Review: Theoretical-Practical Theology Volume 1 & Volume 2 by Ruben Zartman

Petrus van Mastricht. Theoretical-Practical Theology, vol. 1: Prolegomena & vol. 2: Faith in the Triune God. Translated by Todd M. Rester. Edited by Joel R. Beeke. Grand Rapids: Reformation Heritage Books, 2018 & 2019. Pp. lxiii + 238; and xxxv + 660. $50.00 per volume (cloth).


The Dutch Reformed Translation Society continues to do first-rate work, as two volumes (out of seven total) of Petrus van Mastricht’s (1630–1706) enormous Theologia Theoretica-practica have now appeared in English translation. The translator, Todd M. Rester (assisted in the second volume by Michael T. Spangler), is to be commended for a translation that reads quite easily, so much so that I comfortably read the bulk of the first volume while in the waiting area at a car dealership. The ease of reading is maintained by the fact that footnotes are generally brief and used mainly for bibliographic references or to identify some special feature in the text, like the use of a Greek or Hebrew word.

This work represented the culmination of van Mastricht’s thought and experience as a pastor and teacher of theology. It brings before the reader a thoughtful and mature expression of orthodox Reformed dogmatics. Yet readers may wonder if there is a real need for still another systematic theology text. What could earn van Mastricht a place on shelves that already have multiple other complete bodies of doctrine?

Part of the answer to that question is in the name, Theoretical-Practical Theology (cited hereafter as TPT). This is theology brought to bear on Christian thinking, worshiping, and living. As van Mastricht works through the usual subjects for a systematic theology, he deploys a very clear and consistent outline. Each chapter contains an exegetical part, where one special text provides the Biblical basis for what van Mastricht will discuss. For instance, van Mastricht begins discussing the truthfulness and faithfulness of God by providing an exegesis of Romans 3:3–4 (TPT II:279–281). These analyses of particular texts demonstrate the relevance of each passage to the topic under discussion, along with the specifics of what that text teaches on the subject.

The exegetical part is followed by a dogmatic part, in which the given doctrine is clearly stated and proved by additional references to Scripture and by rational arguments. This is where the doctrinal discussion and answers to questions appear. As an example, when dealing with saving faith, the dogmatic part contains not only a definition of saving faith, but also an exploration of what kind of an act it is, what is its proper object, its ends, degrees, and cause (TPT II:5–14).

An elenctic part comes next, where van Mastricht explains who has denied the doctrine, on what basis, and how they may be answered.  A great deal of value can be found in these elenctic or polemical portions.  Relatively few denials of false doctrine are absolutely new, and it is helpful to see how old enemies have been answered before. But the review and rejection of mistaken approaches also serves to clarify and cement true doctrine in the reader’s own mind. The consideration of alternatives goes some way to ensure that our assent to a given doctrine isn’t merely because of a temporary enthusiasm or ignorance of options, but is the settled result of a deliberated judgment.

In his answers to objectors, van Mastricht at times provides pointers to other resources, rather than handling matters extensively himself.  This was inevitable, and is not necessarily a disadvantage. The alternative would have been a much longer work. For instance, with regard to alleged “absurdities, contradictions, and falsehoods” in Scripture, instead of listing and discussing them, he points the reader to Junius, Maimonides, ben Israel, Spanheim, and Walther (TPT I:137). The translation and editing team have done magnificent work in tracking down all the works van Mastricht cites, and providing as detailed bibliographic information as possible. These references, of course, are likely to be more useful to scholars than to general readers.     

Part of the special value of Theoretical-Practical Theology is that a discussion of the application of each doctrine to the Christian life follows its statement and clarification in the dogmatic and elenctic portions. The commitment to ask and answer the question “so what” at each point along the way distinguishes this work from many others. 

Perhaps a comparison will be of service.  Both van Mastricht and Francis Turretin deal with the doctrine that God is simple. In what they affirm about the doctrine, and in how they rebut objections to it, they are clearly on the same page. This is evident from a comparison of TPT II:142–148 with Francis Turretin, Institutes of Elenctic Theology, Topic III.Q.VII.i-xvii.

Both authors point to the Socinians as deniers of simplicity, and reference the same sources. Both mention the Arminian theologian Simon Episcopius.  Both defend and clarify the doctrine of simplicity with similar language, and answer concerns about simplicity and God’s decree, creation, and the Trinity. Their treatments are not identical; from each one, it is possible to learn something not found in the other. To provide an example, van Mastricht speaks of God’s “omnimodal simplicity” (TPT II:146), and Turretin does not use that language. Yet Turretin is certainly not replaced by van Mastricht, since it is distinctively in the Institutes that we find answers to objections raised from such passages as Romans 11:36 or Hebrews 12:9.

However, when van Mastricht draws out five practical applications from the doctrine of God’s simplicity, there is nothing analogous in Turretin. And this section is likely the most helpful to the pastor wondering how to preach about Exodus 3:14, 1 John 1:5, John 4:24, or other passages where the simplicity of God legitimately comes up for consideration. What can one say to a congregation that shows any relevance for this doctrine?

According to van Mastricht, there are five applications for the doctrine of simplicity: (1) that God is the foundation of every perfection and every imperfection is founded in creatures; (2) that we rest upon God alone; (3) that we should worship with a simple heart; (4) that we should be sincere in our manner of life; 5) that we should be contented (TPT II: 148–152). Thus van Mastricht helps the preacher use this attribute of God (or any other) to motivate congregations to worship God for who he is, and also to live in harmony with his revealed character. 

Use of these volumes as a help in preaching was no small part of what van Mastricht had in mind (cf. TPT I:46).  It is quite fitting, then, that his valuable essay on “The Best Method of Preaching” is included in the first volume (TPT I:3–31).

To be sure, there are other dogmatic texts that include application.  One can think of Wilhelmus à Brakel’s The Christian’s Reasonable Service or Thomas Watson’s A Body of Divinity. It is not at all that van Mastricht is unique among the Reformed in thinking that doctrine must be practical. However, the frequency and consistency of his sections on application set him apart; and the clarity of his overall outline makes it very easy to use him as a reference work.

As noted, van Mastricht is not a wholly adequate substitute for the remarkable work of Turretin in clarifying Reformed doctrine over against deviations from it. But van Mastricht does have a distinctive value. He provides a clear, sound, Scripturally-based, dogmatically informed, and polemically tested theology that is then suggestively applied to real issues of living the Christian life. There is significant value in consistently having all those kinds of information in one place. 

These volumes (and the ones forthcoming) are heartily commended especially for the pastor who desires to be properly doctrinal and practical in his preaching. Here is a readable text, with topical discussions of manageable length, which demonstrates how Reformed doctrine arises from God’s word, vindicates it from misrepresentation or distortion, and shows what difference it makes.   

—Ruben Zartman