Wednesday, September 30, 2009

Four approaches to teleology

In his fine book Aristotle, Christopher Shields usefully distinguishes Aristotle’s approach to teleology from two others. Teleological eliminativism is Shields’ label for the view that there is no genuine final causality to be found in the natural order; the atomists Democritus and Leucippus would be two ancient advocates of this view. Teleological intentionalism is his label for the view that there is teleology to be found in the natural order, but only insofar as a divine intelligence has put it there; Anaxagoras would be an ancient representative of this view. Aristotle, as Shields notes, takes an intermediate position: there are final causes inherent in the natural order, but they do not require explanation in terms of a divine ordering intelligence. They’re just there in the nature of things. (This is so, in Aristotle’s view, even though we must affirm the existence of an Unmoved Mover who moves the world as its final cause; for what leads us to the Unmoved Mover is the need to explain motion or change, not the need to explain the existence of final causality per se.)

Andre Ariew, in his article “Teleology” in The Cambridge Companion to the Philosophy of Biology, draws a similar set of distinctions. The materialist, who corresponds to Shields’ teleological eliminativist, denies teleology. The Platonic teleologist, like the teleological intentionalist, affirms teleology but regards it as imposed by a divine intelligence from outside (e.g. by the demiurge of Plato’s Timaeus). The Aristotelian teleologist also affirms teleology but regards it as immanent to the natural order rather than imposed from outside. As Ariew notes, William Paley of “design argument” fame and contemporary Intelligent Design theorists are essentially Platonic teleologists.

These distinctions are very helpful, but they do not exhaust all the possibilities. For as I have noted, Aquinas rejects both Aristotle’s position and that of the Platonic or intentionalist teleologist. His position might be seen as a middle position between theirs. Like Aristotle, and unlike Paley and ID theorists, Aquinas regards final causality as immanent to the natural order. For Paley and ID theory, it is at least possible that natural objects have no end, goal, or purpose; they just think this is improbable. The reason is that they accept an essentially mechanistic conception of nature, viz. one which denies Aristotelian formal and final causes and models the world on the analogy of a machine. The bits of metal that make up a watch have no inherent tendency toward functioning as a timepiece; it is at least theoretically possible, even if improbable, that a watch-like arrangement might come about by chance. And natural objects are like this too: There is nothing inherent in any natural object or system – no essences, natures, substantial forms or anything else corresponding to such Aristotelian-Scholastic categories – by which we might read off final cause or teleology. The world might be like a collection of bits of metal that have by sheer accident come together in the form of something resembling a watch. It’s just that this is so highly improbable – so the argument goes – that the “best explanation” is that some intelligence arranged the bits that make up the world into their present purposive configuration, much as a watchmaker arranges bits of otherwise purposeless bits of metal into a watch.

Like Aristotle, Aquinas will have nothing to do with this picture of nature. For them, the world is not comparable to a machine – that is to say, it is not a complex arrangement of parts which have no intrinsic tendency toward the ends they actually happen to serve, and thus must be forced to do so “from outside” as it were. Rather, all natural substances have essences, natures, or substantial forms, and their final causes are therefore inherent or built-in. For Paley, it at least makes sense to think that the eye (say) might not actually be for seeing. It’s theoretically possible that the fact that eyes tend to result in seeing is an amazing accident. It’s just that, when we weigh the various explanatory alternatives, we find this one so highly improbable that we can rule it out. But for Aquinas, probability has nothing to do with it. The very idea that eyes might not really be for seeing makes no sense and is not even theoretically possible. If eyes are typically associated with seeing, then that can only be because it is in their nature to see. And that in turns entails that their natural end or final cause is seeing. We can know this just by considering eyes themselves, without getting into the question of their origin, divine or otherwise.

Unlike Aristotle, who leaves it at that, Aquinas thinks that the existence of final causes nevertheless requires an explanation, for the reasons sketched in my previous post on teleology; and he also thinks that this explanation must lie – not might lie, not probably lies, but necessarily lies – in the existence of a divine intellect which conserves the order of final causes in being from instant to instant. Here too, Aquinas’s God is not a “watchmaker” god who might have died off in the time that has passed since he finished his work, leaving his finely crafted timepiece to carry on without him. Without the divine ordering intellect, the order of final causes could not be sustained even for an instant.

As usual, the details can be found in The Last Superstition and Aquinas. The point is just that Aquinas’s position cannot be assimilated to that of either Aristotle or Paley. It is, again, a middle ground between them: call it Thomistic teleologism or Scholastic teleologism.

As the latter suggested label perhaps indicates, the situation here might usefully be compared to the debate over the problem of universals. Nominalism and conceptualism are essentially anti-realist positions, regarding universals as artifacts of language or the workmanship of the human understanding rather than having any objective basis. Platonic realism takes universals to exist entirely independently of either the natural world or of any mind. Aristotelian realism takes universals to exist only in the particular things that instantiate them and in intellects which abstract them from these particulars. Scholastic realism – the position of Augustine and Aquinas – takes what is in effect a middle ground position between Platonic and Aristotelian realism. Like the Aristotelian realist, the Scholastic realist affirms that universals can exist only in either their concrete instantiations or in an intellect. But like Plato, he also affirms that they nevertheless have a kind of existence beyond those instantiations and beyond finite, human intellects. For universals pre-exist both the material world and all finite intellects qua ideas in the infinite, divine intellect, as the patterns according to which God creates the world.

