CHRISTIAN FAITH AND ITS "FULFILLMENT" OF THE NATURAL MORAL LAW 
William E. May
Michael J. McGivney Professor of Moral Theology
John Paul II Institute for Studies on Marriage and Family at
The Catholic University of America
Washington, D. C.
In his Sermon on the Mount our Lord said, "Do not think that I have come to abolish the law and the prophets. I have come, not to abolish them, but to fulfill them." Indeed, he continued, "Of this much I assure you: until heaven and earth pass away, not the smallest letter of the law, not the smallest part of a letter, shall be done away with until it all comes true. That is why whoever breaks the least significant of these commands and teaches others to do so shall be called least in the kingdom of God. Whoever fulfills and teaches these commands shall be called great in the kingdom of God" (Matt 5.17-19).
The law to which Jesus here refers is the law given to Moses, whose moral precepts were engraved on tablets of stone. The Catholic theological tradition holds that the moral precepts of the Mosaic law are precepts of the natural moral law,  which is engraved, not on tablets of stone, but on tablets of flesh, i.e., in the human heart.
The question I propose to investigate is how the new "law of love" proclaimed in the gospels "fulfills" and "perfects" the natural moral law. For Jesus likewise said, "I give you a new commandment: Love one another. Such as my love has been for you, so must your love be for each other. This is how all will know you for my disciples: your love for one another" (Jn 13.34-35). I will try to achieve my purpose by considering the following issues: (1) the persons to whom these laws are given and the purpose of these laws, and (2) the "content" of these laws. I will try to show how the new law of love revealed to us through Christian faith "fulfills" and perfects the natural moral law by inwardly transforming (a) the persons to whom these laws are given, (b) their purpose, and (c) their content.
1. The Persons to Whom the Natural Moral Law and the Law of Love Are Given and the Purpose of These Laws
A. The Natural Moral Law
The natural moral law is given, on creation,  to every human being, i.e., to those bodily beings who have been made in the "image and likeness of God" (Gn 1.27), for it is a law rooted in the nature of human beings (cf. Dignitatis humanae, n. 14). The natural law is, in fact, the uniquely human way in which human beings "participate in" what the Fathers of Vatican Council II call "the highest norm of human life," i.e., "the divine law--eternal, objective, and universal--whereby God orders, directs, and governs the entire universe and all the ways of the human community according to a plan conceived in wisdom and in love" (Dignitatis humanae, n. 3), for man "has been made by God to participate in this law, with the result that, under the gentle disposition of divine providence, he can come to perceive ever increasingly the unchanging truth" (ibid.).
All creatures are subject to God's divine and eternal law insofar as they are ruled and measured by it--all, as it were, "participate in" it passively.  But God wills that intelligent and self-determining creatures--and this is what human beings are--participate more nobly in his divine and eternal law as befits their nature. They participate in it not only passively, by being ruled and measured by it, but also actively by coming to know more deeply its ever unchanging truth (cf. Dignitatis humanae, n. 3) and in this way enabling themselves to rule and measure their own free choices and actions in accord with its truth. Thus in Veritatis splendor John Paul II rightly says: "The moral law [i.e., the natural law] has its origin in God and always finds its source in him: at the same time, by virtue of natural reason, which derives from divine wisdom, it is a properly human law" (n. 40).
But what is the purpose of this law? Its purpose is to provide human persons with the truths needed in order to make good moral choices and in this way to make themselves to be good persons. Properly to understand why this is so, we must say something about human action and moral choice.
The truth is that human persons make themselves to be the persons they are in and through the actions they freely choose to do. Human actions are not mere physical events that come and go, for at the heart of human actions is a free, self-determining choice that abides in the human person as a disposition to further choices and actions of the same kind.
Pope John Paul II beautifully brings out this truth in Veritatis splendor. In meditating on the dialogue between Jesus and the rich young man that begins when the young man asks, "Teacher, what good must I do to have eternal life?" (Matt 19.16), the Holy Father repeatedly emphasizes the religious and existential significance of this question. The pope says: "For the young man the question is not so much about rules to be followed, but about the meaning of life....This question is ultimately an appeal to the absolute Good which attracts and beckons us; it is the echo of a call from God who is the origin and goal of man's life" (n. 7). It is, he continues, "an existential and unavoidable question for the life of every man, for it is about the moral good that must be done, and about eternal life. The young man senses that there is a connection between moral good and the fulfillment of his own destiny" (n. 8). This question has existential and religious significance precisely because, as the Holy Father emphasizes later in the Encyclical, it is in and through the actions we freely choose to do that we determine ourselves to be the kind of persons we are. As John Paul II says: "it is precisely through his acts that man attains perfection as man, as one who is called to seek his Creator of his own accord and freely to arrive at full and blessed perfection by cleaving to him" (n. 71). Our freely chosen deeds, the pope continues, "do not produce a change merely in the state of affairs outside of man but, to the extent that they are deliberate choices, they give moral definition to the very person who performs them, determining his profound spiritual traits" (n. 71).  Our freely chosen deeds, in short, are a "decision about oneself and a setting of one's own life for or against the Good, for or against the Truth, and ultimately for or against God" (n. 65). Indeed, we can rightly say that a person's character is the integral existential identity of the person as shaped by his or her own free choices. 
It is, consequently, of crucial importance for human beings to make good moral choices. For them to do so they must know, prior to choice, which alternatives are morally good and which are morally bad. The criteria enabling them to distinguish between morally good and morally bad alternatives are moral truths, and these truths (as we shall see below, in considering the "content" of the natural moral law) are the truths human persons come to know through the mediation of the natural moral law, their uniquely human way of "participating" in God's divine and eternal law, his wise and loving plan for human existence.
The natural moral law, in short, is given to all human beings in order to help them to make true judgments about what they are to do and in the light of this truth to make good moral choices. Yet the natural moral law does not enable human beings to do the good they come to know. They can, as personal experience tragically bears witness, freely choose to act against the truth--they can freely choose to do what they know to be morally bad.
Moreover, the human beings to whom the natural law is given at creation are persons wounded by sin, for all are subject to original sin and to its effects. Through sin concupiscence, the lex fomitis,  has entered the human heart. Concupiscence, which comes from sin and leads to sin,  makes it difficult for human beings to come to a knowledge of the truth, i.e., of the "imperatives" of the divine and eternal law, in which they participate through the natural moral law. Indeed, as St. Paul bears witness, he finds within himself a twofold law--the "law of his mind" (=the natural moral law) and the "law of his members" (=the law of concupiscence, the lex fomitis) (Rom 7.23),  with the result that he does not do the good that he wills but rather the evil that he hates (Rom 7.15). Because of sin and concupiscence the human hearts on which the natural moral law is inscribed have been "hardened" (cf. Matt 19.8). Indeed, while (as we shall see) the first and common principles of natural law can never be obliterated from the human heart, a knowledge of its more specific moral precepts, those we must know if we are to shape our choices and actions in accordance with the truth, is indeed imperiled as a result of sin and concupiscence. It is precisely for this reason, as the Catholic theological tradition holds, that God has graciously made known to us through revelation the most basic specific moral norms, i.e., truths, needed to guide human choices and actions, for these are the truths he gave to humankind in the law given to Moses, the law engraved on the tablets of stone. 
