Appeared in Vol. 5 No. 3 Download PDF here

For over a decade, the proponents of the so called new moral theology have referred to those who adhere to traditional moral norms as undeveloping, impersonal beings who overemphasize the physical in ethical life. Similar charges of “staticism”, “impersonalism” and “physicalism” have been leveled against the scholarly defenders of the entire natural law tradition. In the following incisive clarification of the Thomist basis for natural law ethics, Patrick Lee demonstrates that none of these scare words can be applied to the traditional position, once properly understood. Thus he faults the “new” theologians not only for their false conclusions, but also for a simple ignorance of what they attack.

Recent years have seen among Catholic philosophers in America and England an important revival and development of the Thomist theory of natural law. Spearheaded by Germain Grisez in Canada, and flanked by William May and Joseph Boyle in the U.S., and by John Finnis in England, a prominent group of Catholic philosophers has not only argued cogently for the natural law tradition, but has also shown its fecundity for dialogue with recent philosophical traditions,(1) empirical psychology, cultural anthropology and sociology.(2) In addition to this relatively new group of moral philosophers, who are united by their debt to Germain Grisez, other philosophers have been expounding and defending the natural law for several decades, such noteworthy thinkers as the Catholic Vernon J. Bourke, and non-Catholics Mortimer Adler and Henry Veatch. In both Catholic and non-Catholic philosophical circles natural law ethics is anything but dead and buried, the natural law is alive and well, not only imprinted on men’s hearts, but overflowing into hundreds of scholarly articles and books.

Meanwhile, many theologians have been showing increased dissatisfaction with the very concept of natural law, and some have even dismissed as antiquated, as conditioned by earlier, pre-scientific circumstances, the notion that there are moral absolutes, that an action may be judged universally morally evil apart from circumstances and ulterior purposes-a key tenet of the natural law tradition.(3)

Why are the philosophers in general defending the natural law much more firmly than are the theologians? Why a resurgence of natural law ethics among Catholic philosophers precisely at a time when many theologians addressing Catholic audiences are ready to abandon the entire idea?

Common to the thinkers first mentioned-Grisez, May, Boyle and Finnis-is the conviction that St. Thomas’s ethical thought has in no way been exhausted in the last century during the general Thomistic revival. In fact, all of these philosophers are convinced that the general or “conventional”9 interpretation of St. Thomas’ ethics presented in many textbooks for Catholic schools has been inaccurate on fundamental points.

The importance of this last must not be underrated. These philosophers are not disputing a mere technical or pedantic question. It is much more than that. Germain Grisez has argued, for example, that the difference between the two interpretations is decisive for the controversy on contraception, that the conventional arguments (those based on the natural law theory found in most “manuals”) are inadequate and open to attack, but that the real Thomistic natural law theory can explain why the Church’s position on this matter is the truth.(4)

All of this naturally suggests the following question: have the theologians (i.e., the particular group in question) seen something the philosophers have not, or is it the other way around? The purpose of this essay is to give at least a partial answer to that question. I shall first summarize the real Thomistic theory of natural law, as it has been explicated and developed by Grisez, May, Boyle, and Finnis (contrasting it with the conventional misinterpretation of it); second, examine the broad sources of the theologians’ dissatisfactions; and third, examine each of these basic objections in the light of the real Thomistic theory.

As early as 1964, in his book Contraception and the Natural Law, Germain Grisez pointed up the existence of two prevalent theories of natural law, the “conventional theory”, found in many textbooks for Catholic schools, and the real Thomistic theory. What often passes for Thomistic doctrine, he said, is in fact Suarezian (from the 17th century Jesuit theologian, Francisco Suarez), not Thomistic, and it substantially differs from the Thomistic theory on fundamental issues.

For both theories, of course, the criterion for moral good and evil is in some way human nature itself, transcending the conventions or customs of different peoples and cultures. For both theories there are objective moral absolutes, and basically the same types of actions are prescribed, and the same types of actions proscribed. Yet, how these precepts are based on human nature differs significance, in the two theories.


According to the conventional theory, the rule for the morality of human actions is “human nature adequately considered.”(5) (Goodness consists in the fullness of being, existing to the degree that is due one: the criterion for what is due a thing can only be its nature, hence goodness consists in conformity to one’s nature.) Man’s nature must be considered according to all his instrinsic and extrinsic relations, and not just according to one aspect. According to his instrinsic relations, man is vegetative, sentient, and rational; according to his extrinsic relations, man is a creature, a fellow creature, and ruler of lower creation. Therefore, according to the conventional theory, a human action is morally good if it conforms to human nature, considered in all its intrinsic and extrinsic relations, and morally bad if not. One compares the direction of the action to that of human nature: if they are parallel the action is good; if not, bad.

The theory succeeds in emphasizing the objectivity of morality, something that any Catholic ethics must do. But it does so by making the content of the moral judgment completely speculative, i.e., a statement simply about what is, about a fact. The judgment that an action conforms or does not conform to human nature is a purely speculative, that is factual, judgment. As a result, to get the force of obligation into the judgment, something other than man’s nature must be invoked.

