For at least some Protestants today, the idea of viewing Thomas Aquinas as anything other than an adversary is anathema. For Karl Barth, perhaps the most influential Protestant theologian of the twentieth century, Thomas’ theology represents the antithesis of a Protestant conception of grace and revelation. Pointing to the defects of the theology of his own times, Barth claims that “the practical non-existence of St. Thomas in the sixteenth century has had even graver consequences, in that the Reformers could not clearly perceive the range of the decisive connection which exists in the Roman Catholic system between the problem of justification and the problem of the knowledge of God, between reconciliation and revelation.”
But historically many Protestant theologians did find it worthwhile to engage Thomas’ thought, and not simply as a foil to prop up their own distinctive approaches to theological topics. Among these were the earliest generations of Reformers, for whom Aquinas was not simply absent, as well as the Protestant scholastics of the later sixteenth and seventeenth centuries, who had a number of different reasons for appreciating, modifying, following, or rejecting Aquinas on various points of doctrine.Historically, many Protestant theologians did find it worthwhile to engage Thomas’ thought, and not simply as a foil to prop up their own distinctive approaches to theological topics. Click To Tweet
The initial Protestant interactions with Thomas and Roman Catholic Thomists of one variety or another were to some extent contingent and contextual. Martin Luther’s earliest polemical opponent was the Dominican Silvester Prierias (1456/1457–1527). The Dominicans were well-known for their theological acumen and concern for doctrinal integrity, so it is unsurprising that a member of this order would take up the pen to defend the church and the papacy from Luther’s increasingly critical attacks. A Dominican like Prierias would naturally turn to the thought of Thomas as an authority, and so part of Luther’s exchanges with Prierias included arguments over the nature of Thomas’ theological significance.
As David S. Sytsma helpfully articulates, and contra Barth’s claims of his “practical non-existence,” Luther’s largely negative assessments of Thomas were not universally shared among the earliest generations of Protestant reformers. Former Dominicans, such as Martin Bucer (1491–1551), continued to be positively influenced by their prior intellectual and theological formation. The same is true for the Italian reformers Peter Martyr Vermigli (1499–1562) and Girolamo Zanchi (1516–1590), who were foremost among those John Patrick Donnelly identifies as part of a distinctive “Calvinist Thomism.”
David C. Steinmetz two decades ago, observed, “The story of Thomas Aquinas and Protestantism has yet to be written and it is not identical with the story of Thomas and Luther.” Indeed, the story of the relationship between Aquinas and Protestantism doesn’t end in the earliest generations of the Reformation, but includes the increasingly substantive and extended engagement with Thomas by the Protestant scholastics of the later sixteenth and seventeenth centuries.
Scholasticism, Old and New
To understand why Protestant scholastics would engage with Thomas Aquinas, as well as other medieval figures, we must first understand the phenomenon of scholasticism itself, in its initial expressions and maturation in the medieval period as well as its later development in the early modern era.
Medieval scholasticism emerged out of the historical circumstances surrounding the Christianization, and eventual dissolution, of the Roman Empire. In this way we might understand scholasticism to be a development of monasticism, which sought to preserve and protect authentic Christian discipleship in a world fraught with temptation, corruption, and chaos. As monastic orders founded new institutions, including schools, new forms of instruction and learning took shape. And this is perhaps the best and primary way to understand scholasticism, that is, as a method of study adapted and appropriated for education in schools.We might understand scholasticism to be a development of monasticism, which sought to preserve and protect authentic Christian discipleship in a world fraught with temptation, corruption, and chaos. Click To Tweet
The first medieval scholastic textbook was Peter Lombard’s Sentences, a twelfth-century collection of theological teachings from the patristic period, organized and interspersed with commentary, elucidation, and discussion. By the time of Thomas Aquinas a hundred years later, the Sentences were established as the primary text for scholastic theology. To advance and earn a degree as a theological teacher, a student had to write a commentary on Lombard’s Sentences.
