Intelligent Design and Irreducible Complexity

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1 University of Iowa From the SelectedWorks of David J Depew 1998 Intelligent Design and Irreducible Complexity David J Depew, University of Iowa Available at:

2 Intelligent Design and Irreducible Complexity: A Rejoinder David Depew Rhetoric & Public Affairs, Volume 1, Number 4, Winter 1998, pp (Article) Published by Michigan State University Press DOI: /rap For additional information about this article Access Provided by The University of Iowa Libraries at 05/08/12 5:31AM GMT

3 Intelligent Design and Irreducible Complexity: A Rejoinder David Depew In recent years, a new breed of scientific creationists has insisted that the supposed failures of Darwinism rest not only on gaps in the fossil record and other alleged epistemolã³gica! inadequacies, but more deeply on an overlooked ontological fact about organisms. They are, says Michael Behe, "irreducibly complex" systems, systems "composed of several interacting parts that contribute to the basic function" in such a way that "the removal of any one of the parts causes the system to effectively cease functioning."1 No such entity, it is claimed, can have come into existence bit by bit. Since Darwinian natural selection, the argument proceeds, is supposed to be committed to precisely such a gradualistic model of construction, Darwinism is said to be ruled out as a possible origin of organic organization. Stephen Meyer has taken this line of argument down to the most interesting level of all, the origin of life itself. It is well known that origin-of-life research is continuously stymied by the fact that nucleic acids specify proteins only if they are catalyzed by proteins. How could such an irreducibly complex system have come about? For Meyer, conscious design is the best explanation.2 Arguments of this form go back a long way. Plato was so committed to a version of the argument from design (or rather to design) that he recommended executing any citizen who refused, after remonstration and demonstration, to acknowledge that mere matter cannot produce organic form and function.3 Transmitted by the Stoics to modernity, the argument from design was so persuasively stated in William Paley's natural theology that Darwin devoted his entire life to rebutting it. Darwin was in turn challenged by William Whewell, Richard Owen, and Karl Ernst von Baer. When they asked questions such as, "What's the good of a half a wing?" they were putting forward versions of the irreducible complexity argument. Why, I wonder, are arguments of this sort prominent at the present juncture in the history of evolution-creationism debates? What is the rhetorical exigency for their new urgency? Having speculated about answers to this question, I will go on, in the briefest compass, to assert that the kind of complexity envisioned by Behe is David Depew is Professor of Communication Studies at the University of Iowa in Iowa City, Iowa, where he is also active in the Project on the Rhetoric of Inquiry. Â Rhetoric & Public Affairs Vol. 1, No. 4, 1998, pp ISSN

4 572 Rhetoric & Public Affairs not complex enough to describe organisms, or the process leading to their emergence, and so does not count as a compelling argument against commitment to a modest, and highly circumscribed, version of "naturalism." Creationist arguments, like evolutionary arguments, are developed, deployed, received, and debated under particular discursive conditions, conditions which it behooves a rhetorical critic to reconstruct. In the seventies and early eighties, for example, one heard little of the argument from irreducible complexity, although it could have been formulated at that time. Back then the stage was full of fellows like Duane Gish, who terrorized Darwinians unskilled in the sly ways of the debater by pointing to gaps in the fossil record as a way of breaking the monopoly of evolutionary thought in school curricula. After a while, however, this kind of argument became less prominent in mainstream venues even as the fight for the schools continued. Why? One reason, it seems to me, was epistemolã³gica!. As Charles Alan Taylor points out, creationists of Gish's stamp tacitly relied on a radically inductivist, or Baconian, conception of scientific method.4 Baconian inductionism says that if you cannot point to facts as present to you as the sunshine outside my window on this fine spring day, and if facts just that obvious do not add up to an exceptionless empirical generalization of the (admittedly false) "all-swans are white" variety, you presumably do not have a well established scientific claim. By this standard it was pretty easy to find gaps in the fossil record. By the same standard, however, almost all of science becomes as questionable as scientific creationists asserted evolution to be. So it was difficult for creationists who took this line to point to paradigm cases of successful science as a touchstone against which to indict what they took to be evolutionary theory's failures.5 In the next round of contemporary creationist-evolution debates, Darwinians took the offensive by deploying Karl Popper's idea that what makes a claim scientific is not that it is verifiable, as Baconian inductionism has it, but that it is in principle falsifiable. The high-water mark of this way of thinking was Judge Overton's decision in the Arkansas case in the early eighties. As is well known, a number of philosophers of biology and philosophizing biologists descended on Little Rock to sell the judge on Popper's falsifiability criterion. On these grounds Overton was prevailed upon to declare that creationism was not scientific and so should not be taught in the schools as an alternative theory to Darwinism. That was supposedly because there was nothing that could count against it. If, for example, carbon dating had shown that dinosaurs did not live at the same time as Adam and Eve (let alone Fred and Wilma Flintstone), a creationist could always say that God had rigged the physical evidence to test our faith. Creationists like Gish were relatively tongue-tied by such arguments. Nonetheless, a new breed of scientific creationists, notably the lawyerly Phillip Johnson, soon rose up to argue that by Overton's Popperian standards Darwinism