To accomplish this, the theory invokes God’s will: because God created man’s nature, concludes the theory, this nature is the specific way in which the divine will is communicated to the creature. While man’s nature specifies what he must do and not do, the obligatory force of the imperative derives solely from God’s will.(6), The speculative judgment that an action conforms or does not conform to human nature becomes practical by adverting to God’s will.

According to the Thomistic theory, on the other hand, the transition from the speculative order (thinking about what is, facts) to the practical order (thinking about what is to be done, goods or values) is not achieved through the addition of any premise. Rather, reason has two fundamental functions-speculative reasoning and practical reasoning. And reason becomes practical by starting out that way, that is, by reasoning about what is to be done, instead of about what is.

The only way to reason about what is to be done is to have some goals as starting points for one’s reasoning, some things that are recognized as good in themselves and not just good because contributing to some other goals; otherwise one would have an endless series of goods for another, with no others for which they are good-impossible. The point is clear in spheres more limited than human life as a whole: one cannot figure out what road to take unless he first knows the point or points of destination; a committee cannot decide anything unless it knows what the committee is for, its goal or goals. Just so, a man cannot reason about what is to be done unless he knows what what-is-to-be-done is to be done for. Hence a condition for reasoning practically at all is the knowledge that some thing or things are good in themselves; practical reason needs some goal or goals as principles of its reasoning.

According to the Thomist these goals that form the starting points of practical reasoning are nothing other than the objects of man’s natural inclinations. (It is obvious, or should be obvious, that these goals, or goods in themselves, could not be arbitrary, subject to personal preference or choice; for, to be chosen they would have to be selected on the basis of some previous goal or goals as criteria, and this would bring us back to the original problem.) Man grasps in his natural inclinations that the objects to which they tend are good and therefore to be pursued. This recognition not only makes possible our reasoning about what is to be done, and hence our free action at all, it also prefigures to us the range of what we can be, it prefigures to us the ideals of being human.(7)

For every natural thing has a tendency toward the actualization of its capacities; it is precisely such tendencies that distinguish from each other different types of things, a dog from a tree, a hydrogen element from an oxygen one. The characteristic actions and reactions of a thing manifest that within it is a tendency inclining and determining it toward the fullness of what it can be. Just so, man’s natural tendencies prefigure to him the fullness of what he can be, the specifically human perfections. And it is these human perfections which man grasps in his natural inclinations as goods in themselves, and thus as starting points for his practical reasoning.

Thus, as Grisez, May, Boyle, and Finnis have insisted, the primary criterion in Thomistic ethics for what is to be done is not a human nature, to which one compares the action to see if it runs parallel or not; rather the Thomistic moral criterion consists in the concrete goods towards which man is by nature inclined. Because these goods perfect us as human beings, we ought to-pursue them and never act against them. Because man is a complex being, the goods that perfect him, and  the natural inclinations toward them, are multiple. Among these basic human goods St. Thomas lists: human life itself, the procreative good, speculative knowledge, and friendship or society; Grisez has, I think, filled out the list, adding play, integrity, authenticity, and religion (which last St. Thomas included within knowledge and, friendship).(8)

There is not space here to discuss each of these goods in detail, but three points should be emphasized. First, we must briefly see how these goods are related to the ultimate end of man, according to the Thomist. Although the complete fulfillment of all man’s tendencies, and hence his complete beatitude, can only be had by a direct union with God (the fullness of Being and Goodness), nevertheless, these other proximate goods are not related to that ultimate good as only means to an end, as mere stepping stones; on the contrary, these proximate objects are good in themselves, they are participations in man’s ultimate end and complete beatitude, and should be pursued as such.(9)

Second, as indicated earlier, these goods are not merely extrinsic objects, to be achieved and then forgotten. Rather, these are goods, we realize and participate in, and can always return to to realize more fully; they are open-ended goods not operational objectives.

Third, none of these goods is reducible to any of the others; each good represents a distinctive aspect of human perfection which cannot be accomplished by realizing any of the others. Hence the fundamental moral imperative is that we must respect all of these basic human goods.

Such are, in very brief descriptions, without pausing to discuss controversial points, the “conventional” and Thomistic theories of natural law. The divergence between them may be summarized as follows. For the conventional theory the norm of morality is human nature itself; for the Thomistic theory the moral norm consists in the set of basic human goods, the objects of man’s natural inclinations. For the conventional theory the obligatory force of morality derives solely from God’s will, who created man’s nature; for the Thomistic theory it derives from the goods themselves, which constitute the perfection of being human. For the conventional theory emphasis is placed on order, on keeping within the boundary lines, as it were, of the orientations of man’s nature; for the Thomistic theory emphasis is placed on the goods themselves, towards which man’s nature is oriented.


The present general ferment in moral theology is too well known to need documenting. It is no exaggeration to say that a large group of moral theologians today is in revolt against the traditional Catholic moral system. And since that system has to a great extent been defended by natural law ethics, the latter has also come under attack. The center of the trouble, of course, is the Catholic and natural law traditions’ insistence on universal norms. To buttress their rejection of universal norms, the objections the theologians most frequently make, and the ones they most frequently load with attractive rhetoric, are: 1)that traditional natural law ethics overemphasizes the eternal and the immutable to the point of ignoring important changes in man, and history in general; 2)that it emphasizes the universal or abstract, and ignores the particular or the personal; and, 3)that it ignores the person’s rightful dominion over the natural or the p:.ysical, taking “mere biological laws” as morally normative.

