Intelligent Design and Irreducible Complexity: A Rejoinder

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 epistemológica! 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. © Rhetoric & Public Affairs Vol. 1, No. 4, 1998, pp. 571-578 ISSN 1094-8392 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 epistemológica!. 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...