Traditio is a Latin word that means handing on, especially the handing on from one generation to another of the culture and knowledge built up within a civilization. The process of handing on enables one generation to benefit from the insights and endeavors of others, and it keeps each new generation from starting ab initio to acquire those things that make human life more than merely animal. The value of tradition is hard to overestimate.

Our own age has been greatly concerned to ensure the handing on of scientific knowledge. It is clear to us that science is a communal enterprise; and we have developed efficient, technologically sophisticated means for transmitting the methods, procedures, and results of one generation of scientists to the next. In learning from the work of previous generations of scientific researchers, we may find that we have to revise or even reject some of what the previous generations had accepted; but we make progress in science because we have first learned from the communal expertise of those generations of scientific researchers who have gone before.

It is clear that an analogous point about tradition applies to human civilization more broadly conceived. No culture completely divorced from its common past can flourish, as the deplorable lessons of the twentieth century show, because human expertise of any kind is vested in communities that are extended across times. In the West, the two millennia of the Christian era have yielded a wealth of work in philosophy and theology and the other humanistic disciplines. But in recent decades there has been a growing neglect of this tradition. We have become worried about the kind of parochialism and its concomitant injustices that a blinkered focus on tradition can breed, and so we have been concerned to acquaint ourselves with at least some parts of the culture and knowledge of civilizations other than our own.

This incipient willingness to learn from other cultures is undoubtedly a salutary development, and it serves as a welcome corrective to the provincialism that was characteristic of some areas of the humanities in the past. On the other hand, however, between the great growth of the sciences and the turn to multiculturalism in the humanities, the transmission of the cultural heritage of the West has suffered. This trend should be a concern to everyone engaged in education, but it should be specially troubling for Christians. The Christian tradition encapsulates the communal expertise of many generations of thinkers who labored to explain the nature and flourishing of human persons in a world whose fundamental reality is understood to be a triune deity characterizable both as loving and as love itself.

Like the sciences, this tradition has its failures. But also like the sciences, in its successes this tradition holds great power for good. Both in its impressive successes and in its failures, it has a great deal to teach us.

Just as the sciences have thinkers specially valued because of their stellar contributions to one or another scientific discipline, so the Christian tradition also has notable figures whose work shaped the subsequent course of Western culture in significant ways. Consider, for example, just some of the most famous A’s: Athanasius, Ambrose, Augustine, Anselm, and Aquinas. Thomas Aquinas (1224/6-1274) is distinguished even in the group of these imposing figures. Without doubt, his mind is among the most powerful in the Western tradition, and his influence is correspondingly great.² He lived a demanding academic and ecclesiastical life that ended when he was only fifty (or a bit younger), but his output is nonetheless prodigious; he produced many works, varying in length from a few pages to several volumes. Because his writings grew out of his activities as a teacher in the Dominican order and as a member of the theology faculty of the University of Paris, most are concerned with what he and his contemporaries thought of as theology. But much of academic theology in the Middle Ages consisted in a rational investigation of the most fundamental aspects of reality in general and of human nature and behavior in particular. That extensive domain obviously includes much of what is now considered to be philosophy and is reflected in the broad subject matter of Aquinas’s theological writings.

Aquinas not only made himself master of ancient Greek philosophy as exemplified in the works of Aristotle; but he differed from many of his Christian colleagues in the breadth and depth of his respect for Islamic and Jewish thinkers, especially Avicenna and Maimonides. He saw them as valued co-workers in the vast project of philosophical theology, clarifying and supporting religious doctrine by philosophical analysis and argumentation. His own commitment to that project involved him in contributing to almost all the areas of philosophy recognized since antiquity, omitting only natural philosophy (the precursor of natural science).

A habit of thought with such strong connections to noteworthy antecedents might have resulted in no more than a pious amalgam. But Aquinas's philosophical and theological work avoids eclecticism not only because of his magisterial explication and development of all the main areas of philosophy and theology, but also because of his systematic synthesis of the great intellectual heritage he absorbed. For this reason, his work can serve as something of an encyclopedia of the Western tradition in the many preceding centuries.