5 Intelligent Design and Irreducible Complexity: A Rejoinder 573 was in worse shape than creationism. One way of deploying this "misery loves company" topos was to show that Darwinism does not relate to the facts it is supposed to explain in the same way that Newton's or Einstein's paradigmatic theories do. There is admittedly a gap between what the evolutionist Ernst Mayr calls functional biology and what he calls historical biology.6 Functional biologists can figure out how an organic system works in the absence of any background theory about the origins of that system. Perhaps that is why one can find in the ranks of biologists creationists as well as evolutionists, non-darwinians as well as Darwinians, and, among contemporary Darwinians themselves, people like Richard Dawkins, who takes a genocentric perspective on natural selection, as well as those, like myself, who dislike selfish gene theory even more than they distrust creationism. Given this gap between functional and historical biology, Jonathan Wells and Paul Nelson are right to point out that Dobzhansky at the very least overstated his case when he proclaimed that "nothing in biology makes sense except in the light of evolution."7 What is it, then, when it comes to historical biology or background theories, that makes one person a Darwinian and another a creationist? People like Johnson were quick to assert that for Darwinians it is a metaphysical view of the world, naturalistic and indeed materialistic, that does the trick. Privately, physicists often entertain different metaphysical views of the world. But what makes them physicists is their ability to wield the formalism of quantum mechanics and to use it to interpret evidence. What makes one a Darwinian, on the other hand, is, on this view, the metaphysical materialism that many Darwinians, rising to Johnson's bait, were dumb enough to profess allegiance to. Having done so, it was easy for Johnson to point out that metaphysical claims are precisely what Popper had in mind when he talked about non-falsifiable propositions. Darwinians caught in the webs of this argument can be thankful that few philosophers of science are strict Popperians any more. That is because it is either too easy to falsify a theory or too hard. A plausible alternative is to see science as an ongoing activity that is as constantly open to contestation and revision as any other dimension of culture. In this process, research programs ebb and flow as they alternatively fail or succeed in solving definite problems that face a community of inquirers at any time. One good measure of success is precisely the one invoked by Meyer: inference to the best causal explanation for a phenomenon given the evidence that is contingently available at a given time. How does the creationism-evolution debate stand when measured by this more reasonable standard? Contemporary philosophers of biology who take a problemoriented approach to science usually think of creationism as a degenerative research tradition. What breakthroughs in problem solving, they ask, could we expect if creationism were suddenly to become a paradigm as sociologically, and even scientifically, powerful as it was in the days of Cuvier, von Baer, and Owen? By contrast, these philosophers think of Darwinism as a progressive research tradition. On this

