Friday, February 11, 2005

In Defence of Darwinism: The Wright stuff?

In his essay ‘Planet with a Purpose’, (which Orrin Judd cited in his post Hug a Darwinist), Robert Wright argues that darwinist processes are the explanation for evolution, but that this fact is actually evidence for a Designer – or at least, an initial Creator with a Purpose.

I don’t particularly have a problem with darwinism/Initial Creator compatibilism. Since darwinism says nothing about the origins of life or the universe, it’s not logically incompatible with a non-interfering Creator. But Wright wants to show that an Initial Creator necessarily follows from darwinism. I'm going to show that he fails pretty miserably to acheive this.

He presents his case in an extremely odd way: by trying to show that in an interview he persuaded Daniel Dennett, the well-known philosopher and darwinist, to admit as much.

I’m not going to waste too much time on this element of the essay, first, because there are links in the essay to Dennett’s point blank denial of this admission and a clarification of his position, and second, because I don’t see how this rather childish ‘there, you said it yes you did, I made you!” approach helps Wright’s argument. If the argument is strong enough, it will stand up on its own, whether Dennett admits to it or not (he doesn’t, of course).

So instead, I’ll just look at the argument and conclusion as Wright presents them. But first, it’s just worth addressing an assertion in Wright’s introduction:


When Charles Darwin unveiled his theory of natural selection, he said there was no inherent contradiction between it and religious belief. Maybe, for example, God had used natural selection as the instrument for creating intelligent life...Yet today many intellectuals think that if they're going to be true Darwinians, they should give up on any notion of divinity, any hope of higher purpose. Why? In no small part because of the widely read philosopher Daniel Dennett

Well, there might be some ‘intellectuals’ who, upon reading Dennett, thought they’d better give up on all that God-stuff to get in the darwinist gang, but I don’t know any. Most people I know who accept darwinism seem to have taken roughly the same path as me: they’ve read about it in books, and they accept it as the best current science. The ones who do give it more credence than ID or Creationism tend to be atheists, or skeptical about religion, or at least lacking in Faith, to begin with – which is why they have no different philosophical hang-ups about accepting it than they do about accepting Newtonian physics, chemistry or any other science.

Anyway, on with the Argument. Actually, once you’ve cut through Wright’s rambling, ‘now I’m not saying anything controversial here, but (insert controversial assertion)’ style, you realize that there are really two Arguments, which Wright confuses throughout the essay.

The first – which I’ll call ‘Argument 1’ ­­– goes like this (and honestly, I’m putting this as coherently and as sympathetically to Wright as I can):

1) in some sense of the word, natural selection ‘designs’ things (ie. makes them)
2) in some sense of the word, evolution has a ‘direction’ (ie. things have changed and eventually produced more complex organisms, including humans)
3) therefore, if there is design, which moves things in a direction, it is possible or probable that – contra most darwinists – there is a Purpose to evolution.

It doesn’t take a logical genius to see this isn’t the strongest argument in the world, but let’s have a look at it:

Wright starts with Paley’s famous argument from design, and correctly points out that the work of Darwin provided its refutation:


If you're walking across a field and you find a pocketwatch, Paley said, you know immediately that it's in a different category from the rocks lying around it. Unlike them, it is manifestly a product of design, featuring a complex functionality that doesn't just happen by accident. Well, he continued, organisms are like pocketwatches: they're too complexly functional to just happen by accident. So organisms must have a designer—namely, God. ...Thanks to Darwin, we now know that Paley was wrong. We can explain the complex functionality of organisms without positing a god… Of course, natural selection doesn't work like a watchmaker. It doesn't think ahead and create new features that will add functionality to an organism. Rather, it creates new features randomly, blindly, and then the dysfunctional ones get weeded out as the organisms possessing them die young or for some other reason fail to reproduce.


But now Wright asserts that in one sense, Paley was on to something:


Richard Dawkins, alluding to Paley, called natural selection "the blind watchmaker" in a book by that name. But a blind watchmaker is still a watchmaker. Organisms do have a designer, even if the designer is a somewhat clumsy process, not a conscious, far-seeing intelligence.