Furthermore, the good of having a repository of communal expertise of this sort is not to turn it into a museum piece for the exclusive attention of antiquarians but rather to serve as the basis for further development of the understanding of human beings and the world in which they live. The Christian tradition supposed that it is the task of every generation to develop as well as to hand on the heritage it has received. As Aquinas himself put it, “the whole faith of the Church is grounded in the revelation made in the time of grace to the apostles concerning faith in the unity and trinity [of God]” (ST II-II q. 174 a.6). But, he thought, both by direct divine revelation (see, e.g., ST II-II q.176 a.1 ad 1) and by study and contemplation (see also, e.g., ST I-II q.180 a.4),³ in subsequent generations the whole community can continue to grow in knowledge and wisdom.

Aquinas’s most famous work is his Summa theologiae (ST); and it is a paradigm of philosophy and theology. The first article of the very first Question raises a question about the relation between theology and philosophy. In this article, Aquinas asks whether we need any “other teaching, besides philosophical studies.” The question arises because philosophical studies are characterized not only as dealing with “the things that are subject to reason,” but also as encompassing “all beings, including God,” as a consequence of which there is a part of philosophy that is theology.

On Aquinas's view, no claims appropriate to natural theology, the part of theology that is discoverable by reason alone, are excluded from ST's subject matter. But the claims of natural theology form only a subset of the claims treated in theology, which relies on divine revelation for some of its claims. As Aquinas puts it,

It was necessary that human beings be instructed by divine revelation even as regards the things about God that human reason can explore. For the truth about God investigated by a few on the basis of reason [without relying on revelation] would emerge for people [only] after a long time and tainted with many mistakes. And yet all human well-being, which has to do with God, depends on the cognition of that truth. Therefore, it was necessary for human beings to be instructed about divine matters through divine revelation so that [the nature of human] well-being might emerge for people more conveniently and with greater certainty. (ST I q.1 a.1)

The subject matter of the theology presented in Aquinas’s Summa of theology is thus, in Aquinas's view, the most basic truths about everything, with two provisos: first, it is about God and about things other than God as they relate to God as their source and goal; second, among the things other than God with which it deals, it is especially about human beings, whose study of theology should be motivated by the fact that their well-being depends specially on their grasp of certain theological truths.

Aquinas characterizes theology as a systematic, reasoned presentation of an organized body of knowledge consisting of general truths about some reasonably unified subject matter. It is the enterprise of employing the techniques and devices of philosophy in clarifying, supporting and extending the thought expressed in the propositions that are supposed to have been revealed for theology's starting points. Thus, some of the work of philosophical theology is an attempt to explain revealed propositions and systematically work out their implications.

Not even doctrinal mysteries are impervious to rational investigation, although Aquinas accepts the orthodox view that unaided reason could never have discovered them. Regarding one central mystery, for example, Aquinas says: “It is impossible to arrive at a cognition of the Trinity of the divine persons by means of natural reason” (ST I q.32 a.1). But he says this in the twenty-second of a series of seventy-seven articles of ST devoted to analyzing and arguing about the details of Trinity.

As Aquinas explains in the very article in which he rules out the possibility of rationally discovering that there are three divine persons in the deity:

There are two ways in which reason is employed regarding any matter […] in one way to provide sufficient proof of something fundamental […] in the other way to show that consequent effects are suited to something fundamental that has already been posited […] It is in the first way, then, that reason can be employed to prove that God is one, and things of that sort. But it is in the second way that reason is employed in a clarification of Trinity. For once Trinity has been posited, reasonings of that sort are suitable, although not so as to provide a sufficient proof of the Trinity of persons by those reasonings. (ST I q.32 a.1)

In Aquinas’s view, this work on philosophical theology aids one's understanding of the created world generally and of the human place in it.