As in any similar case, this simple question must be asked and faced: do the challengers understand what they attack? The question is even more urgent in this case since, as I have tried to show, there is some ambiguity about the position of the challenged. The earlier question also remains: have the theologians (i.e., those dissenting) seen something the tradition has not, or is it the other way around? I shall now consider in turn each of the objections listed above.

Objection #1: Concerning the Principles ofHuman Nature and Ethical Life [“Statfcism “]-Discussing the natural law theory presupposed by the encyclical Humanae Vitae (whose footnotes indicate it is Thomistic), Father Charles E. Curran levels against it our objection #1:

Perhaps the greatest reason for the insufficiency in the natural law theory found in the papal encyclical stems from the shift in horizon from a classicist world view to a more historically minded world view. In a,more historically conscious methodology things have a tendency to become `unstuck’. A classicist approach emphasized the eternal, the immutable, and the unchanging. A more historically minded approach stresses the individual, the particular, the temporal, and the changing…. Humanae Vitae in its methodology well illustrates a classicist approach.(10)

Father Bernard Haering expresses the same sentiment in his popular Morality is for Persons:

The present situation can be described as one of coexistence-but not a peaceful coexistence-with this dynamic society on the one hand, and out-moded structures and habits of thought, meaningless rituals, and customs left over from a completely different milieu and a narrower basis of knowledge on the other.(11)

Actually, these accusations of “staticism” contain two arguments, important to distinguish not only on the grounds of logic, but even more so because of the rhetoric involved. First, the charges certainly mean that societies and persons change in important ways, and that the natural law theory, based as it is on the conception of an immutable human nature, simply fails to do justice to these changes. Fr. Haering clarifies the charge in several places, for example:

Rationalistic understanding of the natural law starts with abstract principles which have been found always to reflect a certain truth…. [But] according to [our] view of natural law, there is a twofold source of profound dynamism. First, although the subject is always the same nature of man, the man of the Stone Age and the man of the modern scientific era are totally different in their interests, languages, horizons, consciences, and powers to conceptualize life. Their worlds provoke altogether different kinds of thinking and questions; their cultural backgrounds have very little in common. Even their biological makeup and their psychological reactions are different. Second, as man begins to shape his world he himself changes, and his basic capacity of self-understanding and of self-expression grows and undergoes remarkable changes.(12)

In other words, this argument seems to involve the denial of what seems the very foundation of traditional natural law theory, the existence of immutable and eternal principles concerning man’s nature. In fairness, we should note that Fr. Haering concedes that “the subject is always the same nature.” Yet, while admitting this constancy, he thinks traditional natural law theory pays insufficient attention to the broader areas of change, which include being “totally different” in interests and thinking ana questions. He does not tell us how both can be true at once, how men today can be totally different in interests and thinking and still have the same nature. (Note also, and we will return to the issue, that the opposite of his claim is taken as a truism in modern anthropology and empirical psychology. Dare I accuse Fr. Haering of ignoring the data of contemporary social sciences?)

The “conventional” theory of natural law handles this objection with apparent ease. It replies that man’s essential nature remains forever the same, that the changes in culture, and so forth, are only accidental, that underlying these superficial changes is man’s immutable nature, and that this immutable nature provides the norm of morality.

While this response is partly true, its implications are dubious. Follow it to its logical consequences and the results are, that 1)ethics studies the abstract, and 2)historical and societal effects are ethically uninteresting-both of which our common sense rejects.

The Thomistic theory handles the objection differently. For the Thomist the criterion is not a nature above time, but the concrete goods towards which concrete human beings tend. History and society here are significant in that our manner of realizing these goods, and the degree of realization possible (or encouraged) differ among cultures. The Thomist does affirm a constancy, a constancy in the goods that must be pursued and respected, but a constancy that is not set opposite or underneath cultural changes. Instead, the Thomist affirms a diversity within unity and a unity within diversity. Change exists in the manner and degree possible of realizing the human goods, together with a constancy in the. goods themselves.

What is the evidence for this constancy? Here, the weakness of the conventional., theory shows itself. When we examine the conventional theory’s response, we find that its argument rests on an epistemological , rather than ethical or psychological reality. “Cultures and societies may change, individuals may change, but human nature itself is immutable,” is the essence of its reply. But the human nature referred to has its immutability thanks to the intellect’s work of abstracting it from temporal conditions: it is immutable not intrinsically so, but negatively, because temporal factors have been left out of consideration. This is but-to say that human nature in the real world is mutable. (This argument was precisely St. Thomas’ criticism of Plato’s theory of separate forms or ideas: while Plato concluded that the real objects of thought are immutable and hence separate from matter, St. Thomas replied that Plato had imposed the intrinsic conditions of conceptual thought upon the real objects of thought, and that, on the contrary, although we conceptualize natures as abstracted from matter and time and hence as immutable, in the real world these natures are material and mutable.(13)) Hence the conventional theory’s defense of the constancy of moral principles is inadequate, and leaves the natural law open to the attacks of theologians or philosophers itching to escape universal norms.

