Justice as a Virtue: A Thomistic Perspective by Jean Porter (review)

Jean Porter’s excellent study not only offers a clear and expansive picture of Aquinas on justice but also touches on nearly every other topic in Aquinas’s ethics. Of course, Aquinas himself thinks that no topic in philosophy or theology can be understood, or understood well, apart from its connection to multiple others, and Porter’s book is in this respect, as in so many others, deeply Thomistic. In the course of exploring justice—justice as a virtue, justice as a moral ideal, and the special authority carried by the precepts of justice—Porter also reveals Aquinas’s thought on practical reason, moral inconsistency, virtue, eudaimonism, and normativity.

“Aquinas gets justice right,” Porter asserts (5). Unlike most contemporary theories of justice, which focus on social systems and institutions, Aquinas explains that justice is a virtue. Like all virtues, justice is a habit giving us a stable orientation toward its object. In the case of justice, that stability takes the form of a commitment to valuing each human being as an equal and honoring his or her claims of right on us. In turn, when we make just choices, we more clearly define our ends in life, so that the very exercise of justice helps us to come to an increasingly clearer conception of our own happiness and the place of others’ interests in it. In addition to being a virtue, justice also functions as a moral ideal. In this regard, Aquinas’s views often resemble rather than contrast with those of modern and contemporary philosophers. Drawing on Christian ideas of human equality, the Aristotelian model of justice as equal exchange, and the Roman juridical concept of right, Aquinas theorizes that the inherent value of each human being gives him or her claims against others to protect against harms not only to person or property, but also to honor and respect. The precepts of justice, unlike those governing the other virtues, are precise and strictly binding, as Porter aptly explains in chapter 4, distinguishing justice from other virtues.

Porter’s considerable analytic capacities are on display not just in her careful and creative analysis of justice, but also in her incessantly enlightening discussions of supplementary issues. For instance, chapter 3 argues persuasively that Aquinas recognizes subjective rights, not so much as discrete moral powers, but as “a general moral power for self-determining action, which she can exercise preemptively on the basis of some claim of right” (146). Equally powerful is Porter’s defense of justice as not only consistent with, but as an important element in, a eudaimonistic system of ethics. Responding to Nicholas Wolterstorff’s concern that eudaimonism fails to acknowledge the independent value of other human beings (106–7), Porter explains that, on Aquinas’s view, agents do not appeal to their own happiness as the evaluative measure of what they pursue. Rather, what agents pursue—including honoring the claims of right—has an independent value, and that is why agents integrate it into their conception of happiness. Later, in chapter 5, Porter likens the components of an agent’s happiness to what we now call “meaningful” activity. In fact, it is only by integrating and ranking a complex of meaningful goods—both those of justice and the other virtues—that we can develop the sorts of habits that will direct us to a happy life.

In only two cases did I find Porter’s contentions vague or insufficiently substantiated. First, she maintains that, in discussing moral evaluation in Summa theologiae Q.18, Aquinas places so much emphasis on the agent’s immediate act (as opposed to its consequences, motives, or aim) because, through this operation, the agent “enters directly into relationships with the external world and, especially, with other people.” Hence, a “choice to act in a given way is tantamount to a choice to enter into a relationship of a specific kind” (181–82). The intentional context created by ‘choice,’ even with the hedge supplied by ‘tantamount,’ makes this inference problematic, and...