The science of biology grew exponentially when chemistry began to help explain biological activity (MacDonald & MacDonald, 2010, p. 3); chemistry itself increased in explanatory power when it was able to use physics to elucidate chemical structures and activities; and modern physics seemed to provide a complete and satisfying explanation of the ultimate foundation of all reality. It seemed to philosophers for a while that all things in the world are reducible to the fundamental units of matter postulated by physics and governed by the natural laws of physics so that all scientific theories are reducible to whatever theory is propounded by the ultimate completed physics.⁴

One major problem with this particular approach to a grand unified theory of everything, a problem increasingly recognized and discussed by contemporary philosophers, is that it seems unable to account for the presence of consciousness in the world. That is, it seems to many philosophers that it is impossible that conscious minds are constructed out of the elementary particles of matter given only the basic physical laws studied by physics.⁵ The growing recognition of this problem is responsible for the rising interest in panpsychism. Differing varieties of panpsychism are now being discussed, but what they have in common is a conviction that the most basic elementary bits of matter (whatever physics tells us they are) somehow have a mental as well as a material character. There is human consciousness in the world because everything in the world has at least some mental properties. For panpsychists, the mental does not have to be constructed out of the material; the mental is itself at the ultimate foundation of all reality, and human consciousness has its source in that foundational mentality.

Aquinas also supposes that the mental is at the ultimate foundation of all reality; on his view, too, the mental arises from the mental.⁶ For Aquinas, however, what is foundational is not the attenuated mentality characterizing elementary particles of matter; rather, it is the mind of God. For the panpsychist, human consciousness is brought about somehow by the confluence of the mental characteristics inherent in material bits. For Aquinas, human consciousness has its source in the mind of God.

In the tradition Aquinas inherited and developed, God is understood to be simple. The doctrine of divine simplicity as defended by a proponent of classical theism such as Aquinas is often interpreted as maintaining that God is the ultimate foundation of reality because God is being itself. As some interpreters understand Aquinas’s position, because God is only being itself, God is incomprehensible to human beings and unresponsive to them. In fact, this interpretation supposes that on Aquinas's account of God's simplicity God is not a being at all. Rather God is the necessary ground of all being, without any possibility of change or any admixture of contingency. As is frequently remarked by those who reject this interpretation of the doctrine of simplicity and this view of God, it is hard to see how such a God could act with freedom of will or how he could do otherwise than he does at all. If such a God is like anything at all recognizable by us, he is more like the Force in the Star Wars movies than like the God of the Bible, who is knowable by human beings, richly engaged with them in myriad ways, and definitely able to act otherwise than he does.

But those who take Aquinas's interpretation of the doctrine of simplicity to imply that God is only being itself and not also a being misread Aquinas's position.⁷ In effect, their interpretation takes the doctrine of simplicity to make God metaphysically more limited than concrete things such as composite human beings, who can do otherwise than they do. But this is to get the doctrine upside down. The doctrine of simplicity does imply that at the ultimate foundation of all reality there is being. But it also implies that this being, without losing any of its characteristics as being, is something subsistent, a concrete particular, an individual – in short, a being, an entity – with more ability to act and with more freedom in its acts than any concrete composite entity has.

When at the start of his Summa theologiae Aquinas says that we do not know of God what he is (quid est), Aquinas is not espousing a radical via negativa, as some scholars have supposed (ST I q.3 Prologue). He is maintaining only that, on the doctrine of simplicity, what we do not know is the quiddity of God. As Aquinas explains this point elsewhere, “With regard to what God himself is, God himself is neither universal nor particular” ( ST I q.13 a.9 ad 2). On panpsychist views, which are, on the face of it, hard to understand, the smallest things that are at the foundation of all reality are somehow both mental and material. For Aquinas, there is also something that surpasses our complete comprehension of the nature of God, which has to be thought of both as abstract (that is, as being) and also as concrete and particular (that is, as a being, an entity).

It is important to see here that in taking the doctrine of simplicity to imply that God is both being and a being, Aquinas is accepting and developing two divergent streams of thought, each of which is overwhelmingly influential in the West.

As is well-known, the word ‘philosophy’ is Greek in origin; and in its etymology it means something like the love of wisdom. Wisdom is an abstract universal. Like redness, like fragility, it is not a substance; it does not have any particular dimensions; it cannot exert causal power or receive the effects of anything else’s causal action. In this respect, wisdom is different from a wise person, or a red thing, or a fragile thing. A wise person, a red thing, a fragile thing are all concrete particulars; but wisdom, which Greek philosophy sought, is not. Greek philosophy bequeathed to the West great achievements in metaphysics, epistemology, ethics, and other areas of philosophy because it sought to understand the most foundational parts of reality in abstract, universal terms.

