NONZERO  THE LOGIC OF HUMAN DESTINY  By  ROBERT WRIGHT
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PART I: A BRIEF HISTORY OF HUMANKIND

PART II: A BRIEF HISTORY OF ORGANIC LIFE

PART III: FROM HERE TO ETERNITY

 

 

 

 

 

 

 

 

 

DIRECTION AND PURPOSE IN EVOLUTION
(or: a useful introduction to this exchange between me and philosopher Daniel Dennett)

by Robert Wright

Not long ago I wrote an article for Beliefnet in which I claimed that Daniel Dennett, a professed atheist, had, in the course of an interview on meaningoflife.tv, acknowledged evidence that natural selection may be a product of “design” and evolution may have a “higher purpose” (in some sense of the terms “design” and “higher purpose”; neither Dennett nor I buys “Intelligent Design theory”). In reply, Dennett complained of two things: 1) I’d misinterpreted him; 2) leaving the question of interpretation aside, I’d presented my interpretation in sensationalistic terms—describing his position hyperbolically in the first few paragraphs of the piece and only later adding necessary nuance (for example, the range of things one could mean by “higher purpose”).

I immediately pled guilty to the second charge; the first few paragraphs of my piece were  egregious in their sensationalism. But I’m still not convinced that the piece’s ultimately nuanced interpretation of Dennett’s remarks was unwarranted. The reason is that, notwithstanding Dennett’s attempt to clarify his meaning, still he hasn’t come up with an alternative interpretation of these key segments of the interview that withstands logical scrutiny, as I show here

Of course, we have to take Dennett as the leading authority on what he currently believes, and he says he believes that there is no evidence of higher purpose. I only harp on this issue because I think something important happened during this meaningoflife.tv interview: Dennett made an important concession on a philosophically momentous analytical  point, even if he backed away from the implications of that point once they were presented to him in garish terms, via the aforementioned sensationalism.

In any event—whatever your interpretation of Dennett’s remarks—this videotaped exchange can serve as a useful illumination of some under-explored issues at the intersection of science, philosophy, and religion. With that in mind, I provide the following background introduction to the exchange between me and Dennett. It is essentially an adaptation of the Beliefnet piece with the elements Dennett later objected to removed.

OK, here goes:

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. One Anglican clergyman, in a letter to Darwin, suggested that this was actually a “loftier” conception of God than the old-fashioned idea of God creating humans the easy way, by just molding them out of dust.

Thus, one could in principle have an entirely “materialist,” nuts-and-bolts conception of how evolution works (namely, via natural selection) and yet believe that evolution is ultimately in the service of a higher purpose. In my video interview with the emphatically materialist (and atheist) Dennett, I argued that some of his own views on natural selection’s tendencies might actually provide evidence of some such purpose, at least in a vague way.

My line of inquiry rested on the close connection between two separate questions: whether evolution has a purpose, and whether evolution has a direction. If you’re going to believe, as that Anglican clergyman suggested, that a divine being set natural selection in motion, confident that it would eventually produce some species as intelligent as humans, then you have to believe that natural selection was from the beginning likely to produce such intelligence—that it was in this sense “directional”.

On the question of directionality, Darwinians have long differed. Edward O. Wilson, for example, considers intelligent life a likely product of natural selection, whereas the late Stephen Jay Gould argued otherwise. The evolution of creatures as smart as us was a fluke, Gould said, and its very unlikelihood was evidence that evolution had no purpose.

Before my dialogue with Dennett, his longstanding position had been that Gould was half wrong and half right: 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 isn’t this direction itself evidence of purpose? If a process naturally creates something as complex as great intelligence, doesn’t that suggest that maybe the process was set up for that purpose? I’ve long thought so, but I had never been able to convince Dennett.  He had read my book Nonzero, whose closing chapters address this question, and had been unmoved. So I decided to take a new tack, with a new argument that drew on a famous incident in intellectual history. 

The incident involves William Paley, a British theologian who wrote a book called Natural Theology in 1802, a few years before Darwin was born. In it he tried to use living creatures as evidence for the existence of a designer.

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. Still, Darwinians have to admit that Paley was half-right: This complex functionality does demand an explanation. In fact, most evolutionary biologists would affirm some of Paley’s language: Yes, animals were “designed;” it’s just that the “designer” was natural selection, not 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. 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.

To understand the argument I was making to Dennett—how exactly I was deploying Paley’s logic—you need to know two additional things.

One is that Dennett has long accepted the above line of thought—that natural selection can be called a “designer,” albeit a blind one. The other is that Dennett has long accepted one extension of that line of thought: that natural selection has imbued organisms with “goals,” with “purpose”. Specifically: the goal of organisms is to get genes into subsequent generations. That may not be their conscious goal, but it is nonetheless the basic thing they were “designed” to do. (And their other apparent “goals” are subordinate to it. All animals seek food, for example, but that goal was itself favored by natural selection only because it helped animals survive long enough to transmit their genes.)

