For Thomas Aquinas, human beings must naturally move toward an end we can never reach by nature. We can call this “Aquinas’ anthropological paradox.” Human nature itself gives rise to the paradox, for the natural end of human life is one for which human nature is ill‐suited. For a teleological thinker like Thomas, everything in creation has an end or goal inherent to its nature and toward which its movements are oriented. Even a movement as simple as a stone falling to the ground is oriented toward some end. The stone will continue to fall until it comes to rest happily on the earth. This is because stones are made of the same stuff as earth. And this material stuff of which a stone is composed bestows upon the stone its form, which in turn determines the end of the stone's movements and becomes the weight that pulls it toward that end. But in ancient physics weight does not always pull things downward; fire burns upward, until it finds its home among the stars. So when in the Confessions Augustine says “my love is my weight,”Footnote 1 he means both that inordinate love for earthly things can drag us down like the heavy earthly elements, and that charity is like a fire that draws us upward until our restless hearts find rest in God. Whether we move toward our proper end or away from it, we do so by the weight of our own love.Footnote 2 Love's weight differentiates human motion from that of all other creatures. Humans do not always tend naturally toward our proper end, the way a stone falls toward the earth and fire burns upward toward the heavens. Our disordered love for other goods above our proper end grips us in that restless immobility, by which we cannot move toward what we desire. This, for Thomas, is the human predicament.
So what is this end of human life that we cannot seem to get to? For Thomas, a thing's end is that which fulfills and perfects the nature of that thing—or to use his language, what makes the thing happy.Footnote 3 The happiness of a caterpillar for instance, what fulfills and gives meaning to its existence, is to become a butterfly; of an acorn, to become an oak tree. Of course, what makes something happy will depend on what kind of thing it is, what makes it distinct from other kinds of things. What makes a happy dog will not necessarily make a happy human being. For Thomas, what distinguishes human beings from other kinds of things is that we are rational creatures. So the end toward which we are oriented is in contemplation and understanding.Footnote 4 That is what fulfills and perfects our distinctive human rationality—it makes us happy.
The Rational Problem
But this view presents a couple of problems for rational creatures. One has to do with our being rational, another with our being creatures. The first problem is that, as rational beings, we can think about what we want. Unlike sub‐rational beings, who move toward their proper end instinctually,Footnote 5 human beings deliberate about the movements we make. And if we can think about what we want and what we do, we can think about it badly. That is, everyone agrees, Thomas insists, on what he calls “the aspect of last end…all desire the fulfilment of their perfection.” But not everyone agrees on “the thing in which this aspect is realized.”Footnote 6 Everyone wants to be happy, but no one is quite sure how. “Some desire riches,” Thomas says, “some, pleasure; others, something else.”Footnote 7 All of these can lead to a certain measure of happiness. But all can be used badly and lead away from ultimate happiness as well. The rational creature's path to ultimate happiness is thus paved by a succession of choices about and movements toward particular goods. And none of these acts is for Thomas morally neutral—every action moves one closer to happiness or farther from it.Footnote 8 What we need, then, on some most basic level, is to know what to do.
Give What Thou Dost Command: Aquinas on Law
Teaching people what to do, Thomas says, is the function of the law: that one may “discern what is good and what is evil,”Footnote 9 But discerning is not the same as doing. The law may, “by fear of punishment,” restrain evil,Footnote 10 and hopefully it will lead ultimately to habituation, “since law is given for the purpose of directing human acts; as far as human acts conduce to virtue, so far does law make men good.”Footnote 11
Thomas’ theory of law is highly complex, with a four‐tiered taxonomy: eternal, natural, human and Divine, the last having two subcategories: Old and New. The first category, eternal law, is the Rule—the Order, the Wisdom, the Logos—by which everything in creation is oriented toward and guided to its proper end.Footnote 12 It is the “Divine Wisdom” by which God orders the world.Footnote 13 And because God is everything God has, including God's Wisdom, “His law is not distinct from Himself [sic].”Footnote 14 So Thomas’ discussion of Law begins with God, who orients all creation back to Godself as its ultimate end. Other would‐be laws count as law only to the extent that they reflect and participate in God's eternal law.Footnote 15 Thus, the eternal law is the source of all other types of law.