By contrast, the stream of thought whose source is the biblical texts and the culture which produced them is focused on a concrete particular. The God of the Bible has mind and will, and he can be appropriately addressed with the second-personal pronoun ‘you’. In virtue of being characterized by mind and will, the biblical God is more nearly a person (in our sense of the word ‘person’) than he is an abstract universal. A philosopher can love wisdom and seek it, but wisdom cannot love or seek him. The God of the Bible can seek a person and love her before she seeks or loves him. Sustained reflection on the God of the Bible and the metaphysics it generated also bequeathed to the West great achievements not only in metaphysics, but also in epistemology, ethics, and other areas of philosophy. But that reflection took the ultimate foundation of reality to be a God who can do otherwise than he does, who created human beings in his image, and who loves them and desires union with them.

What is notable about the doctrine of simplicity as Aquinas accepts and develops it is that it melds both these streams of thought, the Greek and the biblical; and the result is impressively fruitful for both philosophy and theology.

To begin to see the power of the idea of divine simplicity which results from this melding, consider, for example, the Euthyphro dilemma, formulated by Plato and still in one form or another much discussed today: do the gods will what is good because it is good, or is what the gods will good because they will it? This is a dilemma because there are serious philosophical and theological costs to each of the options in the dilemma. If the gods will what is good because it is good, then it seems that the gods are not sovereign but are rather bound by the demands of the objective good. On the other hand, if what the gods will is good because they will it, it seems that anything whatever could be good if only the gods will it, so that a radical theological relativism in ethics results.

The doctrine of simplicity, however, provides a way to sail through the Euthyphro dilemma. On the relevant metaphysics of being, being is correlative with goodness. Consequently, since God is being, God is also goodness; that is, insofar as being is God’s own nature, then goodness is also. But on the doctrine of simplicity, it is also true to say that God is a being who is good. For this reason, on the doctrine of simplicity, it is true to say that God wills the good because it is good, but then it is also true to say that the good that God wills is his own nature. The objective character of the good that God wills, therefore, does not impugn God’s sovereignty since it is God’s own nature that constitutes objective goodness. Consequently, nothing outside God binds God’s will. On the other hand, there is no theological relativism because the good that God wills has its source in God’s nature and not in God's own will. God could not will just anything as good because his nature is not changeable.

The doctrine of simplicity also makes a difference to the currently much-discussed problem of God's apparent hiddenness.

The problem is often framed as an argument against the existence of God, formulated roughly in this way. If God exists, he wants a loving relationship with human beings; but many people do not have such a relationship in virtue of lacking knowledge of God's existence. When a person lacks knowledge of God's existence, however, then either that person is responsible for this lack of knowledge or (if God exists) God is. But if there is a God, then he cannot be responsible for this lack of knowledge since he is able to give the knowledge and wants loving relationships with all people. It seems then that if there is a God, the only alternative is to suppose that every person who lacks knowledge of God is himself responsible for his ignorance. This alternative thus assigns some degree of culpability for such ignorance to every person who lacks knowledge of God's existence; but this alternative seems clearly false. Therefore, since each alternative explanation fails, it apparently follows that God does not exist.

But, here too, it makes a difference that, on the doctrine of simplicity, God is being as well as a being with a mind and a will; and since being is correlative with goodness, on the doctrine of simplicity God is goodness as well as being. Furthermore, as Aquinas explains it, beauty is goodness perceptible to the senses (where intellectual vision counts as a kind of sight, too) (Cf. ST I q.5 a.4 ad 1). In being aware of goodness, then, or in sensing beauty, a person is also knowing God, to one degree (however limited) or another. So from a person's sincere self-report that he does not believe in an omniscient, omnipotent, perfectly good God, it does not follow that he does not know God in any way or to any degree.

