[2009/06/22] Leading Darwinists Pool Their Speculations
Leading Darwinists Pool Their Speculations 06/22/2009 June 22, 2009 — The Darwin Bicentennial continued this week with a series of articles in PNAS by leading Darwinists. The Sackler Colloquium, called “In the Light of Evolution III,” explored the history and impact of Darwin’s theory of evolution, and prospects for the future. The lead paper said, “Our intent in this Sackler Colloquium has not been to idolize Charles Darwin, but rather to celebrate the field of evolutionary biology that he played such an important role in developing nearly 2 centuries ago.” The papers are available online without a subscription. Summaries of certain selections follow.
Avise and Ayala: Two Centuries of Darwin.1 John Avise and Francisco Ayala (UC Irvine) introduced the series with an overview of Darwin’s major ideas (natural selection, artificial selection, and sexual selection) and a perspective on his legacy 150 years after the Origin. A flavor of their opinion can be found in the first sentence, where they said Darwin’s theory of natural selection “stands as one of the grandest intellectual achievements in the history of science.” From there, they portrayed him as the Copernicus, Galileo and Newton of biology and the conqueror of the old argument from design for the existence of God. Then, they introduced the other papers in the colloquium. They ended on the question of whether evolution should be called Darwinism. “Our intent in this Sackler Colloquium has not been to idolize Charles Darwin, but rather to celebrate the field of evolutionary biology that he played such an important role in developing nearly 2 centuries ago.”
Ayala: Darwin and the Scientific Method.2 Francisco Ayala explored Darwin’s intersection with trends in philosophy of science. One theme he emphasized was the “contradiction between Darwin’s methodology and how he described it for public consumption.” Darwin presented his findings as if they were inductive conclusions in the Baconian tradition. In fact, Ayala showed, Darwin amassed evidence to support his already settled views. Darwin claimed in his autobiography that he proceeded “on true Baconian principles and without any theory collected facts on a wholesale scale,” but Ayala argues that the facts are very different from these claims. Darwin entertained ideas on transmutation of species early after the voyage of the Beagle. Between then and the publication of the Origin, some 23 years, “Darwin relentlessly pursued empirical evidence to corroborate the evolutionary origin of organisms and to test his theory of natural selection,” Ayala said. Why the contradiction? Ayala claimed that one reason was the bad reputation of the word hypothesis in the 19th century. It conveyed metaphysical speculations without empirical evidence. Darwin wished to avoid portraying himself operating on a metaphysical foundation. He wanted to look like the unbiased scientist coming to his conclusions out of the observations alone. That’s not all:
There is another reason, a tactical one, Darwin claimed to proceed according to inductive canons: he did not want to be accused of subjective bias in the evaluation of empirical evidence. Darwin’s true colors are shown in a letter to a young scientist written in 1863: “I would suggest to you the advantage, at present, of being very sparing in introducing theory in your papers (I formerly erred much in Geology in that way); let theory guide your observations, but till your reputation is well established, be sparing of publishing theory. It makes persons doubt your observations” (ref. 5, vol. 2, p. 323). Nowadays also, scientists, young or old, often report their work so as to make their hypothesis appear as afterthoughts, conclusions derived from the observations or experiments made, rather than as preconceptions tested by empirical observations designed precisely, as it is most often the case in many scientific disciplines, for the purpose of testing a particular “preconception,” a hypothesis.
Ayala defended this contradictory behavior of Darwin by explaining that it really is impossible to do any science without preconceptions. No scientist works by collecting facts without any bias, he said. Scientists usually have a hypothesis in mind before they collect facts. They also tend to focus on questions that interest them. He explored the history of philosophy concerning induction, focusing on Francis Bacon and John Stuart Mill, its biggest promoters. Ayala showed how induction can never prove a statement or lead to universal truths. Science must include more than induction. From there, Ayala discussed other philosophies of science that competed in the 19th and 20th century. He explored demarcation criteria that separate science from pseudoscience. He discussed the fallacies of predictions and the benefits of Popper’s criterion of falsifiability. Strangely, however, he stopped before Thomas Kuhn, as if philosophy of science ended with the logical positivists. Ayala ended by portraying Darwin’s theory of natural selection as a triumph of the hypothetico-deductive method. Darwin presented a theory that was empirically testable, and therefore scientific.