Nominalism and conceptualism, in their anti-realism, are comparable to teleological eliminativism, denying the objective existence of the phenomena in question. Aristotelian realism corresponds to Aristotelian teleologism: just as the former affirms universals but regards them as immanent, existing in their instantiations, so too does the latter affirm a kind of teleology, but only one existing immanent to the things that manifest it. Platonic realism corresponds roughly to teleological intentionalism: like Platonic realism, which regards universals as existing entirely separated from the material world, Platonic teleologism affirms teleology, but only as something which strictly speaking exists apart from the world rather than immanent to it. The patterns we observe in the natural world might lead us to postulate the existence of the Platonic Forms, but the Forms are entirely outside the world. Similarly, the order of the natural world might lead us to postulate the existence of Platonic teleology, but strictly speaking such teleology is – for Paley and ID theory, unlike Aristotle – not in the natural world itself but only outside it, in the mind of a designer.

Scholastic realism, then, corresponds roughly to Scholastic teleologism: Universals are immanent to the natural world, and therefore the natures of things can, at least to some extent and in principle, be known and studied without reference to their creator; and this remains true even though any ultimate explanation of universals and the things that instantiate them must make reference to God. Similarly, the final causes of things are immanent to the natural world and can, at least to some extent and in principle, be known and studied without reference to God – despite the fact that their explanation too must ultimately be referred to God.
Insisting on the immanence of universals and final causes is arguably crucial to avoiding the extremes of occasionalism and deism. For if we deny that universals and final causes – and thus natures and causal powers – are inherent to natural objects, then we are likely to conclude either (a) that there are no secondary causes, and God as first cause is really the only true cause of everything that happens, or (b) that since the world can continue to operate without inherent causal powers, it must also be capable of continuing in operation without the continued operation of the first cause. The first, occasionalist option tends in turn to approach pantheism, while the second, deistic option tends to lead to atheism.

I leave for homework the question of whether these inferences are strictly unavoidable – obviously they would need in any event to be fleshed out. Suffice it to say that there are theological as well as philosophical grounds to prefer what I have called the Scholastic position. As I have emphasized in TLS and elsewhere, there are scientific advantages too. For the further we go in the deistic-cum-mechanistic direction, the more we invite Humean skepticism about causality and thus threaten to make science unintelligible. While the further we go in the occasionalist direction, the less the world seems to reflect impersonal and predictable forces and the more it comes to seem in every detail comparable to the unpredictable behavior of a conscious subject – thus making natural science impossible. (As Alain Besançon has argued, a tendency toward an occasionalist conception of divine causality is part of what distinguishes Islam from Christianity – and this is no doubt one reason why natural science progressed in the West and stagnated within the Islamic world.)

Saturday, September 26, 2009

The difference between McCarthyism and liberalism

McCarthyite: someone who thinks there is a communist hiding under every bed

Liberal: someone who thinks there is a McCarthyite hiding under every bed

Thursday, September 24, 2009

Teleology revisited

Over at his own blog, One Brow (who sometimes comments on this blog) responds to my recent post on the Wright-Coyne-Manzi debate. I appreciate his thoughtful remarks, but I must say that I find his post a bit frustrating. He admits that he has not read The Last Superstition, but puts forward criticisms of its arguments anyway – criticisms that I have already addressed at length in the book! I know that some readers think I drop references to TLS into various blog posts simply as an act of self-promotion; and if it helps to sell a few copies, I certainly don’t mind. But the main point is always to indicate to interested readers where certain issues relevant to the topic of a post have been addressed at greater length. I cannot reasonably be expected to recapitulate the arguments of TLS every time I revisit one of its themes. That’s why people write books: To develop at length arguments and ideas that cannot adequately be dealt with in shorter contexts (e.g. blog posts).

Anyway, one of One Brow’s comments that I would like to address here concerns the central topic of the post to which he is responding, viz. the way in which talk of “algorithms,” “information,” and the like in biology evinces, if it is meant seriously, a tacit commitment to the reality of teleology or final causes. One Brow says:

terms like algorithm and information means [sic] very different things when applied to biological objects or other non-human-created systems than to computer programs. Algorithms are merely cycles enacted and altered by external stimuli and ended, if at all, by other stimuli (possibly external or internal), while information represents how easily a string can be compressed by interpretations [sic] functions that are not aimed specifically at that string. Neither concept has any recognition of teleology or lack thereof, they are statements of content, not purpose.