Furthermore, on the doctrine of simplicity, knowing God will clearly not be a transparent matter; that is, a person can know God through being aware of goodness or sensing beauty without knowing that he is thereby knowing God. A fortiori, it will not be evident to others either; that is, given the doctrine of simplicity, it is also not obvious how others would know whether or not a person had knowledge of God. So, on the doctrine of simplicity, it takes more than a person's self-report of atheism to show that he does not know God. For these reasons, the premiss in the argument from divine hiddenness postulating that there are very many people who have no knowledge of God and no culpability for lacking that knowledge is at best unsupported, if not actually false.

In the previous part of this article, we explained Aquinas's metaphysics according to which a simple God is the ultimate foundation of reality. On Aquinas's understanding of the traditional doctrine of God's simplicity, God is not only being and goodness itself but also a being who is perfectly good. In this part, we draw out some of the consequences this view of God has for Aquinas's account of ethics and a proper understanding of the good of Aquinas's ethics.

Aquinas's ethics is frequently presented as what has been called ‘natural law ethics', according to which the essence of human flourishing is fulfilling the natural law by acting in accordance with reason (see, e.g., Finnis, 1980.) On this view, the good on which Aquinas's ethics is focused is reason or rationality. At first glance, this interpretation of Aquinas's thought seems sensible since he accepts the Aristotelian view that things flourish to the extent that they unfold and perfect their natural capacities. Since, on this interpretation, Aquinas holds the Aristotelian view that human beings are by nature rational animals, Aquinas is taken to hold that human beings flourish to the extent that they reason well and act accordingly. Thus, it seems that, for Aquinas, the ultimate measure or rule which determines whether a human action is rightly ordered to human flourishing is a list of goods such as knowledge, play, life, and so forth to which human beings are inclined to due to their rational nature. According to the natural law interpretation of Aquinas's ethics, human beings reason well if they choose actions which realize the goods to which they tend by nature or choose to avoid courses of actions which undermine the realization of such goods.

But a decisive problem for such an interpretation of Aquinas's ethics is the textual evidence. Summa theologiae I-II is the part of the Summa in which Aquinas expounds his view of human flourishing, and it has 114 questions. But only 18 out of that 114 deal with law, and only one covers natural law. Clearly, Aquinas himself did not suppose that natural law is central for understanding either ethics in general or human flourishing in particular.

A more promising interpretation of Aquinas's ethics and the good essential to it takes it to be a kind of Aristotelian virtue ethics (e.g., McInerny, 1993, pp. 25-26; Kenny, 1999, pp. 15-27). According to this interpretation, for Aquinas acting in accordance with reason is central to human flourishing, as the natural law interpretation also supposed; but, unlike the natural law interpretation, the interpretation of Aquinas's ethics as Aristotelian highlights the centrality of virtues in Aquinas's ethics. Virtues are central, on this interpretation, because a human being can act in accordance with reason only with the help of the virtues, which enable reason to govern the passions. For example, a person needs to acquire the virtues of temperance and courage to keep lust, fear, or other passions from interfering with reason's determination of the good to be sought in a given situation. So, this interpretation supposes, the acquired virtues are central to Aquinas's ethics because they incline human beings to reason well; and when they reason well, they choose actions which realize goods suitable to human nature.

But the interpretation that takes Aquinas to be committed to a kind of Aristotelian virtue ethics is confronted with at least three major problems.

First, on Aquinas’s view but obviously not on Aristotle's, an intimate personal relationship with God is essential to human flourishing. It can begin in this life; and if it continues, it will be fully realized in the afterlife (see, e.g., ST I–II q. 3 a. 8; q. 5 a. 3). What is at the heart of Aquinas's ethics is not reason and the Aristotelian virtues, but personal relationship, and personal relationship with God in particular.

Second, according to Aquinas's definition of virtue, the Aristotelian virtues actually do not qualify as the virtues. That is because Aquinas accepts with approval Augustine's definition of virtue:

Virtue is a good quality of the mind, by which we live righteously, of which no one can make bad use, which God works in us, without us. (ST I–II q.55 a.4, obj.1, sed contra, and corpus)

The Aristotelian virtues do not fit this definition because they are dispositions that are acquired by practice. But for Aquinas, true virtues have to be infused by God (e.g., ST I–II qq. 62-63); although a human being can reject God's infusion of virtue, only God can bring about the virtues in a human being. Furthermore, the infused virtues are dispositions caused by God in human beings to direct them to their ultimate good, namely, union in love with God. The good Aquinas's ethics is focused on is thus something which cannot be acquired by practice or other human means. Given the Christian rejection of Pelagianism, this conclusion should not be a surprise. To suppose that acting in accordance with reason and the acquisition of virtues by practice makes human beings worthy of eternal happiness would certainly be Pelagian.