Like others, Thomas Aquinas wrote a Sentences commentary, but went on to develop his own theological system more fully in works like the Summa contra Gentiles and the Summa theologica, as well as in a number of commentaries on scripture. By Thomas’ time, the standard scholastic format was to explore a topic through a logical progression of answers to questions about the object of study. It was customary to inquire whether something exists before discussing what kind of thing it is, what its qualities or characteristics are, and so on. Often the scholastic exposition would follow as answers to a question (whether explicit or implicit), such as, “What is a sacrament,” and, following that discussion, “What baptism is.”
A basic tool for such logical and systematic treatment of theological topics is the ability to distinguish between different senses of something and between different uses or applications of a truth. Scholasticism, in this way rests on the ability to rightly distinguish terms and definitions as well as practical means and uses. The procedure in Thomas’ Summa theologica to include a set of objections, followed by Thomas’ “On the contrary” and “I answer that,” before concluding with specific responses to the initial objections, is a thoroughgoing development of this kind of logical and systematic exploration of the nature of theological truths.
If Thomas’ synthetic reconciliation of Christian faith and human reason is the pinnacle of medieval scholasticism, Thomas’ system is not the only theological program from the Middle Ages to continue to have influence, and the scholastic program continued into the late medieval period and into the early modern era, even as it was challenged by and responded to other developments, including the rise of humanism and the Reformation.
It is commonplace in early modern intellectual history to speak of another phase or period of scholasticism following that of the medieval era. This later phenomenon is sometimes called “second scholasticism” or “baroque scholasticism,” and it typically refers to the revival of Roman Catholic scholastic theological approaches in the sixteenth and seventeenth centuries. Rather than commenting on Lombard’s Sentences, these later scholastics more often took Thomas’ Summa theologica or other scholastic texts as their point of departure, and continued to develop increasingly complex theological discussions responding to more than a millennium of Christian doctrinal development. A standard format in second scholasticism is the treatment in moral theology of the topics of justice and right (de iustitia et iure), grounded in Thomas’ treatments of them in the Summa theologica.As Protestant communities codified and formalized their confessional identities, it became necessary to develop theological curricula and systems for their primary, secondary, and higher educational structures. Click To Tweet
We can best understand Protestant scholasticism of the early modern period as a particular expression or variant of this broader second or “baroque” scholasticism. That is, as Protestant communities increasingly codified and formalized their confessional identities and built new and reformed already-existing institutions, it became necessary to develop theological curricula and systems for their primary, secondary, and higher educational structures. And just as the medieval scholastics developed a system appropriate to their own circumstances and needs, Protestants (as well as Roman Catholics) of the early modern period developed a methodological approach to learning for their schools. We typically identify this as Protestant scholasticism, but even as Reformed and Lutheran schools had their own distinctive doctrinal emphases and confessional commitments, they shared with each other as well as with Roman Catholics a number of common methodological tools and approaches.
Apologetics and Polemics
One of the reasons that Protestant scholastics retrieved and returned to Thomas Aquinas as an important theological source was because his theology was increasingly a matter of debate and significance for the broader baroque scholasticism. The early modern period saw a revival of Thomism (along with other medieval traditions as well), particularly as Roman Catholics sought to engage Protestant theology. One posture in response by Protestants, first modeled by Luther, was to reject Thomas as an authority. This approach had the benefit of appealing to an authority higher than Aquinas or even Augustine: the Bible.
But another approach was to claim that Roman Catholic appropriations of Thomas, or at least some of their uses of his thought, were inadequate or inauthentic. Protestants, especially those who had been schooled and trained in Thomistic theology, were able to distinguish legitimate and illegitimate uses of Thomas, and in some cases bolster their own arguments by appealing to Thomas for support. This positive appeal to a common authority was an effective strategy for defending one’s own views and undermining an opponent’s position.Protestants, especially those who had been schooled and trained in Thomistic theology, were able to distinguish legitimate and illegitimate uses of Thomas. Click To Tweet
The Reformation era has sometimes been portrayed as an extended argument over the rightful legacy of Augustine, especially as it relates to soteriology. In many ways, the figure of Aquinas looms over the debates of this period in a similar fashion, as scholastics of different confessional commitments and ecclesial communities argued not only about the proper interpretation of scripture, but also about which traditional authorities, from the fathers to the medieval doctors, supported their views.
