The Failure of Natural Theology:
A Critical Appraisal of the Philosophical Theology of Thomas Aquinas
by Jeffrey D. Johnson
Free Grace, 247 pages, $40
H. L. Mencken famously defined Puritanism as “the haunting fear that someone, somewhere, may be happy.” Puritans, and Calvinists more generally, have a reputation for harboring an ungenerous suspicion of even the most innocent delights as sinfulness in disguise. Though this reputation is not necessarily justified, I couldn’t help thinking of Mencken’s barb as I read the opening pages of Calvinist pastor Jeffrey D. Johnson’s book The Failure of Natural Theology. Johnson notes that recent years have seen a revival of interest in Thomas Aquinas’s philosophical arguments for God’s existence. One would think this a cause for rejoicing among Christians, given how many people have abandoned the faith under the influence of the New Atheists and others who claim that Christianity lacks rational justification.
But Johnson sees only a dark cloud in this silver lining. He regards a resurgent Thomism as a threat to Christian belief rather than an aid to it. For the influence of Aristotle on Aquinas entails, in Johnson’s view, conclusions that are incompatible with a Christian conception of God and our knowledge of him. Or at least, they are incompatible with a Calvinist conception of these things. (Johnson seems troubled by the very idea that a pagan Greek philosopher and a medieval Catholic theologian could have influence among contemporary Protestants.)
One might think an attack on Aquinas from a conservative Christian would at least have the merit of being more interesting than the same old same old coming from the likes of Richard Dawkins. Unfortunately, despite being more civil than Dawkins, Johnson is only slightly more competent as a reader of St. Thomas.
Johnson tells us that the Neoplatonic philosopher Plotinus, who influenced Aquinas, “didn’t leave behind any writings.” That will come as a surprise to the generations of students and scholars who have pored over Plotinus’s Enneads, not to mention the publishers who have long kept the work in print. Purportedly quoting the passage from the Summa Theologiae wherein Aquinas presents his Second Way of proving God’s existence, Johnson attributes to this argument the claim that “efficient causes do not extend ad infinitum into the past.” Not only is this not what the text says, but when proving God’s existence, Aquinas purposefully avoids the question of whether the series of causes extending backward into the past had a beginning. A little time with Google reveals that what Johnson presents as a passage from the Summa was not taken from any translation of that work, but instead was cut and pasted from a random source on the internet purporting to reconstruct Aquinas’s reasoning.
It gets worse. Johnson attributes to Aquinas the view that God “does not have any potencies,” which, he says, makes it mysterious how God could exercise any “active potencies or powers” in creating the world. But what Aquinas actually says (in Summa Theologiae I.25.1) is that though God lacks any passive potency (which is the capacity to undergo change), he is “supreme” in active potency (which is the power to bring about effects in other things). Further, because Aquinas denies that philosophy can prove that the universe had a temporal beginning, Johnson argues that Aquinas makes God and the universe equally absolute. But this ignores Aquinas’s well-known view that the universe could not exist even for a moment unless God were conserving it in being, which would be true whether or not it has always existed.
Johnson alleges that, according to Aquinas, we can only ever know a “representation of God” rather than God himself, and indeed that “God cannot reveal his undifferentiated knowledge of himself [to us] even if he wanted.” In fact, Aquinas explicitly says (at Summa Theologiae I.12.1) that “it must be absolutely granted that the blessed see the essence of God.” Johnson repeatedly claims that for Aquinas, all statements about God are merely “symbolic” and “metaphorical.” In fact, Aquinas explicitly says (at Summa Theologiae I.13.3) that “not all names are applied to God in a metaphorical sense, but there are some which are said of Him in their literal sense.”
The source of these errors is Johnson’s misunderstanding of Aquinas’s view that language about God ought to be interpreted in an analogical way. Johnson confuses analogy with metaphor. True, all metaphorical language is analogical, but for Aquinas, the converse is not true—that is to say, not all analogical language is metaphorical. When we describe a man, a book, and a meal as good, we are not using “good” in the same sense in each case. The moral goodness of a man is very different from the literary excellence of a book, and both are very different in turn from the nutritional and culinary virtues of good food. We are stretching the meaning of the word to cover all of the above. We are saying that there is something in the book that is analogous to the goodness we attribute to the man, and something in the meal that is analogous to what we attribute to the book. All the same, we are in each case speaking literally rather than metaphorically. Something similar is true, in Aquinas’s view, of our attribution of goodness to God.
Unfortunately for Johnson, a big chunk of his book, devoted to developing his accusation that for Aquinas we can’t ever get beyond “symbols” and “representations” to knowledge of God himself, rests on this simple error.
