In his influential book The Selfish Gene , Richard Dawkins asserts that “Like successful Chicago gangsters our genes have survived . . . in a highly competitive world, . . . [and so] a predominant quality to be expected in a successful gene is ruthless selfishness.” Therefore, “We are survival machines-robot vehicles programmed to preserve the selfish molecules known as genes.” One might expect from this creation story that Dawkins would repudiate all notions of morality or free will, but not so. Like a Calvinist preacher denouncing the wiles of Satan, he exhorts his readers to robot rebellion. “Let us try to teach generosity and altruism, because we are born selfish. Let us understand what our own selfish genes are up to, because we may then at least have the chance to upset their designs, something that no other species has ever aspired to.”

The logical disconnection between Dawkins’ scientific (or pseudoscientific) explanation of human nature and his moral exhortation may be used to illustrate the starting point for the new natural law philosophy of Germain Grisez, John Finnis, and several others (hereafter collectively designated Grisez-Finnis), which Robert P. George defends in the essays collected in the book under review. At one time the Catholic natural law philosophy of Thomas Aquinas and his followers dominated European thinking, but its metaphysical foundations were undermined as science replaced Aristotelian teleology and Catholic theology with a materialist worldview that considers only efficient causes. The project of Grisez-Finnis is to save natural law by reestablishing it on a secular foundation that does not appeal directly to those metaphysical claims that modern science rejects as outdated.

Even an extreme scientific materialist such as Dawkins has to acknowledge that there is such a thing as moral knowledge, and that it cannot come from science because we cannot derive “ought” from “is.” To avoid allowing the selfish genes to set the moral agenda, Dawkins states a basic proposition that he apparently regards as self-evident-essentially the Golden Rule-and then hastily drops the subject because to develop that line of thought further would undermine his whole project. Just by hinting at the existence of moral knowledge, Dawkins gives us reason to doubt that we actually do live in a world ruled by gangster genes. In such a world honest teachers (if there were any) would be telling their students that a pretense of morality is merely a stratagem by which one gangster induces others to enter into temporary alliances, or cozens some gullible victim to lower his guard.

Grisez-Finnis likewise begin with self-evident first principles that are not derived from any factual propositions about human nature. First, Grisez-Finnis describe some basic human goods, the irreducible categories of things for which it is rational to strive. These have been formulated in different ways, but a typical list would cite life (including health, safety, and procreation); knowledge (including appreciation of beauty); holiness or religion (in the sense of harmony with ultimate reality); self-integration, justice, friendship (in clud ing marriage); and the kind of exercise of skill in work or play that enriches human life. Deliberately missing from this list are such goods as money, which is merely instrumental to achieving more basic goods, and pleasure, which is to be sought not as an end in itself but as a benefit incidental to a rational end, in the way that sexual pleasure is achieved through marriage. Human action is rational when it pursues one or more of the basic human goods, which are “irreducible” and “incommensura ble.” This means that they do not arise from any supposedly more fundamental good and there is no common standard by which one could value them for purposes of exchange.

The basic goods are supplemented by moral principles, sometimes called “modes of responsibility.” The first of these is that we are to strive for integral human fulfillment, meaning that we should lead coherent lives that give each of the basic goods its due. Other important principles are the Golden Rule, which forbids selfishness, and what Grisez-Finnis call the Pauline Principle, which forbids deliberately sacrificing any one of the basic goods to another-i.e., doing evil that good may result. Each of the basic goods must be given its due, and not treated as subordinate to any other good. The new natural law thus contrasts sharply with utilitarianism, which reduces every human satisfaction to the single basic category of pleasure.

The writings of Grisez, Finnis, and their collaborators have been greeted by a barrage of criticism, which is why Professor George has written over three hundred pages of essays in their defense. Much of the criticism comes from scholars of distinction who are favorable to natural law in principle, but who think that the Grisez-Finnis system is not really natural law (because it does not rest on factual propositions about human nature), or that some of its basic propositions are far from self-evident, or that its logic is so convoluted that it tends to turn even the easiest problems into moral dilemmas.

Before getting to the criticisms, however, let us pause to appreciate the worthy goals of the enterprise. I respect the effort to develop natural law principles in terms that might win approval in a secularized age, where a supposedly value-free science holds the epistemological high cards. Some things really are self-evidently good, including the Golden Rule, and there are a variety of fundamentally good things which cannot be reduced to a single measure (such as pleasure). It is better to be Socrates dissatisfied than a fool satisfied, and a philosophy that can’t explain why isn’t much good. Besides, nurturing the qualities of Socrates is the best way to achieve the satisfactions that are cherished by a truly rational being. Proceeding in this way enables us to connect the private good of individuals with the common good of the community, unlike liberal theories of justice that consider only “rights.”

