of nations. The final part of the article shows how Suárez’s principles of human unity, charity, and fraternity are affirmed by recent popes.