6 574 Rhetoric & Public Affairs view, Darwin was merely the founder of a research tradition that has so far had a pretty good run. That is why those who take a problem-solving approach to science are not much moved by arguments, such as those of Wells and Nelson, that delight in telling us what Darwin himself was unable to explain. What Darwin could not explain is not what contemporary Darwinism cannot explain. For contemporary Darwinism is not limited to the same array of interpretive models, evolutionary agencies, or indeed the same set of problems that Darwin was. Darwin's sort of gradualism, for example, could not explain speciation. But the quite different gradualism of Sewell Wright, Dobzhansky, and Mayr certainly could.8 Intelligent design creationists like Behe and Meyer are to be commended for adopting contemporary views about how science actually works. Having foresworn the easy, but empty, rhetorical victories that falsificationism affords, they have put themselves in a position to recognize that one of the differences between our time and Darwin's, and even Dobzhansky's, is a rapidly growing appreciation of the dynamics of complex, often self-organizing systems. Complexity has become a keyword in contemporary science for several reasons. One is that we now have analytical tools, most of which are tied to the rapid growth of computation, that can explore it. Another is that most of what could be learned when nature was looked at through models of simple systems may already have been learned. In this new climate of opinion, it is no surprise that Behe would assert that Darwinians have hitherto underestimated the complexity of the phenomena they are supposed to explain, or that Meyer would argue that this reductionist bias counts among the reasons why the Darwinian tradition has not made more progress on origin-of-life research than it has. I could not agree more. The Darwinian tradition's unseemly attachment to metaphysical materialism serves merely to give a rhetorical guarantee (if there is such a thing) that, in the absence of empirical proof, life will eventually be shown to be consistent with received Darwinian thought. But this is not science. It is scientistic ideology. Meyer is correct to point out, moreover, as Bruce Weber and I also have, that natural selection cannot in principle be the cause of life's origin. For natural selection is a phenomenon that depends upon the sort of variation and heredity that exists only in organisms, and so can hardly explain how organisms came into existence in the first place.9 Nor does Meyer miss the mark when he derides scientists who appeal to sheer accident to explain the origin of life. That is no explanation at all. It is a confession of failure. I do not agree, however, with the conclusions Behe and Meyer draw from these reflections. In part, that is because I think Meyer too quickly dismisses the kind of thinking inaugurated by Ilya Prigogine. The fact that even single-celled organisms, whatever else they maybe, are thermodynamically open dissipative structures characterized by an elaborate system of autocatalytic pathways suggests that there are forms of variation and selection for dissipative efficiency that are not products of

7 Intelligent Design and Irreducible Complexity: A Rejoinder 575 natural selection, but on the contrary are presupposed by it. Natural selection eventually emerged in such systems, and only such systems, when a co-evolving system of proteins and nucleic acids had a positive effect on competition among chemically selective systems for energy fluxes. On this view, the adaptations brought about by natural selection function to facilitate, co-ordinate, integrate, and regulate autocatalytic cycling of self-organizing dissipative structures.10 The ontological dimension of this approach requires us to see organisms as developmental processes rather than as decomposable, machine-like assemblies of discrete parts. The latter may be irreducibly complex in the sense that the operation of each part depends on the operation of others, as Behe explains. But they are not irreducibly complex in the sense that they are, and result from, a complex self-organizing process, characterized as much by positive as by negative feedback, in which patterns of material cycling move toward complexity by a process of ontogenetic bifurcation and division.11 Indeed, the traits of organisms are mutually dependent, and irreducibly complex in the first sense, only because the self-organizing systems that are their foundation are already irreducibly complex in a deeper sense. The first kind of irreducible complexity may be sufficient to rebut forms of Darwinism like those of Dawkins or Daniel Dennett, whose decompositional model of organisms as the survival machines of genes is an attempt to "block the exits" to the supernatural while behavioral and cognitive traits are brought under the control of materialist techno-science.12 But what may be effective against this reductionist, and mostly metaphysical, form of Darwinism is not adequate against a view in which organisms are not, in the final analysis, like machines. Machines do not have ontogenies in the sense that organisms do. Nor, on a process-oriented view of science, is it explanatorily salient to say that in the future they might. Why, then, do intelligent design theorists believe that they have an ironclad either-or argument in which, given the complex mutual dependence of parts in any organism, the most reasonable alternative is intelligent design? Why do they not recognize that a third possibility lies open to them? William Dembski provides a clue when he asserts that organisms and designed objects share the properly of functional organization.13 The creationist asserts that where this property is found there must be a designer, that where there is a watch there must be a watchmaker. The conventional Darwinian says that the functional properties of objects merely appear to be designed. In fact they come about by the algorithmic process of a blind watchmaker, as Dawkins puts it, namely natural selection.14 It is just because both sides toil within the assumption that the properties of organisms and of artifacts are identical in kind, however, that they both take the analogy between organisms and machines too far. Behe says that, "The cell is run by machinesâ quite literally, molecular machines."15 Would Dawkins disagree with that? Would he or Dennett be unhappy with Meyer's assumption that genes "contain" information in the same sense that modern computers do, or with the implication that organisms are merely