Those sentiments qualify me as a friend to natural law, and yet I share some of the common misgivings with respect to the specific Grisez-Finnis system. Their strong version of the incommensurability thesis has a way of turning easy questions into baffling dilemmas, with its ban on “trade-offs” even in situations where common sense seems to require them. For example, the legal philosopher George Wright argued that by this system it is difficult to know whether a golfer who sees a child drowning in a pond should interrupt his game to rescue the child, since he would be sacrificing one basic good (play) for another (life). George responds that “the Pauline Principle is only one norm among a set of moral norms that may guide choice in such situation. Another member of that set is the Golden Rule, and it is this norm that (most obviously) governs the golfer’s choice by defeating his reason not to spend the time required to save the tot.” No doubt that is the right answer, but it seems to follow in spite of the distinctive features of the Grisez-Finnis system rather than because of them. If I knew someone who was pondering a moral difficulty, I would not encourage him to decide what to do by employing a system that provides so many opportunities for confusion and rationalization.

Another common criticism is that Grisez-Finnis often seem to think that everything can be decided by abstract principles, without regard to the facts or to competing considerations. The most obvious example is the ban on artificial contraception and on inherently non-procreative sexual acts, even when engaged in by married couples. According to George (and his coauthor Gerard V. Bradley, in their essay “Marriage and the Liberal Imagination”), it is proper for sterile married couples to enjoy sexual pleasure even though conception is im pos sible, but it is wrong for fertile married couples to use artificial contra ception or to engage in “sodomitical acts.”

This distinction follows because marriage itself is a basic human good that is “consummated and actualized by sexual acts of the reproductive type” regardless of fertility. From this heavily fortified definitional base George and Bradley reason that sexual acts of the reproductive type typically further the good of marriage, and persons (whether married or not) who engage in sexual acts of the nonreproductive type “necessarily treat their bodies and those of their sexual partners (if any) as means or instruments in ways that damage their personal (and interpersonal) integrity.”

That logic rests heavily on an argumentative definition, and it invites some obvious questions. Is there any objective way to determine whether the alleged damage to integrity has actually occurred? If the wife decided to refuse sexual relations to avoid the risk of annual pregnancies, might that damage the marital relationship more than engaging in sexual acts not of the reproductive type? Should any weight be given to the possibility that the wife (or husband, for that matter) could be freed by effective birth control to achieve other basic goods, such as knowledge or skill at play?

George and Bradley’s strongest argument for their position on sexual morality relies upon tradition, including common law tradition. Not long ago, the idea that oral or anal sex is as natural as the reproductive kind would have been greeted with general disgust, and even legal disapproval. In the age of Clinton, we have come a long way. Is this progress or regress? George and Bradley concede that the distinguished legal philosopher Stephen Macedo (among many others) thinks the change is beneficial because he honestly fails to perceive what to them is self-evident. They don’t blame Macedo personally for this defect, but they do say (in an endnote) that “This is not to say that the culture in which such failures of understanding can honestly occur can come into being without culpable and bad faith rationalizations of morally corrupt dispositions and choices.”

That statement deserves a much more prominent place in the argument. What were those culpable rationalizations, who invented them, and how did they become so influential as to mold the culture? Although they try to avoid calling attention to it, the new natural lawyers know very well that their project rests on metaphysical assumptions that the dominant scientific culture rejects. In an important 1987 article in the American Journal of Jurisprudence , Grisez, Finnis, and Joseph Boyle acknowledged in passing that “what we offer here presupposes many theses of metaphysics and philosophical anthropology-for example, that human intelligence is irreducible to material realities, that doing and making are irreducible to one another, that human persons and their actions are caused by an uncaused cause, and so on.”

How, if at all, do Grisez-Finnis’ metaphysical presuppositions square with what science tells us about our origins and our relationship to ultimate reality? Richard Dawkins merely states in unvarnished form doctrines that other scientific metaphysicians take for granted: In the beginning were the particles and the impersonal laws of physics; life evolved by a mindless, non-teleological process in which God played no part; and human beings are just another animal species. Human thoughts and actions are caused by synapses firing in the brain. To claim a special status for humans is to commit the sin of speciesism , a self-serving prejudice that could hardly arise in a culture without culpable rationalizations. I assume that Grisez-Finnis would concede that their system is insupportable if those widely held metaphysical presuppositions are true.

These issues must be confronted. Aquinas was a great thinker because he successfully addressed the challenge to Christian thought that came from Aristotle and Averroes. Would we even remember Aquinas if he had ducked the challenge, and implied to his readers that Christians could afford to ignore it? Although one cannot go directly from “is” to “ought,” an “ought” can and often does imply an “is.” Metaphysics matters, and moral philosophy cannot afford to pretend that it doesn’t.

The new natural law has established itself in a niche in a rarefied corner of the academic world, and this in itself was no easy accomplishment. If Grisez-Finnis mean to expand their influence out of that corner, they are going to have to persuade people to believe the assumptions about ultimate reality on which their enterprise rests.

Phillip E. Johnson is Professor of Law at the University of California at Berkeley. His books include Darwin on Trial, Reason in the Balance , and Defeating Darwinism.