In sum, the natural moral law is given to all human persons on creation so that they can come to a knowledge of moral truth and in the light of this truth make true moral judgments and good moral choices so that they can be morally good persons. Nonetheless, it is difficult for human persons to come to know the truths included in the natural moral law, which is in essence their intelligent, active participation in God's divine, eternal law because their "hearts" have been "hardened" because of sin and concupiscence. Moreover, the natural moral law does not empower human persons to do the good they can come to know. Because of sin and concupiscence human persons are prone to evil. They find themselves in the power of sin (cf. Rom 7.23 ff) so that, frequently, they fail to do the good they come to know and instead do the evil that they hate (cf. Rom 7.15).
B. The Law of Love or Grace
The persons to whom the new law of love or grace is given are Christ's faithful, i.e., those who have been "regenerated" in the waters of baptism. Such persons have, through baptism, entered into the paschal mystery of Christ. They have, in, with, and through Christ, died to sin and, again in, with, and through Christ, have risen to a new kind of life. They have "put on Christ," become incorporated into his body, the Church, and made truly children of God, members of the divine family. They have literally been "divinized," for now they truly share in Christ's divine nature just as he shares in their human nature.
The purpose of the new law of love, inscribed in the "re-created" hearts of these human persons, is to empower them to live in Christ, to live worthily as children of God, brothers and sisters of Jesus, members of the divine family. Its purpose is to enable them to walk worthily in the vocation to which they have been called--the vocation to be perfect, even as the heavenly Father is perfect--so that they may attain an end not achievable by human action and utterly beyond their human nature and powers, namely, life eternal in the divine family, the divine communio personarum.
This summary account of the persons to whom the new law of love is given and of the purpose of this law needs to be more fully developed in order to show us more precisely how the new law of love, given to Christ's faithful, "fulfills" and perfects the natural moral law.
First, the law of love fulfills the natural moral law by "re-creating" the persons to whom the natural moral law is given on "creation." The new law of love "regenerates" those to whom it is given, making them to be literally "children of God," "co-heirs" with Jesus, the only-begotten Son of the Father, true members of the divine family. "The new law [of love]," St. Thomas tells us, "is first and foremost the very grace of the Holy Spirit, which is given to Christ's faithful." Indeed, the "whole power" of this law consists precisely in "the grace of the Holy Spirit, which is given through faith."  Through the love of God, the grace of the Holy Spirit, which is poured into their hearts when, in baptism, they accept in living faith the saving revelation given by God in Jesus, Christ's faithful are inwardly transformed and become "new" creatures in Christ. To grasp this truth rightly we must consider in utmost seriousness the truth that Christians, through baptism, have "put on" Christ, have become conformed to him, become one with him. For, as the Fathers of Vatican Council II declare in a text constantly on the lips of Pope John Paul II, "it is only in the mystery of the Word incarnate that light is shed on the mystery of man. For Adam, the first man, was a figure of the future man, namely, of Christ the Lord. It is Christ, the last Adam, who fully discloses man to himself and unfolds his noble calling by revealing the mystery of the Father and the Father's love" (Gaudium et spes, 22; emphasis added). 
By being regenerated in baptism, when the new law of love is poured into our hearts, human beings are literally "re-generated," "re-born." They become new creatures. The new law of love inwardly transforms them. St. Thomas puts matters this way:
Pope John Paul II, commenting on God's "gift" of the Decalogue, the law given to Moses which summed up the natural law "given" on "creation," notes that the gift of the Decalogue "was a promise and sign of the New Covenant [the law of love or of grace], in which the law would be written in a new and definitive way upon the human heart (cf. Jer 31.31-34), replacing the law of sin which had disfigured that heart (cf. Jer 17.1)" (Veritatis splendor, n. 12). Speaking of the persons made new creatures by God's grace, he emphasizes that, through baptism, the very depths of their being are touched so that they are conformed to Christ, who dwells in the hearts of his believers. All this, he says, in company with St. Thomas the entire Catholic tradition, "is the effect of grace, of the active presence of the Holy Spirit in us" (n. 21). Through baptism, in short, we are given the gift of what Saint Josemaria Escrivá calls "divine filiation." We are "children of God, brothers of the Word made flesh, of him of whom it was said, 'In him was life, and that life was the light of man' (Jn 1.4). Children of the light: that is what we are. We bear the only flame capable of setting fire to hearts made of flesh." 
Thus the persons to whom the new law of love is given, Christ's faithful, are human persons who have been "re-created," made new to the depths of their being. While remaining human they are now divinized, summoned and empowered to live not merely as beings made in the image and likeness of God but also as his very own children, persons "begotten" anew in baptism who can now, with Jesus, call God their Father, their "Abba." Their "hearts," in which the natural law was inscribed "on creation," have been made new precisely because the new law of love and grace is now engraved on them, making them to be "other Christs."
Thus the first way in which the new law of love "fulfills" the natural moral law is by making the persons to whom the new law of love is given new creatures who share in the divine nature just as Christ, their brother, shares in their human nature.
A second way in which the new law of love "fulfills" the natural moral law is by enabling, empowering those to whom it is given not only to know but also to do both what the natural law requires and what the new law of love makes known and possible. In the following section I will be concerned with the "content" of both the natural law and the law of love, i.e., with the requirements of the natural law and the way in which these requirements are further specified by the law of love. Here, however, my concern is with the way the new law of love "fulfills" the natural moral law by empowering human persons to do what they come to know they are to do through the mediation of the natural moral law.
The natural law, as we have seen, is given to human persons so that they can come to know the moral truth needed in order to make true moral judgments. But it does not capacitate human persons to shape their lives in accord with this truth; it does not enable them to choose to do what they come to know they are to do. Moreover, as we have likewise seen already, our struggle to come to know the truth has been made difficult because of sin and concupiscence. These "disabling" factors, by hardening human hearts, close human minds to the truth. But the new law of love, whose purpose is to enable us to be fully the persons God wants us to be, i.e., his loving children, brothers and sisters of his only-begotten Son Jesus Christ, gives us the capacity both to know and to do all that must be done if we are to fulfill our vocation as his children, who, like Jesus, will to do only what is pleasing to the Father. As Pope John Paul II says in Veritatis splendor, "to imitate and live out the love of Christ is not possible for man by his own strength alone." But, he continues, "He becomes capable of this love only by virtue of a gift received. As the Lord Jesus receives the love of his Father, so he in turn freely communicates that love to his disciples. 'As the Father has loved me, so have I loved you. Abide in my love' (Jn 15.9)" (n. 22).
Although we are still capable of sinning even after having been "re-born" in the Spirit until we are confirmed in grace at the Lord's parousia, the new law given to us as Christ's faithful, St. Thomas tells us, "insofar as it is considered in itself, gives us sufficient help so that we can avoid sin."  By virtue of the new law of love we are made connaturally eager both to know and to do the truth. 
