Come, Let us Reason Together

Outside of an Introduction to Philosophy class, one is not likely to encounter the proofs for the existence of God. If one does encounter those proofs, it is even less likely that they are talked about in a favorable light. We live in a time where there is simply no room or no need for such relics of the past. Or at least, there is no felt need. Those in the sciences take the existence of the world as a brute fact that need not be demonstrated. Christians do not want to deny God’s existence, but they are either ignorant of the proofs of the demonstration of God’s existence or else they do not know what to do with them. In his book Proofs of God, Matthew Levering hopes to show that God’s existence can be demonstrated through reason.

The book’s chapters are organized into three time periods: Patristic and Medieval Arguments for God’s Existence, Reformation and Enlightenment Views, and Nineteenth- and- Twentieth-Century Responses. For each period, Levering summarizes the thoughts of seven key figures from that era who have made key contributions to the arguments for and against the demonstration of God’s existence. It is important here to make a key distinction that will help the reader grasp what each figure is trying to do. That is, arguments that God’s existence can be demonstrated and arguments on whether God exists. This difference is crucial in understanding later figures such as Kant, who denies that God’s existence can be demonstrated, but believes that postulating God’s existence is necessary for our use of practical reason. In other words, in the world of philosophy, it is one thing to say that God exists; it is another thing to say that God’s existence can be demonstrated. The tension in church history lies in whether or not Christians can or should affirm both statements. Levering believes you can and should.

The Patristic and Medieval periods might rightly be considered the apex of rational proofs for God’s existence. Indeed, when one thinks of classic proofs for the existence of God such as from motion, causality, or the famous ontological argument, they have their origins here in figures such as Gregory of Nazianzus, John of Damascus, and Anselm. During this broad period, the idea that God’s existence could be demonstrated through rational argument was almost a universal belief. In Levering’s words, “the fathers of the church, along with almost all medieval theologians, held that humans can rationally demonstrate the existence of God” (27). It is not until the late medieval period that serious concerns about the demonstration of God’s existence begin to be raised by William of Ockham, but even then, the idea is far from entirely dismissed.

During this broad period, the idea that God’s existence could be demonstrated through rational argument was almost a universal belief. Click To Tweet Levering points out that the running theme in this period is the influence of Greek metaphysics in both Eastern and Western Christendom. Several theologians argue for God’s existence based on the order of the universe, its finitude and so on but do so from various Greek sources. Tertullian leans on Stoic philosophy, whereas Augustine’s argument for the existence of God is heavily influenced by Platonic and Neoplatonic thought, in the soul’s natural pursuit of the Good and Truth. Anselm’s famous proof for God’s existence as “that than which nothing greater can be thought” follows an Augustinian and Neoplatonic line of reasoning based on degrees of perfection. The most common influence, and perhaps most important, is Aristotelian metaphysics. In the East, Gregory of Nazianzus and John of Damascus make similar arguments for God’s existence based on the motion and order of the universe on broadly Aristotelian lines. In the West, Thomas Aquinas famously puts forth his five proofs for God’s existence, which show influence from a wide range of Greek thought from Aristotle to the Neoplatonists. Finally, William of Ockham goes astray from the others in that he denies fundamental aspects of the other’s arguments. For instance, he does not think that the argument from causality necessitates a being who is Pure Act, because, in theory, there could be multiple Pure Acts. In Ockham, we see the first signs of a changing culture of theology.

In the Reformation, we see the continuation of that shift. It is not a shift entirely away from the proof of God’s existence, but there is a growing skepticism toward the demonstrability of God’s existence. Figures such as Hume and Kant are famous for their rejection of such proofs, and Montaigne provided a kind of proto skepticism by casting doubt on man’s inability to know the laws of nature, let alone the God behind those laws. But the other figures, Calvin, Descartes, Pascal, and Suárez, each in their own way grant that God can be known through rational demonstration and do so, but without the metaphysical assumptions of earlier times. What Levering points out is that outside of Suárez, there is little to no interaction between the earlier proofs. “It should be clear,” says Levering, “that the movement away from the broadly Aristotelian and Neoplatonic demonstrations of God’s existence… did not seriously engage the patristic and medieval arguments for God’s existence” (139).

