This chapter offers Thomistic accounts of natural law and natural justice that differ in important respects from other accounts often associated with Aquinas. The discussion begins by considering Aristotle’s taxonomy of justice in the Nicomachean Ethics and adopted by Aquinas in the Summa Theologiae. This view of justice does not emphasise rules or norms laid down by some higher source, as contemporary natural law accounts often do; rather it emphasises what Aristotle calls particular justice: the personal virtue through which individuals are disposed to respect the legitimate claims – that is, the entitlements – of others. This conception of justice differs significantly from the general or social justice that is emphasized in contemporary political philosophy and jurisprudence. According to the interpretation advanced in this chapter, natural justice is what is owed naturally to members of the community – it provides a pre-conventional yardstick for social dealings, independently of formal legal codes or institutions – and Thomistic natural law is primarily an ethical phenomenon that has been consistently misconstrued in voluntarist and positivist accounts of what natural law entails. Instead of the idea that natural law represents some kind of juridical standard, the author insists that Aquinas’s theory of natural law concerns the intrinsic ethical demand on individuals to act reasonably and responsibly.
Murphy, Tim, Natural Law and Natural Justice: A Thomistic Perspective (2019). Research Handbook on Natural Law Theory (Crowe and Lee (eds), Edward Elgar, 2019), 304–325.