Thomas Aquinas's Summa theologiae

by Bernard McGinn

  Analysis IV. The Virtue of Charity (IIaIIae, qq. 23–46)

  Thomas devotes twenty-four questions to charity. Perhaps the most remarkable thing about his treatment is that he places it in the category of friendship (amicitia), citing Jesus’s words in John 15:15: “I do not call you servants any longer, but my friends” (q. 23.1).20 Because grace perfects nature, Thomas weaves all the natural designations concerning love into his account of caritas, not only friendship, but also love (amor), delight (delectatio), and benevolence (benevolentia). They are all subsumed into this most excellent of virtues, the virtue that for Thomas is the form, or inner reality, of all the virtues.

  Thomas begins with Aristotle’s definition of friendship as a love of mutual benevolence founded on a sharing of goods (Nicomachean Ethics 8.2). Again, however, Thomas has to stretch Aristotle, because the friendship between God and humans consists in God’s sharing his own blessedness, something beyond any human communication. Thomas first turns his attention to the question of charity in itself, that is, how charity is infused into the will and can be increased, diminished, or even lost. Then he considers its objects, namely, how we are to love God, our neighbor, and ourselves with God’s own love. Thomas then asks what the order and the relationship of the different objects of love should be and whether it is more proper to charity to love or to be loved. For Thomas, to love belongs to charity insofar as it is charity in action; to be loved belongs to charity only in a secondary way insofar as a friend desires good for his or her friend.

  Following the pattern set up for the other virtues, Thomas then turns to the effects of charity, distinguishing between internal effects (joy, peace, mercy) and external effects (beneficence, almsgiving, and fraternal correction). Next comes a long treatment of the vices opposed to charity: hate, which is opposed to delight; sloth and envy, opposed to joy; a list of vices opposed to peace (discord, contention, schism, war, quarreling, and sedition); and scandal, opposed to beneficence. Thomas argues that both love of God and love of neighbor belong to charity and that its two acts are integrally related: “The love of God is the goal to which the love of neighbor is directed” (q. 44.2–3). Just as charity is the supreme virtue, so wisdom, the highest of the gifts of the Holy Spirit, is partnered with it. Question 45 is Thomas’s most expansive treatment of divine wisdom, which presupposes both faith and charity (aa. 1, 4, 5).

  The treatment of the theological virtues in the first section of the Secunda Secundae, lengthy as it is, pales in comparison with the expanse of his discussion of the four cardinal virtues of prudence, justice, fortitude, and temperance.21 Employing the same format in talking about them as he did with the theological virtues, Thomas asks once again, (1) what the virtue in question is in itself; (2) what are its parts, general and particular; (3) which of the gifts of the Holy Spirit correspond to it; (4) what are the opposed vices; and (5) what positive and negative precepts relate to it. Prudence, for Thomas, is the main regulating virtue, a cognitive habit that “applies universal principles to the particular conclusions of practical matters, … and regulates the things that relate to the goal” (q. 47.6). The virtue of justice is the subject of the longest treatise on any topic in the Summa (qq. 57–122). After this lengthy treatment Thomas notes (q. 123.1) that the virtues that make humans good can be impeded from following right reason in two ways: by being drawn to an object of pleasure in an irrational way, or by not following reason because of some difficulty that lies in the way. The virtue of temperance deals with the first impediment and the virtue of fortitude treats the second. Their consideration closes his monumental treatise on the virtues.

  The third and last part of the Secunda Secundae deals with acts pertaining to particular classes of people, or associated with people in special ways (qq. 171–89). As usual in his moral theology, Thomas considers these special virtues and vices in a threefold manner. There are some activities that are based on special graces that pertain only to some people; actions that belong to particular states of life—including those associated with active and contemplative lives; and finally actions specific to the particular offices in the church.

