Steven JENSEN.  Knowing the Natural Law. From Precepts and Inclinations to Driving Oughts.  Washington, D.C.: Catholic University of America Press, 2015. Pp. 230. $34.95. 978-0-8132-2733-7.  Reviewed by James T. BRETZKE, S.J., Boston College School of Theology & Ministry, Chestnut Hill, MA 02467.

Works on Thomas Aquinas generally fall into one of two broad categories.  One seeks to bring the Angelic Doctor and his considerable wealth of insights from the 13th century into contact with contemporary culture so that we might gain deeper insight into both.  Notre Dame’s Jean Porter is one of the pre-eminent exemplars of this approach.  The other category, in which this current volume finds its home, is to attempt to take the reader back to the 13th century intellectual world of Thomas Aquinas, and in doing so invites us to set aside our own philosophical, intellectual, and cultural approaches to our world and reclaim the vocabulary of Thomas and then armed with that intellectual equipment to do battle with the modern age.  It is hard to say whether the approach works sufficiently well here, or whether the journey is worth the considerable effort involved, though certainly there are some values, especially for younger students in this sort of work, such as an explanation of some Thomistic terminology and their applications which might be a bit puzzling to the uninitiated (e.g., elucidating the logical premise that a proposition that is per se nota cannot depend on a middle term for its proof).

Jensen, who is associate professor of philosophy at the University of St. Thomas in Houston, argues that Thomism allows one to side-step the naturalistic fallacy and an “unacceptable physicalism” and in fact move legitimately from physical observations of nature “is-statements” to moral “ought-statements.”  Ultimately, Jensen concludes that the problematic of “`deriving' an ought-statement from an is-statement has proved to be a red herring.  An ought-statement is in fact a certain kind of is-statement.  It describes a certain kind of necessity, a necessity that applies to an agent insofar as it has an end.  …Nothing mysterious has materialized in this new ought-statement.  Only our manner pf perceiving has changed.” (pp. 148-9).

Programmatically he begins with a textual analysis in Ch. 2 of ST I-II, Q. 94, art. 2 before continuing his journey from “is” to “ought” by way of four levels of reasoning, beginning with purely speculative knowledge (Ch. 3) and then moving to materially (Chs. 4-6) and then virtually practical knowledge (Chs. 7-9) before concluding with “action” (Ch. 10).

Along the way Jensen engages somewhat the cohort of New Natural Law Theorists (Grisez, Finnis et al.) but the treatment is neither sufficiently sustained or with adequate depth to prove particularly helpful in moving this particular debate forward significantly.

Jensen’s arguments and conclusions though I doubt will be as convincing to those troubled by the naturalistic fallacy and the too-easy-transition from descriptive “is-statements” to moral “ought-statements.”  Here wrestling with some of the leading skeptics, such as Josef Fuchs’ magisterial 1988 article on the topic, would have been illuminating to the debate (in English as "Natural Law or Naturalistic Fallacy?" Ch. 2 in his Moral Demands and Personal Obligations, Washington, D.C.: Georgetown University Press, 1993).

Particularly perplexing from the point of view of a traditional Catholic theological understanding of conscience as treated by Thomas through Gaudium et spes are Jensen’s assertions that moral judgments “will have the character of law only insofar as they are perceived as arising from some external command” (p. 157) and that we are not “’bound’ to pursue happiness, because he [sic] does so by nature.  We are bound to do only what we must do by some external necessity” (p. 159).  This would certainly be in tension with the whole Thomistic tradition of the natural law accessed through conscience as a lex indita, non scripta.  Here too some attention to Fuchs’ work on conscience, especially his essay “Our Image of God and the Morality of Innerworldly Behavior” (Ch. 3 in his Christian Morality: The Word Became Flesh Washington, D.C.: Georgetown University Press, 1987) might have proved quite helpful in resolving this conundrum.

Some of Jensen’s concluding statements give the impression that what he means by the “Is-Ought” connection is somewhat different from the classic critiques of this connection.  E.g. he asserts that there is “nothing ‘hypothetical’ (that is, optional) about the natural law and the ought-statements discovered by our reason.  It is part of our nature, inseparable from what we are” (p. 228).  However, the precise way in which we discover these ought statements seems open to debate, despite Jensen’s sweeping conclusion on his final page that the “real divide between Aquinas and modern ethical theory is not whether we can derive an ought-statement from an is-statement; it is whether we have a human nature with an impetus at its center, driving onward toward our completion.  Barring such a nature, ethics in only a game people play” (p. 229).  I would observe that there still is a considerable area of philosophical and theological discussion possible between these antipodes.