For the Thomist, then, concrete human natures can and do change, but exactly what this means must be understood. Since man is an intelligent and free being, he is called to determine himself to the realization of his potentialities. And since in different cultures he realizes his potential differently, human natures in the real world do change. But this fact is irrelevant to whether moral standards change.

Given that the moral standards are the basic human goods, the objects of men’s basic needs or inclinations, and given that these basic inclinations have in fact not changed, it follows that the moral standards have not changed either.

How does one establish that man’s basic inclinations, and hence the basic human goods, have in fact not changed? The Thomistic answer is, by observation (intelligent and reflective observation, that is) of oneself and others. We need only read the writings that survive from ancient cultures to discover that men then, as well as now, naturally inclined toward the preservation of their lives, the procreative good, knowledge for its own sake, friendship and society, and so on. Is there a man today who would say he has no potential to realize or help realize any of these goods? The Thomist, therefore, does not establish that moral principles are constant by appeal to abstract and supposed eternal truths (for the Thomist, there is only one eternal truth anyway, the Divine). Instead, he adverts to the truth that for as long as there have been men, they have had the same natural inclinations, and therefore the essential goods of the human person are the same today as they ever have been, and the moral principles which these goods prescribe are the same. This is to say that the primary precepts of the natural law (i.e., the precepts concerning the essential goods themselves rather than the conditions or institutions for achieving them) have not changed.

That the basic human drives and goals are constant throughout all cultures is a commonplace among psychologists and anthropologists today. For examples:

Contrary to the statements of.. .exponents of extreme cultural relativity, standards and values are not completely relative to the cultures from which they derive. Some values are as much givens in human life as the fact that bodies of certain densities fall under specified conditions. …No society has ever approved suffering as a good thing in itself. …No culture fails to put a negative valuation upon killing, indiscriminate lying, and stealing within the in-group. There are important variations to be sure …. but the core notion of the desirable and nondesirable is constant across all cultures.(14)

In any culture, given a climate of respect and freedom in which he is valued as a person, the mature individual would tend to choose and prefer the same value directions…. We have the possibility of universal human value directions emerging from the experiencing of the human organism. Evidence from therapy indicates that both personal and social values emerge as natural, ind experienced.(15)

We must accept the importance of drives as motivating factors through-out life. They are `absolutely dependable motives’-found in all men and in all cultures…. Drives, then, form the starting point for our theory of development.(16)

Nothing could be farther from the truth than to say, as Fr. Bernard Haering did, that “the man of the Stone Age and the man of the modern scientific era are totally different in their interests, languages, horizons, consciences, and powers to conceptualize life…. [Their] cultural backgrounds have very little in common.”(17) The real evidence suggests that different cultures are but different ways of cooperating for pursuit of the same basic human goods, varying in emphasis and degree of appreciation, but still having their reason for being from these same goods.

Granted, then, that the moral principles have not changed, could they change in the next generation, or in the one after? To answer, we must distinguish: Were men to receive a new capacity for a specifically distinct and irreducible good, and thus a new basic need or tendency, then a new moral principle would be added, prescribing the pursuit of that good and the avoidance of its contrary. As a matter of fact, with man’s reception of grace and the supernatural virtues, this precise thing has already happened: having received supernatural dispositions or inclinations (dispositions relating to God as He is in His inner Life), man has moral obligations that he would not have in a state of pure nature. (This last, of course, goes beyond the natural law.)

On the other hand, if man lost a capacity for one of the basic human goods, then, naturally, he would no longer be obliged to pursue it, since it would then be impossible. In that case a moral principle would be subtracted, though not in the sense that what was once wrong now became right, but in the sense that man could no longer act with respect to that good at all. (For example, in heaven, pursuit of the procreative good will no longer be possible, and so the prescriptions regarding that good will no longer apply.)(18)

Finally, most of the basic tendencies are necessary to the human being. There is an intelligible and necessary relation between being human and naturally tending toward such goods as preservation of human life, speculative knowledge, aesthetic experience, integrity, friendship and society. This necessary relation, be it noted, is not an abstract relation between eternal or Platonic essences. Rather, it is a necessary relation existing in human beings, and grasped by the intelligence in the concrete data given by observation of things human. It is not an “analytic truth”, unpacking intelligible notes from a verbal definition. It is simply a truth, grasped by our intelligence, that to be a thing which talks, produces art, technology, culture, and the like, necessarily involves being an animal with reason, and that being an animal with reason necessarily entails being naturally inclined toward speculative knowledge, preserving human life, aesthetic experience, integrity, friendship and society, and so on. Hence there is a necessary relation between being a thing which talks, produces art, technology and the like, and being a thing naturally inclined toward the goods mentioned. This necessity exists in the concrete beings, not abstract concepts. And therefore, as long as beings exist who talk, produce art, etc., the basic goods towards which they naturally incline will be the same (leaving open the possibility of additions), and therefore the moral principles which prescribe the pursuit of these goods and proscribe direct action against them are in that sense immutable.

The theologians in question picture the natural law ethician as one who determines the morality of an action by comparing it to an abstract, conceptual essence. This image is far from the truth, and their continual complaints springing from it only show that they have failed to grasp the best in the natural law tradition, Thomistic ethics.

The charge that natural law ethics is only concerned with the static and ignores the dynamic, contains a second argument as well. It also implies that traditional natural law ethics imposes a static view of the ethical life of the individual himself, that it fails to recognize that dynamism or real growth ought to characterize the individual’s moral life. Here again the divergence of traditional natural law theories becomes important.