  In Thomas’s time the two modes of Christian existence that had become traditional in the life of the church were allegorically figured in Martha, representing the active life of service to others, and Mary as the contemplative life of dedication to God (Luke 10). Thomas’s analysis of the two lives (qq. 179–83) is among the most complete of the Middle Ages, bringing together insights from Aristotle and the teachings of the masters of Christian mystical thought, especially Augustine and Gregory the Great. His teaching is largely traditional. Although the contemplative life is higher, as a good Dominican he argued that the best life was not the purely contemplative life of the monks (q. 182.1–2), but instead the life exemplified by friars whose task it was “to hand on to others the things gained in contemplation” (contemplata aliis tradere: q. 188.6). Thomas never wrote a treatise on what today we would call the mystical life; this section in the Summa is as close as he came. The last part of this third section of the Secunda Pars (qq. 184–89) is ecclesiastical, presenting Thomas’s view of the responsibilities of church office in its treatment of the “states of perfection,” or modes of ecclesiastical life (different from the perfection of the individual).

  The Tertia Pars

  Here the topic is Christ. An in-depth treatment of Christ, we are told, “is necessary for the consummation of the whole work of theology” (Prologus).22 The first part, consisting of fifty-nine questions, treats Christology explicitly in two sections: the mystery of the Incarnation (qq. 1–26) and the events of Christ’s life and death (qq. 27–59).23 The second part deals with the sacraments. Introducing this part (qq. 60–90), Thomas notes that “[a]fter the consideration of the things that belong to the mystery of the Word Incarnate, we must deal with the sacraments of the church, which have their efficacy from the Word himself.” The sacraments have a Christological function in making the Redeemer’s saving work available to us.

  Thomas intended to finish the Tertia Pars with a consideration of “the happiness of eternal life to which we come by rising again through him [i.e., Christ].” Sickness and death prevented this, so his disciples, probably under the guidance of Friar Reginald, put together the Supplement dealing with the last four sacraments—penance (begun by Thomas), extreme unction, holy orders, and matrimony (qq. 1–68), and closing with eschatology, that is, the last events of the human pilgrimage: the resurrection of the body, the last judgment, heaven, and hell. These materials were drawn from Thomas’s earlier Writing on the Books of Sentences.

  Analysis V. The Incarnation (IIIa, qq. 1–26).

  Treatments of Christology are found in many of the summae and scholastic syntheses. These accounts tend to mix historical treatments of the events from Christ’s life with theoretical considerations concerning the union of the human and divine natures in the Redeemer. The clear division between the theoretical (qq. 1–26) and the historical (qq. 27–59) sections in Thomas’s Christological treatise is original, as is his wide range of sources. While the use of scripture is richer in the second section than in the first, Thomas’s whole presentation is based on the truths about Christ found in sacra doctrina. The theological insights gained in the consideration of the union of the divine and human natures in the person of the Word provide guiding principles that help the Dominican draw out how Christ’s life is both the cause of our salvation and a model for our imitation. As he says, “Every act of Christ is an instruction for us” (q. 40.1, ad 3). Thomas’s Christology reveals him as a teacher, marshalling scriptural and theological authorities, principles, arguments, both deductive and fitting, to reach conclusions to deepen the reflective understanding of faith.

  Christology deals with a truth that surpasses human understanding—specifically, the mystery of the Incarnation. Thomas does not attempt to uncover the secrets behind the mystery of how the divine Word took human form. Rather, his main goal is to work out a theological grammar
that shows which expressions of the meaning of the Incarnation are coherent with faith and which are erroneous or heretical. Incarnation was a free act of God, as was Christ’s choice to die on the cross. Therefore, the foundations of Christology are not in necessary reasons or arguments. Much of what is contained here is argument from what Thomas calls convenientia, that is, showing the “fittingness” of God’s action in history. Of course, there are also some strictly deductive arguments that can be made from principles held by faith. The interplay between the various modes of argument in Thomas’s Christology is one of its distinctive features.