Dennett: Darwin’s “Strange Inversion of Reasoning”.3 Daniel Dennett (Tufts U) began by claiming that the “scientist who made the greatest contribution to philosophy is Charles Darwin.” He continued with something he has said often, “If I could give a prize for the single best idea anyone ever had, I’d give it to Darwin.” Thus he made it clear right off the bat this was not going to be a serious critique. Instead, the crescendo rose to an allargando maestoso:
In a single stroke Darwin’s theory of evolution by natural selection united the realm of physics and mechanism on the one hand with the realm of meaning and purpose on the other. From a Darwinian perspective the continuity between lifeless matter on the one hand and living things and all their activities and products on the other can be glimpsed in outline and explored in detail, not just the strivings of animals and the efficient designs of plants, but human meanings and purposes: art and science itself, and even morality. When we can see all of our artifacts as fruits on the tree of life, we have achieved a unification of perspective that permits us to gauge both the similarities and differences between a spider web and the World Wide Web, a beaver dam and the Hoover Dam, a nightingale’s nest and “Ode to a Nightingale.” Darwin’s unifying stroke was revolutionary not just in the breadth of its scope, but in the way it was achieved: in an important sense, it turned everything familiar upside down.
From there, Dennett attacked those who believed in God and design. What about this “strange inversion of reasoning” in his title? The line comes from MacKenzie, a critic of Darwin, who spoke of “Mr. Darwin’s meaning; who, by a strange inversion of reasoning, seems to think Absolute Ignorance fully qualified to take the place of Absolute Wisdom in all of the achievements of creative skill.” MacKenzie had just complained that Darwin seemed to say that “ in order to make a perfect and beautiful machine, it is not requisite to know how to make it.” Dennett proceeded to defend that sentence. He drew on Turing’s theory to argue that you can get design from the bottom up, without an intelligent “skyhook” providing the design from the top down. Dennett next began trying to dismantle the arguments of top-down theorists. “Many people can’t abide Darwin’s strange inversion. We call them creationists. They are still looking for skyhooks— “irreducibly complex” features of the biosphere that could not have evolved by Darwinian processes.” He quickly dismissed the traditional creationists and the “mind creationists” (like John Searle and Roger Penrose) who, though accepting Darwinian theory, believe the mind lies outside its scope. Dennett gave more attention to the arguments of Jerry Fodor, Thomas Nagel and Alvin Plantinga. Fodor and Nagel only got a quick treatment for their non-religious critiques of evolution. Plantinga’s “reductio ad absurdum” critique (that we cannot trust our reason if evolutionary naturalism is true) got lengthier treatment. Dennett dismissed the premise, though, that our reason is unreliable under Darwinian theory. The reliability of various organs, he argued, suggests that our minds are also reliable. “Animals that get it right in general fare better than those whose senses deceive them,” he said. Next came the heart of his argument that one can rely on the products of natural selection:
This is adaptationist reasoning, of course, and it is not surprising that creationists of both kinds [full creationists and mind creationists] have typically taken aim at adaptationist thinking in biology, for they see, correctly, that if they can discredit it, they take away the only grounds within biology for assessing the justification or rational acceptability of the deliverances of such organs. We need to put matters in these “reverse engineering” terms if we are to compare organs with respect to their reliability—and not just their mass or density or use of phosphorus, for instance. Such an appeal to the power of natural selection to design highly reliable information-gathering organs would be in danger of vicious circularity were it not for the striking confirmations of these achievements of natural selection using independent engineering measures. The acuity of vision in the eagle and hearing in the owl, the discriminatory powers of electric eels and echolocating bats, and many other cognitive talents in humans and other species have all been objectively measured, for instance. It might seem that the skeptics could short-circuit this defense of our natural reliability as truth-trackers by showing that there can be no gradualistic path to truth-tracking. They could claim that there are no quasi-believers, proto-thinkers, hemisemidemi- understanders; you either have a full-blown mind or you don’t. This is where Turing’s strange inversion comes usefully into play, for his insight has given us a wealth of undeniable examples of just such partial comprehension: devices that can do all manner of impressive discriminative, predictive, and analytic tasks. We may insist on calling this competence without comprehension, but, as the competence grows and grows, the declaration that there is no comprehension at all embodied in that competence sounds less and less persuasive. This is made especially vivid when we reflect that, as we learn more about the nano-technology within our cells, we discover that they themselves contain trillions of protein robots: motor proteins, proof-readers, snippers, and joiners and sentries of all kinds. It is undeniable that the other necessary competences of life are composable from unliving, uncomprehending parts; why should comprehension itself be the lone exception?
