Darwin's Dangerous Idea: Evolution and the Meanings of Life (Penguin Science)

Darwin's Dangerous Idea is divided into three parts. In the first part, "Starting in the Middle", Dennett places the idea of evolution by natural selection in its historical context, then explains it in his characteristically vivacious style. In the second part, "Darwinian Thinking in Biology", he critically examines challenges to Darwin's idea. Connoisseurs of intellectual controversy will especially relish chapter 10 ("Bully for Brontosaurus"), in which Stephen Jay Gould is castigated for misleadingly presenting his views as radical and anti-Darwinian. Finally, in the third part, Dennett discusses the implications of Darwinian thinking for "Mind, Meaning, Mathematics, and Morality." Among the luminaries targeted here are Noam Chomsky and Roger Penrose. Throughout, Dennett manages to synthesise information from many different fields into one unified view of life and its meaning. Writing with style and wit, he again shows that he merits his reputation as one of the best popularisers of science. --Glenn Branch

Darwin's theory as we understand it should start with a definition, and here I quote a definition: " The process in nature by which, according to Darwin's theory of evolution, only the organisms best adapted to their environment tend to survive and transmit their genetic characteristics in increasing numbers to succeeding generations while those less adapted tend to be eliminated." Dennett points out in his discussions that many non-evolution scientists, that is, those in other fields of research, do not really understand this simple idea. They still seem unwilling to accept the theory, although adaptive change has been proven in the scientific literature through extensive DNA and protein studies - see for example a more recent article 7 years after the Dennett book: February 28, 2002, Nature, authors Nick Smith and Dr Adam Eyre-Walker. They measure (quantitatively) the adaptive changes.

There are a number of sub-themes here and one being Gould's theories of evolution. Gould was famous and in the public eye, but back behind the scenes in the evolution world among his peers - according to Dennett - it seems that the situation was a lot more turbulent and controversial for Gould. Dennett describes Gould's "punctuated equilibrium" theory, a sort of stop start idea of steps in evolution that was supposed to overturn Darwin. Dennett thinks that the elimination of small Darwin adaptive steps was a confused and half baked idea (my paraphrase). This of course contains much irony since Gould himself wrote Wonderful Life based on the errors of Walcott and the Burgess Shale. As pointed out by Dennett elsewhere, Dennett explained to Gould that he was writing the book and was commenting on the flaws in Gould's theory. He met with Gould and received all his publications from Gould. At first Gould was helpful, but when Dennett found the inconsistencies among them, Gould went silent in their communications for almost a year, and refused to answer questions pertaining to Dennett's questions. The problem is that Gould had flip-flopped and back-tracked over the years until Gould's sudden non-linear jumps, followed by periods of little genetic change, were in fact toned down to just "speed changes" in Darwin's theory of small adaptive steps. It was no longer a revolution in evolution by Gould.

This Dennett book is far ranging and covers many topics in genetics and evolution. It is 18 chapters long and covers the subjects in a chatty style. The book is not a quick read and would take about a week to read, on and off 3 or 4 hours per day. I read about a quarter in my first read and got excited when I got to pages 156 through 163. Here starting on page 156 he describes how the first molecules or structures of life were formed. He tells us about a possibly of a replicating parasitic macromolecule, or a type of partial or pre-virus. It is likely, or at least possible, that first life was based on fragments of proteins and RNA being attracted to silica surfaces or similar. It is all very interesting, especially the idea that catalysts might have increased the mathematical probabilities of interaction to produce life, and that it is based on just common inorganic molecules found in the silica rich clays of earth's streams and lakes. He has numerous other topics such as the tree of life, ideas about the species, Mendel, "the computer that learned to play checkers", so on and so forth.

I would like thank fellow reviewer Stephen A. Haines ("bigbunyip" - or see my profile page and go to Amazon friends) for bringing this book to my attention. I highly recommend this exceptional book. Here are some other sophisticated science books for the general reader:
Genome (1999) by Matt Ridley, The Fabric of The Cosmos (2004) a physics book by Briane Greene, and Life on a Young Planet: The First Three Billion Years of Evolution on Earth (2003) by Andrew H. Knoll, and for a light treatment of genetics and society read: The Selfish Gene by Richard Dawkins (1989 version updated from 1976), or the original book: The Origin of The Species, Charles Darwin, Modern Library (original 1859, reprinted 1993).