One of the main problems with the “conventional” theory is precisely on this point. Because the source of obligation or motivation is one thing (God’s will) and the criterion of what to do and not to do is another (human nature itself), the moral objective becomes simply to stay within the boundary lines set by human nature. Human nature is placed over against freedom, setting its limits, while freedom can roam as it pleases within those boundaries.

In the Thomistic theory, however, not only is the dynamism of an individual’s ethical life not slighted; on the contrary, this dynamism is the very foundation for the criterion of morality. For the foundation of Thomistic ethics is nothing other than the tendency or dynamism toward full actuality found in the very being (esse) of the human person. To reach back to the metaphysical roots of Thomistic ethics is to see that for the Thomist all created being is dynamic, all created being seeks its perfection or goodness: “It belongs to the same nature [ratio] both to tend toward the end and in some way to rest in the end; …Now these two are found to belong to existence [ssse] itself.”(19) Since moral goodness is nothing other than the specifically human goodness, it follows that ethics rests on the human esse’s dynamism toward perfection. This ethics is not rooted in a static, abstract nature.

Moreover, the goods that form the first principles of practical reason do not.just set boundaries for the range of human freedom, but prefigure to freedom its ideals, prefigure to it the whole range of human accomplishment (on the natural level), beckon the moral agent to an ever fuller life.(20) Failure to grasp these points partially explains the charges of “staticism”; it does not, however, excuse them.

Objection #2: Concerning Rules [Impersonalism]-Closely related, but logically distinct, from the charge of “staticism” is the objection that traditional natural law ethics relies merely on cold, abstract rules to the neglect of concrete human persons. For example, in the recent study on human sexuality, commissioned by the Catholic Theological Society of America, the authors say:

It is not surprising then that recent developments in moral theology have called into serious doubt the impersonalism, legalism, and minimalism that often result from such an act-oriented approach. Focusing on the isolated act and assigning it an inviolable moral value in the abstract left little room for consideration of the personal and interpersonal values that are central to genuine morality.(21)

The implication, met with again and again in the writings of recent moral theologians, is that the insistence on universal norms in traditional natural law theory is due to insensitivity to the concrete human person and worship of abstract rules. A proper understanding of the existential ethics of St. Thomas, however, shows that the defense of ethical absolutes constitutes a defense of the person himself and his inalienable rights. For the basic human goods towards which men are naturally inclined are not merely extrinsic objects to achieve; rather, these are goods we realize and participate in, and so they are intrinsic to the person, irreducible aspects of the human person. Hence to act directly against any of these goods is to act against the human person. (22) That is why actions directed against basic human goods are wrong no matter where, when, by whom, with whom, or in what manner they are done-that is, no matter what the circumstances.

The irony of this charge appears when we reflect on what principles theologians such as Charles Curran and Richard A. McCormick would substitute for some of the traditional universal norms. In effect, they advise us in “conflict situations” to consider the consequences as supreme-to be part-time utilitarians as it were. On this view, we may violate a basic human good in “tough cases”, when the consequences of not doing so would be dire.

But, far from injecting a bit of personalism into an otherwise cold, abstract approach, this move would accomplish the exact opposite. It would make us ignore the intrinsic meaning of the human act itself (the will-act directed toward the destruction of a basic human good), and subordinate it to the calculus of future, expected consequences. Hence this move technicizes rather than personalizes human action.

Precisely because our choices have instrinsic meaning, an act of will directed against a”.,sic human good, which is an essential, personal good, is already morally evil, and cannot recover from that moral evil by any expected consequences or ulterior purposes. The primary measure of morality is not simply the expectation of external consequences (the extreme of utilitarianism), nor is it only the interior attitude of the moral agent independent of his external behavior (the extreme of “situationism”), but it is the intrinsic proportion of the w-1411-act to its (external) object. (23) The moral reality is our love or hatred for persons in all their dimensions, our love or hatred for the basic human goods. We must not condone the reduction of any person to the status of mere utility for expected future consequences. To call such a reduction “personalism” is nothing but a travesty.

Objection #3: Concerning Biological Laws [“Physicalism “]-By far the greatest source of controversy for moral theology in the last decade has been Pope Paul VI’s Humanae Vitae, condemning as intrinsically wrong the direct prevention of conception. This issue has sparked the charge that Thomistic ethics (whence the Pontiff drew his encyclical) places far too much emphasis on the finality of “mere biological laws”. Biological laws, it is argued, are not sacrosanct; they may and should be violated for the sake of “personal” values. The issue also arises in discussions of abortion, homosexuality, masturbation and premarital sex. According to Fr. Charles Curran, this error of  “physicalism” finds its source in St. Thomas’ relying on Ulpian:

The general Thomistic thrust is towards the predominance of reason in natural law theory. However, there is in Thomas a definite tendency to identify the demands of natural law with physical and biological processes…. A major influence is Ulpian, a Roman lawyer who died in 228. (24)

Instead of taking mere biological laws as normative, as did primitive people”,

We contemporary people use artificial heat in the winter and air conditioning in the summer to bring nature into conformity with our needs and desires…. We could never tolerate a theory which equates human happiness with conformity to nature. We interfere with the processes of nature to make nature conform to us.(25)