Natural law names “the rational creature's participation of the eternal law.”Footnote 16 Only rational creatures can be said to obey the natural law, since it delineates the distinctively rational form of participation in God's providential wisdom.Footnote 17 Non‐rational creatures “partake in their own way of the Eternal Reason,”Footnote 18 but their way of partaking is to be passively acted upon by the eternal law, receiving it as their inner principle of motion. Since they “do not partake thereof in a rational manner,… there is no participation of the eternal law in them, except by way of similitude.”Footnote 19 Thus a non‐rational creature's movement toward its end does not constitute obedience to the natural law. The rational creature, by contrast, “has a natural inclination to its proper act and end.”Footnote 20 We can will the good for ourselves, and formulate precepts concerning our movement toward it.Footnote 21 Through this power over our will and our actions, rational creatures reflect and participate in God's providential governance of the cosmos.Footnote 22 And this “participation of the eternal law in the rational creature is properly called [natural] law.”Footnote 23
So far I have emphasized that natural law is a rational participation in God's Eternal Wisdom, but we should also note that it is not a cold, sterile logic. When Thomas says that natural law is “self‐evident to us,”Footnote 24 he means that it is, as it were, “written on our hearts” (Rom 2:15). By her obedience to the natural law, the rational creature tends toward her ultimate end, even if she does so “without ever having gained explicit knowledge of it.”Footnote 25 DeYoung et al. put it simply: “when human beings are functioning as they were designed… these fundamental laws of human nature simply describe their actions.”Footnote 26 Unfortunately, due to the corrupting effect of sin, human beings no longer function as we were designed. Natural human inclinations are no longer a reliable guide to our proper end. What we need is a gift that will make the law be and do for human nature what human nature cannot be and do on its own. We will say more about that later, but now we turn to a more familiar use of the term law.
When we talk about laws, we generally think of codes of conduct determined in and for particular human contexts. This is what Thomas calls human laws, which he says are “particular determination[s] of certain matters.”Footnote 27 Nevertheless, human laws are “derived from the law of nature,”Footnote 28 and to that extent they participate in Divine Wisdom. But human laws are not simply a written form of the natural law—as if the natural law could be contained in human speech. And to the extent that it “deflects from the law of nature,” any human law becomes “no longer a law but a perversion of law.”Footnote 29
We are coming now to increasingly particular concepts. While human laws are universal, in the sense that all human cultures employ them in the ordering of society, natural law applies universally to all rational creatures. Both in turn participate in the Eternal Law, God's providential governance of the cosmos. Aquinas’ final category, Divine Law, is found only in the biblical narrative. Divine Law is divided into two subcategories. The first is the Torah, (what Thomas calls the Old Law), which was “given to the Jewish people.”Footnote 30 The Old Law solves two problems: Ever since our first parents rebelled against God and forfeited the original grace that oriented them toward God as their ultimate end,Footnote 31 we, their descendants have been apt to fail in applying the dictates of reason (natural law). So the Old Law helps the people of Israel heed the natural law, that they “might receive a prerogative of holiness, in reverence for Christ Who was to be born of that people.”Footnote 32 Secondly, the Old Law dictates cultic practices for worshipping the God of Israel, which could not be deduced through reason (applying the dictates of natural law) alone.Footnote 33 This puts the Old Law in the strange class of being both a kind of human law—that is, a determination of culturally particular matters—and at the same time, fully a divine gift of revelation.
Even as a divine gift, however, the Old Law is an “imperfect good.”Footnote 34 Like a medicine that “helps to cure” a patient, but cannot “bring him back to health,” the Old Law can help one along the way to her final end, but it is “not sufficient for the realization thereof;”Footnote 35 for the Old Law can tell someone what to do, but it cannot give her the power to do it. That is precisely what the New Law promises to do.
The New Law helps advance the sojourner on his way toward righteousness, “not only by indicating to him what he should do, but also by helping him to accomplish it.”Footnote 36 The New Law not only commands its followers to love God, it creates the love of God in them. So it recalls Augustine's prayer: “Grant what Thou dost command, and command what Thou wilt.”Footnote 37 How is this possible? How can a law cause someone to obey it? The answer to that lies in the strange characteristics of Thomas’ conception of the New Law.
