Aquinas on Natural Law and the Question of a Kantian Misreading

Article excerpt


The goal of this Article is to provide a brief introduction to some recent debate about what is and is not a Kantian reading of St. Thomas Aquinas's moral theory, in particular his account of natural law. (1) I will proceed in three steps. First, I will briefly review some of the key aspects of Aquinas's account of natural law, drawing primarily from the Summa Theologica. (2) Second, I will sketch the key points in a debate among some leading contemporary German-language scholars--namely, Georg Wieland, Ludger Honnefelder, and Martin Rhonheimer--regarding what is, and what is not, a Kantian distortion of Aquinas's understanding of natural law. Building upon this second section, I will summarize how Martin Rhonheimer's critique of L. Honnefelder and G. Wieland is useful in showing how an "autonomistic" interpretation of Aquinas's doctrine of natural law is tainted by Kantianism. Given that most of the bibliography is in German, I will rely mainly on two works by Rhonheimer that have been translated into English: first, Natural Law and Practical Reason: A Thomist View of Moral Autonomy and second, the chapter entitled "Practical Reason and the 'Naturally Rational'" in The Perspective of the Acting Person: Essays in the Renewal of Thomistic Moral Philosophy where he specifically addresses criticisms of the former work. (3)


St. Thomas Aquinas's account of natural law is located within his treatise on law in Questions 90 to 108. (4) The first question of this treatise is programmatic, articulating fundamental aspects of Aquinas's teaching and providing a general definition of law. In Question 90, we learn that for Aquinas, "[1]aw is a rule and measure of acts" and "something pertaining to reason" which directs actions to the end. (5) "[A]ny inclination arising from a law," moreover, "may be called a law, not essentially but by participation." (6) He writes further that "universal propositions of the practical intellect that are directed to actions have the nature of law," (7) which seems to foreshadow what he will later say about the precepts or principles of natural law. (8) The remaining three articles of Question 90 complete his four-part definition of law: "[A]n ordinance of reason [ordinatio rationis] for the common good, made by him who has care of the community, and promulgated." (9) In an important and overlooked section in Article 4, Aquinas writes that "[t]he natural law is promulgated by the very fact that God instilled it into man's mind so as to be known by him naturally." (10)

In the six articles of Question 91, Aquinas discusses various kinds of law. In Article 2, he treats the eternal law, which functions as somewhat of an exemplar for the rest. He defines it as "the very Idea of the government of things in God," (11) which could be understood as the Divine Mind, as considered under the aspect of how it governs all things. Our interest is in Article 2, where Aquinas asks whether there is a natural law in us. (12) In the sed contra, he quotes a gloss on a text from St. Paul's letter to the Romans 2:14, which considers how "the Gentiles, who have not the law, do by nature those things that are of the law." (13) The gloss reads: "Although they have no written law, yet they have the natural law, whereby each one knows, and is conscious of, what is good and what is evil." (14) This text seems to echo Aquinas's previously cited understanding of how natural law is promulgated by being known naturally. (15)

The response in Article 2 is important. Here Aquinas discusses how

   the rational creature is subject to Divine providence in the most
   excellent way, in so far as it partakes of a share of providence,
   by being provident both for itself and for others. Wherefore it has
   a share of the Eternal Reason, whereby it has a natural inclination
   to its proper act and end: and this participation of the eternal
   law in the rational creature is called the natural law. …