And that about wraps it up for God   August 12, 2004
 57 out of 65 found this review helpful

This fascinating, difficult book has a simple premise: evolution describes a colossal series of individual, algorithmic steps, none of which is accompanied by any specific intention or intelligence.

At first glance this proposition seems non-controversial but, as Dennett makes very clear, the implications of this theory being right are anything but: once you accept this fundamental premise, the ground under certain positions on a number of other hoary old philosophical chestnuts begins to give way:

* God - if there's no need for intentionality or intelligence at any point in the evolutionary process, then as Oolon Colluphid might say, "That about wraps it up for God" - there's no room at the inn (ahem) for *any* God (omnipotent or otherwise) as a creator of the universe, and since religious claims to ethical validity derive from God's status as both the creator and "ruler" of the universe, they too evaporate in a puff of logic;

* Mind/AI - if we evolved from organisms which do not have any form of consciousness, and that process did not itself involve intentionality or intelligence (until the arrival of human intelligence, which Dennett would describe as a "crane") then any account of consciousness *must* be wholly explicable in physical terms, and (though Dennett doesn't say this) it must be conceptually possible, with the correct technology (which we may of course never have), to synthesise not just the functional equivalent of consciousness, but actual consciousness itself.

This second point (but not the extrapolation) is the central thesis of Dennett's equally excellent (and difficult) book "Consciousness Explained". In many ways, I wish I had read Darwin's Dangerous Idea first, for the premises on which Dennett's account of consciousness are based are set out here in a great deal of depth. I don't think I fully "got" Consciousness Explained first time, so I am going to read it again now. After I've read a cheap and trashy thriller first, as a treat for being so good.

As you progress through Darwin's Dangerous Idea, having unequivocally lost the ideas of God and a "soul", a further order of things which are very central to civilisation as we know it start to collapse as well, most notably the ideas that there are external concepts of "right" and "wrong" at all.

Throughout the first three quarters of the book, Dennett is thoroughly persuasive, with the assistance of Richard Dawkins' wonderful idea of the "meme" (which is a great meme in itself); the idea which reproduces itself and mutates within and between human brains: Just as organisms do, "fit" memes find currency and reproduce with ease; and "weak" memes aren't able to occupy enough brains, and eventually die out.

It is analogies like these that display the power of the idea: the Darwinist meme has outgrown biology and is finding application (for which read: reproducing and mutating) in epistemology, ethics, sociology, economics and pretty much every other academic discipline when you stop to think about it. The implications for this, as a unificatory theory of everything, are immense.

Having said all this, Darwin's Dangerous Idea is not without its faults.

At times Dennett is needlessly provocative, and skirts dangerously close to ad hominem arguments in his dismissal of certain competing commentators, most notably Stephen Jay Gould. By being so he gives the impression of not being dispassionate (apologies, by the way, for the double negative, but I mean something different to "passionate"!) about the subject at hand. That's not necessarily a bad thing, but it leads a sceptical reader to question how fairly opposing arguments may have been set out: unless one has read the competing works (and I certainly haven't) for all we know, Dennett may be rendering straw men or at least underselling the points lined up against him.

