Darwin's Dangerous Idea: Evolution and the Meanings of Life. - book reviews

National Review, May 15, 1995 by John Polkinghorne

No one can deny that when it comes to human history, genetic effects are heavily overlaid by the consequences of culture, so much more effective in transmitting information from one generation to the next than the route provided by DNA. Dennett fully acknowledges the power of culture, but, of course, he wants to give a quasi-Darwinian account of it, using Richard Dawkins's concept of memes, the postulated units of ideas held to be comparable to those units of biological structure, the genes. For Dennett, the human mind is a "meme nest." "What makes a person the person he or she is are the coalitions of memes that govern -- that play the long- term roles in determining which decisions are made along the way." Not only does this give an implausibly atomistic account of culture, but it also fails to do justice to the remarkable powers of the human mind. These go far beyond anything that appears susceptible of evolutionary explanation.

Of course, if we could not make generalizations such as "It is a bad idea to walk off a high cliff," we would not have lasted long in the struggle for survival. But an astonishing leap of the human imagination occurred when Isaac Newton saw that the same force that makes the cliff so dangerous also holds the moon in its orbit round the earth and the earth in its orbit round the sun. One can scarcely suppose that Albert Einstein's ability to go even beyond this by turning physics into geometry, and so discovering a theory of the spacetime of the whole cosmos, was the result of our ancestors having had to dodge saber-toothed tigers. Thomas Nagel rightly says, "Why not take the development of the human intellect as a probable counter-example to the law that natural selection explains everything, instead of forcing it under the law with improbable speculations unsupported by evidence?"

One of the most remarkable properties of the human mind is its mathematical ability to "see" the truth of certain propositions which Kurt Gudel has shown cannot be demonstrated within the given logical system under consideration. Roger Penrose (The Emperor's New Mind) has used this to argue that thought is not computing, that the mind is not an algorithmic crane. Needless to say, such a conclusion is unacceptable to Dennett. His response is to suggest that mathematicians do not really see truth in the way that they claim but, rather, that the algorithms "'for' trying to stay alive" have endowed them with the fortuitous power of being able to make "guesses" about mathematics which prove reliable to an astonishing degree. Given the abstract power of mathematics and its apparent distance in most of its aspects from the world of everyday experience, this seems a pretty desperate and feeble response.

Dennett writes in a chatty, perky style, with all the self- confidence one might expect from the author of a book called Consciousness Explained. His present volume is another exercise in rhetorical debate, with the Other Side being not so much religious thinkers, who are more or less out of sight over Dennett's narrow horizon, but people such as Noam Chomsky, Stephen Jay Gould, and John Searle, who do not subscribe to the most rigidly reductionist Darwinian orthodoxy. The book provides an interesting but unpersuasive read. Dennett concludes by writing: