1. The first principle of practical reasoning directs one toward the fulfillment to be realized in and through human acts: Good is to be done and pursued. Since, as St. Thomas points out, people grasp as goods all the fulfillments to which they are naturally inclined, it follows that there is a basic precept of natural law corresponding to each natural inclination (see S.t., 1–2, q. 94, a. 2; sup., q. 65, a. 1). Thomas very briefly sketches these inclinations and the goods to which they call attention, while in chapter five of the present work the basic human goods are described and distinguished in greater detail. The general determinations of the first principle of practical reasoning are these basic precepts of natural law. They take the form: Such and such a basic human good is to be done and/or pursued, protected, and promoted.
2. The practical principle which directs thinking to each basic human good is a self-evident truth. It proposes that particular good as something to be pursued and protected, while directing that what is contrary to it be avoided and prevented. For example, life is naturally understood as a good to be preserved, death as an evil to be prevented. Since, however, basic human goods have many distinct aspects (for example, life can be understood in terms of survival, health, safety, and so on), it is impossible to make a simple, exhaustive list of the basic precepts of natural law.
3. Although these general determinations of the first principle of practical reasoning are self-evident, people usually do not advert to them even when thinking in light of them. A man seeking food for his family or a woman caring for her baby is proceeding on the assumption that life is a good to be preserved, but the principle is taken for granted, not articulated. How the basic human goods can be defended in theoretical reflection has been treated previously (5‑C). But there is another question to be considered: How do they come to be known naturally, so that people take them for granted and use them as starting points in practical thinking?
4. Basic themselves, these principles cannot be learned as conclusions from more basic truths. People do “learn” them, but in a different way. As they develop, individuals experience their natural inclinations and the things which fulfill these inclinations. This experience begins at the sensory level but goes beyond it (see S.t., 1–2, q. 94, a. 2; cf. q. 51, a. 1; q. 57, a. 4). For example, infants are naturally curious, and their curiosity is initially satisfied as a result of instinctive behavior, with intellectual satisfaction the reward. In time, insight into the total experience of natural inclinations and their fulfillment prompts children to project goods as possibilities which can be realized by their own action. Thus, even before they make choices, small children spontaneously act to realize goods they understand. Finally, the experience of free choice itself becomes part of the data for understanding existential goods such as justice and friendship. (Appendix 1 provides a fuller discussion of how one comes to know the basic human goods.)
The principles of practical reasoning clearly are understood by small children. They can consider them one at a time. Simple willing is the disposition toward the good which responds to the basic practical principles; acts done by spontaneous willing require only the further understanding that some possible manner of acting will participate in one of the goods.
The fact that small children in their premoral acts proceed according to the principles of practical reasoning thus far described helps to make clear that an additional principle is required to account for the distinction between moral good and evil. The basic principles of practical reasoning make possible all human acts. Morality is in choices, in acts consequent upon choices, and in forms of voluntariness somehow conditioned by choices or by the failure to make them when one could and should make them. To determine questions of morality, a principle is needed which will refer to choices and indicate how they are to be made.
The process of experience and insight by which we come to know the basic principles of practical reasoning is very different from the process by which we come to have and articulate wants for specific goods, which sometimes are adopted as objectives of freely chosen acts. The latter process (of having and articulating specific wants) presupposes and follows from the former process (that of understanding goods as fields of practical possibility and being disposed to them by simple willing).
One can have a want for a specific good merely in virtue of its appeal to sensory experience and feeling—for example, a sexually stimulating image can arouse sexual desire. Such a want can be articulated as an intelligible objective by thinking of ways in which satisfying the desire might contribute to virtually any of the basic human goods. For example, one can think of the possible experience as an experiment which might satisfy curiosity, as a performance which might be carried on with more or less skill, as a way of lessening pain (sexual tension), as a way of having a feeling, at least, of self-integration (getting rid of temptation by giving in to it), as a way of being true to oneself (a rationalization of perversion used by some), as a way of experiencing and celebrating interpersonal relationship (one of the reasons for marital intercourse), or as a ritual act (such as temple prostitution). One can understand the same possible behavior under two or more goods simultaneously, and thus have multiple reasons which could make it a possible object of choice.
5. These general determinations of the first principle of practical reasoning concern goods which are definite as natural human inclinations are; yet these same goods are to be realized indefinitely—that is, they are always to be realized, and new ways of realizing them can always be found. In acting for a good, one gradually comes to perceive its possibilities more and more fully. Thus, human nature and natural-law morality are both stable and changing (cf. S.t., 1–2. q. 94, aa. 4–5). Stable, in that the givenness and fundamental unalterability of natural inclinations account for the unalterability of the principles of natural law; but also changing, in that the dynamism of the inclinations, their openness to continuing and expanding fulfillment, accounts for the openness of natural law to authentic development.
6. Examples clarify this important point. Since people always know that human life is a good to be acted for, they always know that sickness is to be resisted. The natural inclination toward health and what protects and promotes it is constant and unchanging. Modern medicine, however, has given “health” a much richer content for us than for people of any previous era. Thus, even with regard to the basic good of life, the possibilities of human fulfillment are only gradually specified as humankind realizes and experiences them, then presses on to expand them further. This is even more clear in the case of friendship. One begins to understand what it means before adolescence, and thereafter the basic inclination—to get along with other people—does not change. But as one grows and matures, so does one’s understanding of the possibilities for human fulfillment present in friendship; and specifically Christian friendship has a far richer meaning, modeled on Jesus’ friendship for us, than friendship which is unformed by gospel values.