The “conventional” theory of natural law would argue against contraception, fornication, masturbation and other sexual sins (the area in which this charge of “physicalism” most frequently appears) by simply comparing the order of the act to the order of the procreative faculty. Since the actions do not conform to the order of the faculty, they are judged wrong. Although the conclusions reached are correct, the problem with this approach is that it is not obvious why We use of a faculty oriented toward one good, in order to attain a different good, is instrinsically wrong. Also, it does not seem that the perversion of every faculty is always wrong: is it morally wrong, for instance, to induce vomiting when the digestion of the food eaten may cause pain (a frustration of the nutritive faculty)?(26) Many of the arguments against sexual sins, while reaching true conclusions, do not argue successfully, do not show precisely why the actions in question are wrong.

Germain Grisez and William May have done monumental work in this area, and their work provides the foundations for a needed renewal in familial and sexual ethics.(27) As they point out, the real question is not about the order itself of the faculty, but about the essential and irreducible human good towards which the faculty or power tends. We may licitly frustrate the nutritive power, because its direct object, nutrition, is reducible to the fundamental, and itself irreducible, good of human life; thus, the essential good towards which the power is ultimately ordered is not negated. But the procreative good (at stake in contraception) is an irreducible, essential human good. Therefore, it must be respected and never acted against. So too, the integration of the different aspects of our self, such as the bodily and the spiritual, is a basic human good, and so it must not be negated (as in masturbation(28) or in homosexual acts(29)). In short, the traditional list of sins is indeed a list of sins, but they are sins because they are acts aimed directly against basic human goods. What Grisez and May have done is apply St. Thomas’ principles to these questions, something that St. Thomas himself did not always seem carefully to do. Hence much of the controversy surounding the traditional positions on sexual questions has resulted from the confusion between the Thomistic position and its consistent application on the one hand, and an inadequate understanding of natural law on the other.

But more interesting than this confusion is the view of the human person implicit in such charges of “physicalism”. The more primitive societies, it is argued, viewed sex almost exclusively from the biological or physiological level, whereas today we are realizing and emphasizing more the interpersonal dimension. Human sex, the argument continues, is essentially “an encounter between persons.”(30)

As Grisez has shown, the tacit assumption in these charges is that the biological processes have no meaning in themselves, but receive their total meaning through the imposition of intentions. The person is implicitly identified with a consciousness or “subjectivity”, somehow lurking behind the body and using it as an instrument.(31) Biological processes and physical acts, therefore, are not of themselves personal, but become personal by being assumed into the personal sphere. Hence the violation of “mere biological laws” becomes quite neutral: all is permitted on the biological level, and hence in physical sex, as long as “another person is not treated as a thing.”

In truth the human person is not just a consciousness or “subjectivity” using the body as a tool, but a composite of body and soul, so that his or her biological processes are integral aspects of the person he or she is. Man’s animality is not on one side and his rationality (or “subjectivity”) on the other; rather, these different aspects of the person permeate each other, so that man’s animality is rational and his rationality animal.(32) Hence the inclinations that man shares with other animals are not in man purely animal or subhuman. And so, the bodily aspect of man is intrinsically personal, and the goods towards which his animal inclinations tend are human, personal goods. (This should be very obvious to all, though it is not, in the case of the procreative power: the object of this power is a new human being, made in God’s image. Yet it is frequently argued that what is at stake in contraception is a “mere biological” process.)

The implicit dualism behind the charge of “physicalism” shows clearly in the arguments of Fr. Charles Curran:

One cannot brand all premarital sex under the same blanket condemnation of fornication. There is quite a bit of difference between sexual relations with a prostitute and with a spouse to be. Criteria which cannot come to grips with the differences involved in such cases do not seem to be adequate criteria. An emphasis on the physical and the natural, as opposed to the personal aspect of the action, also falls to see the need of growth and development as a person gradually strives to achieve a mature sexuality.(33) (Emphasis added)

It also shows clearly in the arguments of Fr. Bernard Haering:

For modern people, it is hardly conceivable that we can read from the common nature of animals the norm for marital intercourse and the rearing of children! That nature which man has in common with animals is the subject of biology and zoology but in no way does it specify an ethical norm. As for theology, it has no place in biology; its role is defined in the context of man’s relationship to God and his fellowmen. What pertains only to the biological or zoological domain remains theologically neutral. Whenever the biological enters the human context, it also enters theology, and precisely at the point of a person’s responsibility to God and to his fellowmen …. (34)

Curran can contrast the physical and the natural with the personal aspect, only if the personal does not already include the physical and the natural. Haering can speak of the biological entering the human context, and therefore theology, only if of itself it is outside the human or personal order. Though the authors in question consciously disavow any dualist view of man, such a view becomes a tacit assumption when they speak of the foundations of natural law.

This revolt against traditional moral norms is proclaimed by the theologians in question as a liberation from biological laws for the sake of personal values, as “a great step forward for mankind”, a proof that contemporary man has grown up and left behind childish and “primitive” views. In truth, however, the attitude implicit in their arguments and positions is merely the reappearance of a much older and sinister outlook, one against which Western man has had to struggle for many centuries.

