How can justice be both a virtue or perfection of the human person and an external normative ideal? In this book, Jean Porter shows how, for Thomas Aquinas, both the virtue of justice, which governs the will, and external ideals of justice are acquired through human relationships, in particular, through the emotions or moral passions. This extraordinarily clarifying study of Thomas’ virtue of justice sheds light on many aspects of his ethics and moral psychology, including the role of will, reasons, and emotions, and the formation of moral ideals.

Porter begins with a chapter outlining Aquinas’ descriptions of justice as a virtue and as a normative ideal. Thomas’ account of the ideal of justice treats all human beings as worthy of equal regard, as seen in his account of sins against justice. The equal worth of each human being is both a theological claim and a truth intelligible through natural law.

Chapter 2 offers a clear summary of Thomas’ view of the will, showing that even though an understanding of our good is innate, the will needs habits in order to pursue it. While the choices we make aid or hinder us in pursuit of our final end, we also discern the final end through the process of living out and reflecting on those choices.

The next chapter explores the ways Aquinas’ account of justice is and is not an understanding of rights inhering in the individual as a subject. Porter's model of formation of the will through action and reflection reappears, explaining how we incorporate explicit rules of justice into our schema of the good life as we live, interact with others, and come to understand what is due to them.

Chapter 4 asks how norms of justice act on the will. Porter introduces cognitive science and shows how it parallels Aquinas’ understanding of the role of the “moral passions.” Moral concepts originate in ways of relating, being experienced through morally salient emotions before we form reflexive, reasoned concepts of moral right (187ff.) Laws reflected on through reason, and relational interactions experienced through emotions and incorporated into a relational self-concept, can both teach key moral lessons, such as, in the case of justice, the unique value of the human person.

The final chapter explores how the will can both direct us toward our highest good and mediate our relationships with others—returning to the question that began this review. As humans develop, our sense of great goods and of others and their due are formed through the same discursive process. Particular justice is not at odds with general justice in the way it may seem, because both imply commitments to being a particular type of person, pursuing a particular way of life.

Porter's reading of Aquinas combines laser-like detail with voluminous depth. At times, she spotlights the consistent ideological scaffolding that undergirds Aquinas’ claims but that he himself has not bothered to show. Elsewhere, she uses his frameworks to say what Aquinas did not, but could. Porter is scrupulous in identifying where she goes beyond Aquinas, though she never intends to say something he could not agree with.

Porter's use of cognitive science, and her elevation of emotions in moral formation, challenge limiting readings of Aquinas’ understanding of reason. Especially in light of that, I wished for attention to recent work using intellectual disability to deepen or challenge Aquinas’ anthropology. For example, Miguel J. Romero shows how Aquinas’ categories of the human can include persons with such disabilities, while Elizabeth Antus finds that their witness challenges Thomas’ prioritization of reason. Porter also asserts somewhat briefly that her book helps compare Aquinas to justice theorists like Rawls. It would be interesting to see the book's contribution to this perennial contrast developed in more detail, whether by Porter or by a scholar of her work.

This rigorous and magisterial work rewards careful attention. It will benefit theologians and philosophers in fields as varied as human rights, virtue, and anthropology, and any scholar who seeks to better understand how the pursuit of justice fulfills our human nature.