Aquinas’s Theory of Natural Law: An Analytic Reconstruction, by Anthony Lisska. Oxford: Clarendon
Press, 1996, 320pp.
Anthony J. Lisska, in his Aquinas's Theory of Natural Law: An Analytic Reconstruction, undertakes to
provide an account of Aquinas's theory that will merit the attention of analytic philosophers. He does so
largely through arguing that Aquinas' theory of natural law depends upon accepting the notion that man
has an essence and that this essence can be understood largely in terms of the "natural kinds"
recognized by Kripke and Putnam. He develops a plausible interpretation of "essence" as
"dispositional properties," and provides an explanation of these "dispositional properties" as the formal
cause which is in a state of "becoming" to the final cause of human flourishing. He thereby frees
Aquinas' theory from the charge that it is based upon a "static essence", a view which has led many to
dismiss Aquinas. Lisska's presentation is valuable for its updating of Thomistic categories in terms
accessible to analytic philosophers; if such serves to draw the attention of analytic philosophers to
Aquinas, a great service will have been performed.
The book also offers a valuable review of scholarship concerning the philosophy of law,
contemporary commentators of Aquinas (such as McInerny, Veatch, Finnis, and Nussbaum),and
various nonThomistic philosophers (such as Dworkin, Nozik, and Rawls) and a dialogue between
them. Readers who do not have decent familiarity with the scholarship he cites will find the text of
considerable less usefulness. Lisska's treatment of authors is uneven; he responds fairly thoroughly
and usefully to Finnis and Veatch, but the little he does with Nussbaum seems largely to misrepresent
her work and threatens to mislead those not familiar with her work to group her work together with that
As do most after-After Virtue treatment of ethics, Lisska's discussion profitably makes much use
of the claims made by McIntyre concerning the failed enlightenment project of ethics which attempted
to provide a foundation for ethics based on some disembodied reason and which then collapsed into a
Nietzschean emotivism. Lisska also provides a good updating of the development of McIntyre's
evaluation of Aquinas in his after-After Virtue publications. Lisska's text demonstrates, as has many
others, that we all owe McIntyre a debt of gratitude for providing such a clear matrix in which to situate
discussions of ethics. We owe Lisska a debt of gratitude for insisting that the work of Veatch, Simon,
McInerny, and Maritain deserve a reading as interpretations of Aquinas and as philosophic positions
worthy of wider patronage.
One project of the book is to defend Aquinas' natural law theory from the claim that it is vitiated
by the naturalistic fallacy. Here I think he admirably succeeds in showing how "value" is not something
invalidly appended to factual statements for Aquinas; Lisska's discussion of Aquinas' identity of being
and goodness shows how there is not a strict bifurcation of fact and value for Aquinas. Lisska's
presentation is perhaps especially effective against those, as Finnis, who wish to reinterpret Aquinas as
a kind of Kantian who does not derive norms from nature.
While Lisska asserts that he will be drawing his understanding of ANL theory from the ST I-II,
qs. 90-97 and Aquinas' Commentary on Aristotle's Nicomachean Ethics, he really does very little with
the Commentary. I also think he is wrong to neglect the portions of the Summa Contra Gentiles which
bear upon natural law. Lisska's eagerness to win over analytic philosophers perhaps leads him to
downplay portions of A.s philosophy that would be objectionable to them. Lisska rightly insists that A.
natural law theory is dependent upon a philosophical anthropology but perhaps he is not altogether true
to Aquinas in failing to deal with portions of A's text that connect human nature very closely to nature.
Lisska's neglect of the SCG and his fairly adamant and sudden rejection of those who would use
Aquinas' principles to reject contraception (p. 251) perhaps also indicate a determination to make A.
acceptable to analytic philosophers at the expense of a fully faithful presentation of Aquinas.