Finally, on Aquinas's view, even the infused virtues are not sufficient for human flourishing. That is because Aquinas accepts the traditional Christian doctrine that human beings also need the gifts and fruits of the Holy Spirit (see, e.g., ST I-II qq. 68, and 70).

The gifts are dispositions infused into a person by the Holy Spirit that comes to indwell a person who does not reject God's love and grace. They render a person apt to listen to and follow the internally discernible voice of God. Speaking of the gifts, Aquinas says,

These perfections are called ‘gifts', not only because they are infused by God, but also because by them a person is disposed to become amenable to the divine inspiration. (ST I-II q.68 a.1)

And a little later he says, “the gifts are perfections of a human being, whereby he is disposed to be amenable to the promptings of God” (ST I-II q.68 a.2).

There are twelve fruits of the Holy Spirit, and they also have a central role in Aquinas's ethics (see, e.g., ST I-II q. 70 a.3). As their name suggests, these fruits are the outcome of the gifts of the Holy Spirit and the relationship with God established by the Holy Spirit’s indwelling a person. The first three fruits are love, joy, and peace; and, as Aquinas explains them, they are consequences of shared love between a human person and God. There is love because a human person is in a relationship of love with the deity; there is peace because what that person most desires, he already has; and there is joy because he is his beloved's, and his beloved is his. The next fruits of the Holy Spirit are patience and long-suffering, because even with all the gifts and fruits of the Holy Spirit, there will still be suffering of one sort and another in this life; but the fruits are ways of dealing with that suffering in communion with God. Manifestly, then, Aquinas's virtue ethics is very different from that of Aristotle.

This brief sketch of Aquinas's ethics shows why, from Aquinas's point of view, both natural law ethics and Aristotelian virtue ethics are unsatisfactory as ethical theories. Neither one privileges the relational dimension of human nature and flourishing. For Aquinas, their account of the human good has to count as inadequate. On his view, their understanding of human nature is inadequate.

To get a better grasp of the foundational role of relationship in Aquinas's account of human nature,⁸ it is helpful to begin with the prologue to the whole section on ethics in ST I-II. There Aquinas says,

human beings are said to be made in God's image, insofar as this image implies an intelligent being endowed with free-will and self-movement. […] Human beings are made in God's image inasmuch as they too are the principle of their actions insofar as they have free-will and are in control of their actions.

Like Aristotle, Aquinas takes human beings to be rational animals; but, on Aquinas's account, as rational animals, human beings are creatures of their creator; and they bear a likeness to God because they have both intellect and free will. This image of God in human beings is central to what human beings are. They are not just substances with a rational nature; as creatures, they are what they are in virtue of being related to their creator.

In addition, on Christian doctrine, although there is just one God, there are three persons in this one God. So human beings are made in the image of God not only in having intelligence and free will but also in bearing the image of the Trinity. On the complicated doctrine of the Trinity, the persons of the Trinity are subsistent relations. In a metaphysically analogous way, subsistence and relationality characterize human nature also. Human beings are substances and so subsistent; but because they are creatures, relationality is also essential to their nature. Being related to God is constitutive of human nature, too.

And so Aquinas says,

There is one general way by which God is in all things by essence, power, and presence, [namely,] as a cause in the effects participating in his goodness. But in addition to this way there is a special way [in which God is in a thing by essence, power, and presence] which is appropriate for a rational creature, in whom God is said to be as the thing known is in the knower and the beloved is in the lover […] In this special way, God is not only said to be in a rational creature but even to dwell in that creature. (ST I q.43 a.3.)

In Aquinas’s view, then, human flourishing is relational in nature. True, it is the rational nature of human beings that gives them their capacity for this relation. But they flourish when they know and love God, and when God indwells in them as “the thing known is in the knower and the beloved is in the lover.”

