Justin Logan brought to my attention a recent debate that’s been going on between Robert Wright and Daniel Dennett, two of the more prominent writers on evolutionary theory. This weekend I spent a little time looking into it. Long story short: Wright is misleadingly making a big deal out of nothing and his argument for his claims doesn’t hold up to scrutiny.
The controversy became prominent when Andrew Sullivan linked to an article by Robert Wright with a post that reads: “AN ATHEIST RECANTS: Philosopher Daniel Dennett, author of the influential 1995 book, “Darwin’s Dangerous Idea,” now says he sees a higher purpose in the universe. Bob Wright breaks the news.”
That’s a rather misleading headline, and if Sullivan had been a little bit careful he would have known that Dennett said no such thing. Given the tone of Wright’s article, though, Sullivan can be forgiven. Wright dramatically overstates Dennett’s supposed concession, which isn’t really a concession at all. Here’s how Wright describes what Dennett said:
I have some bad news for Dennett’s many atheist devotees. He recently declared that life on earth shows signs of having a higher purpose. Worse still, he did it on videotape, during an interview for my website meaningoflife.tv… Dennett didn’t volunteer this opinion enthusiastically, or for that matter volunteer it at all. He conceded it in the course of a dialogue with me—and extracting the concession was a little like pulling teeth. But his initial resistance makes his final judgment all the more important. People who see evidence of some larger purpose in the universe are often accused of arguing with their heart, not their head. That’s a credibility problem Dennett doesn’t face. When you watch him validate an argument for higher purpose, you’re watching that argument pass a severe test. In fact, given that he’s one of the best-known philosophers in the world, it may not be too much to say that you’re watching a minor intellectual milestone get erected.
If you actually watch the video, you will see that this is not at all what happened. The actual interview is more like a poor Socratic dialogue, with Wright doing most of the talking and Dennett giving short, non-committal responses to obviously loaded questions. Wright presents Dennett with a series of hypotheticals about the evolutionary process, hypotheticals that Dennett rejects. All he gets Dennett to agree to is that if Wright’s hypotheticals were accurate, then Wright’s conclusion that there is evidence for design would be valid. This is the concession that Wright trumped up into a minor intellectual milestone – even though Dennett never accepted those hypotheticals!
Here is how Dennett describes the interview in an email he sent to Wright, forwarded to Andrew Sullivan, and that was eventually published on Protein Wisdom:
“Wright. blahblah, Dennett, NO. Wright, blahblahblah. Dennett, No
again. Wright, blahblahblahblahblah, Dennett STILL NO. Wright, But
won’t you agree that IF blahblahblahblahblah, Dennett, Well, yes, .if
all you mean is . . . . Wright, TaDAA! Dennett agrees with me!”
Having watched the video once before reading Dennett’s reply and again after, I agree with that assessment. Bottom line: the leading philosopher of atheistic Darwinism didn’t concede a damned thing. Unfortunately, he hasn’t written a detailed rebuttal to Wright’s argument (or if he has, I couldn’t find it). Wright’s argument has surface plausibility, though, so it’s worth dissecting it.
Wright’s argument hearkens back to that of a pre-Darwinian theologian named William Paley. In Wright’s words:
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.
Paley was only half right. The functional complexity of organisms does call out for explanation. The beauty of Darwinian theory is that it shows that the explanation doesn’t have to be God – it explains how nature can have complexity without teleology.
In a nutshell, natural selection explains biological complexity via the competitive replication of genes. It begins with individual strands of DNA and eventually leads to complex organisms like us. We are designed, but designed by the clumsy process of genetic replication, not from a pre-ordained blue print.
The explanation is a purely statistical one, boiling down to the relative population of specific genes in each generation of the gene pool. However, this is a cumbersome way of talking about evolution, so we allow metaphors of purpose to slip back into the discussion. The most famous of these is Richard Dawkins’ “selfish gene.” Thinking of genes as selfish competitors for replication and of organisms as their vehicles for war (and cooperation!) is an excellent way of making the theory intuitive. Hence the evolutionary biologists’ joke: What is a chicken? Just an egg’s way of making another egg.
That’s a fine and helpful way of thinking about things as long as one remembers that it’s just a metaphor. Genes aren’t really selfish and natural selection doesn’t really have the purpose of producing more genes – not in the same sense as we would describe a human being as being selfish or as having purposes.
Dennett, Dawkins, and Wright all basically agree on these points when describing the process of evolution. Wright steps into new territory by taking Paley’s argument and applying it to the Earth as a whole. If one could step back and watch the evolution of life on this planet, he says, one would find its unfolding complexity similar to the process by which an embryo becomes an adult creature. Functional differentiation occurs. One sees flying things, crawling things, swimming things; trees act as lungs, humans act as stewards, and fiber optics begin to form a worldwide neural network. As Wright says:
If you watched evolution on this planet unfold from a distance (and on fast forward), you would find it strikingly like watching the maturation of an organism (“epigenesis”). So why can’t the part of Paley’s argument that can be validly applied to an organism’s maturation—the idea that it suggests a designer of some sort—be applied to the whole system of life on earth?