  Thomas had already treated the Incarnation at length in Book 3 of his Writing on the Sentences and in the Summa contra Gentiles IV.27–55. This may account for the fact that few of the topics treated in questions 1 to 26 are new (only 14 articles out of 151). Still, on several issues the treatment of the Incarnation in the Tertia Pars is original. The first question deals with the fittingness of the Incarnation. Article 3 asks whether the Word would have become incarnate even if Adam had not sinned. Various scholastic teachers had answered this question in different ways, and there was a tradition of cosmic Christology, arguing on the basis of passages in John and Paul that the perfection of the universe made it fitting that God should become man even in the absence of human sin. Others followed Augustine in saying that the scriptures teach that the Incarnation took place in order to repair the damage caused by Adam’s sin. In the Writing on the Sentences and the Summa contra Gentiles Thomas held that either view was possible. Here he argues that “it is more fittingly said that the work of the Incarnation was ordained by God as a remedy for sin, so that had sin not existed there would not have been an Incarnation.” As ever, Thomas sticks close to scripture. He was convinced that the biblical passages about Christ’s primacy deal with final causality only, that is, they teach about the fittingness of the Incarnation in relation to the return of sinful humanity to its goal, not about a Christology implicit in creation itself. Others, such as Duns Scotus, disagreed.

  Questions 2 to 6 investigate what the union of God and man in Christ actually is (quid sit). The union cannot take place in either the divine or human nature as such (otherwise one nature would be changed into the other), so it must take place in the person (Greek: hypostasis) of the Word (q. 2.2). In technical terms, it is a “hypostatic union.” A person, understood as “an individual substance of a rational nature,” possesses a nature but is distinct from it (e.g., we do not say “John is humanity,” but “John is a man”). Therefore, says Aquinas, “If human nature is not united to the Word of God in the person, it is not united at all and faith in the Incarnation is totally removed and the whole Christian faith is uprooted.” The hypostatic union involves a special kind of grace, the grace of union which Thomas defines as “the personal existence itself that is freely and divinely given to human nature in the person of the Word and is the term of the act of assumption.” Thomas makes a distinction between “union,” which signifies the fact that Christ is both God and man, and “assumption,” which is the action by which the Person of the Word takes up human nature into himself (q. 6.6).

  In considering knowledge as one of the perfections of Christ, Thomas differentiates Christ’s different kinds of knowledge: his divine knowledge, his beatific knowledge, the knowledge infused in him by the gift of the Holy Spirit, and finally that which he acquired by the exercise of his human intellect (q. 9.4, and the whole of q. 12). Even before the Resurrection, Thomas insists that Christ had the special privilege of existing both as a comprehensor, one who possessed the vision of God, and as a viator, one who existed as a human learner. Thomas holds that on the human level Christ advanced in knowledge with regard to both intellectual habits and acts of knowing (q. 12.2), thus paying more attention to Christ’s acquired knowledge than other scholastics did. The final perfection that Thomas investigates is Christ’s “power,” that is, the range of his ability to act (q. 13). He shows that as a human being, Christ had to respect certain limits to his power—God alone is truly omnipotent. Christ had real human emotions (passiones), such as physical pain, sadness, fear, wonder, and anger (q. 15.5–9). While Thomas qualifies the extent to which Christ possessed these human emotions more than theologians would today, this section of his Christology was original in its time.

  The first twenty-six questions of the Tertia Pars are among the most sustained accounts of Christology in all of scholastic theology, but Thomas decided that even this was not enough, so he crafted a treatment of the “deeds and sufferings” (acta et passa) of Christ’s life, death, resurrection, and exaltation in questions 27 to 59. Though often neglected, this detailed and existential treatment of Christ’s life is original and important. Thomas divided it into four parts: Christ’s entry into the world (qq. 27–39), the course of Christ’s life (qq. 40–45), Christ’s exit from the world (his death on the cross; qq. 41–52), and finally his exaltation after this life (qq. 53–59). Here Thomas draws extensively on the patristic authors, especially their biblical commentaries. Especially impressive is the way Thomas develops the theology of Christ’s work of redemption, coordinating the notion of satisfaction for sin with other biblical motifs, such as reconciliation, merit, sacrifice, obedience, and especially love, the primary motivation for our salvation. At the end of his massive treatment of Christology, Thomas concludes in a typically laconic way, “Enough for now about the mystery of the Incarnation” (q. 59.6, ad 3).