Dennett argues that living things share their innovations with each other. He argues for a “crane” (technology sharing) instead of a “skyhook” (a designing intelligence) for the adaptations in life. He includes humans in his system:
Is it “metaphorical” to attribute beliefs to birds or chimpanzees? Should we reserve that term, and many others, for (adult) human beings alone? This lexical dearth helps to sustain the illusion that there is an unbridgeable gulf between animal minds and human minds—despite the obvious fact that similar quandaries of interpretation afflict us when we turn to young children. Just when do they exhibit enough prowess in one test or another for us to say, conclusively, that they “have a theory of mind” or understand numbers? How much do we human beings need to know to understand our own concepts? There is no good, principled answer to this question.
So, dodging questions about necessary and sufficient conditions, Dennett feels we can just argue from analogy with endosymbiosis. The first eukaryotes imbibed their microbe neighbors and a major transformation occurred. Similarly, “along the path from amoebas and cuckoos to us, there was a major transition with powers to rival the endosymbiotic birth of the eukaryotes: the evolution of language and culture, one of the great cranes of evolution,” he said. “In both cases, individual organisms were enabled to acquire, rapidly and without tedious trial and error, huge increases in competence designed elsewhere at earlier times.” He neglected to specify when or where that transition occurred on the path from amoebas to cuckoos to us. It must have been late in human evolution, because language and culture appeared suddenly (according to evolutionary anthropology) among beings who were anatomically equal or superior to ourselves. When it occurred, though, it made the “biologically ‘sudden’ Cambrian explosion” look gradual. Within 10,000 years, the ratio of humans + pets + livestock went from 0.1% of terrestrial vertebrate biomass to 98% (as calculated by MacCready). Dennett attributed this incredibly rapid explosion in knowledge to “cultural evolution.” Since then, we got the internet, spam, and all the good things that language enabled. It’s all part of the evolutionary toolkit that makes itself from the bottom up. The grand finale section of Dennett’s paper takes it to the extreme: “Bootstrapping Our Way to Intelligent Design, and Truth.” Just like man’s ability to improve the straightedge has evolved over time, “Such representations make possible highly efficient, guided, foresighted trajectories in design space.” From there, Dennett declares victory over Plantinga’s challenge:
And our indefinitely extendable recursive power of reflection means that not only can we evaluate our progress, but we can evaluate our evaluation methods, and the grounds for relying on evaluation methods, and the grounds for thinking that this iterative process gives us grounds for believing the best fruits of our research, and so forth. Science is a culturally transmitted and maintained system of truth-tracking that has identified and rectified literally hundreds of imperfections in our animal equipment, and yet it is not itself a skyhook, a gift from God, but a product of adaptations, a fruit on the tree of life. That is, in outline, the response to Plantinga’s premise. We have excellent internal evidence for believing that science in general is both reliable and a product of naturalistic forces only—natural selection of genes and natural selection of memes. An allegiance to naturalism and to current evolutionary theory not only doesn’t undermine the conviction that our scientific beliefs are reliable; it explains them. Our “godlike” powers of comprehension and imagination do indeed set us apart from even our closest kin, the chimpanzees and bonobos, but these powers we have can all be accounted for on Darwin’s bubble-up theory of creation, clarified by Turing’s own strange—and wonderful—inversion of reasoning.