Wright is arguing that the Earth is just like William Paley’s pocketwatch – its complexity calls out for explanation. The explanation could be God, or it could be some as yet undiscovered theory that would explain the Earth’s complexity in the same way that evolution by natural selection explains the complexity of organisms. God or theory – Wright says that we (and Dennett) have to accept that one or the other is needed. (Wright seems to lean toward the God option, but the choice is irrelevant for this discussion.)
There are two ways we can attack this argument. The first, and the one chosen by Dennett, is to say that A) the Earth isn’t undergoing a process similar to embryogenesis and that B) evolution doesn’t exhibit directionality and purpose.
A) Dennett rejects the comparison of Earth to embryo by noting that embryogenesis is not a straightforward rise in complexity. He notes several times that a large part of the process of development in humans involves a massive die off of the neurons we are born with. He readily concedes, however, that we do see a rise in functional differentiation. I admit that I find this first part of Dennett’s rebuttal unconvincing, but, in fairness, I don’t think Dennett really cares about being fully engaged in the argument so much as he just wants to clarify that Wright has misrepresented his views.
B) The second part of Dennett’s rebuttal is that evolution doesn’t exhibit directionality and purpose. Here, I think, he is on much firmer ground. While he does argue that evolution will tend to give rise to intelligence, he doesn’t believe that this is a trend that is necessarily heading anywhere in particular. Rather, he expects intelligence to arise in a saw tooth pattern, constantly rising and falling. Humanity is but the slightest blip in geologic time and we’ve yet to prove that our evolutionary path is a stable one (nuclear containment, anyone?)
The argument could be made even more stringently by an evolutionary biologist like Stephen Jay Gould, who argued that natural selection would not necessarily lead to intelligence, even in the saw tooth pattern Dennett predicts. In any case, it is very much an open question whether evolution has any directionality whatsoever, much less the strong directionality that Wright’s argument requires.
The second way to attack Wright’s argument is to object to the evolution metaphor. Recall the joke about a chicken being an egg’s way of making another egg. How the heck do we analogize this to a planet? Unless the rumblings from Mt. St. Helens are the first pangs of birth, the planet does not appear to be reproducing itself anytime soon.
One reason that evolution is such a good theory in biology is because we can see the antecedents of today’s creatures. We’ve also identified their means of replication, locating the genes that we can then metaphorically impose selfish purposes upon. We don’t have any similar antecedents for the Earth.
Fortunately, there are other ways besides evolution to explain complexity. Complexity can simply be an emergent property of a system made up of much simpler components. Wright’s argument appears to hold water simply because he ignores these other explanations. As Joe Pulitzer at Protein Wisdom puts it:
Mr. Wright looks for the divine where most would find physics and planetary mechanics. He does this by attempting to get the level of focus at a high enough level to exclude evolution and then immediately makes a wishful assertion that this is where the divine lies. Anyone familiar with “the God of the Gaps” is familiar with this technique. What makes it novel is that there isn’t even a gap here, just the writer’s omission of other fields of science other than biology.
And, I would add, new studies into complexity. If all of this seems like an evasion of Wright’s argument, consider this one that I just made up:
If you watched the development of the world economy unfold from a distance (and on fast forward), you would find it strikingly like watching the maturation of an organism (“epigenesis”). From initial hunting and gathering, to agriculture, then to manufacturing, and finally to the rise of the service sector, you would see a dramatic rise in functional differentiation. The freeing of trade and the creation of modern telecommunications can even be seen as a kind of global nervous system. This complexity calls out for an explanation. There must be some higher purpose at work here.
I hope you don’t find that argument convincing. There are a great many fascinating aspects of the modern economy that are worth studying, but no one would seriously suggest that we’re somehow missing the big explanation behind them all. Economics, history, psychology, etc. are adequate tools for understanding how that spontaneous order arose.
The same is true of the complexity we see in the world as a whole. Mysteries abound, but it is far too early to be having a Paley moment. Physics, planetary mechanics, ecology, climatology, and the interactions of evolved creatures still have much to tell us about the spontaneous order they have created. There is no reason conclude that there must be a designer or designing process of which we are somehow completely ignorant.
Stripped of its academic jargon, Wright’s argument is no different from my silly argument about the economy. It’s a very sneaky attempt to join an obvious argument (that it is worth trying to explain how the Earth became so complex) to a false, unstated one (that we don’t have a clue how it happened) to reach his unwarranted conclusion that there must be a higher purpose or theory at work.
Dennett gives Wright credit for taking exploring a new avenue of thought, so it’s unfortunate that Wright has made such incredible claims about his argument. Dennett also says that Wright’s approach doesn’t appear promising. I would have to agree.