2. The "Content" of the Natural Moral Law and of the New Law of Love
A. The Natural Moral Law
What is the "content" of the natural moral law? That is, what truths to guide human choices and actions pertain to it? To answer this question I will first summarize the teaching of St. Thomas, then examine the relevance of some key texts in John Paul II's Veritatis splendor, and then summarize the thought of Germain Grisez, John Finnis, and Joseph Boyle, Jr., on this matter. As will be seen, I believe that the Holy Father's teaching is rooted in the thought of St. Thomas regarding the natural law. I also believe that John Paul II, by explicitly relating the natural law truths which have, through divine revelation, been made known to us in the precepts of the Decalogue, to goods perfective of human persons, helps us to grasp more clearly the movement from the first principles or truths of natural law to specific moral norms, a matter left somewhat undeveloped and implicit by St. Thomas. I further hold, as will be seen, that Grisez, Finnis, and Boyle have clarified this movement to an even greater degree.
i. The teaching of St. Thomas
According to St. Thomas there is an ordered progression in our active participation in God's eternal law, or in our growing knowledge of the natural law, in the way in which, as the Fathers of Vatican Council II affirm, man can, "under the gentle disposition of divine providence, come to perceive ever increasingly the unchanging truth" (Dignitatis humanae, 3). For in the thought of St. Thomas the natural law, in its most formal and precise sense, consists of an ordered series of "precepts" or true propositions of practical reason.
The first set in this ordered series is made up of "those common and first principles,"  "of which there is no need for any 'edition,' save insofar as they are written in natural reason as self-evidently true, as it were."  Among such first and common principles is the truth that "good is to be done and pursued and evil is to be avoided,"  and all those precepts based on this ordination of practical reason.  Now, "since good has the meaning of an end, and evil the meaning of what is contrary, it thus follows that reason naturally apprehends as good and consequently to be pursued through action all those things to which man has a natural inclination, and [reason naturally apprehends] their contraries as evils and hence to be avoided."  Thus, among the first and common principles of natural law are to be included principles (truths) that identify basic forms of human flourishing as goods to be pursued and done--goods such as life itself, the transmission and education of life, living in fellowship with others, knowledge of the truth, especially about God, and the like. 
But, and this is of utmost significance, Thomas likewise includes, among the first, common, and nondemonstrable principles of natural law such precepts as "do injury to no one,"  "do unto others what you would have them do unto you,"  and "love the Lord your God with your whole heart and your neighbor as yourself."  In fact, he clearly regards the precept that we are to love God and neighbor as the moral truth in whose light the precepts pertaining to the second set or "gradus" of natural law precepts can be known, for he explicitly appeals to this precept as the principle upon which the precepts found in this second set depend.
Consequently, if St. Thomas's thought is carefully analyzed, it is evident that the first set or "gradus" of first and common natural law precepts includes two subsets of true propositions meant to guide human choices and actions. This division into two subsets, I must point out, is not made by Thomas himself, but if one considers his thought carefully one can recognize these subsets. The first subset contains the fundamental practical principle that good is to be done and pursued and its opposite avoided and principles specifying basic forms of human flourishing as the goods that are to be pursued and done (life, knowledge of the truth, living in society, etc.). These truths guide human choices and actions by orienting us to the goods perfective of human persons.  These natural law principles make intelligent choices and actions possible. All human persons, the morally upright and the morally bad alike, appeal to principles of this kind to render their actions intelligible (i.e., to rationalize them).  But these natural law principles--principles of practical reasoning--are not of themselves moral principles or truths enabling us to distinguish adequately between morally good and morally bad alternatives of choice.
The second subset of first and common precepts belonging to the first set or "gradus" of natural law precepts which St. Thomas identifies are, however, principles of this kind: such principles as "do injury to no one," "do unto others and you would have them do unto you," and above all "love the Lord your God and your neighbor as yourself." These normative first principles enable us to discriminate between morally good and morally bad alternatives of choice, i.e., of human acts. Among these St. Thomas identifies as most basic--and here he is simply following the teaching of our Lord (cf. Matt 22.37-39)--the principle that we are to love God and neighbor.  This is the fundamental moral principle of natural law, and the other principles included by St. Thomas in this subset of first and common natural law precepts--the Golden Rule ("do unto others as you would have them do unto you") and the principle that we are to do "injury to no one"--can be regarded as principles showing us how we are to love our neighbor and avoid intentionally doing evil to him.
All the natural law precepts considered thus far, St. Thomas teaches, belong to the first set or "gradus" of natural law precepts: its first and common principles or truths. St. Thomas holds that the second set or "gradus" of natural law precepts includes those "that the natural reason of everyone immediately and of itself judges are to be done or not done."  Such precepts are proximate conclusions from the first or common principles of natural law.  Their truth can be grasped, the Common Doctor says, "immediately, with but little consideration."  While "more determinate" than the primary precepts of natural law, they can, he says, be easily grasped by the intelligence of even the most ordinary individual.  Such precepts belong "absolutely" to the natural law.  They can, Thomas concedes, become perverted in some instances because of sin and bad habits, and because they are so necessary for our salvation they therefore have need of a further "edition," namely, through divine [positive] law,  for these are the precepts found in the Decalogue. They are specific moral norms or truths meant to guide human choices and action and are, St. Thomas says, absolute and completely indispensable, even by God. 
Thus, for St. Thomas the second set or "gradus" of natural law precepts, which are "proximate conclusions" from the primary precepts and, indeed, truths whose truth can be shown best in light of the first principle that we are to love God and neighbor, are the precepts of the Decalogue. Thomas holds that we move "immediately," with but "little consideration," from the first and common precepts of natural law to the precepts of the Decalogue. But one can ask, which first and common precepts of natural law best serve as premises to show the truth of the precepts of the Decalogue? Aquinas holds that the twofold law of love of God and neighbor serves as the premise in light of which one can show the truth of the precepts of the Decalogue. However, the movement from this first moral principle to its "proximate conclusions" is not explained in any detail by St. Thomas.
According to St. Thomas the third "gradus" or set of natural law precepts includes those truths about human choices and actions that are known only "by a more subtle consideration of reason."  They are like conclusions drawn from the second set of natural law precepts (the precepts of the Decalogue),  and are known only by the "wise." I believe that for Thomas the "wise" refers, not necessarily to people with high intelligence quotients or advanced degrees, but to those in whom the virtue of prudence has been perfected, i.e., the saints. To know these truths "much consideration of diverse circumstances" is required, and properly to consider these is something that belongs to the "wise," by whom those not perfect in virtue should be instructed. 
Here I think it important to note that elsewhere, in his Summa contra gentiles, St. Thomas made it clear that we offend God only by acting contrary to our own good.  This is worth noting as we shall now see clearly.
ii. The teaching of Pope John Paul II in Veritatis splendor
John Paul II takes up the normative requirements or truths of natural law in his presentation, in Chapter One of the Encyclical, of the essential link between obedience to the Ten Commandments, which the Catholic tradition has always recognized as requirements of natural law, and eternal life. In his presentation of this essential link the Holy Father makes it clear that the primordial moral requirement of natural law is the twofold law of love of God and love of neighbor, and that the precepts of the second tablet of the Decalogue are based on the truth that we are to love our neighbor as ourselves.