A corollary is that we are not perfect truth-trackers, he ended, “but we can evaluate our own shortcomings by using the methods we have so far devised, so we can be confident that we are justified in trusting our methods in the foreseeable future.” And here’s his stinger at the end of the march of progress begun by Charles Darwin: “It took Darwin to discover that a mindless process created all those reasons.” The intelligent designer is us. “We ‘intelligent designers’ are among the effects, not the cause, of all those purposes.”
Ruse: The Darwinian Revolution.4 Michael Ruse (Florida State U) evaluated the “meaning and significance” of the so-called Darwinian Revolution. How revolutionary was it? Was there a revolution at all, and was it a Darwinian revolution? The short answer is in the abstract: “I argue that there was a major change, both scientifically and in a broader metaphysical sense; that Charles Darwin was the major player in the change, although one must qualify the nature and the extent of the change, looking particularly at things in a broader historical context than just as an immediate event; and that the revolution was complex and we need the insights of rather different philosophies of scientific change to capture the whole phenomenon. In some respects, indeed, the process of analysis is still ongoing and unresolved.” Unlike Ayala, Ruse discussed Thomas Kuhn and many other recent thinkers in the history of science – a relatively new discipline sparked by Kuhn’s “engaging and influential” book, The Structure of Scientific Revolutions (1962). Ruse’s article is a back-and-forth romp through the debates about Darwin’s influence and whether or not his ideas should be called revolutionary. His knowledge of history adds the expected nuances and controversies without coming to much of a firm conclusion. There’s a lot of “on the other hand” qualifiers for every strong statement. This example paragraph discusses religion:
In the Darwinian case there are 2 levels of activity and interest. Without pretending that the divisions are completely simon-pure, there is the level of science and the level of metaphysics (recognizing that this includes things that might be considered scientific at one end and religious or otherwise ideological at the other end). On one hand, there is the scientific theory of evolution through natural selection, the central topic of the Origin. On the other hand, there is what scholars like Robert M. Young, borrowing a title from Thomas Henry Huxley, used to refer to as the debate over “man’s place in nature.” While today we would never dare to use that kind of language, in essence they got it absolutely right. At some level, the Darwinian revolution destroyed forever the old picture of humans as somehow miraculously special, symbolically and literally as touched by magic. Admittedly, to this day Christian fundamentalists (and those of other religions) refuse to accept this, but it is true. Even if you think that you can still be religious, a Christian even, you have to rethink dramatically, emotionally even more than intellectually, what it means to be a human. Starting with a certain modesty about ourselves.
Why should not said modesty include intellectual modesty about our ability to figure out where we came from? Ruse did not ask that question. He did raise a number of other things to consider, though: such as how much credit to give to Darwin for the revolution, as opposed to Alfred Russell Wallace, Edward Blyth,4 Robert Chambers, Herbert Spencer and other contemporaries of Darwin. Ruse agrees that Darwin was the primary influence. He qualified that, though: “Clearly some nuanced thinking is needed, starting with the fact that there was 150 years of evolutionary thinking before Darwin, including speculations by his own grandfather Erasmus Darwin.” Ruse does a lot of name-dropping in the article. If you want to see vignettes of Cuvier, Hegel, Malthus, Huxley, Owen, Sedgwick, Kelvin, Wilberforce, Dobzhansky, Kuhn, Elliott Sober, Robert Richards and a host of others dead and alive with snippets of their opinions about evolution, the Darwinian Revolution, progressivism, and the debate between formalism and functionalism, they’re all here.5 But what does Ruse himself think? In his conclusion, he makes the study of these subjects sound like an open-ended hobby for him: “let us say that a complex phenomenon like the Darwinian revolution demands many levels of understanding.Blunt instruments will fail us as we try to understand scientific change. It is necessary to tease strands apart and consider them individually as we try to understand and to assess what is going on.” Decisiveness is not one of his virtues.
Sober: Did Darwin Write the Origin Backwards?6 Elliott Sober (U of Wisconsin, Madison) made a case that Darwin should have emphasized common ancestry first and natural selection second, rather than the other way around.