As far back as the second century A.D., St. Irenaeus narrated a very similar logic, when he explained the position of the Gnostics, whom he fought resolutely:

For, as it is impossible for the earthly element to partake in salvation, not being susceptible of it, so it is impossible for the spiritual element (which they pretend to be themselves) to suffer corruption, whatever actions they may have indulged in. As gold sunk in filth will not lose its beauty but preserve its own nature, and the filth will be unable to impair the gold, so nothing can injure them, even if their deeds immerse them in matter, and nothing can change their spiritual essence. Therefore the most perfect among them do unabashed all the forbidden things of which Scripture assures us `that they which do such things shall not inherit the kingdom of God.'(35)


Although the new gnostics do not proclaim matter to be positively evil, still the basic premise is quite similar: that of itself the physical has no meaning for the human person, a spirit or “subjectivity”.

Gnosticism is usually associated in sexual morality with rigorism, but as an historical fact, gnosticism or extreme dualism has always in practice led to both rigorism and libertinism; the medieval Manicheans, for instance, were as well known for the one as for the other. Whether you conclude from their premise that sex is inherently evil or that all is permitted in sex as long as “another person is not treated as a thing”, the basic idea is the same-the gnostic idea that the physical of itself has no meaning for the person.

The same logic was used by such gnostic sects as the Beghards, the Catharists, the Anabaptists, and the Quietists, to justify “merely biological” disorders.(36) The so-called liberation from biological laws is not a new discovery by modern scientific man; it is a patrimony from ancient gnostic man.


I have noted that among Catholic philosophers today there is a resurgence of natural law thinking, and that precisely at this time, there is a great deal of dissatisfaction with traditional natural law ethics among moral theologians. I noted a divergence in interpretations of the natural law, a divergence between the “conventional” theory (for lack of a better label), presented in many textbooks for Catholic schools, and the real Thomistic theory, explicated by Germain Grisez, William E. May, Joseph Boyle, and John Finnis. I asked whether the theologians in question have seen something the philosophers have not, or whether the opposite is the case.

Examination of three of the most basic objections raised by the moral theologians against the natural law tradition suggests that the philosophers have seen something the theologians in question have not. The charges of “staticism”, impersonalism, and “physicalism” show nothing but a failure to grasp Thomistic principles and implicit errors on the nature of the human person. What the philosophers have seen, and the theologians in question have missed, is the best in the natural law tradition: the ethical principles of St. Thomas Aquinas.


1 For a beginning in the literature: Germain Grisez, Contraception and the Natural Law (Milwaukee: Bruce, 1964); Abortion.- the Myths, the Realities and the Arguments (N.Y.: Corpus, 1970); Germain Grisez and Russell Shaw, Beyond the New Morality, The Rosponsiblities of Freedom (London: Notre Dame, 1974); William E. May, ‘ Human, An Invitation to Christian Ethics (Dayton, Ohio: Pflaum, 1975); Joseph M. Boyle, “Aquinas and Prescriptive Ethics” in Proceedings of the American Catholic Philosophical Association, vol. 46 (1975), pp. 82-95; John Finnis, “Natural Law and Unnatural Acts” in Help Journal, vol. 11 (1970), pp. 365-387.

2 See especially G. Grisez, Contraception and the Natural Law, pp. 60-72; William May, Becoming Human, pp. 53-75; W. May, “The Natural Law, Conscience and Developmental Psychology”, Communio, vol. 2(1975), pp. 3-31.

3 E.g., Charles E. Curran, Themes in Fundamental Moral Theology (London: Notre Dame, 1977), pp. 121-142.

4 G. Grisez, Contraception and the Natural Law, pp. 19-42, 46-53, 60-72, 76-103; Cf., G. Grisez, “A New Formulation of a Natural Law Argument against Contraception”, The Tboniist, vol. 30 (1966), pp. 343-356.

5 A clear presentation along these lines is: Thomas J. Higgins, S.J., Man as Man: The Science and Art of Ethics, rev. ed. (Milwaukee: Bruce, 1958), see especially pp. 64-68. An important source is: Francisco Suarez, S.J., De legibus ac Deo legislatore. For brief treatments of different theories of natural law see: Thomas E. Davitt, S.J., The Nature of Law (St. Louis: B. Herder, 1951).

6  See Suarez, Ibid., BK. II, cc. 8, 13, 14, 15.

7 St. Thomas, Summa Theologiae, Pt. I-II, q.94, a.2; q.1, a.6c. Cf. G. Grisez, “The First Principle of Practical Reason: A Commentary on the Summa Theologlae, 1-2, Question 94, Article 2″, Natural Law Foram, vol. 10 (1965), pp. 168-201. Grisez’s article has been reprinted in: Anthony Kenny, ed., Aquinas: A Collection of Critical Essays (Garden City: Doubleday, 1969).

8 St. Thomas, Summa, Pt. I-II, q.94,a.2; G. Grisez and R. Shaw, Beyond the New Morality, pp. 64-74.

9 St. Thomas, Summa, Pt. I-II, q.l,a.6, ad 1 and ad 2; q.3, a.2, ad 4; a.4, a.5.

10 Charles E. Curran, “Natural Law and Moral Theology” in: Charles Curran, ed., Contraception: Authority and Dissent (N.Y.: Herder and Herder, 1969), p.169.

