AQUINAS AND THE NATURAL LAW
A Derivationist Reading of ST I-II, Q. 94, A. 2
Peter Seipel
ABSTRACT
Recent decades have seen a shift away from the traditional view that
Aquinas’s theory of the natural law is meant to supply us with normative
guidance grounded in a substantive theory of human nature. In the present
essay, I argue that this is a mistake. Expanding on the suggestions of Jean
Porter and Ralph McInerny, I defend a derivationist reading of ST I-II, Q. 94,
A. 2 according to which Aquinas takes our knowledge of the genuine goods
of human life and their proper ordering to one another to be self-evident only
to the wise who are able to discern the truth about our God-given human
nature. I then show that this reading provides a better account of Aquinas’s
view than two recent alternatives: John Finnis’s brand of inclinationism and
Daniel Mark Nelson’s virtue-based interpretation.
KEY WORDS: Thomas Aquinas, natural law, human nature, natural
inclinations, new natural law, John Finnis
How do we know what the genuine goods of human life are? And how do
we know the proper way in which to pursue them? These are central
questions in moral philosophy, but there is no scholarly consensus
today as to whether Aquinas attempts to answer them in his well-known
theory of the natural law. In recent decades, many scholars have moved
away from the derivationist reading of Aquinas that we find in commen-
tators such as Thomas J. Higgins (1958) and D. J. O’Connor (1967) and
toward the inclinationist interpretation of the new natural lawyers.
According to John Finnis (1980; 1998), one of the most well-known and
outspoken defenders of inclinationism, our knowledge of the genuine
goods of human life is based on the operation of practical reason and not,
as the derivationist model would have it, derived from a metaphysical
theory of human nature. In addition to supporters of new natural law,
there are also some commentators—including, among others, Daniel Mark
Nelson (1992) and John Bowlin (1999)—who argue that Aquinas’s theory
of the natural law provides only limited normative guidance. Nelson,
arguably the most radical proponent of this position, has defended a
Peter Seipel is a Ph.D. candidate in philosophy at Fordham University. His research interests
include moral relativism and virtue theory. Peter Seipel, Fordham University, Philosophy
Department, Collins Hall 101, 441 E Fordham Road, Bronx, NY, pseipel@fordham.edu.
JRE 43.1:28–50. © 2015 Journal of Religious Ethics, Inc.