I argue that common ancestry has evidential priority. Arguments about natural selection often make use of the assumption of common ancestry, whereas arguments for common ancestry do not require the assumption that natural selection has been at work. In fact, Darwin held that the key evidence for common ancestry comes from characters whose evolution is not caused by natural selection.
Sober argued that evolution by natural selection is a poor characterization for Darwin’s theory. For evidence, he pointed to the one illustration in the Origin: the famous branching-tree diagram. That’s an argument for common ancestry, he said. Natural selection is incidental to it. Historically (as Ruse also explained), many early evolutionists leapt onto common ancestry without agreeing that natural selection was the primary explanation, or even a factor at all. To be a true Darwinian, ignore the evidential priority he gave to natural selection. Just think like a tree:
Tree-thinking is central to reasoning about natural selection, both for Darwin and for modern biology. The reverse dependence is not part of the Darwinian framework, as we learn from Darwin’s Principle. You do not need to assume that natural selection has been at work to argue for common ancestry; in fact, what Darwin thinks you need to defend hypotheses of common ancestry are traits whose presence cannot be attributed to natural selection. This is the evidential asymmetry that separates common ancestry from natural selection in his theory. So, did Darwin write the Origin backwards? The book is in the right causal order; but evidentially, it is backwards.
Richards: Re-evaluating Darwin’s place in the history of thought.7 The one paper that threatened to diminish Darwin’s glory in his bicentennial year is this one by Robert J. Richards. Avise and Ayala warned, “Richards presents a revisionary argument that seems likely to be highly controversial.” His thesis is that Darwin wanted to present a picture of man progressing toward a pinnacle of morality. That seems opposite the usual picture of Darwin turning man into a natural ape. Didn’t he turn the tables on the teleology of William Paley and the natural theologians? Quite the contrary, Richard argues: “Darwin accomplished this revolution, however, not so much by discarding the older framework as by reconstructing from within it.” He introduces this theme:
The danger of Darwin’s ideas resides in the extraordinary way he used rather traditional conceptions. The usual assumption is that Darwin killed those barren virgins of teleology and of purpose, scorned moral interpretations of nature, and strode into the modern world escorting the stylish concepts of modern materialism and secularism. I believe, on the contrary, that Darwin’s theory preserved nature’s moral purpose and used teleological means of doing so. Darwinian evolution had the goal of reaching a fixed end, namely man as a moral creature. This is something Darwin implied in the peroration at the end of the Origin, when in justifying the death and destruction wrought by natural selection, he contended that “the most exalted object we are capable of conceiving” is “the production of the higher animals”.
To Richards, Darwin thought of natural selection as an “intelligent and compassionate force.” He took that cue from the guiding hands of animal breeders, who culled the unfit from their herds for the health of the whole. If man could do this in a short time, could not nature achieve even greater ends over long ages? “The model by which Darwin attempted to explain to himself the operations of natural selection was that of a very powerful, intelligent being that manifested “forethought” and prescience, as well as moral concern, for the creatures over which it tended,” Richards said. “Thus, as Darwin initially conceived natural selection, it hardly functioned in a mechanical or machine-like way; rather, it acted as an intelligent and moral force.” It was a way out of the brutality of nature. Those that survive the struggle are happy: “the vigorous, the healthy and the happy survive and multiply,” Darwin wrote. Did Darwin say such things to assuage the concerns of those who wanted to retain some religious faith with their evolution? Probably not, but “For Darwin, the conviction of progress was a deeply embedded part of his theory.” This included the idea (contra Michael Ruse and Stephen Jay Gould) that evolution had a trajectory toward a goal. Darwin wrote, “Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely the production of the higher animals directly follows.” What higher goal than the human mind? Richards sees in Darwin a mirror image of Milton who, in Paradise Lost, justified suffering as the path to a higher good. Evil had an exalted object. “That most exalted purpose could only be human beings with their moral sentiments,” Richards argued. What does that mean for 21st-century Darwinians? Alas, it seems to be only a historical anecdote. After the Origin entered the public arena, his friends deflated any exalted notions of progress. “Darwin gradually came more and more to view the operations of natural selection much as did Huxley and Haeckel [i.e., as purely mechanistic], and in friendly opposition to Gray and Wallace [i.e., as goal-directed],” Richards said. “At that point, Darwin became a neo-Darwinian.” Richards’ controversial thesis about Darwin’s early teleology-tinted selectionism, when all is said and done, won’t leave any sermon echoing through the years for today’s evolutionists. From the 1860s onward, Darwinism would represent materialism, mindlessness, undirectedness, and purposelessness.