Thomas Aquinas was thus important for the Protestant scholastics, in part because he was so foundational not only for Dominicans but also Jesuits and other Roman Catholic scholastics. In the same way that the earliest generations of Reformers often took over scholastic distinctions employed by medieval theologians as well as their own contemporary opponents, sometimes rejecting and often revising these distinctions, so too did later Protestant scholastics contend with their adversaries about the proper understanding of scholastic distinctions, theological traditions, and the teachings of Aquinas himself.
Constructive and Systematic
If the Protestant scholastics looked back to Aquinas in part as an apologetic and polemic strategy to oppose their theological adversaries, these weren’t the only motivations for a retrieval of the teachings of the Doctor Angelicus. Many Protestant scholastics found Aquinas’ theology helpful for their own constructive and systematic projects. In this way, Aquinas was among those in the historic Christian tradition to whom Protestant theologians of the sixteenth and seventeenth centuries looked to for edification, inspiration, and enlightenment. To the extent that Thomas’ synthesis represented the best of the medieval scholastic tradition, his thought was appreciated as characteristic of the “sounder scholastics.”Aquinas was among those in the historic Christian tradition to whom theologians of the sixteenth and seventeenth centuries looked to for edification, inspiration, and enlightenment. Click To Tweet
There has been significant scholarly debate and discussion over the extent to which particular theologians have been influenced by Thomas and Thomistic theology more generally relative to other influences, whether patristic, medieval (e.g., Scotus), humanistic, philosophical, or otherwise. But in general it seems safe to say that Thomas was foremost among those figures of the medieval period to whom Protestant, and especially Reformed, scholastics engaged in the formulation of their own theology.
A few examples might suffice to show the range of topics in which Thomas was constructively and positively engaged by Protestant scholastic authors. The Reformed theologian Franciscus Junius (1545–1602) was an early scholastic teacher at the University of Leiden in the Netherlands. In his treatment of law in a discussion of the contemporary significance of the Mosaic political administration, Junius relies heavily on a Thomistic distinction between eternal, natural, divine, and positive law. Moreover, Junius invokes a variation of Thomas’ insight with respect to the relationship between nature and grace. Where Thomas had asserted that “grace does not destroy nature, but perfects it,” Junius writes that “grace perfects nature; grace does not, however, abolish it.”
This same formula is adapted in the later Synopsis Purioris Theologiae articulated by the Leiden theological faculty in 1625. In their discussion of divine providence, the theologians of Leiden write that “divine providence does not corrupt nature, but perfects it; it does not take it away, but guards it.” Aquinas is later explicitly cited in the same topic on the question of God’s permission of sin, and later on the topic of original sin. Following Aquinas (and Junius), the Leiden synopsis also affirms the fourfold Thomistic legal typology.
The Synopsis Purioris Theologiae originated as disputations presided over by the theological faculty at the schools in a series of curricular cycles. This speaks to the importance of genre for identifying scholastic theology. If we understand scholasticism in general to refer to a methodology applied in the context of schools, then we can understand particular genres to be more properly characterized as scholastic as opposed to some other type. That is, scholastic texts are those that arise from or are oriented to teaching and learning in the institutional setting of schools (whether medieval or early modern). Not everything written by someone (such as Junius) identified as a scholastic author is a scholastic text. There are other theological genre–to say nothing of texts in other disciplines–such as devotional, confessional, and exegetical works that may or may not be characterized by scholastic methods depending on the occasion for their composition. And scholars have explored how Thomas’ works, especially his commentaries, were received in the Reformation and post-Reformation periods not only in technical scholastic disputations but also in their exegetical endeavors.