He begins by noting that our Lord, in responding to the question posed by the rich young man, "Teacher, what good must I do to have eternal life?" (Matt 19.16), makes it clear that its answer can be found "only by turning one's mind and heart to the 'One' who is good....Only God can answer the question about what is good, because he is the Good itself"(n 9; cf. nn. 11, 12). He continues by saying, "God has already given an answer to this question: he did so by creating man and ordering him with wisdom and love to his final end, through the law which is inscribed in his heart (cf. Rom 2.15), the 'natural law'...He also did so in the history of Israel, particularly in the 'ten words,' the commandments of Sinai" (n. 12). John Paul II next reminds us that our Lord the told the young man: "if you wish to enter into life, keep the commandments" (Matt 19.17). John Paul II says that Jesus, by speaking in this way, makes clear "the close connection...between eternal life and obedience to God's commandments [which]...show man the path of life and lead to it" (n. 12). The first three of the commandments of the Decalogue call "us to acknowledge God as the one Lord of all and to worship him alone for his infinite holiness" (n. 11). But the young man, replying to Jesus' declaration that he must keep the commandments if he wishes to enter eternal life, demands to know "which ones" (Matt 19.19). John Paul II says, "he asks what he must do in life in order to show that he acknowledges God's holiness" (n. 13). In answering this question, Jesus reminds the young man of the Decalogue's precepts regarding our neighbor. "From the very lips of Jesus," the Holy Father observes, "man is once more given the commandments of the Decalogue" (n. 12). These commandments, he continues, are based on the commandment that we are to love our neighbor as ourselves, a commandment expressing "the singular dignity of the human person, 'the only creature that God has wanted for its own sake'" (n. 13, with an internal citation from Gaudium et spes, 24).
It is at this point that John Paul II develops a matter of crucial importance for understanding the truths of natural law and the relationship between the primordial moral requirement to love our neighbor as ourselves (which, it will be recalled, was identified by St. Thomas as one of the "first and common precepts" of natural law) and the quite specific commandments of the second tablet of the Decalogue (commandments included by St. Thomas in the second set of natural law precepts, "proximate conclusions" from the first and common principles which everyone can grasp "with a modicum of consideration").
For at this point in the Encyclical, in a remarkably important passage, John Paul II, appealing to the words of Jesus himself, emphasizes the truth that "the different commandments of the Decalogue are really only so many reflections of the one commandment about the good of the person, at the level of the many different goods which characterize his identity as a spiritual and bodily being in relationship with God, with his neighbor, and with the material world....The commandments of which Jesus reminds the young man are meant to safeguard the good of the person, the image of God, by protecting his goods" (n. 13). He goes on to say that the negative precepts of the Decalogue--"You shall not kill; You shall not commit adultery; You shall not steal; You shall not bear false witness"--"express with particular force the ever urgent need to protect human life, the communion of persons in marriage," and so on (n. 13). These negative precepts of the Decalogue, which protect the good of human persons by protecting the goods perfective of them, are among the universal and immutable moral absolutes proscribing intrinsically evil human acts, the teaching representing the "central theme" of the Encyclical (cf. n. 115).
I believe that in this text John Paul II has helped to clarify the movement from the first and common precepts of the natural law, in particular, the truth that we are to love our neighbor as ourselves, to the specific moral norms found in the second tablet of the Decalogue, precepts which St. Thomas called "proximate conclusions" from the first and common principles of natural law. In reviewing the teaching of St. Thomas we saw that in his judgment the practical reason "of anyone whatsoever" can easily, immediately, and with but little consideration proceed from the truth that we are to love God and neighbor to the truth of the precepts of the Decalogue. But is this movement so easy, so immediate? Writing in an age of faith, when the saving truths of divine revelation as proclaimed and understood by the Church were commonly accepted by the society in which he lived, St. Thomas seems not to have devoted considerable attention to this matter. Yet he did acknowledge, as we have seen, that human judgment regarding these specific moral norms, these natural law "precepts," can indeed be perverted: hence the need for God to make their truth known to us through the revelation given to Moses, reaffirmed by our Lord, and faithfully preserved by the Church.
John Paul II, by explicitly linking the precepts of the Decalogue to the command that we are to love our neighbor as ourselves, and by explicitly linking love of neighbor to a love of and respect for the goods perfective of human persons, has in my opinion helped us see more clearly how the love commandment can serve as a premise in whose light the truths of the Decalogue's precepts can be shown to be true. John Paul's point is that we can love our neighbor only by loving and respecting the goods perfective of him. Thus by explicitly relating the precepts of the Decalogue to real goods perfective of the human persons whom we are to love as we love ourselves, John Paul II, I believe, has helped us understand the movement from the first and common principle of natural law that we are to love our neighbor as ourselves to the truth of the precepts of the second tablet of the Decalogue.
iii. The thought of Grisez, Finnis, and Boyle
These authors explicitly distinguish among the "first and common principles of natural law," which, as we have seen, form the first set or "gradus" of the truths constituting the "content" of natural law. Aquinas, as we saw above, includes among these principles both those directing us to pursue and do the good and identifying the real goods of human persons that are to be pursued and done in action and normative principles, of which the most basic is the twofold law of love. Yet St. Thomas does not explicitly distinguish between these two sorts of "first and common principles." Grisez, Finnis, and Boyle explicitly draw attention to these different sorts of first principles of natural law, identifying the first sort, i.e., those identified by St. Thomas in Summa theologiae, 1-2, 94, 2, as "principles of practical reasoning," i.e., principles ruling out purposelessness in action and directing us to pursue the goods perfective of us as human persons, and identifying the second sort of first principles--the twofold commandment of love, the Golden Rule, and others (which St. Thomas identified in other passages, e.g., in Summa theologiae, 1-2, 100, 3)--as the first moral principle of natural law (the twofold command to love) and its "specifications," which they call "modes of responsibility."
With St. Thomas and Pope John Paul II they say that the primordial moral principle of natural law can rightly be formulated in religious language as the twofold command to love God and neighbor. Commenting on this formulation, they observe that "for Jews and Christians God is the supreme good and source of all goods." Thus "loving him requires the cherishing of all goods...[including] the basic human goods....And loving one's neighbor as oneself at least excludes egoism and means accepting the fulfillment of others as part of one's own responsibility"  --i.e., one loves one's neighbor by willing that the goods of human existence flourish in him or her. They explicitly recognize that the twofold love commandment of the Bible authentically expresses in religious language the fundamental or first moral principle of natural law.
Yet they think that this way of formulating the first normative principle of natural law is not entirely satisfactory "for purposes of ethical reflection and theology....To serve as a standard for practical judgment," Grisez writes, "a formulation must refer to the many basic human goods which generate the need for choice and moral judgment."  It should do so because the function of the first moral principle is to provide us with a criterion for distinguishing which alternatives of choice are morally good and which are morally bad. Thus, Grisez, Finnis, and Boyle believe that the first moral principle of natural law, expressed religiously as the twofold command of love, can be expressed more clearly for purposes of ethical and theological analysis if it is more closely related to the first principles of practical reasoning which direct us to pursue and do the good to which we are naturally inclined. This means that it should articulate "the integral directiveness of the first principles of practical reasoning, when they are working together harmoniously in full concert." 
Consequently, they hold that the first principle of morality can be more precisely formulated philosophically and theologically as follows: "In voluntarily acting for human goods and avoiding what is opposed to them, one ought to choose and otherwise will those and only those possibilities whose willing is compatible with integral human fulfillment," i.e., with an openness to and love for all the goods truly perfective of human persons and of the persons in whom those goods are meant to flourish. 