The problem with what One Brow is saying here – if I understand him correctly, anyway – is that he is just mistaken in assuming that his claims are necessarily inconsistent with the claims I made. And what this reflects is a basic failure to understand what the Aristotelian-Thomistic (A-T) tradition means by “final cause" or “teleology.” (Like Coyne, One Brow seems annoyed that defenders of Aquinas are always complaining that critics don’t understand his arguments. And yet rather than show that the charge is false, the critics’ responses only ever seem to provide further evidence for the charge! What can I say? Don’t blame the messenger, guys…)

Let me make some general remarks about what the A-T tradition does mean, then, before coming back to One Brow’s comment. 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.

In fact Aristotle and Aquinas are concerned with something far less high-falutin’ than all that. 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 – for example the sort, like the sands of the sea for multitude, who made snotty and uncomprehending remarks in response to Manzi’s response to Coyne (as you’ll find if you can stomach plowing through Coyne’s combox) – 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 usual, see TLS – and, now, Aquinas – for more.)

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.

Now, let me return, at last, to One Brow’s remarks. One Brow says that to describe natural selection and other natural processes as “algorithmic” is simply to note that they are “cyclical.” And what he means by this, I gather, is that they embody regular causal patterns (in particular, patterns of what Aristotelians call efficient causation). Competition between species leads to changes in the gene pool, planets tend to orbit stars in patterns roughly conforming to Kepler’s laws, and so forth. But there is, One Brow says, no “purpose” being served by any of this. The purpose of natural selection is not to lead to better organisms, because it has no purpose; and the purpose of planetary orbits is not to generate seasonal changes on the planets themselves, because they have no purpose either. A causes B in a cyclical pattern, with no external purpose being served by that pattern; and that’s that.

If this is what One Brow means, though, he is not saying anything that is incompatible with what I have been saying. For whether natural selection, planetary orbits, or anything else serves a purpose in the sense in question is irrelevant to the existence of teleology. The claim isn’t that the fact that A causes B in a cyclical pattern entails that there is some plan or purpose outside the cycle that the pattern exists in order to further. The claim is that the mere existence of the cycle is all by itself a manifestation of teleology. The argument isn’t “A tends to cause B; therefore there must be some purpose outside of both A and B the realization of which this causal relationship exists in order to further.” It’s rather “A tends to cause B; therefore, causing B must be inherent or natural to A.”

If that claim sounds obvious and trivial, then terrific: You’re starting to understand Aristotle and Aquinas, because it’s supposed to be obvious and trivial. Or rather, it would be trivial if not for three factors: First, if Aquinas is correct, this obvious and seemingly trivial fact cannot be explained unless there is a divine intelligence directing causes to their effects. Obviously that is a substantive claim, not a trivial one. Second, when you work your way up through ever more complex levels of material reality, you find correspondingly more complex manifestations of final causality or teleology, and in the case of human beings this has significant moral implications. (Indeed, from an A-T point of view it is a precondition of there being any such thing as morality at all.) Third, what is obvious and trivial to common sense has become obscured by 400 years worth of intellectual squid ink, as modern philosophers have moved ever farther away from the classical tradition and indulged in ever more bizarre exercises in what P. F. Strawson called “revisionary metaphysics.”

One Brow also denies that attributing “information” to natural processes implies the existence of teleology. But there are two problems with this. First, if he means that “information” in the technical, Claude Shannon sense doesn’t by itself entail semantic content of the sort we associate with purpose, then he’s right, but that doesn’t undermine the claim at issue. For where A carries Shannonian information about B, that is only because there is a causal connection between A and B, so that we are back to the original A-T point that such an (efficient) causal connection presupposes final causality.

Second, it is not at all clear that scientists who speak of “information” and the like really do confine their usage to the narrow, Shannonian sense of the term. As John Searle (among others) has complained for decades now, fast-and-loose computer science and information-theoretic talk pervades contemporary intellectual life, and has afforded materialistic explanations (e.g. of the mind) a specious plausibility they would not have if the relevant terminology was used more precisely. The thing is, some of this talk – that is, some of the talk that attributes something like semantic “information” to material processes – is by no means unmotivated. As Daniel Dennett likes to say, there are “real patterns” in nature underlying the “intentional stance” we find it useful to take toward certain natural phenomena. And that these patterns seem to require an intentional or semantic description is evidence of even richer levels of teleology than the sort I’ve been describing in this post.

Such richer levels of teleology – in complex inorganic systems, in biological phenomena, and in human thought and action – are, from an A-T point of view, certainly real. And they are, of course, the sort that Paley and Co. tend to focus on (though even here their understanding of teleology is very different from the A-T conception). But I have focused on the most rudimentary sort of teleology – the sort manifest in even the simplest causal connections – because that is all that is required for an argument like Aquinas’s Fifth Way.

Wednesday, September 23, 2009

Mark Johnson at very kindly calls his readers’ attention to Aquinas. If you haven’t yet done so, please do go check out his site – lots of interesting stuff there.

I love the 80s

Gotta admit that this and this are pretty funny. Good thing they don't know I grew up in the SF Valley. (Like, that is so totally ad hominem! Fer sure.)

Friday, September 18, 2009

Now available: AQUINAS

The first anniversary of the publication of The Last Superstition is just around the corner. How will you celebrate? You could drink a bottle of Aquinas – not a bad idea. But while doing so, why not read a hot-off-the-press copy of my new book Aquinas?