We might expect Thomas to define the content of the New Law by expositing passages from the Gospels, especially the Sermon on the Mount. He does some of this, but in the end he insists that “the New Law had nothing to add [to the Old Law] as regards external action.”Footnote 38 Instead, for Thomas, the New Law refers fundamentally to a gift of God added to human natureFootnote 39 by the “grace of the Holy Ghost,” which in one place Thomas says “is given through,”Footnote 40 and in another, “is shown forth by”Footnote 41 faith in Jesus Christ, and it “worketh through love.”Footnote 42 In other words, for Thomas, the New Law is a gift of the Holy Spirit, given through faith, which becomes a source of righteousness in the soul. Servais Pinckaers has it this way: “the principle of the New Law…is not the Gospel viewed as a text or as an external word, comparable to a physical body, but rather a life principle, the breath of God which animates this body.”Footnote 43
We can imagine what Thomas is getting at here by comparing it with his theory of knowledge. To know something, for Thomas, is to receive its form immaterially in the soul.Footnote 44 The same logic is at play in Thomas’ theory of law: To know the law is to receive its form in the soul, to have it “written on your heart” (Jer. 31:33), as it were. We have already seen that, for Thomas, God's Eternal Law “is not distinct from Himself [sic].”Footnote 45 To know and to obey the law, then, is to receive the form of the God in the soul. The New Law is none other than the Holy Spirit present in the adherent shaping her soul in conformity with God's Wisdom.
Entirely from Without: Aquinas on Virtue
Still, it is not enough to know what to do in any given situation, nor even to have the supernatural power to do it. No movement toward to away from happiness begins from a neutral position. Every deliberation one makes follows from her previous ones, like steps down an ever‐steepening slope. With each step changing directions becomes increasingly difficult. The more one lies, the harder it is to find her way back to the truth. The more one speaks the truth, the more unpleasant it becomes for her to lie. Thomas calls this life‐forming process virtue, which he defines as “the perfection of a capacity,”Footnote 46 and elsewhere as an “operative habit”Footnote 47—that is, a habit ordered toward action. As DeYoung et al. summarize it, “virtues are the sorts of habits that both perfect human nature and in so doing also properly order their actions to their ultimate end.”Footnote 48 It may be useful to think of virtue like a skill, which also is a kind of habit. Think of how the movements of a skilled violinist are well formed, not clumsy or leaden. This form is always there, and is expressed in outward perfection when she plays. A skilled violinist experiences the sound and feeling of a violin differently from a novice because of the skill that gives shape to her hand and ear and so forth. Likewise an honest person, because of the form of her soul, experiences lying and cheating differently from a dishonest person: an honest person is not attracted by getting away with a lie.
Of course, Thomas well aware of, and even affirmed, Augustine's teaching that all virtues “are infused together with charity”Footnote 49—the love of God that God alone gives. So Bonnie Kent wonders what to make of Thomas’ decision to define virtue as a habit: What good is there in all the studiousness and patient practice that Aristotle believed necessary for developing a remarkable life, when genuine virtue requires nothing less than a divine gift? Is Thomas merely giving Augustine a tactful nod while rejecting his teaching in favor of Aristotle's?Footnote 50 To the contrary, Thomas navigates the distance between these two traditions by distinguishing different kinds of virtue. The natural or moral virtues, Thomas believes, can be developed by way of habituation. But the habits that constitute ultimate human happiness—the love of God, for instance, or faith—one cannot hope to develop on her own. Thomas calls these habits theological virtues for two reasons: because “inasmuch as they direct us aright to God,” their object is the love of God,Footnote 51 and secondly, because they are infused in us by God “entirely from without.”Footnote 52 Thomas even goes so far as to call them divine virtues, “not as though God were virtuous by reason of them, but because of them God makes us virtuous, and directs us to Himself.”Footnote 53
So Thomas turns away from a straightforwardly Aristotelian framework, toward a more Augustinian definition of the virtues as that “which God works in us without us.”Footnote 54 Even to the moral virtues, developed by habituation, Thomas gives an infused counterpart. For any virtue that orients one toward her ultimate good (“good as defined by the Divine Law”), he says, “cannot be caused by human acts…but is produced in us by the Divine operation alone.”Footnote 55 Moreover, those virtues acquired by habituation “are virtues in a restricted sense, but not simply: for they direct man well in respect of the last end in some particular genus of action, but not in respect of the last end simply,” while the infused virtues are said to be “perfect,” and “deserve to be called virtues simply: since they direct man well to the ultimate end.”Footnote 56
The Creature Problem
I said at the beginning of this essay that the rational creature faces two problems in attaining happiness. The first had to do with our being rational beings, our proclivity to misunderstand our end and how to reach it. We need a law to show us what to do; and we came to see also that the law must go further, giving us the power to obey it. We need to develop the skills and habits to make our progress toward happiness smooth and delightful; and we came to see also that, because of the kind of thing that fulfills rational beings, some of these virtues would need to be none other than divine gifts.