8 576 Rhetoric & Public Affairs their "readouts"? This analogy guided the formation of modern molecular biology. Like many analogies, it generated some good science and, more recently, a biotechnological revolution. But in singling out genes for causal efficacy at the expense of other epigenetic processes it created a scientific myth, a myth that will eventually reveal its limits, let us hope not tragically.16 Complex evolving processes and their self-organizing properties are not, in the final analysis, like designed entities. It does not matter, accordingly, whether the watchmaker is blind or sighted. For as Weber and I have put it, there is no watch.17 This claim gives rise to what I take to be naturalistic research programs in evolutionary biology. I recognize, however, that the emergence of the sciences of complexity forces us to recognize an ambiguity in the notion of naturalism itself, and so invites me to be clear about what I mean. Minimally, I take naturalism to mean that we should presume that science, by shifting its conceptual structure as much as by marshaling empirical evidence, will continue to solve baffling problems in ways that do not depend on the supernatural. It means that we should not stand in the path of science by invoking God too quickly. Even for theologians there is a good prudential reason for acceding to that claim, while at the same time hoping that science and the supernatural can live with one another on increasingly better terms. For what usually becomes evident when God is invoked prematurely is either that someone's science was too limited, or his God was too small, or both. Admittedly, there is an historical connection between the naturalistic heuristic that I commend and philosophical materialism, which I do not. This connection, where it is not reducible to the claptrap of Enlightenment rhetoric, was formed by the perception that reductionistic methods and atomistic ontologies have always facilitated the problem-solving prowess of science. I think it unlikely, however, that this perspective will stand up in the future. Indeed, I suspect that the old philosophical notion of materialismâ the sort of thing we associate with Hobbes, or indeed with Dawkins and DennettÂ is likely to fall into virtual unintelligibility long before science ceases to solve problems without appealing to the supernatural. It is true that by its very nature techno-science will always focus on what it can tear down, put back together again, and generally manipulate and mimic, and that its advocates will always tell us that their latest success shows that that is all there is. But creationists, who are interested in a far deeper, less manipulative inquiry into the nature of things than techno-scientists, should infer as little from this as I do. Notes 1. Michael J. Behe, "Intelligent Design as an Alternative Explanation for the Existence of Biomolecular Machines," in this issue. 2. Stephen C. Meyer, "DNA by Design: An Inference to the Best Explanation for the Origin of Biological Information," in this issue.