Aquinas is an in-depth but accessible introduction to the philosophical thought of the Angelic Doctor. St. Thomas’ key metaphysical ideas are set out in detail, their relation to current issues in analytic philosophy is explored, and common caricatures and misunderstandings are swept away. The core of the book is an extended, critical but sympathetic treatment of the famous Five Ways, which situates them in the broader Aristotelian-Thomistic metaphysical context apart from which they cannot properly be understood, reveals how the standard objections rest on a failure to appreciate this context, and shows that each of the arguments is still defensible today. This is followed by a similarly A-T metaphysics-informed treatment of Aquinas’s philosophical psychology and moral theory. Readers of The Last Superstition will be interested to see some of its topics developed in greater detail and in a more academic and – for those of more tender sensibilities – entirely non-polemical fashion.

Some pre-publication blurbs:

“At last. A concise, accessible and compelling introduction to Aquinas's thought. Feser shows that Aquinas's philosophy is still a live option for thinkers today.” Kelly James Clark, Professor of Philosophy, Calvin College

“Lucid, cogent, and compelling. Required reading.” Christopher Kaczor, Associate Professor of Philosophy, Loyola Marymount University

“Useful and easy to read. Students and scholars will find this highly beneficial.” Fulvio di Blasi, President, Thomas International

What else is in the book, you ask? I got your Table of Contents right here:


1. St. Thomas

2. Metaphysics

Act and potency
The four causes
Essence and existence
The transcendentals
Final causality
Efficient causality

3. Natural Theology

The First Way
The Second Way
The Third Way
The Fourth Way
The Fifth Way
The divine attributes

4. Psychology

The soul
Intellect and will
Immateriality and immortality
Hylemorphic dualism

5. Ethics

The good
Natural law
Religion and morality

Further reading

Remember, Christmas is coming, so you’ll need copies for family, friends, your priest, minister, rabbi or imam, colleagues, acquaintances, enemies, the milk man, the mail man, Domino’s Pizza delivery guys, and whatever random people you might meet on the street. So, as they say in Chicago, order early and often!

Thursday, September 17, 2009

Heisenberg on act and potency

What’s that? You say you’re itching for more quotes from popular science books written by major early twentieth-century quantum physicists, which tend to support a classical metaphysical picture of the world? Well OK then, friend, you’ve got it. Today let’s take a look at Werner Heisenberg’s Physics and Philosophy.

Like many scientists of his generation (and unlike contemporary scientists like Richard Dawkins and Jerry Coyne), Heisenberg knew something about philosophy and its history, and took its problems seriously. In particular, he recognized that empirical science requires for its intelligibility a sound philosophy of nature (or metaphysics, as we might say today, though the other term is preferable – the philosophy of nature concerns the preconditions of there being an intelligible natural world, while the concerns of metaphysics are more general than that). Moreover, he saw that a return to certain classical philosophical notions was essential to making sense of modern physics.

Of course, it can hardly be maintained that Heisenberg subscribed in any wholesale way to a classical metaphysical picture of the world; he proposes, for example, that quantum theory calls for a revision of the law of the excluded middle. But he did at least tentatively endorse something like the fundamental notion of Aristotelian-Thomistic (A-T) metaphysics – the famous distinction between act and potency.

Regarding the “statistical expectation” quantum theory associates with the behavior of an atom, Heisenberg says:

One might perhaps call it an objective tendency or possibility, a “potentia” in the sense of Aristotelian philosophy. In fact, I believe that the language actually used by physicists when they speak about atomic events produces in their minds similar notions as the concept “potentia.” So the physicists have gradually become accustomed to considering the electronic orbits, etc., not as reality but rather as a kind of “potentia.” (pp. 154-5 in the 2007 Harper Perennial Modern Classics edition)

And again:

The probability wave of Bohr, Kramers, Slater… was a quantitative version of the old concept of “potentia” in Aristotelian philosophy. It introduced something standing in the middle between the idea of an event and the actual event, a strange kind of physical reality just in the middle between possibility and reality. (p. 15)

And yet again:

The probability function combines objective and subjective elements. It contains statements about possibilities or better tendencies (“potentia” in Aristotelian philosophy), and these statements are completely objective, they do not depend on any observer; and it contains statements about our knowledge of the system, which of course are subjective in so far as they may be different for different observers. (p. 27)

Discussing, more generally, the relationship between matter and energy in modern physics, Heisenberg says:

If we compare this situation with the Aristotelian concepts of matter and form, we can say that the matter of Aristotle, which is mere “potentia,” should be compared to our concept of energy, which gets into “actuality” by means of the form, when the elementary particle is created. (p. 134)

Now an A-T philosopher would want to clarify and qualify these claims. In the first two quotes, Heisenberg contrasts “potentia” with “reality.” What A-T says, though – and what Heisenberg himself clearly means, given the context – is not that potentials are not in any sense real, but rather that qua merely potential they have not been actualized. (Act and potency are in fact both real, but they are different kinds of reality. Part of the point of the distinction is to note that Parmenides’ notorious absolute distinction between being and non-being is too crude: There is, within the realm of being, a difference between the actuality of a thing and its potentials, and the latter are not to be assimilated to sheer non-existence.)