It often is suggested today that human nature changes. If so, actions appropriate in one time and place would no longer be appropriate in another. Moral truths would be transient.21 How does the account of natural law articulated here help to deal with this question?
One point to notice is that the basic forms of good open up the possibilities which make for all sorts of cultural solutions under varying historical conditions. But one does not find a human culture in which death is considered good and life bad, or one in which conflict within the group is regarded as humanly fulfilling. The problems are basically the same for people always and everywhere.22 The beliefs about what will help solve them are different. Insight into human possibilities is more or less extensive and accurate in some places and times than in others.
From the perspective of Christian faith, the effect of sin cannot be overlooked. Without the light of divine revelation, humankind is incapable of consistently grasping and accurately following out the implications of what truly is humanly good. The New Testament authors were well aware that the conventions of societies do not always direct persons to their true fulfillment, and so they warned against the temptation to conform to conventions at odds with the gospel (see Rom 12.2; Eph 4.17–19; 5.3–8; 1 Pt 4.2–3). Very often, whole societies settle for solutions which mutilate human nature. This mutilation is a kind of change, but not one which sets new and better standards.
At the same time, the open-endedness of human goods, their multiplicity, and the extremely varied opportunities provided by diverse natural and cultural environments for participating in them do make for a great deal of variety and invite a creative approach to human life.23 Human nature in its historical actuality can be changed for better or for worse—this is a fundamental assumption of Christian morality with its awareness of the impact of sin and grace. Thus Vatican II teaches that Christ, the perfect man, reveals to human persons what human nature can and should be. All human persons can be united to him and perfected in him (see GS 22, 29, 41, 45; LG 13, 40).
The human nature which is a standard for morality is not a formal essence and set of invariant relationships, as was suggested by inadequate, scholastic natural-law theory. Rather, the standard is the basic possibilities of human individuals as bodily creatures, endowed with intelligence, able to engage in fruitful work and creative play, psychically complex, capable of more or less completely reasonable action, in need of companionship, capable of love, and open to friendship with God in whose image they are made. If these possibilities in their basic givenness are what is meant by “human nature,” then human nature does not change. Thus, after an extended description of cultural changes through history, Vatican II teaches: “The Church also maintains that beneath all changes there are many realities which do not change and which have their ultimate foundation in Christ, who is the same yesterday and today, yes and forever” (GS 10; cf. Heb 13.8).
Indeed, when “nature” is understood in terms of basic human possibilities, the very notion that human nature could change is logically absurd, for “change” not only in respect to actuality but also in respect to basic possibility would no longer be change but simple loss of identity. Thus, those who use human historicity to support the new morality need not be taken seriously, for they cannot show that there are human persons for whom life, knowledge, friendship, and so forth are not basic goods.
21. For a typical statement of the view being evaluated here, see Charles E. Curran, Contemporary Problems in Moral Theology (Notre Dame, Ind.: Fides Publishers, 1970), 116–36. See also Michael Bertram Crowe, The Changing Profile of the Natural Law (The Hague: Martinus Nijhoff, 1977), 258–59, 266–75, and 286–89. In part, Crowe bases his position (289) on St. Thomas’ statements that human nature is mutable, but Crowe himself had shown in a previous article that these statements only mean that human nature exists in diverse conditions which leave human persons (unlike angels) open to change: Michael B. Crowe, “Human Nature—Mutable or Immutable?” Irish Theological Quarterly, 30 (1963), 204–31. In part, Crowe’s grasp on natural law is defective, since he interprets the first principle as a moral imperative (Changing Profile, 177) and in general thinks of human nature’s role according to scholastic natural-law theory (criticized in 4‑F). With its formalistic understanding of nature, this theory cannot accomodate the dynamism of history; hence, Crowe, Curran, and others imagine that human nature and natural law must be thought to change to make room for this dynamism. If one understands human nature as an open-ended set of possibilities for personal and communal self-creation, then this dynamism can be explained in terms of unchanging human nature expressed in a basically unchanging understanding of goods to be realized in ever new ways. Against the historicism of post-Hegelian thought: Dario Composta, “Anchora sul diritto naturale: l’antropologia classica di fronte al diritto naturale, in un confronto con le recenti filosofie negatrici,” Euntes Docete, 32 (1979), 117–38.
22. See Alexander MacBeath, Experiments in Living: A Study of the Nature and Foundations of Ethics or Morals in the Light of Recent Work in Social Anthropology (London: Macmillan, 1953); Morris Ginsberg, On the Diversity of Morals (London: Mercury Books, 1962), 130–48; Robert H. Lowie, An Introduction to Cultural Anthropology, new and enlarged ed. (New York: Rinehart, 1940).
23. From this point of view, cultural evolution is seen to be as essential and constant as any of the other unchanging aspects of human nature. See David Bidney, Theoretical Anthropology (New York: Columbia University Press, 1953), 120–24, and subsequent chapters; A. Irving Hallowell, “Self, Society, and Culture in Phylogenetic Perspective,” Evolution after Darwin, vol. 2, The Evolution of Man, ed. Sol Tax (Chicago: University of Chicago Press, 1960), 309–71; Charles Fay, “Human Evolution: A Challenge to Thomistic Ethics,” International Philosophical Quarterly, 2 (1962), 50–80. Fay’s work is helpful, but one cannot always agree with him. In particular, he seems (63–64) to consider the underlying constant factors to be universals; in one sense, this is true: They hold for all humankind. But they also are concrete realities of the order of potentiality. The potentialities which are constant are no more abstract than the actualizations which vary.