Aristotle earns the distinction of having put forward the first comprehensive philosophical theory of justice. After the end of the antique world, St. Thomas Aquinas was the first philosopher and theologian to return to Aristotle’s theory of the just. Not only did he do so with the requisite systematic precision; he also developed a new philosophical interpretation of justice. In the present article I shall outline, with the brevity expected of me here, the fundamentals of Aristotle’s theory of justice. This will be followed by a summary of the core aspects of Aquinas’s notion of justice, whose grounding in normative reason will be identified in Aquinas’s treatise on law and political theory, and explicated accordingly.

This article is part of a larger project defending a version of divine command theory in ethics. What I am interested in from Scotus is that he combines such a theory with a view that grounds ethics in nature, especially human nature. In order to understand this combination, we need to start with his view of the two affections. Scotus takes from Anselm the idea that humans have in their will two basic affections (or intellectual appetites), what he calls the affection for advantage (affectio commodi) and the affection for justice (affectio justitiae). All acts of the will, on this view, stem from one affection or the other. Behind Anselm is Augustine's insistence, which Scotus alre refers to frequently, that God is to be enjoyed and not used (even though entering into God's love is our greatest happiness), and everything else is to be used and not enjoyed.

I. INTRODUCTION

Ever since Muslim thinkers came into contact with Greek Philosophy and science in the seventh century, the relation between Islamic philosophy and theology has been an uneasy one. Muslim philosophers often felt compelled to defend their philosophical activities against the suspicions and attacks of the theologians, and some developed considerable energy and effort to the harmonization of philosophy and religion on some fundamental points.

I. INTRODUCTION: THE PROBLEM

Akrasia (or, weakness of the will), often defined as “the moral state of agents who act against their better judgment”—a definition first given by Aristotle in the Nicomachean Ethics, depicts one of the most human of predicaments.Risto Sarrinen, Weakness of the Will in Medieval Thought: From Augustine to Buridan (New York: E. J. Brill, 1994), p. 1. Similar definitions can be found in, e.g., Aristotle, Nicomachean Ethics VII, 1045b10–15; Donald Davidson, “How is Weakness of the Will Possible?” in Moral Concepts, ed. J. Feinberg (Oxford: Oxford University Press, 1970) p. 93; William Charlton, Weakness of Will (Oxford: Basil Blackwell, 1988), p. 1. We know what we ought to do, and we try. But, for one reason or other, we sometimes choose to act contrary to our better judgment.Being influenced by Socratic reasoning, some philosophers have argued that, in principle, one cannot freely and intentionally choose to act against one’s better judgment, if (1) one rationally judges what is best for oneself, (2) one prefers to act according to one’s rational judgment, and (3) one is free to make one’s own choice. See, e.g., Davidson, “How is Weakness,” pp. 93–113; and R. M. Hare, Freedom and Reason (Oxford: Oxford University Press, 1963), pp. 78–79. Despite the logical difficulty, many believe that weakness of the will is a fact.

Thomas Aquinas is commonly thought to hold that human beings will happiness and do so necessarily. This is taken to mean first that human beings are not able to will misery for the sake of misery and therefore not capable of pursuing misery for its own sake. Secondly, everything that human beings do will they will for the sake of happiness, and since human beings are moved to act on the basis of what they will, all of their actions are performed for the sake of happiness. This claim is subject to doubt because it seems to many to be false on empirical grounds. Often, people choose things that they know and are willing to admit do not make them happy. Often, people choose things without even thinking about their happiness. Aquinas’s theory must deal adequately with such apparent counterexamples. But his account faces an objection of a different nature, an objection raised by John Duns Scotus.