11 Bernard Haering, Morality is for Persons (N.Y.: Farrar, Straus and Giroux, 1971), p.4.

12 Ibid., p. 154. Compare the more recent, but not as popular, Ethics of Manipulation (N.Y.: Seabury, 1975) pp. 62-66.

13 St. Thomas, Summa, Pt. I, q.84, a.1; q.85, a.1, ad 1; In Boethil de Trinitate, q.5, a.2c.

14 Clyde Kluckhohn, “Values and Value Orientations in the Theory of Action: An Exploration in  Definition and Classification” in T. Parsons and E. Shils, eds., Toward a General Theory of Action (Cambridge: Harvard U. Press, 1959) p.148.

15 Carl Rogers, “Toward a Modern Approach to Values: The Valuing Process in the Mature Person” in Journal of Abnormal and Social Psychology, vol. 68 (1964), p. 167.

16 Gorden Allport, Pattern and Growth in Personality (N.Y.: Holt, Rinehart and Winston, 1961) p.91. Cf.: Abraham Maslow, Motivation and Personality (N.Y.: Harper, 1954) pp. 66ff; A. Maslow, “A Theory of Human Motivation” in Psychological Review, vol. 50 (1943). For a general assessment of anthropologists’ and psychologists’ views, see: Peter A. Bertocci and Richard A. Millard, Personality and the Good (N.Y., David McKay, Co., 1963).

17 B. Haering, Morality Is for Persons, p. 154.

18 See G. Grisez, Contraception and the Natural Law, pp. 115-126.

19 St. Thomas, De Veritate, q.21, a.2.: “eiusdem rationis sit tendere in finem, et in fine quodammodo quiescere; … Haec autem duo inveniuntur competere ipsi esse.” Cf. Frederick D. Wilhelmsen, Christianity and Political Philosophy (Athens, Georgia: University of Georgia Press, 1978), p.33.

20 See W. May, “The Natural Law, Conscience and Developmental Psychology”, pp. 24-31.

21 Anthony Kosnik, et al., Human Sexuality, New Directions in American Catholic Thought (New York: Paulist, 1977) p.89.

22 G. Grisez and R. Shaw, Beyond the New Morality, pp. 128-136.

23 St. Thomas, Summa, Pt. I-II, q.18, a.2c and ad 3; Cf.: G. Grisez, Abortion, the Myths, the Realities and the Aguments, pp. 292-297; W. May, Becoming Human, pp. 79-107; J. Boyle, “Praeter Intentionem in Aquinas” in The Thomist, vol. 42 (1978), pp. 649-665; J. Finnis, “Natural Law and Unnatural Acts”, pp. 366-379.

24 C. Curran, Themes in Fundamental Moral Theology, p.35.

25 Ibid., p. 42.

26 G. Grisez, Contraception and the Natural Law, pp. 19-32.

27 In addition to their other works already cited, see: G. Grisez, “Dualism and the New Morality” in Atti del Congresso Internazionale (Roma-Napoli, 17-24 April 1974); Tommaso d’Aqaino nel suo SetNmo Centenarlo, vol. 5: L’Agir Morale (Napoli: Edizione Domenicane Italiane, 1977), pp. 323-331; W. May, “Sexuality and Fidelity in Marriage” in Commnnio, vol. 5 (1978), pp. 274-293; W. May, “Fertility Awareness and Sexuality” in Linacre Quarterly, vol. 46 (1979), pp. 20-26.

28 Integrity as a basic human good consists in the inner harmony of different aspects of the self: see G. Grisez and R. Shaw, Beyond the New Morality, pp. 67-68. The masturbator identifies his body as a mere tool for gratification or release of tension, and identifies himself, thus, as a pure consciousness making use of his body. Hence masturbation violates the basic human good of integrity, in this case the harmony of body and soul; it is a dualism in practice. See also: G. Grisez, “Dualism and the New Morality”, loc. cit.

29 Similar to masturbation, in homosexuality the person negates his or her own maleness or femaleness, in an impossible quest to complement the homogeneous. That is, sexuality demands a complementarity; in ignoring this demand, the homosexual either reduces his sexuality to an implicit narcissism or, by seeking in the other what is not there, reduces him to an instrument for experienced security or gratification.

30 For example, the authors of the study on human sexuality commissioned by the CTSA want to redefine the purpose of sex as: “creative growth toward integration”. If the word were being learned for the first time, who would ever guess from such a definition of its purpose that sex had anything to do with the body?

31 G. Grisez, “Dualism and the New Morality”, entire.

32 For an exposition of Aquinas’ defense of this point, see my “St. Thomas and Avicenna on the Agent Intellect”, forthcoming in The Thomist.

33 C. Curran, Themes in Fundamental Moral Theology, p. 174.

34 B. Haering, Medical Ethics (Notre Dame, In.: Notre Dame, 1973) p.55.

35 St. Irenaeus, Adversus Haereses, I, 6, 2-3, cited in Hans Jonas, The Gnostic Religion (Boston: Beacon Press, 1963) pp. 270-271.

36 Ronald Knox, Enthusiasm, A Chapter in the History of Religion (London: Oxford, 1950) pp. 103, 100, 136, 258-259.