But we have a deeper problem still, one that has to do with our being creatures. We are not fit for the happiness we seek. Sure, with a bit of help we can lead a happy life in contemplation of the essence of things. But what fulfills a rational creature is not just the contemplation of the essence of things. Contemplation always points beyond itself to something higher, something that can never be attained by a mere mortal. Happiness for the rational creature is the perfection of her rational nature.Footnote 57 Because this is the highest part of the rational creature's soul, it must attain to the highest intelligible object. At least this is the Aristotelian line of reasoning that Thomas takes up. He saw in it an opportunity to argue that perfect human happiness consists in nothing less than the vision of God's essence.Footnote 58 Aristotle's intellectual quest for understanding as the end of human life opens the possibility of interpreting the traditional Christian promise of beatific vision in light of humanity's natural desire for truth. Thomas learned from Aristotle that the search for truth comes finally to rest in knowledge of the essence of the First Cause. Indeed, to know the essence of a thing is primarily to know what caused it. Desire remains in the intellect, therefore, until it perfectly comprehends the essence of the First Cause. Only then will it achieve its ultimate happiness, in which there is no more desire, no more searching, only perfect rest and fulfillment.
This move does not come without its price. It puts Thomas in the somewhat awkward position of positing two separate but related ends of human life, “a twofold ultimate perfection of rational or of intellectual nature.”Footnote 59 The first is an imperfect kind of happiness, proportioned to the rational creature's natural capacities, which the rational creature can therefore “procure of its own natural powers.”Footnote 60 Thomas frequently identifies this first kind of happiness with the development of the cardinal virtues.Footnote 61 But humans are called to a happiness “above” this one: the vision of God's essence, which, of course, “is beyond the nature of every created intellect.”Footnote 62
The relation between these two ends functions as a kind of analogy (in Thomas’ technical sense of that term).Footnote 63 Just as all things participate in God's being, so natural happiness, insofar as it is found in contemplation of the Divine Cause, can be said to participate in beatific vision.Footnote 64 Yet we should not conceive of the vision of God simply as a more perfect happiness—it is of a different class all together. This is the way analogy always works in Thomas: a lower thing may bear a certain likeness to some higher thing, but the resemblance never goes in the opposite direction. For instance, God is not a super human, like us but greater to an infinite degree. God's Being is of a different order. God is Being Itself. Likewise, the vision of God is of a different order than natural human happiness. Beatific vision is seeing God as God is in Godself, not knowing God merely as the principle of one's created existence. It is seeing into the essence of God the way one peers into the soul of a friend. For Thomas, to see something in this way is to take the form of the thing seen immaterially in one's mind. To know a friend, for Thomas, is literally to have her in your heart. Or as Davies puts it, “to know what a thing is means having what it takes to be the thing, without actually being the thing itself.”Footnote 65 Thus, what ultimately makes human beings happy, the vision of God, requires what is proper to God alone; namely, the divine form.Footnote 66
The radical implication is that human beings are excluded from ultimate happiness unless God somehow makes us capable of performing the divine act of seeing God in God's essence. If beatific vision is “is natural to the divine intellect alone; and this is beyond the natural power of any created intellect,” as Thomas says it is, then “the created intellect cannot see the essence of God, unless God by His grace unites Himself [sic] to the created intellect, as an object made intelligible to it.”Footnote 67
Clearly, there is no question whether, for Thomas, one attains to beatific vision by her own capacities. In fact, for Thomas, God's grace is necessary not only for one to attain her ultimate happiness in the vision of God; it is necessary to attain even natural happiness. In question 109 of the Prima Secundae, Aquinas explores this question “of the necessity of grace.” He begins with a fairly straightforward formula: If we are talking about acts that are natural to human beings, then human capacities will suffice and grace will not be necessary. If we are talking about a supernatural act, like the vision of God, then grace is needed. But things quickly become more complicated.Footnote 68 For instance, in the second article of the question Aquinas asks “whether man can wish or do any good