So Wright shamelessly contrives to get the word ‘design’ into the natural selection equation:


Paley was right to look at organisms and surmise that (a) they had a designer (in some sense of the word); and (b) this designer had imbued them with goals, with an overarching purpose (however ignoble a purpose genetic proliferation may seem to us).

Well yes, they have a ‘designer’ if you redefine the word ‘design’ to mean ‘not-design’, and add some wanton personification to a range of physical processes. But that level of doublespeak tends to lead to confusion. Either Wright doesn’t know this, or, more likely, he does know this, and is attempting a bit of clumsy sleight-of-hand.

Having ‘established’ the first part of Argument 1: "natural selection ‘designs’ things"; Wright gets to the second, "evolution has a ‘direction’" by taking a weak definition of the word ‘direction’, ie. things have moved in a certain way, and confusing it with a strong definition (it had to move in this particular way). He explicitly points out this difference when describing Dennet’s position:

Natural selection had been fairly likely, sooner or later, to produce an intelligent species of some sort; but, no, this was not evidence that evolution had any overarching purpose, that natural selection was itself a product of design. Evolution had a direction of sorts, Dennett believed, but it definitely had no purpose.

But Wright then goes on to use the word ‘direction’ in the strong sense for the rest of his article. He provides no practical evidence or rational argument to suggest that the ‘direction’ evolution has taken is anything other than arbitrary – he just asserts that it is so:

But isn't this direction itself evidence of purpose? If a process naturally creates something as complex as great intelligence, doesn't that suggest the process was set up for that purpose?

So that’s Argument 1:
1) natural selection is a form of design if you define ‘design’ as ‘not-design’
2) evolution has a ‘direction’ if you define ‘direction’ as ‘the arbitrary way it happened to go’
3) so if there is ‘design’ and ‘direction’, there is probably a ‘designer’ or ‘director’.

Argument 2 has a slightly more interesting angle, but is perhaps even sillier than Argument 1.

First, Wright restates Paley’s argument as if he’s got a new angle on it.

A single egg cell replicates itself, and the offspring cells in turn replicate themselves, and so on. Eventually the resulting lineages of cells start exhibiting distinctive specialties; there are muscle cells that beget muscle cells, brain cells that beget brain cells. If Paley were around today to watch videos of this process he would say: Wow!—Look at how exquisitely directional this process is; the system grows in size and in functional differentiation until it becomes this large, complex, functionally integrated system: muscles, brains, lungs, etc. This directionality is evidence of design!

Well, yes, Paley would say that. And he said it at the time – it’s just the argument from complexity all over again. Describing the process of an organism’s maturation as complex rather than its physical appearance does not alter the fact that Darwin refuted the argument (as Wright has already stated).

Next, Wright takes a sort of ‘Gaia’ approach to the Earth, comparing it to an organism:

…you can describe the history of evolution on this planet in a way that closely parallels this description of an organism's life cycle. First, a few billion years ago, a single primitive cell divides. The resulting offspring cells in turn replicate themselves, and eventually different lineages of cells (that is, different species) emerge…One lineage—let's call it homo sapiens—is particularly good at thinking. It thus launches a whole new process of evolution, called cultural evolution, that leads to the invention of wheels and legal codes and microchips and so on. Humans use the fruits of cultural evolution to organize themselves on a larger and larger scale. As this social organization reaches the global level, and features a richer and richer division of economic labor, the whole thing starts to resemble a giant organism. There's even a kind of planetary nervous system, made of fiber optics and other stuff, connecting the various human brains into big mega-brains that collaborate to solve problems. (And some of the problems are global—how to head off global warming and global epidemics, for example.) Meanwhile, as the human species is becoming a global brain, gradually assuming conscious control of the planet's stewardship, other species—also descended from that single primitive cell that lived billions of years ago—perform other planetary functions. Trees are lungs, for example, generating oxygen.


