Redefining a Vocabulary – Edward FeserJanuary 3, 2011
If you are going to understand Aristotle and Aquinas, the first thing you need to do is put out of your mind everything that you’ve come to associate with words like “purpose,” “final cause,” “teleology,” and the like under the influence of what you’ve read about the Darwinism vs. Intelligent Design debate, Paley’s design argument, etc. None of that is relevant.
If you think that what Aristotelians or Thomists mean when they say that teleology pervades the natural world is that certain natural objects exhibit “irreducible specified complexity,” or that some inorganic objects are analogous to machines and/or to biological organs, or that they are best explained as the means by which an “Intelligent Designer” is seeking to achieve certain goals, etc., then you are way off base. I realize that that’s the debate most people – including writers of pop apologetics books – think that arguments like the Fifth Way are about. They’re not. Think outside the box. “What hath Thomas Aquinas to do with William Paley?” Nothing. Forget Paley.
The core of the A-T “principle of finality” can be illustrated with the simplest sort of cause and effect relation you might care to take. As Aquinas sums it up: “Every agent acts for an end: otherwise one thing would not follow more than another from the action of the agent, unless it were by chance” (Summa Theologiae I.44.4). By “agent” he doesn’t mean only conscious rational actors like ourselves, but anything that serves as an efficient cause.
For example, insofar as a chunk of ice floating in the North Atlantic tends, all things being equal, to cause the water surrounding it to grow colder, it is an “agent” in the relevant sense. And what Aquinas is saying is that given that the ice will, unless impeded, cause the surrounding water to grow colder specifically – rather than to boil, to turn into Coca Cola, or to catch fire, and rather than having no effect at all – we have to suppose that there is in the ice a potency, power, or disposition which inherently “points to” the generation of that specific effect. That the ice is an efficient cause of coldness entails that generating coldness is the final cause of ice. And in general, if there is a regular efficient causal connection between a cause A and an effect B, then generating B is the final cause of A.
Now already I can hear some readers sputtering replies like the following: “So what divine ‘purpose’ is the ice supposed to serve, then? To chill our martinis? To give furriers a market for their products? What superstition! And what about that iceberg that sank the Titanic? What about hypothermia, frostbite, and the ‘brain freeze’ I suffered through the last time I had a Slurpee? Where’s the omni-benevolence of your Flying Spaghetti Monster sky-god now, huh? HUH?!”
Whoa, whoa, whoa. Slow down, and calm down. Nobody said anything about either human purposes or divine purposes. Indeed, there is nothing whatsoever in the specific claim under consideration that has anything to do with “purposes” at all, if what is meant by that is the idea that the ice or the coldness serve some end beyond themselves in the way that a bodily organ functions for the good of the organism of which it is a part, or a machine serves the ends of its designer.
To be sure, each of the latter examples would involve teleology of a sort; but it is not the sort in question here. The claim so far is only that where there is an efficient causal connection between A and B, then generating B is the final cause of A in the sense that A inherently “points to” B or is “directed at” B as its natural effect. That’s it. So far, then, nothing has been said about either “design” or a “designer,” because the point has nothing to do with design. Nor does it have anything to do with complexity, “specified” or otherwise.
We’re talking about ice here – ice! – not the bacterial flagellum, eyeballs, or any of the other hoary chestnuts of the Darwinism-versus-ID dispute. Indeed, we’re talking about something many naturalistic philosophers have come to endorse in contexts far removed from philosophy of religion or the Darwin wars – albeit without realizing that they are more or less reviving a Neo-Scholastic philosophy of nature.
When a mainstream naturalistic philosopher like David Armstrong speaks of the “dispositions” physical objects possess as manifesting a kind of “proto-intentionality,” and when a mainstream naturalistic philosopher like George Molnar argues that the causal powers of material objects exhibit a kind of “physical intentionality,” they are certainly not claiming that there is an intelligent designer who made the world with certain ends in view. But they are (even if unwittingly) more or less stating in modern jargon what the A-T tradition meant by the principle of finality.
As Christopher Martin notes in his important book Thomas Aquinas: God and Explanations, modern philosophers tend to think that, where teleological arguments for God’s existence are concerned, getting from the existence of teleology to the existence of God is easy, but establishing that there really is any teleology in the natural order in the first place is difficult or impossible. But as Martin also notes, this is more or less the reverse of the view taken by thinkers like Aquinas.