without grace.” Following the formula, we might expect this task to fit well within the bounds of human capacity. But some well‐wishing and well‐doing, it seems, is beyond natural human capacities. “In the state of integrity,” as human nature was created “in our first parent before sin,” Thomas says, “man by his natural endowments could wish and do the good proportionate to his nature.” Thus “in the state of perfect nature man needs a gratuitous strength superadded to natural strength for one reason, viz. in order to do and wish supernatural good.” But sin disrupts the formula: “in the state of corrupt nature,” such as we now have “after the sin of our first parent…man falls short of what he could do by his nature, so that he is unable to fulfill it by his own natural powers.” Thus we need gratuitous strength superadded to natural strength “for two reasons, in the state of corrupt nature, viz. in order to be healed, and furthermore in order to carry out works of supernatural virtue.”Footnote 69
So Thomas believes that grace is needed for all kinds of happiness. Because of the corrupting effect of sin, grace is necessary to heal and restore nature in order that it may achieve even natural human happiness. But to attain ultimate happiness in the vision of God is beyond natural human capacities even in their pristine state. This problem is intrinsic to what it means to be human—what we called Aquinas’ anthropological paradox—and is thus logically prior to the fall, which only exacerbates it.Footnote 70 Thus, for Thomas, grace must not only restore nature insofar as it is marred and corrupted by sin, it must also elevate nature to do what nature cannot do on its own.Footnote 71
Conclusion: From Pagan Striving to Augustinian Grace and Back Again
Thus far, we have observed a shift in Thomas’ soteriology from an Aristotelian understanding of human movement toward the good to a more Augustinian one. Now, by way of conclusion, we are in a position to trace this shift in Thomas’ doctrines of virtue, law and grace.Footnote 72 We saw that initially Thomas considered virtue an interior principle of motion, and the law an external one.Footnote 73 However, “Aquinas's initial classification of interior and exterior principles of action quickly becomes complicated by his Christian additions to the Aristotelian elements with which his ethics begins.”Footnote 74 As we saw, Thomas’ recognition that the ultimate happiness of a rational creature lies in the vision of God, an act for which divine capacities are required, meant that he ultimately had to conceive of virtue as a divine God, which originates outside the human heart. Likewise, Thomas’ understanding of law became, in the New Law, an interior principle of motion, the power of the Holy Spirit to do what the law commands. So Aquinas shifted his points of emphasis about virtue and law in opposite directions: virtue from interior to exterior, law from exterior to interior. But in both cases this was a move from Aristotelian striving to Augustinian grace, shifting the soteriological weight from human capacity to the work of God.
In Thomas’ doctrine of grace, the change of location is different. Initially, he understood grace as an external principle of motion, whereby God moves people toward their proper end. Grace must be an external principle for Thomas, since rational creatures lack the capacity to move toward our natural end in beatific vision of God. How else could one arrive at divine vision besides being moved by God? This initial understanding would have worked for from an Augustinian perspective—it removes any reliance on one's own capacities. But it did not ultimately work for Thomas.
According to Thomas, God not only brings all things to an end appropriate to their nature; God does so in a way appropriate to their nature. God will help human beings move toward our end, for instance, in a way that maintains our nature as rational, moral agents.Footnote 75 For grace to be a wholly external force—God moving us like a chess pawns toward beatific vision—is for human nature to lose what makes it distinctively human. When something is moved in this way, solely by an external force, it is what Aquinas calls “violent motion.” Since most things have by nature the capacity to move toward their proper end, it is no coincidence that violent motions generally move things away from their proper end (think of throwing a stone into the air, away from the earth that provides the stone with its form). As creatures who lack the capacity for divine vision, we must be moved to our proper end by an external principle; but as rational, moral agents, we cannot be so moved. As rational beings, we must be self‐moved to our proper end; but as creatures, we cannot move ourselves to that end. This paradoxical doctrine of grace is, of course, just another iteration of Aquinas’ anthropological paradox, one that has been the source of as much heat as light in the history of theology in Thomist traditions.