9 Intelligent Design and Irreducible Complexity: A Rejoinder Plato laws 909a. 4. Charles Alan Taylor, Defining Science (Madison: University of Wisconsin Press, 1996), It does not seem odd to me that fundamentalists, oriented as they are to the state of the question of nineteenth-century creationist-evolutionists debates, would unreflectively appeal to nineteenthcentury conceptions of scientific method. For I suspect that most of what counts as folk science at any time is composed of bits and pieces of what used to be cutting-edge science found floating around in the soup of culture some time later. What does seem odd to me, however, is how many Darwinians who participated in the largely unilluminating debates of the seventies and early eighties rose to the bait by declaring loudly that evolution is a "fact fact fact" instead of calling this Baconian criterion into question. 5. The root of the problem is that on the Baconian view the delivery of the empirical goods means that the claim in question is no longer a theory. It is now a fact. It was on precisely this assumption that Ronald Reagan could famously declare of evolution, "Well, it's just a theory." Baconians like Reagan think of theories the same way mystery writers do. A theory is an appeal to something that has not been observed in order to explain, by hypothetical reasoning, what one does observe, but fails as yet to understand because parts of the story are missing. If and when one gets the missing pieces of evidence, led by the clues and prediction of the theory, the theory itself disappears. This is not what happened, however, when Einstein's theory displaced Newton's. The falsification of Newtonian mechanics did not mean that Einstein's mechanics was any less of a theory or any more of a fact. In science, theories forever mediate the commerce between humans and the world. The only interesting questions are what a theory is and when it is reasonable for a community of inquirers to accept or reject it. 6. Ernst Mayr, Toward a New Philosophy of Biology: Observations of an Evolutionist (Cambridge, Mass.: Harvard University Press, 1988). 7. Jonathan Wells and Paul A. Nelson, "Some Things in Biology Don't Make Sense in the Light of Evolution," in this issue. See Theodosius Dobzhansky, "Nothing in Biology Makes Sense Except in the Light of Evolution," The American Biology Teacher 35 (1974): See David J. Depew and Bruce H. Weber, Darwinism Evolving: Systems Dynamics and the Genealogy of Natural Selection (Cambridge, Mass.: Bradford Books/MIT Press, 1995), Depew and Weber, Darwinism Evolving, Darwinism Evolving, See Susan Oyama, The Ontogeny of Information: Developmental Systems and Evolution (New York and Cambridge: Cambridge University Press, 1985) for an expression of this "new epigeneticist" perspective. In contrast to the implied remnants of preformationism that lurk in "gene talk," Oyama, in the process of deconstructing the nature-nurture dichotomy, articulates a version of epigã nesis in which faithful reproduction is part of an orderly process of progressively articulated development. On this view, each species has a species-specific set of developmental resources, including but not limited to genetic information, that are expressed in an autopoietic process, which does not need a central information source to construct species-specific traits in each new generation. Rather, the resources needed to complete each stage of development are constructed by the total set of resources at play in the immediately prior stage, so that fiinctional information is the result of ontogeny rather than ontogeny being the effect of the transmission of information stored in a genetic program. Building on this insight, Paul Griffiths and Russell Gray have argued that natural selection should be regarded as acting on variation in developmental processes and life cycles. See Paul Griffiths and Russell Gray, "Developmental Systems and Evolutionary Explanation," The Journal of Philosophy 9\ (1994):

10 578 Rhetoric & Public Affairs 12. Daniel Dennett, Darwin's Dangerous Idea: Evolution and the Meanings of Life (New York: Simon & Schuster, 1995). 13. William A. Dembski, "Reinstating Design Within Science," in this issue. 14. Dawkins, The Blind Watchmaker (New York: Norton, 1986), see also Dennett, Darwin's Dangerous Idea. 15. Behe, "Intelligent Design as an Alternative Explanation," in this issue. 16. This is the view of Evelyn Fox Keller, Refiguring Life: Metaphors of Twentieth-Century Biology (New York: Columbia University Press, 1995). 17. Depew and Weber, Darwinism Evolving,

Scientific Dimensions of the Debate. 1. Natural and Artificial Selection: the Analogy (17-20)

I. Johnson s Darwin on Trial A. The Legal Setting (Ch. 1) Scientific Dimensions of the Debate This is mainly an introduction to the work as a whole. Note, in particular, Johnson s claim that a fact of