In short: Dennett has long believed that William 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). 

The gist of the argument I made to Dennett was this: What if you took this part of Paley’s logic—the valid part—and applied it not to individual organisms, but rather to the whole system of life on this planet? Doesn’t it suggest that the whole system had a designer (again, in some sense of that word). To see what I mean, let’s look again at an organism through Paley’s eyes, only this time let’s look at its whole life span, starting at the very beginning.

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!

As it happens, 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. Some of these lineages eventually become multicellular (jellyfish, birds) and exhibit distinctive specialties (floating, flying, etc.).

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 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.

In other words: 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?

Convinced? Even if not, you’re at least ready to go to the videotape, and watch me try to sell Dennett on this line of thought. After viewing it, you can come back here to read my post-mortem:

Dennett’s climactic concession may not sound dramatic. He just agrees reluctantly with my assertion that “to the extent that evolution on this planet” has  properties “comparable” to those of an organism’s maturation—in particular “directional movement toward functionality”—then the possibility that natural selection is a product of design gets more plausible. But remember: He has already agreed that evolution  does exhibit those properties. Ergo: By Dennett’s own analysis, there is at least some evidence that natural selection is a product of design.

Or so I thought after I conducted the interview. But, as I noted at the outset of this essay, when I published this interpretation Dennett said no, that’s not what he meant in these key segments of the interview. As I also noted above, Dennett hasn’t yet come up with a logically defensible explanation of what he did mean in these segments, as I explain here. Maybe he will someday.

Meanwhile, in closing, a few other points about this issue:

1) Again: to say that natural selection may be a product of design isn’t to say that the designer is a god, or even a thinking being in any conventional sense. Conceivably, the designer could be some kind of natural-selection-type process (on a really cosmic scale). In that event, to speak of evolution as having a “higher purpose” might be misleading, since for many people that term implies a divine purpose. But “higher purpose” can be defined more neutrally. You can say that organisms have a “higher purpose” in the sense that (a) they have a purpose (genetic proliferation) and (b) the purpose was imparted by a higher-level process (natural selection)—so much higher, in fact, that all organisms on earth were oblivious to it until revelation came in the form of Charles Darwin. Analogously, if you accept the argument that I posed to Dennett (and that he seemed to accept but retrospectively disavowed), you can say that evolution’s directionality is evidence of “higher purpose.”

2) How much evidence? Accepting my argument wouldn’t mean conceding a strong case that natural selection was in some sense a product of design. The argument is just that (a) to the extent that evolution exhibits directionality of the kind I’ve just described, there is at least some evidence of design; and (b) evolution does exhibit some of this directionality. Anyway, however strong you deem the evidence, I contend that it’s growing. Over the last few years alone, cultural evolution—notably the mushrooming of the internet—has made the term “global brain” less of a stretch.  

3) If there is indeed a “higher purpose,” what would it be? Answering that question would be a little presumptuous. For all we know, the “maturation” of the ecosystem is in an early phase, nowhere near manifesting any ultimate purpose it may have (just as, say, a three-year-old human is nowhere near manifesting the “purpose”—genetic proliferation—for which natural selection “designed” it). But if you’re interested in theological speculation, you might check out the recently re-released collection of essays The Future of Man by the mystical Jesuit priest (and paleontologist) Pierre Teilhard de Chardin. Teilhard deserves credit for seeing and grappling with the direction of cultural evolution early on; he was writing about the emerging giant planetary brain more than half a century before I had heard of the internet. (But note: Unlike Dennett and I, Teilhard wasn’t a strict Darwinian; he didn’t believe that nuts-and-bolts natural selection is the sole propulsive force of evolution. And as long as I’m distinguishing myself from others who see the possibility of purpose in evolution: I’m not part of the “intelligent design” school; like Teilhard, intelligent design theorists, such as William Dembski, see forces other than natural selection at work, whereas I’m just saying that natural selection, though able to do all the work of designing organisms, may itself be a product of design.)

4) If we don’t know what the purpose of life is, can we at least say whether it’s something we should be happy about—whether any “designer” of natural selection would  merit the term “divine”? Well, natural selection is in some ways a horrible creative process; much past death and suffering are the price paid for the evolution of our species. So it isn’t easy to argue that natural selection’s creator would be a wholly good being (or process)—just as thoughtful Christians, for example, don’t find it easy to reconcile all the suffering in the world with their notion of a benevolent, omnipotent deity. Still, one could mount an argument that evolution on this planet has at least some of the hallmarks of the divine—a directionality that is in some ways moral, even (in some carefully delineated sense of the word) spiritual. In fact, I’ve mounted such an argument in the last chapter of my book Nonzero.

--March, 2005

The above is adapted from an article that originally appeared in Beliefnet.