Modern theological education is built upon a division of labor. Biblical scholars perform exegesis. Systematic theologians construct doctrine. Historical theologians trace doctrinal development. Practical theologians focus on ministry and application. Spiritual formation is often assigned to yet another field. The result is a theological encyclopedia composed of specialized disciplines, each possessing its own methods, literature, and academic culture.

The benefits of such specialization are undeniable. Yet specialization has also produced fragmentation. Exegesis is often pursued without doctrinal synthesis. Doctrine is sometimes developed with little sustained engagement with Scripture. Historical theology can become antiquarian description. Practical theology may begin with experience rather than revelation. Spiritual formation is frequently detached from dogmatic reflection. What once belonged to a unified theological enterprise now appears as a collection of neighboring but largely independent disciplines.

Petrus van Mastricht offers a striking alternative. Contemporary scholarship has rightly highlighted his famous fourfold method of exegesis, doctrine, polemics, and practice. Yet the significance of that method has often been misunderstood. The fourfold structure is not merely a pedagogical device for organizing theological material. It is the visible expression of a deeper theological conviction concerning the nature and purpose of theology itself.

This article argues that Mastricht’s fourfold method is the outworking of a more fundamental principle: theology is “the doctrine of living for God through Christ.” Because theology possesses this end, exegesis, dogmatics, polemics, and practice are not separate theological disciplines but successive moments within a unified movement from divine revelation to holy living. Mastricht therefore offers not merely an alternative pedagogical method but an alternative vision of theology itself, one capable of challenging the fragmentation that characterizes much modern theological study.

The Modern Fragmentation of Theology

The modern theological encyclopedia largely assumes that theology consists of distinct disciplines. Although these disciplines often interact, each possesses its own object, method, and institutional location. Biblical theology investigates the historical and literary dimensions of Scripture. Systematic theology organizes doctrinal claims. Historical theology traces doctrinal development across time. Practical theology studies the application of theology within the life of the church. Spiritual theology concerns Christian formation and devotion.

Such distinctions were not entirely absent from earlier theological traditions. Nevertheless, in premodern and early modern theology these activities ordinarily belonged to a larger unified theological enterprise. Theologians moved naturally from exegesis to doctrine, from doctrine to polemics, and from polemics to application because they understood these activities as aspects of a single task.

Mastricht stands within this older tradition. His work does not merely combine several disciplines. Rather, it presupposes that these disciplines cannot ultimately be separated. Theology is one science because its object, source, and end are one. The fragmentation of theology into autonomous disciplines would have appeared foreign to his understanding of the theological task.

To understand why, one must begin not with Mastricht’s fourfold method but with his definition of theology.

Theology as the Doctrine of Living for God Through Christ

The center of Mastricht’s theological method appears in his famous definition: “This theoretical-practical Christian theology is nothing less than the doctrine of living for God through Christ.“¹ This definition is often cited but insufficiently appreciated. It does not merely describe theology’s subject matter. It establishes theology’s governing purpose.

The definition contains four inseparable elements. Theology is doctrine. It consists of truth revealed by God and received through faith. Theology concerns living. Its object is not merely speculative contemplation but the formation of human life. Theology directs that life toward God, who is the supreme end of all human existence. Finally, this Godward life is lived through Christ, whose mediatorial work makes communion with God possible.

The significance of this definition cannot be overstated. Mastricht does not define theology as a science of divine things, a collection of revealed truths, or a system of doctrines. While each of those descriptions contains truth, none adequately expresses theology’s purpose. Theology exists to direct human life toward God through union with Christ.

Consequently, theology possesses an inherently teleological structure. It moves toward an end. Every doctrine, every argument, every act of interpretation serves the larger goal of living for God. Theology therefore cannot terminate in knowledge alone. Knowledge is necessary, but it remains incomplete until it issues in worship, obedience, and communion with God. This conviction governs everything that follows in Mastricht’s method.

Exegesis as the Beginning of Theology

The teleological structure of Mastricht’s theology first appears in his treatment of Scripture. Significantly, even the Prolegomena begins with biblical exegesis rather than abstract methodological reflection. Mastricht derives his understanding of theology from Paul’s instructions to Timothy concerning teaching and exhortation (1 Tim. 6:2–3).² From this passage he develops a twofold ministerial responsibility. The teacher must first instruct the intellect through the exposition of truth and the refutation of error. He must then exhort the will so that truth becomes embodied in practice.³ Theology therefore begins with revelation and understanding, but it does not end there.

This pattern reveals an important feature of Mastricht’s method. Exegesis is not an independent discipline existing alongside theology. Exegesis is theology’s point of departure. Scripture provides the truth that theology seeks to understand, organize, defend, and apply. Theological reasoning therefore remains dependent upon Scripture at every stage. The modern separation between biblical studies and systematic theology would have been unintelligible to Mastricht. The theologian is necessarily an exegete because theology arises from Scripture. Yet exegesis alone is insufficient because Scripture’s purpose is not merely interpretation but transformation.