Furthermore, energy in the modern sense wouldn’t count as matter in the Aristotelian sense if what Heisenberg means by that is “prime matter,” viz. matter without any form whatsoever; for energy in the modern sense, given that it has a specific physical description, has form. (It might instead be, though, that what Heisenberg means to suggest is only that energy is the most fundamental kind of in-formed matter.)

In any event, it is clear that what Heisenberg is defending is a core thesis of A-T philosophy of nature, namely that we cannot make sense of the physical world behaving as it does without attributing to its basic components inherent powers which point beyond themselves to certain (often as yet unrealized) ends – a thesis that, as I have noted before, contemporary writers like Ellis, Cartwright, Molnar, and other “new essentialist” philosophers of science are starting to rediscover.

Saturday, September 12, 2009

Schrödinger, Democritus, and the paradox of materialism

Erwin Schrödinger was yet another of those early twentieth-century thinkers cognizant of the deeply problematic character of the mechanistic conception of the material world inherited from the early modern period – and yet another to see, in particular, that this conception of matter, far from opening the way to a materialistic solution of the mind-body problem, in fact created the problem and appears to make any materialistic solution to it impossible.

The reason does not (as one might suppose) have anything essentially to do with quantum mechanics, of which Schrödinger was one of the fathers. It has rather to do with a relatively simple philosophical point which was first made by the likes of Cudworth and Malebranche and repeated in recent years by writers like Nagel and Swinburne (as noted in the second of the earlier posts linked to above). Two relevant texts are Schrödinger’s essay “On the Peculiarity of the Scientific World-View” (from What is Life? and Other Scientific Essays) and chapter 6 of his Mind and Matter, entitled “The Mystery of the Sensual Qualities” (reprinted in What is Life? with Mind and Matter and Autobiographical Sketches – a more recent volume which does not include the earlier essay).

To summarize what I’ve said at greater length in earlier posts, the philosophical point in question is that the early moderns’ move of redefining matter so that it is devoid of color, odor, taste, sound, and the like as common sense understands them necessarily made these sensory qualities inexplicable in materialistic terms. Hence, if one is going to affirm the existence both of matter (as redefined by the moderns) and of the sensory qualities (or “qualia,” as they have come to be known, relocated from the external world to the internal world of the mind), then it seems one is necessarily committed to mind-body dualism of some sort (whether substance dualism or property dualism). The only way to avoid such dualism is either to reject the existence of matter (as Berkeley did), to reject the existence of the sensory qualities (as eliminativists do explicitly and most other materialists do implicitly), or to reject the mechanistic conception of matter that led to the problem in the first place (as Aristotelians do; though Aristotelianism still leads to a non-Cartesian form of dualism – what David Oderberg calls hylemorphic dualism – for reasons that have nothing to do with sensory qualities or qualia).

To be sure, Schrödinger himself does not explicitly draw an anti-materialist conclusion. He notes merely that what he calls the “objectivation” of matter – the conceptual removal from it of anything that smacks of the personal or of mind (cf. Thomas Nagel’s “objective/subjective” distinction) – makes the mind itself deeply mysterious. This is compatible with views like Colin McGinn’s “mysterianism” or Joseph Levine’s “explanatory gap” position, which affirm materialism even as they deny that we can understand, or at least (in Levine’s case) that we do in fact understand, how materialism can be true. Not that Schrödinger himself affirms this kind of view either; he simply calls attention to the problem raised by the modern conception of matter without trying to resolve it. (For my part, I consider McGinn’s and Levine’s positions non-starters. You might as well say, in response to Gödel, “Maybe the consistency of a formal system containing computable arithmetic really is internally provable after all, and our minds are just constitutionally incapable of seeing how.”)

Schrödinger’s emphasis is also less on the mind-body problem per se than on the epistemological paradox he sees implied by the modern “objectivation” of matter. As he puts it in “On the Peculiarity of the Scientific World-View”:

We are thus facing the following strange situation. While all building stones for the [modern scientific] world-picture are furnished by the senses qua organs of the mind, while the world picture itself is and remains for everyone a construct of his mind and apart from it has no demonstrable existence, the mind itself remains a stranger in this picture, it has no place in it, it can nowhere be found in it. (p. 216)

That is to say, the picture modern science (as informed by an “objectified” mechanistic conception of matter) paints of the natural world presents it as devoid of the sensory qualities and of anything personal. And yet the picture itself exists only within the minds of persons – scientists themselves – and takes as its evidential base the senses, and thus the very sensory qualities it refuses to locate in nature.