More curiously, having already picked fights with the religious, the spiritualists and the Marxist biologists, rather late in the piece Dennett wades into the ethics debate. He might have been better advised to leave morality for another time. His final two chapters purport to apply the "universal acid" of Darwinism to ethics. You would expect this to be a rout, but after noting (quite correctly) that between them such great minds as Hobbes, Mill, Kant and Rawls failed utterly to formulate any sort of method for adjudicating right and wrong, Dennett reaches not the obvious conclusion that there is no such thing (which seems to me to be the plain implication of everything the evolutionary theory stands for), but instead puts failures of moral judgment down to insufficient information at the time of judgment formation (one never knows *all* the facts, so one can't be expected to get it right) and ventures the suggestion that there is an evolutionarily explicable moral code, but we just can't always access it.
It is not clear why he even thinks this is necessary, especially since the very lesson of evolutionary biology is that it's quite possible for something extremely clever to come about by a concatenated series of not very clever steps. If this is enough to get humans from protoplasm to cave man, I couldn't fathom what Dennett's interest was in defending the notion that from cave man forwards, humans have needed some externally derived conduct code, especially when the one thing which is undeniable from recorded history is that that competing civilisations have never progressed their cause by being nice to each other. The final two chapters in my view can therefore be skipped without significant loss.

All in all, and notwithstanding these minor grumbles, I think this is an extremely valuable and thought-provoking book.

Olly Buxton


Applying acid and rebuilding with cranes   July 9, 2004
 23 out of 27 found this review helpful

Dennett states his thesis unequivocally: "If I were to give an award for the single best idea anyone ever had, I'd give it to Darwin . . ." Newton, Einstein, Galileo and Copernicus all helped topple humanity from its self created egocentric pedestal. None of these, however, had the universal impact of Darwin's idea of natural selection through change over time. The mechanism of biological evolution, as Dennett points out, has spread to every science from cosmology to atomic physics in a single century. This achievement demands we understand the Idea fully. Dennett has provided us with inspiration to perform that study, offering us excellent guidelines to assist in the task. This is an excellent and valuable book.

Dennett coins or adopts a few "catch phrases" to help us understand how the Idea works. In presenting Darwin's thesis in a historical context, Dennett offers the term "universal acid," showing how "change over time" toppled firmly held beliefs. "Universal acid" has been seized upon by numerous critics in the media arguing that Darwin's Idea eroded beliefs without providing replacements. Dennett counters this charge, declaring that rigorously investigated natural events will lead to the establishment of new, realistic values. He accepts the comforting value of faith, but will not concede its insistence on possession of truth. Truth is achieved by investigative effort, not granted by divine revelation.

He utilizes a familiar term, "algorithm" in explaining how the evolutionary process works through the language of DNA. To Dennett, an algorithm is a "stupid piece of information" since it does nothing itself. However, the algorithm is easy to understand and reliable in any environment enabling it to perform. In evolution, algorithms represent the step by step process through which groups of individuals become new species. Another of his terms, "the crane," relies on the algorithmic idea, which are the foundation on which cranes rely. Cranes, of course, are building tools. In evolution, cranes rest on previous conditions, building up new forms through the adaptive process. It's a terribly slow and inefficient method, but over time it works. The proof is that you're reading this now.

This book is a most thorough effort to address Darwin's idea in a philosophic framework. Not a biological text, DDI urges us to reconsider our values in light of the realities Darwin's Idea. Dennett want us to think logically and clearly without resorting to easy answers and taking shortcuts in arriving at conclusions. He achieves this with finesse, tempered with a fine wit to sustain our attention. It's a readable and challenging work, conveying meaningful concepts for furthering human progress. More significantly, it's a most valuable work. Only Darwin's Origin transcends it in impact on shaping values. In a world where Harry Potter books are banned from churches for being "soft on witchcraft" and evolution is given short shrift in public schools, it's clear that Dennett's theme requires greater attention.
[stephen a. haines - Ottawa, Canada]


Handles the 'universal acid' superbly.   May 14, 2003
 14 out of 20 found this review helpful

This was an excellent book, particularly in its consideration of the applications of evolution to human society. Dennett points out and corrects the flaws in various misapplications of Darwin's idea, notably by the extreme genetic determinists; culture and memes must play an important role in human behaviour.

I was particularly impressed with his use of Nietzsche when considering the history of morality. Nietzsche was another great whose ideas were misinterpreted by extremists, and much of his work follows on from that of Darwin: how did morality evolve, and what happens to human values if we reduce ourselves to being just another product of evolution?

A fine addition to the boundary between science and philosophy. Thank you, Daniel Dennett!