An Eclectic Inheritance
Not all reception of Thomas by Protestant scholastics was positive. In its discussion of idolatry, for example, the Synopsis Purioris Theologiae cites Thomas negatively in his claim “that images of the Trinity and of Christ should be worshiped with the same adoration with which the prototypes are worshiped, and that there are not two adorations but only one and the same.” The Synopsis goes on to vehemently criticize such idolatrous practices. This shows that Protestant scholastic retrieval of Aquinas was eclectic, in the sense that positive appropriation depended on a normative evaluation of the doctrinal fidelity and logical integrity of the arguments they encountered. The puritan Richard Baxter (1615–1691), himself an eclectic scholar, aptly remarked, “Our students would not ordinarily read Aquinas, Scotus, Arminensis [Gregory of Rimini], Durandus, &c. If there were not in them abundance of precious truth which they esteem…. There are very few points of the Protestant doctrine, which I cannot produce some Papist or other to attest.”
While Karl Barth’s concern with the state of theology in his own day led him to warn against both Roman Catholicism–especially Thomism–and the liberal Protestantism he encountered in the church and academy, he understood that a real reckoning with the traditions of theology was necessary. Karl Barth once wrote, “Nothing that can claim to be truly of the Church need shrink from the sober light of ‘scholasticism.’ No matter how free and individual it may be in its first expression, if it seeks universal acceptance, it will be under constraint to set up a school and therefore to become the teaching of a school. Fear of scholasticism is the mark of a false prophet. The true prophet will be ready to submit his message to this test too.” The Protestant scholastics engaged Thomas Aquinas and retrieved his theology because doing so helped advance their purposes to set up orthodox, catholic schools and systems of theology, properly grounded in and reformed on the basis of the Word of God. They received Thomas as a subsidiary authority where they found him helpful and constructive. Thomas’ theology had to be responsibly reckoned with in their day as it must be in ours as well.
 Karl Barth, “No!” in Emil Brunner and Karl Barth, Natural Theology, trans. Peter Fraenkel (Eugene, OR: Wipf & Stock, 2002 ), 101.
 David S. Sytsma, “Appreciating and Appropriating a ‘Sounder Scholastic’: Thomas Aquinas and the Protestant Reformation,” Credo Magazine, vol. 12, no. 2 (June 23, 2022).
 John Patrick Donnelly, “Calvinist Thomism,” Viator 7 (1976): 441-455.
 David C. Steinmetz, Luther in Context, 2d. ed (Grand Rapids: Baker, 2002), 58.
 Thomas Aquinas, Commentary on the Sentences, Book IV, Distinctions 1–50, trans. Beth Mortensen, Peter Kwasniewski, and Dylan Schrader, vol. 7, Latin/English Edition of the Works of St. Thomas Aquinas (Green Bay, WI; Steubenville, OH: Aquinas Institute; Emmaus Academic, 2018), 7, 117.
 See Wim Decock and Christiane Birr, Recht und Moral in der Scholastik der Frühen Neuzeit 1500–1750 (Berlin: De Gruyter, 2016); and Jordan J. Ballor, “Deformation and Reformation: Thomas Aquinas and the Rise of Protestant Scholasticism” in Aquinas among the Protestants, ed. David VanDrunen and Manfred Svensson (Hoboken: Wiley-Blackwell, 2018), 27–48.
 See Sytsma, “Appreciating and Appropriating a ‘Sounder Scholastic.’”
 Franciscus Junius, The Mosaic Polity, trans. Todd M. Rester, ed. Andrew M. McGinnis (Grand Rapids: CLP Academic, 2015), 60–64.
 STh. I q.1 a.8 ad 2; Junius, The Mosaic Polity, 38.
 Synopsis Purioris Theologiae, vol.1, ed. Dolf te Velde, trans. Riemer A. Faber (Leiden: Brill, 2015), 269.
 Synopsis Purioris Theologiae, 280–81; 372–73.
 Synopsis Purioris Theologiae, 434–35.
 See, for instance, David S. Sytsma, “Thomas Aquinas and Reformed Biblical Interpretation: The Contribution of William Whitaker,” in Aquinas among the Protestants, ed. David VanDrunen and Manfred Svensson (Hoboken: Wiley-Blackwell, 2018), 121–43.
 Synopsis Purioris Theologiae, 474–75.
 Richard Baxter, A Key for Catholicks (London: R.W. 1659), 365–66.
 Karl Barth, Church Dogmatics: The Doctrine of the Word of God, Part 1, vol. 1 (New York: T&T Clark, 2004), 279.