Darwin's Dangerous Idea: Evolution and the Meanings of Life

Wonderfully mature exposition of evolutionary theory and current controversies 2010-06-22

Reviewer: Herbert Gintis

I bought this book in 1995 and really hated it. But ten years later I couldn't remember why I had such negative feelings about the argument, so I purchased another copy in 2006, but just got around to rereading it. It is a wonderful book, offering the beginning reader a mature exposition of basic evolutionary theory and the expert an insightful interpretation of recent controversies among biologists, often offering highly persuasive resolutions to arguments that have shed much more heat than light in the biology and philosophy journals. I cannot imagine the source of my earlier negative feelings, except perhaps his treatment of gene-culture interaction, to which I return below.

One could summarize the interpretive part of the book by saying that in disputes between Richard Dawkins et al. on the one hand and Stephen Jay Gould et al. on the other, Dennett almost always sides with the former, supplying more cogent arguments than Dawkins himself, and aptly countering the latter, despite the brilliance of their argumentation. Most important, Dennett strongly defends an adaptationist view of evolution against the spandrels/just-so-stories critique as presented in the famous paper by Stephen Jay Gould and Richard C. Lewontin, "The Spandrels of San Marco and the Panglossian Paradigm: A Critique of the Adaptationist Programme", Proceedings of the Royal Society of London B 205 (1979):581-598. Dennett likens evolution to a nexus of algorithms, so that natural selection is a form of engineering. The interpretation of phenotypic characteristics as adaptations is then just a plausible form of "reverse engineering." Dennett thus asserts, correctly I believe, that "Gould and Lewontin's fabled refutation of adaptationism is an illusion." (p. 261).

After dealing with the critique of adaptationism, Dennett devotes an additional chapter to Stephen Jay Gould's various other critiques of "Darwin fundamentalism," including Gould's critique of Darwinian gradualism and his "punctuated equilibrium" alternative. Gould's strategy in presenting iconoclastic alternatives was generally to write books and article for the general public rather than presenting detailed professional expositions in biology journals. This earned the ire of many academic biologists and paleontologists, and in the charged atmosphere created by Gould's attempt to "run around" the biological establishment, it was not surprising that the professional assessments of his arguments were generally negative and even derisive. Dennett in 1995 soberly and dispassionately reviews the evidence, uniformly to Gould's detriment. I believe more recent evidence is even more hostile to Gould's various claims. Steven Jay Gould was a brilliant and talented biologist, but not the radical innovator he so desperately desired to be.

Dennett is especially critical of Gould's critique of the "gene's-eye view" of evolution as presented in Dawkins' brilliant The Selfish Gene (1976). Dennett defends Dawkins exposition of gene-centered evolutionary theory, but argues that Dawkins' inference concerning human altruism and cultural malleability are severely overdrawn. He then draws on Dawkins' argument concerning "memes" in The Extended Phenotype" (1982) to make the case that the gene's-eye view in the case of humans does not have the depressing right-wing implications Dawkins relishes in espousing in The Selfish Gene. A more modern argument is that gene-level selection, individual-level selection, and even group-selection models will all give the same answer if the proper accounting relationships are obeyed. The difference among the three approaches is that for different analytical purposes, one or another of the three approaches may be simpler and more insightful. For instance, in social species the structure of social life becomes a key contributor to the enhanced fitness of group members, so that a multi-level selection approach in which the accounting relations take the costs and benefits of behavior to be a function of social organization is more insightful than a lower-level approach that simply takes the costs and benefits as given.

Dennett also has a careful chapter in which he shows that Dawkins' concept of a meme can be used as a counterbalance to a purely genetic approach to human evolution. "The primary difference between our species and all others," he reports, "is our reliance on cultural transmission of information, and hence on cultural evolution. The unit of cultural evolution, Dawkins' meme, has a powerful and underappreciated role to play in our analysis of the human sphere." (331)

I think the meme concept is a loser because it is too detached from the gene concept to render a mimetic analysis evolutionarily coherent. The correct theory is that of gene-culture coevolution, as developed by several authors, including Cavalli-Sforza and Feldman: Marcus W. Feldman and Luigi Luca Cavalli-Sforza, "Cultural and Biological Evolutionary Processes, Selection for a Trait under Complex Transmission", Theoretical Population Biology 9,2 (1976):238-259, .Luigi Luca Cavalli-Sforza and Marcus W. Feldman, Cultural Transmission and Evolution (Princeton, NJ: Princeton University Press, 1981), Boyd and Richerson: Robert Boyd and Peter J. Richerson, Culture and the Evolutionary Process (Chicago: University of Chicago Press, 1985) and Dunbar: Robin M. Dunbar, Grooming, Gossip, and the Evolution of Language (Cambridge, MA: Harvard University Press, 1996). Unfortunately, and inexplicably, the names of these authors do not even appear in the text or bibliography.

Gift 2010-05-03

Reviewer: Shirley M. Marquina

Darwin hmmm....well Darwin great scietist of our past. This was a gift for a friend but I still recommend to buy.