For these reasons, Aquinas's ethics makes a relationship of love central to all human flourishing, and it makes love central to ethical action as well. And that is why, given Aquinas's views, acting in accordance with reason is not enough for the true human good and the Aristotelian virtues are not real virtues.⁹ A person can act in accordance with reason and have the Aristotelian virtues and still not flourish because he has closed out the love of God (see, e.g., ST I-II q.63 a.2 ad 2). Reason is good because it is a condition of the possibility of shared love between a human being and God. But reason is not the ultimate rule or measure of the goodness of human actions because human beings can use their rational powers well and still not flourish, because they are living in isolation or attempted self-sufficiency.

One special good of Aquinas's ethics is the way in which it weaves second-personal relations, that is, relations of the sort Buber famously called T-Thou’ relations, into one ethical synthesis.¹⁰ An analogy with music helps to illustrate the point.

On Aquinas's view, there preexists in the mind of the creator a plan or order of his creation. This plan in God's mind is what Aquinas's thinks of as the eternal law in the mind of God; and, on Aquinas's view, it is the supreme rule or measure of human action (see, e.g., ST I-II q. 93, and q. 21, a.1). In an analogous way, the composer of a symphony thinks about the notes of the symphony and their order, the arrangement and use of instruments, and many other things that go to make up the composition of the symphony. The score of his symphony is in a sense the supreme rule or measure of the music he has in mind. And in order to be good, the musicians in an orchestra performing that symphony need to use their instruments to produce sounds in accordance with what is written in the score of the symphony. Their playing is bad if they produce sounds that miss what the composer's score mandates.

But, the individual musician’s ability to play what is in the composer's score is not enough for being a good musician in the orchestra's performance of the symphony. Playing according to the score is one thing. It is another thing entirely to play following the directions of the conductor who interprets the symphony and whose grasp of the music has to govern the whole orchestra. Clearly, to be a good musician in the orchestra requires not only skill with a musical instrument but also the ability to relate in the right way to the orchestra's conductor. When the musicians of the orchestra are united in their relationship to the conductor, then they are not just skilled at their instruments; rather, then their performance of the composer's music is good, and they are good musicians.

In an analogous way, being in accordance with reason is necessary for a person's action to be in accordance with the eternal law in the mind of God; but it is not sufficient for the action to be good. The goodness of a person's action is also determined by that person's relation to the creator; to be good, a person's action needs to be in harmony with the creator. This harmony requires not just that a person wills what God wills and loves what God loves, but that a person loves God as well.¹¹ It is harmony between God and human beings that enables human beings to do good actions.

The musical analogy also helps us understand better the role that the gifts of the Holy Spirit play in Aquinas's ethics. A musician can be quite talented and skilled; but on his own he cannot do what is needed to be a good musician in an orchestra, and he cannot play his part of the symphony well. In an analogous way, the gifts of the Holy Spirit are relational dispositions infused by the indwelling Holy Spirit that connect a person to God in love (see, e.g., ST I–II q.68 a.1). They thus transform a person from someone acting in accordance with reason into someone familiar with God. In that condition, a person has a certain connaturality with God, so that in relationship with God he understands what actions are in accordance with God's eternal law and is disposed to do them.¹² So, for example, Aquinas says,

For those who are moved by Divine instinct, there is no need to take counsel according to human reason, but only to follow their inner promptings, since they are moved by a principle higher than human reason. This then is what some say, viz., that the gifts perfect human beings for acts which are higher than acts of virtue. (ST I–II q.68 a.1)

Finally, the musical analogy can also illumine the notion of the fruits of the Holy Spirit, which, like the gifts, are second-personal in character (see, e.g., ST I–II q.70 a.1).

A musician who plays his parts of the score of the symphony can of course take pleasure in his doing so well and can thus enjoy the exercise of his talents. There is a sense in which he is successful as a musician when he does so. But it is another thing entirely for him to experience the joy in the orchestra's successful performance of the symphony that results when each musician plays well in virtue of being rightly related to the conductor. The relationship with the conductor transforms the pleasure each musician might have had just in his own solitary playing into the joy of being part of a well-played symphony.

