American Journal of Jurisprudence 39 (1994), with Gerard Bradley.
The theory of practical reasoning and morality proposed by Germain Grisez, and developed by him in frequent collaboration with John Finnis and Joseph Boyle, is the most formidable presentation of natural law theory in this century. Although work by Finnis and others has brought this “new natural law theory” (NNLT) to the attention of secular philosophers, the theory is of particular interest to Catholic moralists. This is because NNLT provides resources for a fresh defense of traditional moral norms, including those forbidding abortion, euthanasia, and other forms of “direct” killing, as well as sexual immoralities such as fornication, sodomy, and masturbation. In part, no doubt, because it provides such resources, Catholics who dissent from the Church’s teaching of these norms have criticized NNLT. Catholic moralists of unassailable orthodoxy (such as the Thomist philosopher Ralph McInerny) have also challenged the NNLT. Their disagreements are essentially interpretative. Grisez and his collaborators locate themselves within the broad framework of the Thomistic tradition, and have advanced interpretations of Thomistic texts in support of key claims. Redoubtable Thomists have challenged those interpretations and, more globally, NNLT’s Thomistic credentials.
Other philosophers, including some non-Catholic natural law theorists, question NNLT’s status as a theory of natural law. Because NNLT’s proponents hold that moral norms cannot be deduced or inferred purely from antecedent facts about human nature, these critics say it cannot be a theory of natural law. Because its proponents eschew a voluntaristic account of moral obligation (and so speak not of a “lawgiver” but of the claims of reason), and because they (particularly Finnis) are critical of much natural law theorizing about the positive law, NNLT is not, critics say, a theory of natural law.
Professor Jean Porter’s recent appraisal of NNLT avoids all these familiar grounds of criticism. She challenges “proportionalism” by the same arguments she advances against Grisez and Finnis. She sketches an alternate position, which she considers broadly Thomistic, but engages no interpretative issue. Porter apparently rejects the claim that practical principles (such as moral norms) cannot be deduced or inferred from purely factual premises, but her disagreement with Grisez and his collaborators on this point is a minor feature of her critique. Although there is evidence that she rejects at least some of the tradition’s moral norms, we must assume that this follows from her criticisms of NNLT, and is not a basis for them.