Though misrepresenting my views is a less serious offense than misrepresenting Aquinas’s, I can’t help but note that Johnson does that, too. Following Aristotle, Aquinas holds that an analysis of the nature of motion leads to the conclusion that there must be a divine Unmoved Mover who keeps the world going from moment to moment. In that sense, Aquinas holds that Aristotle’s natural science provides a foundation for knowledge of God. Johnson argues that this Aristotelian-Thomistic argument fails, and he attempts to enlist me on his side, alleging that even I “admit” that “sense experience” and “arguments grounded in natural science” cannot get us to a divine Unmoved Mover.
This is a curious mischaracterization of my views. In the essay from which Johnson quotes, I argue that you cannot get to theism using the methods of physics as those methods are typically understood today, which are much narrower than the methods Aristotle included as part of physics. As I go on to argue in that essay, if one does take on board Aristotle’s methods (which, these days, are classified instead as part of the philosophy of nature), then you can get to theism.
Aquinas, like other traditional theologians, holds that God is simple in the sense of not being made up of parts, and immutable in the sense of not undergoing change. Johnson says he agrees with Aquinas about that much, but objects to Aquinas’s purported further attribution to God of something Johnson calls “immobility.” What is immobility? It isn’t entirely clear. Sometimes by “immobility” Johnson seems to have in mind changelessness (which is the same thing as immutability). But in other places Johnson uses “immobility” to mean the absence of “the willful exertion of power.” Yet contrary to what Johnson asserts, Aquinas never denies that God willfully exerts power. As noted above, Aquinas holds that God is supreme in active power.
Johnson goes on at great length about this “immobility” thesis, which he wrongly attributes to Aquinas, alleging, among other purported offenses, that the idea is incompatible with the Trinitarian claim that God is three divine Persons. How so? Because, Johnson says, the thesis implies that there is no “differentiation” in God. But a purported lack of differentiation in God would follow not from “immobility” per se, but rather from divine simplicity—which Johnson himself says he accepts! Johnson’s discussion of these matters is too woolly and superficial to be of much interest, but what he fails to see is that if his criticisms drew any blood at all, they would take down his own views no less than Aquinas’s.
The title of Johnson’s book reflects another of its deeply muddled themes. “Natural theology” is the attempt to arrive at knowledge of the existence and nature of God through purely philosophical arguments. Johnson, like many other Calvinists, objects to the very idea, though he tells us he has no problem with what he calls “natural revelation.” What’s the difference? Natural theology infers or reasons from the world of our experience to a divine first cause with attributes such as omnipotence, omniscience, and perfect goodness. Johnson alleges that because this involves philosophical argumentation, it cannot be known by all or with certainty, and that in any event it amounts to relying on human wisdom to construct a mere idol. Natural revelation, by contrast, involves a certain and direct or non-inferential awareness of the true God’s existence and nature, and one that is had by all human beings. Johnson claims that natural revelation in this sense is what biblical writers like St. Paul affirm (for instance, in the first chapter of the Epistle to the Romans).
The problems with all of this are obvious. First, it is just silly to allege that, because it relies on human reason, natural theology amounts to the construction of an idol. You might as well say that the Bible presents us with a manmade idol rather than the true God, on the grounds that it is written in human languages (Hebrew, Aramaic, and Greek), and that we need to use our human eyeballs in order to read it and our human cognitive powers in order to understand it.
Second, the claim that all human beings know non-inferentially and with certainty that there is a single omnipotent, omniscient, and perfectly good creator of the universe is manifestly false. There are, after all, atheists, and also people who believe in God but have various mistaken beliefs about him (that he is identical with the world, that he is not all-powerful, and so on). Johnson would insist that such people don’t really lack knowledge of God and his nature, but are merely trying to repress what is obvious to them. Needless to say, this foot-stomping simply begs the question and does nothing to answer the evidence against Johnson’s thesis.
Johnson would retort that the Bible itself teaches “natural revelation” in his sense, rather than natural theology. Says who? Aquinas and other classical theists hold that what biblical writers like Paul had in mind was in fact natural theology, and that it is precisely through the possibility of philosophical arguments that God’s existence and nature can be known from the natural world. Johnson claims that this is a misunderstanding of the relevant scriptural passages. But he merely asserts this. He gives no non-question-begging arguments for this interpretation. To demonstrate something from the Bible, you need to do more than thump it.
But it is only fair to note that Johnson’s views are by no means universally shared by Protestants. Theologians like James Dolezal and institutions like the Southern Evangelical Seminary are contributing to a revival within Protestantism of the view that Aquinas’s philosophical theology is the ally, not the enemy, of the biblical conception of God.
Edward Feser is the author of Five Proofs of the Existence of God and Aquinas.
