Nova et vetera

How does the natural law fit the definition of law? Opinions clash among different interpreters of Saint Thomas Aquinas. Stephen Brock's book provides both a magisterial and a definitive answer to this question.

Like fine wine, this book has been fermenting and maturing for almost thirty years. Originally a doctoral dissertation, this recently published work has been rewritten, and to a certain extent, reworked by the author with respect to some of its content.

Without disregard for nuances, the first chapter introduces the reader to four different groups of Aquinas's interpreters. The first two groups question the full legal character of the natural law in its dependence to the eternal law. The third one questions its naturalness. The fourth group, instead, upholds both the divine origin of the natural law's full legality in its dependence on the eternal law, as well as its natural character.

Brock places Dom Odo Lottin, Wolfgang Kluxen, Germain Grisez, and John Finnis in the first group. They maintain that the natural law is a law only in a qualified sense and that it does not entirely fulfill the definition of law. The natural law would provide an intrinsic morality. It should be treated independently from the eternal law. The second group is composed by authors such as Frederick Copleston, Alan Donagan, or Gregory Stevens. Similar to the first group, they argue that the natural law is an autonomous self-standing law, legislated by human reason. Thus, it should be treated independently from the eternal law, except to point out its ultimate origin.

The author who exemplifies the third position is Ernest Fortin. Reacting against Finnis, Fortin's position jeopardizes the natural character of the natural law. In his view, the legal force of the first principles of practical reason is not fully actualized until one recognizes the divine institution sanctioning them. [End Page 981]

All the authors of the fourth group uphold that the natural law is fully a law on account of its divine origin and that it is also entirely natural insofar as it is naturally known by human reason. Herein Brock places commentators of Saint Thomas such as Francisco Suarez, Dominic Farrell, Lawrence Dewan, and himself. He also includes in this last group other philosophers such as G. E. M. Anscombe and Peter Geach. In the course of his whole study, Brock shows how Aquinas's true position differs from the other members of this group. Special attention is given to the differences between Aquinas's true mind and the interpretations offered by Suarez, Farrell, and, to a certain degree, even by Dewan. In order to better appreciate the depth of this process, I have found it very helpful to read Farrell's The Natural Law According to Aquinas and Suarez in conjunction with Brock's work.

The second chapter targets the natural law's legal character in its dependence to the eternal law. It proves that Thomas provides a strict definition of the natural law when he says that it is nothing but a participation of the eternal law in the rational creature. This chapter opens with a historical study concerning the influence of the Summa Fratri Alexandri in the Summa theologiae (ST). Aquinas's understanding of the dependence of the natural law on the eternal law turns out to be more systematic and refined. It is based on a fuller comprehension and development of what law is (the ratio legis).

The remainder of the second chapter consists in a superb commentary regarding ST, I-II, q. 91, a. 2, on whether something existing in man is fit to be called a natural law. Promulgation is the element of the definition of law that specifies the different kinds of laws. Hence, the natural law is differentiated from the others by its natural promulgation, namely, by the act through which the order of the eternal law (already instituted by God...