This epistemological paradox was a major theme of E. A. Burtt’s The Metaphysical Foundations of Modern Physical Science (Burtt being, as I have noted before, one of several major early twentieth-century scholars who emphasized the problematic character of the mechanistic revolution, before this theme went down the academic memory hole sometime in the 1960s). But awareness of it goes back much farther than that – indeed (and as Schrödinger reminds us) all the way back to the 5th century B.C., and in particular to Democritus, one of the fathers of atomism. In a famous fragment, Democritus imagines a conversation between the intellect, which (as Democritus naturally assumed) must endorse the atomists’ banishment of the sensory qualities from nature, and the senses, which form the evidential basis for the atomist theory:

Intellect: “Color is by convention, sweet by convention, bitter by convention; in truth there are but atoms and the void.”

Senses: “Wretched mind, from us you are taking the evidence by which you would overthrow us? Your victory is your own fall.”

It must be emphasized that Democritus is, commendably, calling attention to a difficulty facing a theory that he himself endorses; and that we have no idea how, or even if, he tried to resolve it. It is by no means obvious that any materialist in the intervening millennia has done any better. Many of them have done worse; indeed, vulgar materialists of the New Atheist stripe typically show no awareness that there is a problem here in the first place. Unfortunately, this includes Daniel Dennett, a well-known philosopher of mind. Dennett explicitly endorses an eliminativist position vis-à-vis the sensory qualities (see e.g. his essay “Quining Qualia”) – which is to his credit insofar as (I would argue) any consistent materialist must ultimately be an eliminativist anyway. What is not to his credit is his utter blindness to the deep philosophical puzzles such a position opens up, his peddling of shameless caricatures of anti-materialist views, and in general his refusal to concede that opponents of materialism are motivated by serious philosophical concerns.

Schrödinger provides us with a plausible account of the origins of this sort of blindness (in scientists, anyway – philosophers like Dennett should know better). In “The Mystery of the Sensual Qualities” he writes:

Scientific theories serve to facilitate the survey of our observations and experimental findings. Every scientist knows how difficult it is to remember a moderately extended group of facts, before at least some primitive theoretical picture about them has been shaped. It is therefore small wonder, and by no means to be blamed on the authors of original papers or of text-books, that after a reasonably coherent theory has been formed, they do not describe the bare facts they have found or wish to convey to the reader, but clothe them in the terminology of that theory or theories. This procedure, while very useful for our remembering the facts in a well-ordered pattern, tends to obliterate the distinction between the actual observations and the theory arisen from them. And since the former always are of some sensual quality, theories are easily thought to account for sensual qualities; which, of course, they never do. (p. 164)

In the case at hand, neuroscientists who begin, as every empirical scientist must, with observations – that is to say, with conscious experiences whose character is determined by various sorts of qualia or sensory qualities – go on to construct a theoretical description of the physical and neural processes associated with perception. This theoretical description then takes on, as it were, a life of its own, coming to seem as real or even more real than the concrete experiences that led to it, and the language in which the former is couched comes to be applied to the theorist’s description of the latter. Thus an explanation of “heat” in the sense of molecular motion comes to seem, especially when coupled with neuroscientific data, an explanation of “heat” in the sense of a certain kind of tactile sensory quality; an explanation of “red” in the sense of light of a certain wavelength comes to seem an explanation of “red” in the sense of a certain kind of visual sensory quality; and so forth.

But this is a muddle, a subtle committing of the fallacy of equivocation. The key theoretical concepts – molecular motion, light wavelengths, neural firing patterns, and so forth – are always understood in light of a broadly mechanistic conception of the natural world which follows the early moderns’ project of excluding final causes, sensory qualities and the like from matter and redefining it in abstract mathematical terms. To “explain” sensory qualities or qualia in such “scientific” (i.e. mechanistic and “objectified”) terms is thus really to change the subject. Earlier generations of philosophers and scientists realized this, which is why few of them were materialists – they saw that, by definition as it were, sensory qualities could not be “material” given the new conception of matter. But later generations – especially the current generation of scientists, who tend to be far more specialized and often seem less philosophically-minded or philosophically-educated than their predecessors – have forgotten this conceptual history. And this forgetfulness and philosophical shallowness together with the practical successes of modern science have hardened many of them – or at least the more vocal of the pop science writers among them – into a crude scientism which assumes that there are no philosophical problems, or at least no serious ones, which science is not capable of answering.

Thus, when philosophers come along – whether dualists or the more sophisticated and fair-minded sort of naturalist (e.g. a Searle, a Nagel, or a Chalmers) – and point out that existing neuroscientific “explanations” of consciousness and the like do not in fact explain the relevant phenomena at all, it comes to seem like these philosophers are inventing a new problem in a desperate and obscurantist attempt to salvage a belief in human dignity and specialness. In fact they are simply calling attention to a very old problem that the mechanistic theoretical model itself has created, and of which earlier generations of philosophers and scientists were well aware. In fact it is scientism which fosters obscurantism, ignoring as it does clear conceptual distinctions and forcing all intellectual life into a methodological procrustean bed. And in fact the mechanistic “objectified” conception of matter inherited from the early moderns is not a scientific discovery at all but a philosophical posit, and one which creates philosophical problems rather than solves them.