1. John C. Avise and Francisco J. Ayala, “In the light of evolution III: Two centuries of Darwin,” Proceedings of the National Academy of Sciences, online June 15, 2009, doi: 10.1073/pnas.0903381106. 2. Francisco J. Ayala, “Darwin and the Scientific Method,” Proceedings of the National Academy of Sciences, online June 15, 2009, doi: 10.1073/pnas.0901404106. 3. Daniel Dennett, “Darwin’s ‘strange inversion of reasoning,’” Proceedings of the National Academy of Sciences, online June 15, 2009, doi: 10.1073/pnas.0904433106. 4. Ruse mentions something about Blyth that may not be well known: “Edward Blyth (27), with whom Darwin was to have very cordial and helpful correspondence (he actually drew Darwin’s attention to an important earlier essay by Wallace) explicitly denied that his thinking had evolutionary implications.” 5. Ruse likes to tease his evolutionary colleagues at times. Gently challenging Dennett’s vote on natural selection as the best idea anyone ever had, he quipped, “One could debate this (Plato’s theory of forms gives it a good run for its money), but all will certainly agree that something really big happened around and because of the Origin in 1859.” 6. Elliott Sober, “Did Darwin write the Origin backwards?”, Proceedings of the National Academy of Sciences, online June 15, 2009, doi: 10.1073/pnas.0901109106. 7. Robert J. Richards, “Darwin’s place in the history of thought: A reevaluation,” Proceedings of the National Academy of Sciences, online June 15, 2009, doi: 10.1073/pnas.0901111106.
Well, they tried. This gathering of hard-core Darwinists patting themselves on the back was a hubristic show of farce. “Our intent has not been to idolize Charles Darwin...” Too late. Dennett tried really hard to wrestle out of the Plantinga hammerlock (see 04/14/2008). He tried with all his fluff to show that mindless nature can do it all. He grabbed his bootstraps and pulled with all his might. He was floating in the air – in his dreams. Reality check: Dennett didn’t reach back far enough into presuppositional space. His argument relied on fallacies of analogy and extrapolation, but worse, he didn’t realize he was relying on metaphysics for his explanation. He was helping himself to all kinds of choice metaphysical concepts by engaging in the very act of explanation: laws of logic, the correspondence theory of truth, sensation, observation, interpretation, explanation, and much more. In effect, he was building his crane while hanging from the skyhook. Since his case is hopelessly circular despite his denials of circularity, it carries no more juice than an extension cord plugged into itself. Ayala was guilty of card stacking the history and philosophy that suited his case, but ignoring the many revolutions that occurred after logical positivism collapsed. Ruse, jovial fellow that he is, has all the nuance of a jellyfish, and all its backbone, too. He rambles on and on, dropping names everywhere to show he is well-read, but in the end revealing little more than the sophistication of his ignorance. He will criticize Darwinians to a point but never to endanger his membership in the Darwin Party Cocktail Lounge, where Sober is having a hangover on Dar-wine, rearranging the sequence of two myths as if they will produce a truth. And Richards? He played shake a spear at Darwin, but couldn’t throw it. His final act was “Little Ado About Nothing.” In no case did this scholarly colloquium of intellectuals admit to the usual academic requirement for an open marketplace of ideas. They did not invite Plantinga, Behe, Dembski, or Meyer. No; they just stayed in their little Darwin Party smoking parlor, inhaling each other’s hot air, convincing each other that their smoke rings were better designed than those of their yawning colleagues. If these self-congratulating Darwin Cigar aficionados would just stay put in their smoke-filled room, they could all enjoy their lung cancer together. Unfortunately, their poison leaks out into the media, politics, law, and culture as second-hand smoke, inhaled by the unsuspecting as scientific incense.