Having appreciated the work of Richard Muller, and his students, and having benefited immensely from their writings, I am still far from an expert in the area of Reformed scholasticism. Nevertheless, my thinking as a Reformed theologian has been greatly enriched by the fruit of their labors. For this, I am exceedingly grateful.
Yet, I struggle still with grasping (and joining in with) the celebration of “Reformed Thomism.” Truth be told, I am unsure what exactly it is. Is it the use of the scholastic method in doing Reformed systematic theology? If so, then great. I find that method wonderful. Is it the approach to theology that seeks precision, even down to the most minute detail? Again, I have no complaints there. I’m all about it. Does it have to do with the use of Aristotelian categories to help us explain theological concepts? If so, let the celebrations begin and let’s pillage Egypt. Lastly, does it have to do with setting forth what has often been called “classical theism” with a clear articulation of the attributes of God such as his aseity, simplicity, spirituality, immutability, eternality, and infinitude? Here too I am an enthusiastic supporter. If that is what is meant by “Reformed Thomist,” then sign me up. Though I prefer the more generic label of “catholic.”
Be that as it may, I suspect something more is intended with the label of “Reformed Thomist.” And I suspect it has something to do with the way theological prolegomenon is done. Much chatter has been heard about Muller’s great work on Reformed scholasticism, and especially the first volume on prolegomenon. I will skip the details of that chatter for now (if you know, you know). And though I am no expert in this particular area, I try to read broadly in the tradition and have noticed something that gives rise to my question for my friends who regard themselves as Reformed Thomists.
To set up my question, let’s take for example J. H. Heidegger’s abridged summary of Reformed theology, The Concise Marrow of Theology. Now before saying more, it should be noted that I recognize taking this work as an example is not completely fair. After all, this is just a summary of his larger, still untranslated work, the Medulla. The Concise was meant as a stepping-stone for initiates to learn the system of theology before moving to the larger work. Think of the relation between Berkof’s Summary compared to his full Systematic Theology.
Anyway, Heidegger’s Concise gives us a, well, concise summary of how he (along with other Reformed scholastics) saw the relationship between prolegomenon and the rest of the Reformed theological system. And here, with Heidegger, we do see some similarities with Thomas’ approach to reason and nature. Heidegger witnesses to a dual approach to theological knowledge. The first comes by way of “the dictation of reason alone.” Reason alone renders man inexcusable, but it does not save him. Now, what does “reason alone” mean? What is it “alone” from? Presumably from revelation. Heidegger goes on, in the very next article (same page) to speak of revealed theology (standing against the natural theology that comes by the dictates of reason alone). Revealed theology is teaching about God concerning salvation and the worship of God. Revealed theology then perfects reason but does not destroy it.
This strikes me as clearly Thomistic. Thomas too places reason distinct from sacred theology (founded on revelation). In other words, Heidegger, like Thomas, does not seem to have a notion of what we might call natural revelation. Reason is that part of nature—common to all—that points us to the knowledge of God but is not itself the knowledge of God. It only leads us to the existence of God, not who God is as triune. Reason therefore leaves us without excuse for rejecting the existence of God, but it does not reveal God directly, and it does not reveal the triune God.
Now we are getting closer to my question. This dual approach seems to me to set up a problem of consistency for later in his theology. Take for example the covenant of works. Heidegger begins with two options for the knowledge of God: reason and revelation. Reason tells us that there is a (generic?) conception of God available to all men. Revelation tells us about salvation (given sin). Where then does the covenant of works fit into those two options? The covenant of works is prelapsarian, so it does not fit well into his idea of revealed theology. And the covenant of works contains more than what reason can give.
In the locus on the covenant of works, Heidegger explains that it is known “more obscurely from nature and more clearly from revelation.” He explains that the natural part consists of man’s conscience and from his natural appetite for the highest good. Reason is not mentioned here. Nor is conscience and natural appetite mentioned in his section on natural theology. But, and this is mystifying, the terms of the covenant of works—which in this locus he clearly speaks of being a revelation of God to prefall Adam—is not mentioned as a part of revealed theology back in the first locus. In other words, his prolegomenon—as it sets up a dual approach to the knowledge of God through reason and revelation—runs countercurrent to his theology of the covenant.
So, here is my question: Would Heidegger not be better off had he in his prolegomenon spoke of revelation as the alone way unto the knowledge of God?
If he had done that, then he could have accounted for (1) reason, conscience, and appetite all as a general revelation of God, and (2) the covenant of works as an act of special revelation of God to man in the prelapsarian situation. In this way, there is only one way to know God (revelation) given in two “books:” nature and God’s spoken word. This would eliminate the dual epistemology and subsume all knowledge of God under a singular mode: revelation. This, furthermore, would connect nicely to the Reformed notion of the image in which man is created in original knowledge, righteousness, and holiness. Man from the outset received the knowledge of God from (1) outside himself in creation, (2) within himself in reason, conscience, and appetite, and (3) from God’s spoken word in the terms of the covenant of works. These three being all aspects of the one mode of revelation.
Anyway, that question I ask of my Reformed Thomist friends and brethren is a sincere one, and I remain open to instruction here. Hopefully such a question can serve as a clarifying focus point for future fruitful discussion.
 Richard A. Muller, Post-Reformation Reformed Dogmatics, vol.1, Prolegomena to Theology, 2nd ed. (Grand Rapids, MI: Baker Academic, 2003).
 J. H. Heidegger, The Concise Marrow of Theology (Grand Rapids, MI: Reformation Heritage Books, 2023).
 Heidegger, Concise, 9.
 Heidegger, Concise, 10.
 Which seems different from theologians like Augustine and Bavinck who hold to the revelation of the Trinity in nature (i.e., the vestiages doctrine).
 Heidegger, Concise, 61.