Obviously I am not claiming to establish these large claims here. (Doing so is in large part what The Last Superstition is about.) And obviously there are different moves a materialist might try to make in order to get around the problems in question (though, equally obviously, I don’t myself think any such moves can succeed). The point is that the problems are real ones, and serious ones. Any naturalist who dismisses them as motivated by irrational religious fanaticism is either ignorant or dishonest; certainly Democritus, Schrödinger, Burtt, Searle, Nagel, Chalmers et al. have no theological ax to grind. It goes without saying that our knowledge of the human brain has come a very long way since the 5th century B.C. But philosophically speaking, the history of materialism from Democritus to Dennett marks a precipitous decline.

Addendum 9/14: It occurs to me on re-reading the post that the Chalmers reference in the first sentence of the second-to-last paragraph is, coupled with the “or,” unintentionally misleading: Chalmers is a naturalist, but he is also a dualist of sorts. My apologies. The conceptual lay of the land vis-à-vis this subject is extremely complex, the range of possible positions is very large, and it is difficult briefly to summarize the issues without oversimplification – especially when (as was the case with this post) one is writing late on a Saturday night!

Wednesday, September 9, 2009

The sordid topic of Coyne

I could not resist the paraphrase of Isabella Rossellini in Death Becomes Her. Beyond that, I’m not sure it’s worth saying more than I already have on the subject of Jerry Coyne’s unfortunate recent forays into theology. Vis-à-vis matters philosophical, Coyne speaks neither with knowledge nor, it seems, in good faith. But some of his critics speak with both. Check out this post by Brandon Watson and this post by James Chastek.

Sunday, September 6, 2009

Manzi on the Wright-Coyne dispute

I argued in The Last Superstition that whatever one thinks of Darwinism, its truth or falsity is (contrary to what New Atheists like Richard Dawkins suppose) irrelevant to the cogency of the Thomistic proofs of God’s existence, including Aquinas’s Fifth Way (which Dawkins incompetently assimilates to Paley’s Design argument). Indeed, if Darwinism has any relevance to the latter argument at all, it is in fact by slightly reinforcing rather than undermining it. The reason is that Darwinism, like any scientific theory, posits various causal mechanisms, all causal mechanisms presuppose (for reasons set out in TLS) final causality, and thus (since the take-off point of the Fifth Way is the existence of final causality) Darwinism, qua scientific theory, only lends further support to the Fifth Way.

I also argued in TLS that the application by biologists, physicists, and other scientists of concepts like “algorithm,” “information,” “software,” “program,” etc. to the natural world evinces a tacit recognition of the reality of teleology or final causation. The reason (set out, again, in detail in TLS) is that the sort of directedness-towards-an-end that these concepts entail just is the core of the Aristotelian-Scholastic conception of final causality.

A third point emphasized throughout TLS is that the Thomistic proofs, like most of the classical arguments for God’s existence, do not stand or fall with the question of whether the universe had a beginning in time. Even if (as the pagan Aristotle held and as the Christian Thomas Aquinas was happy to concede for the sake of argument) the universe had no beginning, the need for a first Uncaused Cause would remain. For “first” in the thinking of Aristotle and Aquinas does not mean “first in time” but rather “ontologically most fundamental,” and what they are interested in explaining is not how the universe came about at some point in the past but rather what keeps in going at any given moment. (Creation for Aquinas fundamentally just is the divine conservation of the world in being.)

In an interesting commentary over at The Daily Dish on the dispute between biologist Jerry Coyne and Robert Wright (author of The Evolution of God), Jim Manzi makes some observations which dovetail with these points.

This is admittedly least obvious with respect to the last point. Manzi notes that, contrary to what Coyne seems to suppose:

evolution does not eliminate the problem of ultimate origins. Physical genomes are composed of parts, which in turn are assembled from other subsidiary components according to physical laws. We could, in theory, push this construction process back through components and sub-components all the way to the smallest sub-atomic particles currently known, but we would still have to address the problem of original creation. Even if we argue that … prior physical processes created matter, we are still left with the more profound question of the origin of the rules of the physical process themselves.

And Manzi concludes that:

If you push the chain of causality back far enough, you either find yourself more or less right back where Aristotle was more than 2,000 years ago in stating his view that any conception of any chain of cause-and-effect must ultimately begin with an Uncaused Cause, or just accept the problem of infinite regress.

Now, Manzi’s point is susceptible of two alternative interpretations. He might mean that if you trace the origins of complex material structures back in time to ever earlier stages in the history of the universe (or of some hypothetical series of branching universes, perhaps) then you will eventually either have to reach some temporal beginning point and un Uncaused Cause of that beginning point, or accept a mysterious infinite regress.

If that is what Manzi means, then he is not giving an Aristotelian defense of theism. Again, Aristotle and his followers do not argue for a temporal beginning of the universe (even though some of them do happen to believe, on independent grounds, that it had such a beginning). Nor do they think that an infinite regress is a “problem.” For by “infinite regress,” one either means an infinite regress of accidentally ordered causes extending backward in time – in which case such a regress is perfectly possible (and, indeed, actual, in Aristotle’s own view) – or one means an infinite regress of essentially ordered causes of the sort that trace ultimately to simultaneously operating instrumental causes here and now – in which case such a regress is, not merely “problematic” or mysterious (as if such a regress could exist in some as-yet unknown fashion), but flatly impossible in principle. (Again, all of this is explained at length in TLS.)