  After finishing the Christological treatise, in question 60 Thomas turns to a consideration of the sacraments.24 He divides the section into a treatment of sacramentum in general (qq. 60–65) and a consideration of what by his time had become the doctrine of the seven specific sacraments of the church (qq. 66–90). The understanding of “sacrament” underwent a shift in the twelfth century, away from a broad notion of sacrament as the full range of rituals and practices used in Christian life toward a carefully defined concept of seven rites ordained by Christ and handed on by the apostles as the means by which Christ and his grace become present to believers. Thomas had considered the sacraments in his two previous syntheses, but there are new accents in his treatment in the Summa. The scholastics had inherited two understandings of the term sacramentum—Augustine’s stress on sacrament as a “sacred sign,” and Isidore of Seville’s notion of a “sacred secret.” By the time of Peter Lombard (d. 1160), the Augustinian notion of the sacred sign had prevailed, but with a growing emphasis on the idea that the seven “true sacraments” were signs that caused grace. This concern with causality was not just an academic conceit; it was an attempt to do justice to Paul and John’s depiction of the power inherent in baptism and the Eucharist. But how can a sign be a cause? And how are the divine and human agents related in the administration of the sacraments? What is the difference between the “sacramental” signs of the Old Testament, especially circumcision, and the sacraments of the New Testament? Why and how do some sacraments, such as baptism and holy orders, effect a permanent change in the recipient so that they are not to be repeated, while others, such as penance and the reception of the Eucharist, are repeatable? These and other questions led Thomas to devote considerable attention to this aspect of sacra doctrina.

  Thomas places the notion of sacrament “in the category of sign” in question 60.1, before providing his specific understanding in article 2: “A sacrament is a sign of a sacred thing insofar as it sanctifies people.” The Christological core of Thomas’s teaching is set forth in article 3 where he discusses the triple signification of sacrament as including (1) the effective cause of our sanctification, namely, Christ’s Passion understood as the whole Paschal mystery; (2) the form (formal cause) of our sanctification, that is, the grace of Christ and the Holy Spirit and the virtues attendant upon it; and (3) the final cause, namely, eternal life. A sacrament, therefore, is a unique kind of causal sign that is simultaneously commemorative of the past, demonstrative of what is taking place in the present, and prognostic of the future. The acts of w
orship that constitute the sacraments as saving signs require the use of both a material element (e.g., washing with water in baptism) and verbal formulas, the words of faith that express the meaning of the action (q. 60.4–8). After investigating the necessity of the sacraments, Thomas takes up the question of how the sacraments function as causes of grace in question 62. In questions 27 to 59 Thomas showed how Christ’s human nature functioned as an instrumental cause of our salvation insofar as this human nature was joined to the person of the Word (i.e., an attached instrument). In question 62 he extends this insight by arguing that the sacraments are detached instrumental causes of salvation: “And therefore, the sacraments of the New Law are at one and the same time a cause and a sign. Hence, as is commonly said, ‘They bring about what they signify’” (62.1, ad 1; and a. 5).25 Question 63 considers the nature of the permanent effect (character) of the sacraments, which is the reason why some sacraments can only be received once. This, as Thomas explains, is because the character is a deputation that enables the recipient to take a specific role in Christian worship. Question 64 takes up the respective roles of God, Christ, and the human minister in administering the sacraments in terms of the distinction between God’s originating causality and the instrumental causality of the human minister. Finally, question 65 shows why it was fitting that Christ instituted seven sacraments. In Thomas’s understanding of the sacramental system there is both a movement from above by which God in Christ brings down saving grace to humanity, and a movement upward in the church’s worship of its God and Savior, so that, in Liam Walsh’s words, “[the sacraments] allow God to act humanly in signs made by humans.”26

  Having established the nature, efficacy, and number of the sacraments, Thomas proceeds with his investigation of each sacrament, beginning with baptism (qq. 66–71), proceeding to confirmation (q. 72), and moving on to the Eucharist (qq. 73–83), which he argues is the most important sacrament (q. 65.3). Thomas finally took up the sacrament of penance, which was always much discussed in scholastic literature. He managed to write only seven questions (qq. 84–90) before the incident of December 6, 1273.