Just as the first principle of practical reasoning--good is to be done and pursued and its opposite is to be avoided--is specified by identifying the real goods of human persons that are to be pursued and done in action--goods such as life itself, knowledge of the truth, harmony with others and with God, etc.--so too, these authors propose, the first moral principle of natural law, formulated religiously as the twofold command of love and formulated more philosophically and theologically as noted in the previous paragraph, is further specified by identifying ways of choosing that are not compatible with respect for "integral human fulfillment," i.e., with the whole range of real goods perfective of human persons. They note that St. Thomas himself had identified some of these further specifications of the first moral principle, for he had included, among the common and first principles of natural law, such normative principles as the Golden Rule and the principle that we are to do evil to no one. The purpose of these further specifications, which they call "modes of responsibility," of the first moral principle is to "pin down" the primary moral principle by excluding as immoral actions which entail willing in specific ways incompatible with a will toward integral human fulfillment. 
Grisez, Finnis, and Boyle express these "modes of responsibility" negatively, because formulating them in this way shows that it is impossible for these normative principles to come into conflict, because one can simultaneously forbear choosing and acting in an infinite number of ways.  Thus they express the Golden Rule or principle of fairness as follows: "One should not, in response to different feelings toward different persons, willingly proceed with a preference for anyone unless the preference is required by intelligible goods themselves," and they express the principle formulated by St. Thomas as "one ought to do evil to no one" in two ways: (1) "One should not be moved by hostility to freely accept or choose the destruction, damaging, or impeding of any intelligible human good," and (2) "One should not be moved by a stronger desire for one instance of an intelligible good to act for it by choosing to destroy, damage, or impede some other instance of an intelligible good."  In addition to the three modes of responsibility just noted, these authors identify five more, but it is not necessary for my purposes to list all of them.  Put briefly, they exclude ways of choosing and willing whereby one would intentionally ignore, slight, neglect, damage, destroy, or impede real goods of human persons or act in ways based purely on nonrational feelings or in ways that unfairly and arbitrarily limit participation by human persons in these goods.
In the light of these basic normative principles, which specify ways of choosing and wililng incompatible with a will toward integral human fulfillment, one can then show clearly the truth of specific moral norms. Such norms are discovered by considering the ways a proposed human act relates a person's will to the basic goods perfective of human persons and by considering such a proposed human act in the light of the first principle of morality and its specifications or modes of responsibility.
Many specific moral norms, while true, are not absolute or exceptionless. They are not absolute because they are open to further specification in the light of the same moral principles from which they were derived. Keeping promises is an example, and so too is returning goods to one from whom one has borrowed them (the example used by St. Thomas in Summa theologiae, 1-2, 94, 4 to illustrate a norm that is binding only for the most part). We are obliged to keep our promises and return borrowed items because these acts are required by the principle of fairness or the Golden Rule (one of the "modes of responsibility"). However, when keeping a promise or returning a borrowed item would harm the human good of harmony among persons and if this good could be protected by breaking the promise or by not returning the borrowed item without being unfair or violating the Golden Rule, then the obligation to keep the promise or to return the borrowed item ceases. The very same moral principles or "modes of responsibility" that generate the specific norm also justify exceptions to such non-absolute moral norms.
But other specific moral norms, including those found in the precepts of the Decalogue, are absolute or exceptionless. One ought never intentionally to kill innocent human beings [the fifth commandment as understood in the Catholic tradition], commit adultery or have intercourse with someone not one's spouse, and so forth, because one willing to do the human acts specified by these moral objects is indeed choosing to damage, destroy, or impede the good of human life and the good of marital communion and cannot not be choosing to do this. Nothing can further specify these acts which would prevent them from violating the normative requirement that we are not to adopt by choice a proposal to damage, destroy, or impede a fundamental human good. In freely choosing to act in this way, we are willing to "do" evil, and we show that we are not willing to honor integral human fulfillment, for honoring integral human fuilfillment means accepting, loving, and cherishing the goods perfective of human persons. 
I believe that the work of Grisez, Finnis, and Boyle, like the teaching of Pope John Paul II in Veritatis splendor, helps us to understand more clearly the movement from the first and common principles or precepts of natural law to what St. Thomas termed its "proximate conclusions," i.e., the precepts found in the Decalogue. They thus help us to understand more fully the "content" of natural law.
B. The New Law of Love or Grace
How does the "content" of the new law of love or grace "fulfill" and perfect the content of the natural law? The "content" of the new law of love or grace is, as we have seen already, essentially "the very grace of the Holy Spirit, given to Christ's faithful."  But is there, in addition to this, any other new content of the new law which fulfills and perfects the content of the natural law?
To answer this question I will first briefly offer a summary of the position of St. Thomas, and then examine the teaching of John Paul II in Veritatis splendor and the thought of Grisez.
i. St. Thomas and the "content" of the new law of love or grace
Several theologians today claim that there is no specific content to the new law, that there is no specific Christian ethic, i.e., no moral principles or norms specific to Christian faith. Rather, all the normative requirements of human action, even action by Christians, are supplied by the moral principles and norms of the natural law. Theologians holding this position frequently appeal to the authority of St. Thomas to support their claim. A passage from Louis Janssens illustrates and represents this position. Janssens writes:
Although what Janssens says here is true, one can ask whether this adequately represents the mind of St. Thomas, who did not formally address the precise kind of question currently debated by Catholic theologians. For while he said what Janssens reports, he also insisted that there are specifically Christian moral virtues, infused divinely into the being of those united to Jesus Christ through charity, and that these virtues are the intrinsic principles from which specifically Christian ways of acting proceed.  He also insisted that Christians are specifically required to do such things as fast and give alms.  Moreover, and I believe that this is of great significance, St. Thomas taught that the Lord's Sermon on the Mount (cf. Matt 5) "contains completely the information needed for the Christian life. In it the inner movements of the person are perfectly ordered."  In saying this St. Thomas was simply reaffirming a Christian tradition going back to the Fathers of the Church. Indeed, as St. Augustine so aptly said, "If a person will devoutly and calmly consider the sermon which our Lord Jesus Christ spoke on the mount, I think that he will find in it, as measured by the highest norms of morality, the perfect pattern of the Christian life." 
This suggests that if we closely consider the beatitudes and explicitly relate them to the new law of love proclaimed by Jesus, we may be able to see more precisely how the "content" of the new law of love fulfills and perfects the content of the natural law. In Veritatis splendor John Paul II does this, and so too does Germain Grisez in his effort to show the specificity of Christian ethics, of the "new law of love and grace."
ii. Pope John Paul II and the "content" of the new law of love
In Veritatis splendor the Holy Father emphasizes that the twofold command to love God above all things and to love one's neighbor as oneself is found in both the Old Testament and in the New Testament. It is common both to the old covenant and to the new covenant. But, he likewise recalls for his readers, Jesus, who "asks us to follow him and to imitate him along the path of love, a love which gives itself completely to the brethren out of love for God," gives a new commandment, for Jesus says: "This is my commandment, that you love one another as I have loved you" (Jn 15.12). Commenting on this passage (and other passages, e.g., Jn 13.14-15, 34-35) from the Gospel according to John, the pope emphasizes that this means "following Christ." But "following Christ," he writes, "is not an outward imitation, since it touches every man at the very depths of his being. Being a follower of Christ means becoming conformed to him who became a servant even to giving himself on the cross (cf. Phil 1.5-8). Christ dwells by faith in the heart of the believer (cf. Eph 3.17), and thus the believer is conformed to the Lord" (n. 21).
