Above: Ludwig van Beethoven in 1804.
Below: The opening of Beethoven’s Fifth.
Among St. Thomas Aquinas’ celebrated five proofs of the existence of God, the Fifth Way holds a special place: it is the only one which explicitly attempts to show that the cosmos is dependent on some Intelligent Being, Who directs all natural objects towards their built-in ends. In this post, I’m going to critically analyze Aquinas’ Fifth Way – or more specifically, Professor Edward Feser’s reconstructed version of this argument by Aquinas. On Feser’s account, the argument proceeds from a set of very simple facts about the natural world, and then demonstrates that the only way to explain these facts is by positing an intelligent being (or beings) guiding the behavior of natural objects towards their characteristic effects. But Feser doesn’t stop there: he maintains that the conclusion of the Fifth Way is not merely that there is an intelligent being guiding Nature, but rather, an Intelligence Who sustains Nature in being. Moreover, this guiding Intelligence can only be a Being Whose essence is identical with its very act of existence – in other words, an Intelligence Who is Being itself, and Who can therefore be identified with the God of classical theism. And there can only be one such God: an Intelligence Who is Being itself is necessarily unique. Feser contends that Aquinas’ argument (when properly understood) is a valid proof, which can provide us with absolute certitude that God exists, making Intelligent Design theory redundant. On Feser’s view, the existence of an Intelligent Creator of Nature can be rationally demonstrated without arguing that the cosmos had a beginning, or that its laws are fine-tuned, or that neo-Darwinism is false.
I would like to say at the outset that Professor Feser’s reconstructed version of the Fifth Way is by far the most detailed formulation of Aquinas’ argument that has been put forward by any Thomist scholar. Feser has done an excellent job of attempting to elucidate the underlying logic of the Fifth Way – and in this regard, he has (I believe) gone further than any other Thomist scholar. I think Feser deserves to be commended for this noble effort, even though I happen to think that the argument he puts forward doesn’t work.
Whereas Professor Feser sees the Fifth Way as the jewel in the crown when it comes to proofs of God’s existence, I regard it as more of a rough diamond, which needs a lot of cutting and polishing in order to bring out its hidden beauty. What I intend to argue in this post is that the basic thrust of Aquinas’ Fifth Way is correct, but that the argument requires substantial revision: key premises of the argument need to be amended, and several steps in the argument’s logic need to be filled in. I shall also contend that while Feser’s reconstructed version of the Fifth Way is an exegetically plausible account of Aquinas’ argument, it fails if it is taken as an argument that is meant to convince 21st century atheists of the existence of God. In a nutshell, the reason why I think Feser’s argument cannot succeed against 21st century atheism is that it is too metaphysically top-heavy, relying as it does on no less than twenty metaphysical assumptions, some of which (I shall argue) are either wrong or highly contentious. Most modern-day skeptics are very leery of metaphysical claims, full stop. If someone wishes to try and convince modern skeptics of God’s existence on philosophical grounds, then they had better make sure that their metaphysical assumptions are so airtight that they cannot be intelligibly denied, and in addition, they had better limit those assumption to no more than a handful. The reason why I added the latter condition is that the modern-day skeptics I have debated tend to be highly distrustful of the reliability of human thought processes regarding matters metaphysical. While they might be prepared to concede that each of the premises in a metaphysical argument for God’s existence appears unassailable when taken singly, they will argue that the truth of the entire set of premises in such an argument is open to doubt – especially when there are twenty of them. Perhaps, they will suggest, a “metaphysical blind-spot” on our part prevents us from recognizing what’s wrong with one or other of these premises. On this view of human reason, any argument with a large number of metaphysical premises is inherently dubious.
Professor Feser has made a laudable attempt to “flesh out” the unstated premises in Aquinas’ (very brief) Fifth Way. Nevertheless, I would maintain that even Feser’s reconstructed version of the argument still contains major logical and metaphysical gaps that need to be plugged.
EXECUTIVE SUMMARY: What’s wrong with Feser’s argument – and how to fix it