Like the gifts of the Holy Spirit, the fruits of the Holy Spirit are second-personal in character.¹³ Aquinas explains them as the emotional condition of someone who is connected in love with God. Aquinas says this about the first three fruits of the Holy Spirit – love, joy, and peace:

[God] himself is love. Hence it is written (Rom.v.5): The love of God is poured forth in our hearts by the Holy Spirit who is given to us. The necessary result of this love is joy, because every lover rejoices at being united to the beloved. Now love has always the actual presence of God whom it loves. So the consequence of this love is joy. And the perfection of joy is peace […] because our desires rest altogether in [God]. (ST I-II q.70 a.3.)

In fact, for Aquinas, the Holy Spirit so fills a person with a sense of the love of God and his nearness that joy is one of the principal effects of the Holy Spirit. Aquinas says,

the ultimate perfection, by which a person is made perfect inwardly, is joy, which stems from the presence of what is loved. Whoever has the love of God, however, already has what he loves, as is said in 1 John 4:16: ‘whoever abides in the love of God abides in God, and God abides in him.’ And joy wells up from this. (In Gal, cap. 5, lect. 6, 330)

“When [Paul] says ‘the Lord is near,’ he points out the cause of joy, because a person rejoices at the nearness of his friend” (In Phil, cap. 4, lect. 1, 154).

For Aquinas, then, the contribution of the fruits of the Holy Spirit to the moral life is not a matter of the passions being governed by reason, any more than it is in the case of the gifts of the Holy Spirit. Rather, the fruits of the Holy Spirit are a matter of being transformed in second-personal connection to God, in a relationship of love that is for human beings flourishing in joy.

Thus, embedded in the relationship with God, everything which might be thought to be good in a human person, her acting in accordance with reason or following the eternal law in the mind of God, becomes something much more beautiful, just as the skills of a good musician in an orchestra flourish in the relationship to the conductor that yields the joyful experience of a well-produced performance of a symphony.

The power of Aquinas’s worldview is exemplified in his life as well as in his work. And so it is appropriate to finish with two anecdotes regularly told about him. Just as the stories about Francis of Assisi bring the man to life whether or not they are historically accurate in every detail, so whether these stories about Aquinas are hagiographical or historically accurate, they show us the character of the man. For this reason, they make a fitting end to this brief account of the value of his work for us today.

Aquinas was believed to have frequent religious experiences that were deeply moving for him. On one occasion, a Dominican brother who was present while Aquinas was celebrating mass reported that he heard Christ actually speak to Aquinas from the crucifix. “Thomas,” the brother reported Christ as saying to Aquinas, “you have spoken well of me. What do you want as a reward for yourself?” And, as the brother told the story, Aquinas said to Christ, “Non nisi te, Domine” – Only you, Lord. Aquinas wrote religious poetry which is still sung throughout the Catholic community today, and this particular anecdote is fleshed out in one of those poems. His poem, Adoro te devote, finishes with Aquinas saying to Christ, whom Aquinas takes to be really present in the consecrated bread and wine on the altar,

“Veiled Jesus, whom I now look upon,

when will what I so desire come to be?

When will I see your face unveiled,

and in the vision of your glory blessed be?”

Near the end of his life, on or about 6 December 1273, while he was saying mass, something happened to Aquinas that left him unwilling to keep writing. His secretary Reginald of Piperno, who loved him, tried hard to persuade him to go back to work. The third part of Aquinas's Summa theologiae was still unfinished, and Reginald argued that the importance of this master work mandated that Aquinas return to writing and finish it. But Aquinas is reported to have responded, “Reginald, I can't.” And when Reginald persisted, Aquinas finally told him, “By comparison with what I have seen and what has been revealed to me, everything I have written seems like straw.” What he wanted then, as he explained to Reginald, was just to die, to be with the God whom he had somehow seen in the revelation that made him want to quit writing. And soon afterwards he did die, on 7 March 1274 at Fossanuova, Italy.

For Aquinas, whose writings are a towering example of the capacity of human reason, his life and death show that what was central to his work and also to him was persons, and especially the person of his beloved Lord.