But Manzi’s remarks can be interpreted in another, more Aristotelian way. He might mean that even if the universe had no beginning in time, the basic laws that govern it, and the fact of their continual operation at any given moment, would still require an explanation. Talk of “laws of nature” is more a modern than an Aristotelian way of speaking, but the basic point remains that there is nothing inherent in material reality that can account for the “actualizing” of its “potential” for existing and operating in just the way it does at any particular instant. Unless we trace it down to that which is “pure actuality,” an Unmoved Mover or Uncaused Cause sustaining it in being and operation here and now and at any moment we are even considering the question, we would have no way in principle to account for why the universe exists at all and operates in precisely the way it does. The “problem of infinite regress” on this interpretation is not a matter of accepting a mystery which might have a solution – just one we do not and perhaps cannot discover – but rather the fatal (to naturalism) problem that without acknowledging that the regress of essentially ordered causes operating here and now terminates in an Unmoved Mover, the material world becomes unintelligible even in principle. (You know the drill: See TLS for the details.)

Manzi is clearer on the issue of final causality. Coyne seems to think that to attribute purposiveness to evolution entails seeing the human species, specifically, as having somehow been the end result toward which natural selection was working; and he trots out the usual ad hominem response to critics of Darwinism to the effect that they just can’t handle evolution’s humbling implications, blah blah blah. But as Manzi notes, this completely misses the point. Let the human race be as cosmically insignificant as you like; neither our existence nor that of any other particular species is at all relevant to the question of evolution’s “purposiveness.” The point is rather that Darwinism claims to identify an “algorithm” by means of which natural processes generate new species. And if this “algorithm” talk is taken seriously, then (to put things more strongly than Manzi does) it necessarily entails, given the nature of algorithms, that there is an end-state towards which the processes in question point – not, to be sure, the generation of some particular species (human or otherwise) at some temporal culmination point, but rather the (in principle non-stop) generation of species after species meeting certain abstract criteria of fitness. (It is an error to think that the existence of final causes in biology would entail some sort of “omega point” a la Teilhard de Chardin. Aristotle, after all, believed that the motion of the heavenly spheres was both teleological – since the spheres were in his view moved by their “desire” to emulate the Unmoved Mover – and also endless. His physics and astronomy were mistaken, but that does not affect the philosophical point about the nature of teleology. Even if evolution proceeds forever, that would not make it non-teleological.)

As I argue in TLS, all the computer science talk physicists, biologists, and other contemporary scientists have taken on board with such gusto really isn’t compatible with the “mechanistic” or anti-teleological conception of the material world to which they are still officially committed. Hence one either has to agree with the judgment of thinkers like John Searle that talk of “information,” “algorithms,” etc. is at best a misleading set of metaphors and at worst a complete muddle; or, if one thinks such talk is indispensible (and there is good reason to think it is) one must acknowledge that something like the Aristotelian conception of nature is correct after all.

James Ross has made similar arguments in a series of writings, such as his essay “The Fate of the Analysts: Aristotle’s Revenge: Software Everywhere,” and, most recently, in his book Thought and World: The Hidden Necessities. And, of course, I have noted the many neo-Aristotelian themes to be found in the work of many contemporary philosophers and scientists – including many who have no theological ax to grind – both in TLS and in earlier posts like this one and this one. Far from completing the anti-teleological mechanistic revolution – which was, strictly speaking, a philosophical revolution rather than a scientific one (albeit a philosophical revolution modern scientists have tended to swallow hook, line, and sinker) – the advent of the algorithm actually completely undermines it.

One reason so many commentators on the so-called “religion vs. science” debate don’t see the Aristotelian implications of the modern scientific ideas to which they appeal is that they simply don’t understand what Aristotelians mean by “final causality” in the first place, and in general -- as I never tire of complaining -- are beholden to a fossilized set of “Enlightenment”-era clichés and caricatures of what Aristotelians and Scholastics really thought. Not understanding classical philosophy (whether Aristotelian, Platonist, Thomist, or whatever) they naturally also do not understand the theology it inspired. Hence they take William Paley and his successors – rather than an Augustine, an Aquinas, or even a Leibniz – as their guides to what the divine nature must be like, if there is a God. Hence, rather than directing their arguments against the (classical philosophy-informed) classical theism that has historically defined Christian orthodoxy, they target a (currently popular but historically aberrant) anthropomorphic conception of God. Perhaps Coyne, Dawkins, et al. draw some blood when this conception is their target; and then again, perhaps not. Either way, their arguments are utterly irrelevant to the question of the existence of the God of Athanasius, Augustine, Anselm, and Aquinas – and thus of Abraham, Isaac, and Jacob.

But that theme calls for a separate post…