on 12 August 2004
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.