Why Theology Must Become Systematic

The movement from exegesis to doctrine forms the next stage of Mastricht’s method. Here his defense of systematic theology becomes particularly important. Mastricht insists that theology must be taught according to a method in which theory and practice “always walk in step together.“⁴ He offers several arguments for theological method. God is a God of order. The covenant itself is “ordered in every respect” (2 Sam. 23:5). Scripture contains numerous examples of doctrinal arrangement, including the Decalogue, the Lord’s Prayer, Hebrews 6:1–2, and the doctrinal structures of the Pauline epistles.⁵

Most importantly, theological truths are distributed throughout the biblical canon. The doctrine of God, Christ, salvation, and the church cannot be derived from a single passage or book. These truths are scattered throughout Scripture and therefore must be gathered and arranged. Systematic theology thus emerges from exegesis rather than competing with it. The theologian does not impose order upon Scripture. He discovers the order already present within divine revelation and seeks to express it faithfully.

This insight may be summarized in a single proposition: systematic theology gathers what Scripture scatters. Such a formulation captures the heart of Mastricht’s defense. Theological systematization is not a departure from Scripture but an act of obedience to Scripture’s own unity and coherence.

Polemics as the Preservation of Truth

If exegesis discovers truth and doctrine organizes truth, polemics protects truth. Mastricht’s inclusion of an elenctic dimension within every theological locus is often interpreted as a reflection of seventeenth-century confessional controversies. While historical circumstances undoubtedly contributed to its prominence, a deeper rationale is present.

Theology exists to direct believers toward God through Christ. False doctrine therefore represents more than intellectual error. It threatens the church’s ability to live faithfully before God. Because doctrine serves godliness, the preservation of doctrine becomes an essential theological task. Polemics is consequently not an autonomous discipline. It is an extension of theology’s pastoral purpose. The theologian refutes error because truth leads to life and error leads away from it. Defending doctrine therefore belongs organically within the theological enterprise itself. The sequence remains necessary and intact. Revelation yields doctrine. Doctrine requires protection. Protection serves godliness.

Practice as Theology’s Proper End

The most distinctive aspect of Mastricht’s methodology appears in his treatment of practice. Unlike many theological systems in which practical concerns appear only at the conclusion, Mastricht insists that every theological article possesses a practical dimension.

His governing principle is straightforward: “Theory and practice always walk in step together.“⁶ Theory must precede practice because the intellect must first perceive truth. Yet practice must follow because theology reaches its fulfillment only in holy living. Theology that remains confined to the intellect has failed to achieve its proper end.

This conviction explains Mastricht’s repeated appeal to Titus 1:1, where Paul speaks of “the knowledge of the truth that accords with godliness.” Theology is not merely knowledge of truth. It is knowledge ordered toward godliness. The practical sections of Mastricht’s loci are therefore not appendices. They are the culmination of the theological process itself. Exegesis, doctrinal formulation, and polemical defense all exist for the sake of directing believers toward God. Practice is not one discipline among others. It is theology’s telos.

The Unity of Theology Against Modern Fragmentation

Viewed from this perspective, Mastricht’s method presents a significant challenge to modern theological specialization. Modern theological disciplines frequently operate as parallel enterprises. Biblical scholars perform exegesis. Systematicians formulate doctrine. Historians describe doctrinal development. Practical theologians focus on ministry and application.

Mastricht would likely regard such fragmentation as a distortion of theology’s nature. For him, these activities belong together because theology itself is one. Theology begins with revelation, proceeds through understanding, defends the truth against error, and culminates in holy living. The stages are distinguishable but inseparable. His fourfold method therefore should not be understood as a collection of disciplines placed side by side. It is a description of theology’s natural movement. Revelation leads to understanding. Understanding leads to doctrinal formulation. Doctrine requires defense. Defended doctrine issues in worship and obedience. Theology remains one because its source is one, its object is one, and its end is one.

Conclusion

The significance of Petrus van Mastricht’s theological method lies deeper than his famous fourfold structure. Exegesis, dogmatics, polemics, and practice are not independent disciplines assembled into a convenient pedagogical arrangement. They are successive moments within a unified theological movement grounded in his definition of theology as “the doctrine of living for God through Christ.”

This insight allows us to understand why Mastricht refuses to separate Scripture from doctrine, doctrine from practice, or knowledge from godliness. Theology begins with divine revelation and ends with a transformed life. Every stage serves this larger purpose.

In an age marked by increasing theological specialization, Mastricht offers a compelling vision of theological unity. His method reminds the church that theology is not ultimately a collection of academic disciplines. It is the church’s ordered pursuit of the knowledge of God so that believers may live for God through Christ.

Notes

1. Petrus van Mastricht, Theoretical-Practical Theology, vol. 1, Prolegomena, ed. Joel R. Beeke, trans. Todd M. Rester (Grand Rapids: Reformation Heritage Books, 2018), 98.
2. Mastricht, Theoretical-Practical Theology, 64–65.
3. Mastricht, Theoretical-Practical Theology, 64–65.
4. Mastricht, Theoretical-Practical Theology, 67.
5. Mastricht, Theoretical-Practical Theology, 67–69.
6. Mastricht, Theoretical-Practical Theology, 67.