Moreover, John Paul II shows, in discussing the Beatitudes, how those who follow Jesus become conformed to him by living according to the Beatitudes. He notes that the Beatitudes "are not specifically concerned with certain particular rules of behavior. Rather, they speak of basic attitudes and dispositions in life." In fact, he says, "the Sermon on the Mount demonstrates the openness of the commandments and their orientation towards the horizon of the perfection proper to the Beatitudes. These latter are above all promises, from which there also indirectly flow normative indications for the moral life. In their originality and profundity they are a sort of self-portrait of Christ, and for this very reason are invitations to discipleship and to communion of life with Christ" (n. 16).
In this passage John Paul II explicitly says that normative indications for the moral life flow indirectly from the Beatitudes. This implies that in the light of the Beatitudes specific norms for Christ's faithful can be generated. John Paul II does not pursue this subject in his Encyclical, but it seems to me that his teaching is open to this interpretation and development.
Moreover, in discussing the self-determining nature of free choice, John Paul II observes that "emphasis has rightly been placed on the importance of certain choices which 'shape' a person's entire moral life, and which serve as bounds within which other particular everyday choices can be situated and allowed to develop" (n. 65). He then declares that "there is no doubt that Christian moral teaching, even in its Biblical roots, acknowledges the specific importance of a fundamental choice which qualifies the moral life and engages freedom on a radical level before God. It is a question of the decision of faith, of the obedience of faith (cf. Rom 16.26) 'by which man makes a total and free self-commitment to God, offering "the full submission of intellect and will to God as he reveals"'" (n. 66, with an internal citation from Dei Verbum, 5).
Since "everyday choices" are at the core of the human actions we do, and since these choices are to be guided by moral truth, this implies that for those who have committed themselves to be conformed to Christ and to follow him because of their baptismal commitment [John Paul II here is obviously referring to our baptismal commitment] there are moral truths intended to guide the "everyday choices" of Christ's faithful, of those who are committed to love, even as they have been and are loved by God in Christ.
John Paul II in addition emphasizes that each Christian, in addition to having the common vocation of all Christians to holiness and specific vocations to marriage or to the priesthood or to the consecrated life, has a unique personal vocation. He stressed this in his very first encyclical Redemptor hominis (see n. 71) and developed it further in his 1988 apostolic exhortation Christifideles laici in which he wrote:
iii. Germain Grisez and the "content" of the new law of love
Grisez, commenting on the Johannine passages in which Jesus gives his disciples the new law of love, argues that the new law of love, which is the first or fundamental moral principle of the Christian life, i.e., of those human persons who have been regenerated in the waters of baptism and made literally God's children, inwardly transforms the law of love as formulated in the Old Testament. He had earlier, as we have seen, proposed that the twofold law of love, which St. Thomas regarded as the basic moral principle of natural law, can be formulated more precisely for philosophical and theological purposes as directing us to choose and otherwise will those and only those possibilities whose willing in compatible with integral human fulfillment. In the light of new law of love proposed in the Gospel, Grisez believes that we can say that "Christian love transforms the first principle of morality into a more definite norm: One ought to will those and only those possibilities which contribute to the integral human fulfillment being realized in the fulfillment of all things in Jesus." 
Moreover, because they are united to Christ in baptism, Christians are summoned and committed to share in his redemptive work. This indeed is what is entailed in their baptismal commitment, i.e., in the free choice whereby they died to the Adamic man and rose to a new life made possible by their union with Jesus. The task of Christians is to complete, in their own flesh, "what is lacking in Christ's afflictions for the sake of his body, the Church" (Col 1.24). Jesus wills that his brothers and sisters complete the redemptive work he has begun so that "we all attain to the unity of faith and the knowledge of the Son of God, to mature manhood, to the measure of the stature of the fullness of Christ" (Eph 4.13), until Jesus "will change our lowly body to be like his glorious body by the power which enables him even to subject all things to himself" (Phil 2.21).
The new law of love thus fulfills and completes the first basic moral principle of natural law by further specifying it in the light of the sinful condition of humankind and the redemptive work of Jesus, in which his followers are summoned to participate.
The new law of love likewise inwardly transforms, fulfills, and perfects the "modes of responsibility," that is, principles such as the Golden Rule and the requirement that we are to do injury to no one, never to adopt by choice proposals to damage, destroy, or impede any basic human good.
Grisez develops this idea in his reflections on the Beatitudes. The Beatitudes, the blessings given by our Lord to his faithful disciples, are rooted in the new command that Jesus gives us to love others even as he loves us. Grisez thus proposes that the Beatitudes are "modes of Christian response" specifying the requirements of the new law of love. These modes of Christian response specify ways of acting that mark a person whose will, enlivened by the love of God poured into his heart, is inwardly disposed to act with the confidence, born of Christian hope, that integral human fulfillment is indeed realizable in and through union with Jesus. These are the modes characterizing the life of persons who, by reason of their living faith, are called "blessed" by the Lord. They are internal dispositions, inclining the Christian to do what is pleasing to the Father and what contributes to the redemptive work of Jesus. 
Thus the new law of love deepens and fulfills the basic moral requirements of the natural law, the moral principles pertaining to the first set or "gradus" of natural law precepts by further specifying them in the light of man's sinful condition and the redemptive work of Jesus, in which Christ's followers are to participate and, indeed, to which they are committed by their baptismal promises.
With respect to the second set or gradus of natural law precepts, which St. Thomas identified with the precepts of the Decalogue, the "proximate conclusions" from the first and common principles of natural law, the new law of love interiorizes them and deepens their significance. It likewise fulfills and perfects the third set or gradus of natural law precepts, those known to the "wise," i.e., to the saints. The new law of love does so because it summons Christians, in whom the virtue of supernatural prudence has been infused along with charity, to fulfill their vocation as Jesus' brothers and sisters, to become as perfect as the heavenly Father is perfect. Christians have the common vocation to sanctity: "as he who called you is holy, be holy yourselves in all your conduct, since it is written, 'You shall be holy, for I am holy'" (1 Pet 1.14-16).
Grisez, like John Paul II, emphasizes that in addition to their common vocation to holiness, each Christian has a unique and irreplaceable vocation within the family of God. Not only are different Christians called to different ways of life in the world--the married life, the priestly life, the religious life, the life of a single person within the world--but within each state of life each Christian has his or her own unique role to play in filling up what is lacking in Christ's afflictions and in bringing his work of redemption to completion. Grisez points out that Vatican Council II insists that each one of us has a personal vocation to carry out as a member of Jesus' people. Indeed, "by our faith we are bound all the more to fulfill theses responsibilities [our earthly ones as Christians] according to the vocation of each one" (Gaudium et spes, 43). Thus Grisez notes that one specific moral norm incumbent upon Christians is that they are obliged to discern their personal vocation and to carry it out.  In carrying out this vocation, they must be guided by the Beatitudes, the "modes of Christian response," and in their light articulate for themselves specific moral norms for making their everyday choices as followers of Christ. These specifically Christian moral norms would seem to pertain to what St. Thomas called the third set or "gradus" of natural law precepts, i.e., those known only to the "wise." These specific moral norms are norms known to the Christian faithful who are graced with Christian prudence, which leads them to articulate for themselves, in light of the Christian modes of responsibility or Beatitudes, norms for making the "everyday choices" necessary to carry out faithfully their own personal vocation as persons called to participate in Christ's redemptive work.