This is, by Levering’s admission, the section of the book that gets the most attention. Here the skepticism of an earlier time has blossomed into a much larger canopy. Four of the seven figures in this chapter defend the demonstrability of God’s existence. However, as evidenced by figures like Wittgenstein and Heidegger, it is in a time “during which atheism became standard fare among intellectuals” (141). The proofs offered though are not a revival of the classical arguments of the church fathers. Instead, figures like John Henry Newman, Maurice Blonde, and Pierre Rousselot turn inward and rely on the inner experience of human nature as evidence for God’s existence, though each in his own way. Only one theologian, Garrigou-Lagrange, returns to Aquinas as a rebuttal to Kant and Hume’s critique on causality. The final theologian of the group, Karl Barth, denies that God’s existence can be demonstrated because God alone can reveal himself in Jesus Christ. The only proof Barth believes is credible is Anselm’s because it starts with faith and is not an attempt to disclose the absolute being of God. For Barth, “any alleged rational demonstration of God’s existence actually says nothing whatsoever about the real God” (193, Emphasis mine).

We have lost sight of the value of the logical demonstration of God’s existence because we grant the skeptic’s premise that such proofs do not exist or do not work. Click To Tweet Levering offers a compelling and thorough survey of the historical development of the arguments for and against the proofs of God’s existence. One of the best parts of this book is not something that Levering explicitly points out but demonstrates quite well in the figures he chooses to survey: when the metaphysics of the church fathers are abandoned, demonstrations for God’s existence do not go away; nor do they turn from one form of objective metaphysics to another. Instead, the proofs of God turn inward, and more and more our subjective experience of the world becomes the standard by which we judge whether God’s existence can be demonstrated, or if he exists at all. After Calvin, who does believe that God objectively reveals himself in the world, only those who return to the metaphysics of the church fathers seem able to resist the pull towards subjectivity. As brilliant as Pascal’s wager might be, a wager is at best, nothing more than an educated guess. Levering describes Pascal’s view quite aptly this way: “if we follow the desire and intuition of our heart, we can find our way to God” (112). The prophet Jeremiah would surely argue there is a better way.

One weakness of the book, at least in terms of Levering’s own analysis or commentary, is the lack of consideration of sin’s effect on our reason. Indeed, the one person in the book to make such an observation is Calvin, who denies the need (not efficacy) for metaphysical proofs because of our innate knowledge of God. We know God exists, but in our sin, we fall into idolatry and thus need supernatural revelation to guide us to the one true God (see David Haines’s treatment of Calvin in this issue of Credo). Throughout the book, Levering will talk about the difficulty of speaking about God and the limits of human reason which often errs. But he does not frame those limitations and difficulties as a result of sin’s effects on reason. It would have been valuable for Levering to survey and critique the thought of someone like Van Til, a twentieth-century theologian, because sin’s corrupting effects on our reason is Van Til’s entire project. Regardless of whether one agrees with Van Til’s conclusions or not, Levering is right to insist that Christians take seriously again the rational demonstrations of God’s existence, but he must also give serious attention to sin’s effects on our reason. (Consult David VanDrunen’s interview which explains why natural theology is legitimate if we correctly understand pervasive depravity).

Levering’s response to Calvin is, I think, fair. He says, “If humans have strong intuitions that God must exist, such intuitions deserve to be followed up by rational arguments – whose demonstrative power Calvin certainly affirms” (138). I think this gets to the heart of the issue for Christians today. We have lost sight of the value of the logical demonstration of God’s existence because we grant the skeptic’s premise that such proofs do not exist or do not work. But there is simply no reason to grant that premise. Once we abandon that concept, what grounds do we have for critiquing the subjectivity of our detractors? “The heavens declare the glory of God” is not a song of subjective experience; it is an acknowledgment that this finite world cannot cause, sustain, or order itself.

Finally, Levering shows how we have misplaced the location of the proofs in the Christian life. It is often assumed because of the term “proofs” that such things land solely in the realm of apologetics. But Levering offers a helpful corrective to this notion in his introduction. “And far from being simply an apologetic or defensive ploy in the Christian tradition, the demonstrations are a mode of praising God as the “I am” (Exod. 3:14)” (7). This book urges the Christian to do something quite unfamiliar to us in our day: when God says, “come let us reason together”, he is also calling us to praise.