This book has quite a bit to recommend it. Most books that attempt to survey the debates between the Darwinian thought, the dominant paradigm in evolution, have a clearly defined axe to grind, but this volume includes an equal number of essays by both defenders of Darwinian orthodoxy and ID theorists. Significantly, it also includes chapters dealing with more nuanced perspectives, including theistic evolution and some of the preliminary work of theorists who suggest an as yet undiscovered "law" of complex organization. This latter group is an important, but often overlooked, set of Darwin critics. Nonetheless, for most readers, and certainly the bulk of reviewers, it will be the debate between the ID theorists and the defenders of NDE that commands the most attention.
The first two essays of the book, by Michael Ruse and Agnus Menuge provide a broader context for the debate. Ruse reviews the use of design arguments throughout history and explains why Darwin's 'Origin of Species' was apparently so devastating to most of them. Menuge's essay reviews some of the recent literature on the debate, in particular Barbara Forrest's influential
Creationism's Trojan Horse written with Paul Gross. The latter, like many "critiques" of intelligent design was more a misrepresentation and ad hominem attack than a thoughtful study.
Perhaps the most interesting exchange in this volume is between Kenneth Miller and Michael Behe. Miller attempts to undermine Behe's claim that the flagellum is an irreducibly complex structure. Accepting Behe's argument that such structures have multiple components, and his claim that if any one of those components are missing, the structure ceases to function, Miller proceeds to argue that the flagellum is not irreducibly complex. In particular, he claims the Type Three Secretory System (TTSS) found in some pathogenic bacteria is in fact subset of the materials used to build the flagellum, and since the TTSS is "functional" this in an of itself dismisses with intelligent design, or at the very least, with the concept of irreducible complexity. Behe responds to this, and other criticisms of a similar nature, by noting that Miller has not, in fact, addressed his argument. The flagellum is irreducibly complex because it ceases to function "as a flagellum" if any one part is removed. That portions of a flagellum might have other uses is hardly to the point. Referring back to his famous mousetrap analogy, Behe notes that any given piece of a mousetrap might have some other use: the base, for example, could also be used as a paperweight. But these alternate uses do not mitigate the problem of having all the pieces come together, in a precise and orderly fashion, in order to gain a new function that was neither present beforehand, nor could be subject to natural selection since missing multiple portions renders the function to be selected useless. In short, by pointing to the TTSS, Miller is pointing to yet another irreducibly complex system, and using it to "explain" the flagellum. This reviewer found Miller's arguments very powerful on a rhetorical level, but Behe's response convincing. I had a similar reaction to the essays by Robert Pennock and Stephen Meyer.
But in this book the design theorists do not always have the last word. The essay by Elliot Sober stands on its own as the most powerful critique of design I have ever read, and none of the other authors, nor indeed the reviewers, seem to have fully taken cognizance of it. In brief, Sober argues that the detection of design requires not one but two filters. The first may well resemble one that Dembski has proposed in his book
The Design Inference but the second is the unspoken assumption that we would recognize the motives of a designer. Of course, we all make design assumptions all the time, as Dembski notes in his own essay. But implicit in those assumptions, according to Sober, is the recognition that we know, if not the motives, at the least the general methods of the designer. We know this because the designers we have encountered in our own lives are human, and therefore much like ourselves. But what can we assume to know about a designer of life and how s/he(it) would, or would not, operate? Frequently advocates of intelligent design point to the SETI project as an example of how design inferences can be applied to a foreign intelligence. But Sober is skeptical that anything, even something as apparently universal as a series of prime numbers, would necessarily be recognized by a truly foreign intelligence as evidence of design. And there is little reason, he adds, for assuming that we would recognize the purposeful designs of other alien intelligences, much less of God.
The interesting thing about Sober's argument is that it apparently undermines not just intelligent design, but also one of the main arguments for Darwinian Evolution. This is the argument from "imperfect" or flawed designs. Darwinians frequently complain that the presence of "flaws" in the designs we observe, for example the panda's thumb, is evidence against intelligent design. But this argument, which is as old as The Origin of Species itself, and which is made repeatedly in Darwinian apologetics, from Philip Kitcher's recent
Living with Darwin to the essay by Francisco Ayala in this volume, presumes more about that nature of a designer than any ID theorist every has. There is no reason to suppose a designer would chose "perfection" as an object of design. If Sober is correct, identifying non-human design is nearly impossible, because the task requires more knowledge of the designer than we can ever have. And his analysis applies not only to ID, but to a major component of the argument for evolution.
As someone who is frankly sympathetic to ID, I am at a loss as to how anyone could respond to Sober's argument. Certainly neither Ayala, Pennock, nor Dembski attempted to do so in this volume. It would seem to me that both ID theorists and their critics make an implicit assumption that a designer is, in some sense, like us. But this begs the question, on what basis do they make such assumptions? And the answer would be, on the basis of the western Judeo-Christian-Islamic monotheistic tradition, which states explicitly that God made man in the image of himself. This understanding of God so permeates our culture that even those, like Richard Dawkins, who loudly proclaim their atheism, seem bound by it. The central disagreement then between ID theorists and their most responsible critics, involves how God is like us, and how He is not. And indeed, rereading this volume from that perspective, one quickly realizes that the many, if not most, of the arguments made by the group supposedly opposing the intrusion of religion into science are theological in nature. So perhaps Sober's greatest contribution to this volume, besides his express purpose of cautioning those who would use design arguments indiscriminantly, is in highlighting just how many of the supposedly scientific arguments of our day are permeated by religious thought. This thoughtful essay alone is worth the price of the volume.