Now, in this little Gaia story I could note the spurious conjecture, the tenuous parallels and the fact that Wright completely ignores such things as mass extinctions, but I’ll stick to the logic of Argument 2:

1) Paley’s argument from complexity is valid after all, if applied to the development of an organism rather than its appearance
2) the world is like an organism, in that it has ‘evolved’ in a similar way to the maturation of an organism
3) so Paley’s argument applies to the world
4) so there must be some kind of design
5) so there’s probably a designer.

Wright fails to explain why step 1 is valid, is on extremely dodgy ground with step 2, doesn’t show why 3 should be the case, and the rest is consequently irrelevant.

Wright concludes by insisting that he isn’t, like Behe or Dembski, an Intelligent Design theorist, because he thinks there is no interference by God in the actual mechanisms of evolution.

But if he thinks that he’s provided any reasons for believing that a Creator or Designer logically follow from the fact of evolution, then Wright, I’m afraid, is Wrong.

5 Comments:

Blogger orrinj said...

Don't be the last one off the sinking ship.

February 11, 2005 8:20 PM  
Blogger Hey Skipper said...

Well, OJ, that sure was informative.

I have harped on this before, but I will harp on it again, because it is both so bloody obvious, and oddly unnoticed: Unlike a watch, or a car, or Mt Rushmore, life is a recursive system: the output of one generation is the input to the next, with variation included in the loop.

No one--and I do mean no one--can dispute this.

Also, and this is beyond dispute, leaving aside life for the moment, all recursive systems exhibit self organized complexity over time, without any intervention whatsoever beyond starting the system and supplying it with energy.

This is apparently where Wright invokes some kind of designer (since it need employ only randomness, an odd characteristic for something qualifying as a design), but this designer isn't the one the religionists desire to impose.

For them, continual, active supernatural guidance is essential (for reasons I shall go into more extensively in an upcoming post). However, this requires them to prove that life, which appears to have all the characteristics of a recursive system, contains one or more specific qualities making that appearance illusory.

Wright (whose book Non-Zero I rather liked) simply fails to note this essential characteristic of life, and how the watchmaker analogy is so violently wrong: watches leave no descendants.

Also, this quote struck me as odd:

"Evolution had a direction of sorts, Dennett believed, but it definitely had no purpose."

The sort of direction it has is neatly encapsulated by this phrase: Nature abhors a vacuum.

February 12, 2005 8:41 AM  
Blogger Unknown said...

Hi Orrin, welcome to the DD.

I doubt that either of the two ships, the HMS Darwin or the USS Creation will sink anytime soon. Especially with the poor, antiquated armament that Creation has to fight with. Wright's Nerf-Torpedo has done no damage.

Good take-down Brit. Wright reminds me of the businessman on holiday who will use the most contrived connection possible between his company's business and the location and activities that he pursues on his holiday just in order to classify his holiday as a business trip and deduct it from his taxes. It is as if he were treating the endeavor as one of these creative thinking workshops held by marketing types in order to contrive the most improbable connections between their product and some popular public sentiment such as patriotism or love of family. Interesting as an exercise, but noone need take it seriously.

February 13, 2005 9:54 PM  
Anonymous Anonymous said...

Not to mention that biologists, such as Gould, with his "drunkard's walk" essays, point out that the "direction" of evolution is from one cell to more than one cell -- there is no other direction possible.

Calling this "directed" is a bit like saying water demonstrates intelligence by always flowing downhill, as if water could choose to flow differently than directed by gravity.

February 15, 2005 11:09 PM  
Blogger Hey Skipper said...

Ed:

If I remember Gould's drunken argument properly, he found the odds of evolving extremely complex life forms as far longer than one might think.

Ironically, it was Robert Wright, in his book Non-Zero, who rubbished Gould's argument by pointing out the logical flaws in it. As it turns out, the drunk's walk is less random than it superficially appears.

Unfortunately, it has been awhile since I read the book, and can't remember Wright's argument in detail.

February 16, 2005 12:35 PM  

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