Monday, September 9, 2013
The return of final causality
I commend to you the late historian of philosophy Paul Hoffman’s paper “Does Efficient Causation Presuppose Final Causation? Aquinas vs. Early Modern Mechanism.” The paper appeared in the 2009 volume Metaphysics and the Good: Themes from the Philosophy of Robert Merrihew Adams, edited by Samuel Newlands and Larry Jorgensen, and I am pleased to find that it is available online. It is part of a growing number of works by contemporary thinkers outside the Thomistic orbit which sympathetically reconsider or even defend (as Hoffman does) something like an Aristotelian conception of teleology.
Other examples include John Hawthorne and Daniel Nolan’s paper “What Would Teleological Causation Be?”; Thomas Nagel’s book Mind and Cosmos; the idea of “physical intentionality” in the work of causal powers theorists like George Molnar, John Heil, and U. T. Place; Monte Ransome Johnson’s book Aristotle on Teleology; and J. Scott Turner’s The Tinkerer’s Accomplice. And then of course there are defenses by self-consciously Thomistic writers, like David Oderberg’s “Teleology: Inorganic and Organic”; and my own books and articles, such as “Teleology: A Shopper’s Guide” and “Between Aristotle and William Paley: Aquinas’s Fifth Way” (the latter forthcoming in Nova et Vetera).
In Hoffman’s case the focus is on what he usefully characterizes as the “stripped-down core notion” of final causality operating in Aquinas’s analysis of efficient causation. This is to be distinguished from more “full-bodied” kinds of finality or teleology, such as the sort we see in biological phenomena. The stripped-down notion involves mere directedness toward an end. Aquinas defends what later Scholastic writers call the principle of finality, according to which “every agent acts for an end.” (See e.g. Summa Contra Gentiles III.2) That is to say, if A is the efficient cause of B, that is because generating B is the final cause of A, the end toward which A points. If A were not so directed, there would be no reason why it is B that A generates rather than some other effect or no effect at all. This thesis is essentially what causal powers theorists like Molnar, Heil, and Place have rediscovered, and Hoffman defends it in the article.
Notice that, contrary to a common fallacious inference, this basic thesis is in no way undermined by the fact that some illustrations of the idea of finality or directedness toward an end involve scientific errors or simplifications. For example, Aristotle and his medieval followers held that heavy objects naturally tend to fall down to the earth, specifically. Of course, that is not correct, for there is nothing special about the gravitational pull of the earth per se. I’ve given examples like the way ice tends to cool the environment surrounding it, or the way the phosphorus in the head of a match tends to generate flame and heat when the match is struck, or the way the moon tends to orbit the earth rather than flying off into deep space. Obviously the scientific facts underlying these phenomena are far more complicated than these simple descriptions let on.
Do such errors and simplifications cast doubt on the principle of finality (as is sometimes claimed)? Not in the least. To see the fallacy, suppose I said that there are such things as murders and gave as examples of murderers Dr. Sam Sheppard and Charles Manson. You reply: “Your claim is falsified by the fact that Sheppard was actually innocent, and Manson only gave orders to accomplices, who actually carried out the killings.” Obviously this would be a silly reply. That a particular claim about a certain murder turns out to be false, and that certain other murders are more complicated than merely postulating a single murderer who directly kills the victim, in no way casts doubt on the reality of murder per se.
But it is no less silly to say “Aristotle was wrong about the natural motion of sublunar bodies, therefore there are no final causes” or “The moon’s orbit has to do with the Earth’s gravity well, therefore there is no final causality here” or “What happens when ice is in water involves a complex exchange of energy among the molecules in the liquid water and the molecules in the ice, therefore there is no final causality here.” For whatever the scientific details concerning gravitation, cooling, burning, etc. turn out to be, they will involve patterns of efficient causation (gravitational attraction, molecular interaction, etc.). And these, Aquinas argues, will necessarily presuppose finality.
In short, science can tell us whether a particular example of finality is a good one, but it cannot tell us whether or not there is such a thing as finality in the first place. That is a topic for philosophy of nature and metaphysics, because it has to do with the nature of efficient causality as such, not the specific details of this or that instance of efficient causality. (And no, that does not make claims about final causality “unfalsifiable” in the sense of being immune to rational evaluation and criticism. For the methods of physics, chemistry, etc. are simply not the only methods of rational evaluation and criticism. Claims about basic arithmetic and logic are susceptible of rational evaluation and criticism despite not being the sort of thing we can evaluate in the specific ways we evaluate claims of chemistry or physics; scientism itself is susceptible of rational evaluation and criticism despite its also not being the sort of thing we can evaluate in the specific ways we evaluate claims of chemistry or physics; and so forth.)