For Aquinas, it is easy to show that teleology exists; for without it, efficient causation becomes unintelligible. (As I have noted many times, the moderns’ abandonment of final causality is the source of all the puzzles about causation that have plagued modern philosophy since Hume.) What takes work is showing that the existence of teleology entails the existence of God. After all, Aristotle himself, even though he firmly believed both in final causality and in the existence of an Unmoved Mover, did not think that final causality needed an explanation in terms of the Unmoved Mover, or indeed any explanation at all. He took it to be just a fundamental feature of the natural world; his argument for the Unmoved Mover begins instead with the existence of change or motion, not the existence of teleology.
Aquinas disagrees with Aristotle here. But, just as when arguing for the existence of teleology, so too when arguing from the existence of teleology to the existence of God, Aquinas does not appeal to “irreducible complexity,” to the way biological species are adapted to their environment, to the “fine tuning” of the laws of physics, nor to any other of the evidences emphasized by modern proponents of the “design argument.” Nor does he argue from a purported “analogy” between the universe and the products of human design. Nor does he weigh probabilities or argue “to the best explanation.”
Again, you need to put Paley and Co. completely out of your mind. And again, the basic idea is much simpler than all that. It is essentially this: For a cause to be efficacious – including a final cause – it has actually to exist in some way. It’s not just that for A to be the efficient cause of B, A must exist – as it obviously must – but also that for B to be the final cause of A, B must also exist, in some sense, otherwise, being nonexistent, it could not be efficacious. Hence for the “coldness” that the ice generates to function as a final cause, it has to exist in some way; for an oak to function as the final cause of an acorn, it too has to exist in some way; and so forth.
Now there are only three options here: B must exist either in the natural world; or in some Platonic heaven, as a Form; or in an intellect which “directs” A towards B as A’s natural end or goal (as a carpenter has the table in his intellect as the end or goal of his hammering and sawing). Now by hypothesis, B does not exist in the natural world: the whole point is that the coldness that the ice will produce, or the oak that the acorn will grow into, have not yet come about but are initially merely “pointed” to by the ice or the acorn. Nor does B exist as a Platonic Form – at least not if, like Aquinas, one endorses moderate (or Aristotelian) realism about universals, instead of Platonic realism.
The only place left for B to exist, then, is in an intellect; and it must be an intellect that exists outside the natural order altogether. For the causal relations in question are totally unintelligent: ice and acorns do not have intellects, nor is there any intelligence at the level of the even more fundamental causal processes studied by basic physics and chemistry. And all the intelligence that does exist within the material world – in us, for example – presupposes the operation of these unintelligent causal processes (since the existence of our bodies, and thus of us, presupposes them). So, there is no place left for the intellect in question to be than outside the natural order. That is to say, all the causal relations that exist in the natural order exist at all only because there is an intellect outside the natural order which “directs” causes to their effects.
Obviously this line of argument raises all sorts of questions: Why accept the metaphysical assumptions underlying the argument? Why assume that there is only one such intellect directing efficient causes to their effects, or that it has all the various divine attributes? Why should we believe that an intellect could be something outside the natural order, and thus something immaterial, in the first place? All good questions, and all dealt with in The Last Superstition and (in greater detail) in Aquinas. But the point for now is to give a sense of how very different is the argument summarized in Aquinas’s Fifth Way – and like all the Five Ways, it was only ever meant to be a brief summary, not a self-contained one-stop proof – from Paley’s “design argument.”
In particular, in addition to the differences already noted, there is this crucial one: To reject Paley’s divine designer is ipso facto to reject the “design” Paley claims to see in nature. But to reject Aquinas’s notion of a divine intellect is not ipso facto to reject the existence of teleology. One could instead adopt Aristotle’s view that teleology is just a basic feature of the natural order requiring no explanation.
To be sure, this may not be a defensible position at the end of the day – that teleology ultimately entails a divine intellect is precisely Aquinas’s claim. But the point is that, as Aquinas acknowledges and Paley and his successors do not, the inference from teleology to an ordering intelligence is not immediate. There is logical space for an alternative understanding of teleology, and it requires significant philosophical work to rule that alternative out. Establishing the existence of teleology in the natural order is a necessary condition for the success of an argument like the Fifth Way; it is not a sufficient one.