A philosophy book that stuff scientists (like me) can get behind 2009-10-10

Reviewer: cassdog

Dan Dennett manages to achieve a great deal in a relatively short book. Through a series of insightful, clever though experiments and self-referential terms the author manages to allow the reader to think about evolution, morality and the meaning of life in unique ways. That is one of the great strengths of the book is that the author uses these techniques to allow us to rethink and reformulate some stale ideas in more vivid ways. I haven't read many books by philosophers and I must admit that the writing style and the literary focus were a bit disorienting. But once I understood the types of issues and problems that were important to philosophers I began to appreciate this world. Plus, this was a philosophy book about a topic I am well read on and very interested in, namely evolution. Dennett does a good job of writing a philosophy book that can appeal to a wider audience. Dan Dennett effectively builds up a whole world for the purposes of this book. Unless you are willing to follow him in his quirky thought-processes you won't get far. He defines several terms (design space, greedy reductionism, cranes and skyhooks) and then effectively uses this new dictionary to discuss his thoughts. If you are willing to follow him, you are in for a treat.

A good, but overly scientific, introduction 2009-09-12

Reviewer: Daniel Slick

Dr. Dennett's work is a good introduction to the idea of evolution and its resultant consequences. As a Catholic theologian-in-training, I found his discussion on the moral and ethical implications of evolution lucid and well-argued. Getting to that part of the work, however, was an issue. Having had difficulties in science courses in school, I found his scientific discussions of the Tree of Life, among other subjects, to be something that must be slugged through.

On the whole, I give Dr. Dennett high marks for examining the theory of evolution with an objective and logical eye. While his opinions and viewpoints are not absent from the text, they are most often supported with logical or scientific evidence. Though it does get mired in scientific language, I recommend this book to those that wish to better understand evolution and its consequences.

Not for philosophers 2009-08-06

Reviewer: Randall McCutcheon

I think Dennett is a smart guy and he's written some impressive arguments in favor of wild theses (like for instance there being no qualia), but this book strikes me as an obvious attempt to write a bestseller. It's filled with quotes from Richard Dawkins, Stephen Jay Gould et. al. (people who have written bestsellers). It also isn't particularly polite, nor all that impressive. On the other hand, it's well researched and rather informative.

The book purports to be about Darwin and evolution but really it's a catch-all defense of scientific materialism. Basically Dennett calls any attempt to argue against scientific materialism the search for a "skyhook"...a rope extending from the sky on which to prop up an otherwise doomed theory. He contrasts this with the notion of a "crane"...a hook that extends from up high somewhere, but is ultimately attached to and supported from the ground. This is a useful distinction when it is first introduced, but the term "skyhook" becomes in practice a derogatory one, used without distinction to disparage both would-be spiritualists and reputable thinkers trying to deal with scientific materialism's well known shortcomings (e.g. consciousness, which Dennett ignores completely here). Most annoying of all, Dennett uses rather rude language to describe what he takes to be unthinkable mistakes in some of the theories of a few genuinely elite thinkers grappling with major issues, while in these same pages being guilty of some fantastic gaffs of his own on mundane matters. (For example, he uses the word "howler" to describe some ideas that I don't find all that ridiculous at all; for a real "howler", check out Dennett's argument for mitochondrial Eve on page 97.)

Examples: ten pages into this book, Dennett takes a swipe at what he calls "John Locke's conceptual paralysis", referring to this: "For it is as impossible to conceive that ever bare incogitative Matter should produce a thinking intelligent Being...." Locke wrote that.

Maybe Locke was right, maybe he was wrong. But, on some readings of "thinking intelligent Being", that evolution by natural selection is an unassailable fact has got nothing whatever to do with it. It's a theory about matter in motion. If you think a theory about matter in motion can explain the origin of mind, then you automatically think that mind is nothing but matter in motion. Which is exactly what Locke doesn't think. On the contrary, it is Dennett that has been paralyzed conceptually here.

The issue isn't evolution, it's consciousness. Either (1) our brains run programs in which each input determines a unique output, or (2) our brains run programs in which each input determines an array of outputs, phased along a continuum of branching realities, and consciousness plays a role in choosing between the branches (from one perspective, just chooses, for lack of a better word, a branch to follow). Maybe (1) is the case. It might well be. It is a rather unfortunate picture, because it makes minds epiphenomenal, but maybe that's the way things work. You want to trash the argument from design, go ahead. You may just get a universe of anemic design for your trouble.

Cling though we may to the dogma of scientific materialism, we can't *know* that (1) is the case--we don't have the programs and not having them, can't check. (Dennett acknowledges as much on p. 237..."Predicting that someone will duck if you throw a brick at him is easy from the intentional...stance; it is...intractible if you have to trace the...neurotransmitters from optic nerve to motor nerve, and so forth." Precisely what you'd have to do to verify (1).) Meanwhile (1) can never explain consciousness (the title of one of Dennett's other books notwithstanding, which should probably be changed to "Consciousness Explained Away" anyhow) and AI has only failures to report. Meanwhile, to discard (2) simply because it seems too wild is to exhibit the sort of pigheadedness Dennett unfortunately attributes to Locke.

There are compelling anecdotal reasons for suspecting something like (2). We know from our own case we have minds, and frankly, it's not particularly conceivable that minds could arise solely from the motion of matter (there is a reason we still read Locke, these many centuries on). It makes the fact of our reasoning power, product of natural selection that it is, more plausible. Brains wouldn't have to be so precise to be good to have around. Just having enough complexity at a refined enough level to induce enough sensitivity to initial conditions to lend a lot of variety of output strictly from quantum effects would already be incredibly helpful. (Indeed, it is incumbent on proponents of (1) to demonstrate that the brain isn't subject to quantum effects at all...it's unrealistic that every branch in the tree would yield rational behavior.) Indeed, such brains could even operate efficaciously on principles of *association*.

Which, by the way, is still the only plausible mechanism in town, by which I mean, the only mechanism that might plausibly arise by natural selection; it might behoove mind theorists to figure out how to play the game with it.