Lisska also strives to show that A. NL theory can stand independently of any theological claims
and also any tight connection with eternal law, or God. Here he is not careful enough to distinguish
what A. believed as far as how NL is to be justified philosophically and how Aquinas thought it serves
as the foundation of all spontaneous moral reasoning. Certainly, A. thought moral reasoning
necessarily operates in accord with nl, principles; he thought those principles required an
acknowledgement of God as the lawgiver but did not think that all moral reasoners needed to be
conscious of the dependence of their reasoning on God.
The severance of NLT from a tight connection with God makes it difficult to find a source for
obligation in ethics -- it quite reduces Aquinas to an Aristotelian; one "ought" to be good because
thereby one achieves "happiness" or as Lisska prefers "human flourishing." Aristotle thought the desire
for goodness was so tied to the Greek beloved aesthetic good and to the quality of "nobility" that it was
sufficiently compelling for the few, though he thought only the few would find it so compelling. Aquinas'
recognition that the desire to be good is identical to the desire to be "God-like" and that losing out on
being "God-like" is much more than the failure to achieve human-flourishing is an element essential to
his ethics. To reduce Aquinas' ethics to an ethics of "human flourishing." rather guts it of its full power.
Lisska's analytic orientation also causes him to misstate some of the fundamentals of Aquinas.
The two first major philosophical "presuppositions" of Aquinas that he identifies are "A realist
metaphysics is possible" and "Essential properties are possible." Lisska is quick to assert that he is not
making claims about "possible worlds" here but he does not seem to make it sufficiently clear that
Aristotle thought a "realist metaphysics" and "essential properties" to be necessary for a cogent
explanation of reality. No valid reasoning is possible without a realistic metaphysics and without a
recognition of essences.
What fails to emerge from Lisska's account is that A. would largely argue not that others ought
to accept his principles but that in fact they do without acknowledging that they do; that is, A. would
argue that all ethical systems must ultimately refer to human nature to justify their claims; they either
refer to a true account of human nature or a false one, but all ethical claims ultimately are claims about
what is beneficial for human beings -- and that one must know the nature of human beings to determine
what is beneficial for them.
One wonders if Lisska's use of the psychological theories of Carl Rogers is likely to make
Aquinas' work more appealing to analytic philosophers. While analytic philosophers may not find
sociological studies any more enticing, I suspect A. would have found sociological studies of how
certain behaviors affect society to be confirmatory of some of his natural law principles (are alcoholics,
those who commit adultery, homosexuals, etc. happy even by their own testimony?).
Lisska also makes some forays into trying to discover in A.'s NLT a basis for the modern
interest in "natural rights." He acknowledges that his attempt is only a initial foray; certainly a much
tighter definition of right and of the relation between duties and rights are necessary for a truly useful
A few other quarrels that I have with Lisska may be worthy of mention. His references to
practical reason seem to suffer from a failure to recognize that Aristotle and Aquinas spoke of practical
science as well as practical reason and prudence. The insistence of L. and others that A. thought
speculative reason and practical reason to be quite separate activities fails to acknowledge that A. may
well have believe practical science to be quite dependent upon speculative science.
Lisska's book sports three appendices and a bibliography that are not quite as they might have
been. Lisska provides his own translations of A.'s questions on NL but makes the usual error of not
including the portions on the old law (98-19?) that have some important relevance for NL. His use of
McNabb's review of A.'s legal writings belies his own neglect of the SCG and the old portions of the
Summa. I find McNabb's outline of A.s theory of NL reprinted in Appendix 3 to be misleading. Since A.
defines NL as participation in EL and DL as God's revelation of EL, the place of both of them under
"non-eternal" law seems misleading (and is it right to consider "divine law" to be positive law. The
bibliography does not include some authors referenced in the text (James Ross and Fred Miller, for
instance). The glossary seems unnecessary for what seems to be a very sophisticated audience.
Occasionally I sought footnote references for claims made in the text where there were none.
Lisska's book has much of interest for those who think Aquinas has much to offer contemporary
philosophers and have been following the various attempts to situate A. within the contemporary
debates. Again, if it also serves to convince non-Thomists that they have something to learn from
consulting the thought of Aquinas and his interpreters, much will be gained.