The new law of love, which is essentially the grace of the Holy Spirit given to Christ's faithful, "fulfills" the natural moral law in the following ways:
1. First, it "regenerates" the persons to whom the natural moral law is given, making them to be not ony beings made in the image and likeness of God but truly God's children, members of the divine family, for it unites them to Jesus who shares with them his divinity just as he shares their humanity.
2. Second, it inwardly enables Christ's faithful, now new creatures in Christ, both to know more easily the requirements of the natural law and to do the good that it requires.
3. Third, the new law of love inwardly transforms the natural law's basic moral norm, religiously expressed as love of God and of neighbor as oneself, by further specifying it: those to whom the new law of love are given are to love even as they have been and are loved by God in Christ, i.e., with a healing, redemptive kind of love.
4. Fourth, the new law of love inwardly transforms the natural law's "modes of responsibility" by specifying more precisely the modes of response characteristic of Christians, who are to love as Christ loves: they are to shape their choices and actions in accord with the Beatitudes so that they will receive the blessings promised by Jesus to his followers.
5. Fifth, the new law of love further specifies specific moral requirements of the moral life by summoning Jesus' followers to participate in his redemptive mission, to discern their own personal vocation and fulfill it, to discern, with the Christian prudence infused in their hearts, the specific requirements demanded by the Beatitudes or modes of Christian response in the everyday choices they must make in carrying out their personal vocation to participate in Christ's redemptive work.
1. Originally published in Anthropotes: Rivista sulla persona e la famiglia 7.2 (1991) 157-169, I have revised this paper substantively in order to integrate the teaching of Pope John Paul II in his encyclical Veritatis splendor (1993) and recent developments in Catholic moral thought. In revising this text I have also attempted to take into account intelligent criticisms of the earlier paper given by Benedict Ashley, O.P.
2. See, for instance, St. Thomas Aquinas, Summa theologiae, 1-2, 100, 1; 100, 11.
3. Thus St. Thomas, for whom the natural law is "nothing other than the light of understanding infused in us by God," says that "God gave this light and this law to man at creation." See his In Duo Praecepta Caritatis et in Decem Legis Praecepta Prologus: Opuscula Theologica, II, No. 1129, Ed. Taurinen. (1954), 245: "lex naturae...nihil aliud est nisi lumen intellectus insitum nobis a Deo, per quod cognoscimus quid agendum et quid vitandum. Hoc lumen et hanc legem dedit Deus homini in creatione." This text of St. Thomas is cited by Pope John Paul II in his Encyclical Veritatis splendor, n. 12, with the reference to St. Thomas given in note 19. In this note the Holy Father also refers to St. Thomas, Summa theologiae, 1-2, q. 91, a. 3 and to Catholicae Ecclesiae Catechismus, n. 1955.
4. The conciliar text does not explicitly use the expression "natural law" to name humankind's participation in God's eternal divine law. However, it is clear that this was the mind of the Council from the fact that an official footnote appended at this point in the text [footnote no. 3] expressly calls attention to some key texts of St. Thomas, namely, Summa theologiae, 1-2, 91, 1; 93, 1, and 93, 2, where St. Thomas is concerned with the relationship between God's eternal law and natural law. Thus, in 93, 2, Thomas says: "Every rational creature knows it [the eternal law] according to some irradiation of it, greater or less. For all knowledge of the truth is a certain irradiation and participation in the eternal law, which is unchangeable truth...but all men somehow know this truth, at least with respect to the principles of natural law" ("omnis creatura rationalis ipsam [legem aeternam] cognoscit secundum aliquam eius irradiationem, vel maiorem vel minorem. Omnis enim cognitio veritatis est quaedam irradiatio et participatio legis aeternae, quae est veritas incommutabilis....Veritatem autem omnes aliqualiter cognoscunt, ad minus quantum ad principia communia legis naturalis"). In Summa theologiae, 1-2, 91, 2, Thomas says that the natural law is the participation of the eternal law in the rational creature. It is to be noted that the Abbott translation of the Documents of Vatican II fails to include this footnote, as does the first edition of the Flannery translation. Later editions of the Flannery translation, fortunately, include this important reference.
5. See Summa theologiae, 1-2, 91, 2 and ad 3.
6. On this see Summa theologiae, 1-2, 91, 2 and 93, 6. This truth about the active participation of intelligent beings in God's eternal law is well brought out by D. O'Donoghue, "The Thomist Concept of Natural Law," Irish Theological Quarterly 22 (1955) 89-109, especially 93-94. See also Martin Rhonheimer, Natural Law and Practical Reason:A Thomist View of Moral Autonomy, trans. Gerald Malsbury (New York: Fordham University Press, 2000), pp. 234-256.
7. Thus St. Thomas says that "doing is an action that abides in the agent himself" ("agere autem est actus permanens in ipso agente") (Summa theologiae, 1-2, 57, 4). This truth is at the heart of the distinction between doing and making. Making is a transitive act that passes from the agent to some product external to the agent, and our interest focuses on the product made. Thus it is preferable to have edible cakes baked by a moral monster than indigestible ones produced by a saint. But doing is a deed that abides in, either to perfect or degrade, the agent, and our interest focuses on the person and his or her character. And doing abides in the agent precisely because at its core is a free, self-determining choice. This truth is central to the teaching of Vatican Council II, Gaudium et spes, n. 27, where the Council Fathers rightly note that crimes against human life, while harming their victims, poisoning civilization, and dishonoring the Creator, also more seriously degrade and harm their perpetrators than their victims.
It is important, moreover, to recognize that every making entails a doing, for the maker chooses to do something, namely, to produce his product (e.g., a human baby in the laboratory, to produce the abortifacient drug RU, a pornographic magazine, or a copy of the Bible or the Summa of St. Thomas) and thus determines himself to be the kind of person willing to make this kind of product.
8. At this point in the text of Veritatis splendor, n. 71, the Holy Father cites a beautiful passage from St. Gregory of Nyssa's De Vita Moysis, II, 2-3 (PG 44, 327-328) that eloquently expresses this central truth: "All things subject to change and to becoming never remain constant, but continually pass from one state to another, for better or worse....Now, human life is always subject to change; it needs to be born ever anew....But here birth does not come about by a foreign intervention, as is the case with bodily beings...; it is the result of a free choice. Thus we are in a certain way our own parents, creating ourselves as we will, by our decision."
9. On this see Germain Grisez, The Way of the Lord Jesus, Vol. 1, Christian Moral Principles (Chicago: Franciscan Herald Press, 1983), p. 59.
10. St. Thomas discusses the lex fomitis in Summa theologiae, 1-2, 91, 6.
11. See St. Augustine, De Nuptiis et Concupiscentia, I.25 (PL 44.429-430). The Council of Trent made its own St. Augustine's teaching on concupiscence; see Henricus Denzinger and Adolphus Schoenmetzer, eds. Enchiridion Symbolorum (34th ed.: Romae: Herder, 1973), n. 1515.
12. It is instructive to note that St. Thomas refers to this passage of St. Paul in the sed contra to Summa theologiae, 1-2, 91, 6, where he discusses the lex fomitis. See note 10 above.
13. On this see, for example, St. Thomas Aquinas, Summa theologiae, 1-2, 99, 2, ad 2.
14. St. Thomas Aquinas, Summa theologiae, 1-2, 106, 1.
15. John Paul II constantly refers to this passage as utterly indispensable for properly understanding who we are; it constitutes, for example, a central theme of his Encyclical Veritatis splendor. See, for instance, n. 2 of that Encyclical.
16. St. Thomas Aquinas, Summa theologiae, 3, 69, 5.
17. Saint Josemaria Escrivá, Christ Is Passing By: Homilies by Josemaria Escrivá de Balaguer (New Rochelle, NY: Scepter, 1986), nn. 65, 66.
18. St. Thomas Aquinas, Summa theologiae, 1-2, 106, 1, ad 2.
19. St. Thomas and others speak of "connatural" knowledge, such as the knowledge between friends, which differs from knowledge acquired in a more "objective" and scientific way insofar as it is mediated through affectivity, in particular, through love, which unites. Precisely because they love one another, friends know the secrets of their hearts. But through grace God has made human persons his friends, with whom he shares his secrets.
20. St. Thomas Aquinas, Summa theologiae, 1-2, 100, 1.
21. Ibid., 100, 8; cf. 100, 11.
22. Ibid., 94, 2.
25. Ibid. St. Thomas here speaks of three levels of human goods: one, which we share with all substances, includes being or life itself, since vivere viventibus est esse; a second, which human persons share with animals (but, of course, in a uniquely human way), includes the good of handing on life and educating it; and a third, specific to human persons, which includes such goods as living in fellowship with others, knowledge of the truth, especially about God. In this text, moreover, Thomas makes it clear that he is not setting out to provide an exhaustive list of human goods but rather an illustrative list, for he says that there are "like" (similia) goods and goods "of this kind" (huiusmodi). Moreover, in the very next article, 94, 3, he explicitly refers to our natural inclination to act in accord with reason, thus identifying the “good of practical reasoning” as a basic good of human persons toward which we are naturally inclined.
26. Ibid., 95, 2.
27. Ibid., 94, 4, ad 1.
28. Ibid., 100, 3, ad 1.
29. Grisez, The Way of the Lord Jesus, Vol. 1, Christian Moral Principles, pp. 178-183, provides what he believes is an exhaustive or taxative list of such basic human goods. Four are "reflexive" or "existential" inasmuch as choice enters into their meaning. Harmony is the common theme of these goods which are: harmony within the self (personal integrity); harmony among one's judgments, choices, and actions (personal authenticity); harmony with other human persons (peace, justice, friendship); and harmony with the more-than-human source of truth and being or God (religion). Three of these goods are "substantive": human life itself (including health, bodily integrity, and the handing on of human life and its education); knowledge of the truth and appreciation of beauty; play and work. In their co-authored essay, "Practical Principles, Moral Truth, and Ultimate Ends," American Journal of Jurisprudence 32 (1987), at 107-108 Grisez, Finnis, and Boyle agree on this list. In his The Way of the Lord Jesus, Vol. 2, Living a Christian Life, Grisez argues that marriage, which he had earlier regarded as a good reducible to the goods of friendship and of human life, is a distinct basic human good. See pp. 559-565. Here I should note that St. Thomas himself, in Summa theologiae 1-2, 94, 2, does not formulate first principles such as “life is a good to be protected and pursued,” “knowledge of the truth, living in society with others etc. are goods to b e done and pursued” but such formulations clearly follow from what he says, namely, that “reason naturally apprehends as good and therefore to be pursued in action all those things to which we are naturally iinclined” and that we are naturally inclined to the goods of life, knowledge of the truth, living in society etc.
30. Thus a murderer frequently appeals to the good of life (his own) to rationalize his choice to murder someone. Sin is not irrational; it is unreasonable, but not unintelligible. Sinners act for some good, and ultimately for the sake of some intelligible or basic good.
31. See St. Thomas, Summa theologiae, 1-2, 100, 3, ad 1.
32. St. Thomas Aquinas, Summa theologiae, 1-2, 100, 1.
33. Ibid., 100, 3.
34. Ibid., 100, 1.
35. Ibid., 100, 11.
36. Ibid, 100, 1.
37. Ibid., 100, 11.
38. Ibid., 100, 3. On this point see the splendid essay of Patrick Lee, "The Permanence of the Ten Commandments: St.Thomas and Some Modern Commentators," Theological Studies 42 (1981) 422-433.
39. Summa theologiae, 1-2, 100, 1.
40. Ibid., 100, 3.
41. Ibid., 100, 1.
42. Summa contra gentiles, 3. 122: “Deus non offenditur a nobis nisi secundum quod agimus contra nostrum bonum.”
43. Germain Grisez, Joseph Boyle, and John Finnis, Nuclear Deterrence: Morality and Reality (Oxford and New York: Oxford University Press, 1987), p. 284.
44. Grisez, The Way of the Lord Jesus, Vol. 1, Christian Moral Principles, p. 184.
45. Grisez, Finnis, Boyle, "Practical Principles, Moral Truth, and Ultimate Ends," 128.
46. Grisez, The Way of the Lord Jesus, Vol. 1, Christian Moral Principles, p. 184; Grisez, Finnis, Boyle, Nuclear Deterrence: Morality and Reality, p. 283. See "Practical Principles, Moral Truth, and Ultimate Ends," 128.
47. Grisez, The Way of the Lord Jesus, Vol. 1, Christian Moral Principles, p. 189.
48. Ibid., p. 191.
49. Ibid., p. 225.
50. They can be found in ibid., p. 225.
51. Ibid., pp. 257-258.
52. St. Thomas Aquinas, Summa theologiae, 1-2, 106, 1.
53. Louis Janssens, "Considerations on Humanae Vitae," Louvain Studies 2 (1969) 237-238. See also the essays by Joseph Fuchs, Bruno Schueller, Richard McCormick, Charles E. Curran and others in Readings in Moral Theology. No. 2: The Distinctiveness of Christian Ethics, ed. by Charles E. Curran and Richard A. McCormick, S.J. (New York: Paulist Press, 1980).
54. St. Thomas Aquinas, Summa theologiae, 1-2, 51, 4; 63, 3. On this matter see John F. Harvey, O.S.F.S., "The Nature of the Infused Moral Virtues," in Proceedings of the Catholic Theological Society of America 8 (1955).
55. St. Thomas Aquinas, Summa theologiae, 2-2, 32, on almsgiving; 2-2, 147, on fasting.
56. Ibid., 108, 3.
57. St. Augustine, The Lord's Sermon on the Mount, I, 1; trans. John J. Jepson, S.S., in Ancient Christian Writers, No. 5 (Westminster, MD: The Newman Press, 1948), p. 11.
58. Grisez, The Way of the Lord Jesus, Vol. 1, Christian Moral Principles, p. 605.
59. Grisez, The Way of the Lord Jesus, Vol. 1, Christian Moral Principles, pp. 627-650.
60. Ibid. See also the book devoted to this subject which Grisez wrote with Russell Shaw in 2003: Personal Vocation: God Calls Each One by Name (Huntington, IN: Our Sunday Visitor, 2003).
Version: 27th January 2004