Thomas Nagel’s recent endorsement of Stephen Meyer’s latest book, Signature in the Cell (2009), has generated a firestorm of debate. In the Times Literary Supplement, the atheist philosopher and professor at New York University, wrote:
“Stephen C. Meyer’s Signature in the Cell: DNA and the Evidence for Intelligent Design (HarperCollins) is a detailed account of the problem of how life came into existence from lifeless matter – something that had to happen before the process of biological evolution could begin. The controversy over Intelligent Design has so far focused mainly on whether the evolution of life since its beginnings can be explained entirely by natural selection and other non-purposive causes. Meyer takes up the prior question of how the immensely complex and exquisitely functional chemical structure of DNA, which cannot be explained by natural selection because it makes natural selection possible, could have originated without an intentional cause. He examines the history and present state of research on non-purposive chemical explanations of the origin of life, and argues that the available evidence offers no prospect of a credible naturalistic alternative to the hypothesis of an intentional cause. Meyer is a Christian, but atheists, and theists who believe God never intervenes in the natural world, will be instructed by his careful presentation of this fiendishly difficult problem.”
Nagel’s positive review provoked instant outrage from his fellow atheists. While Nagel has been critical of scientific naturalism in the past, the recommendation of Meyer’s book as one of the years’ best brought fierce condemnation in the blogosphere and beyond. Brian Leiter has described him as a disgrace and more, while Stephen Fletcher, a chemist and professor at Loughborough University, is simply incredulous:
“The belief that we share this planet with supernatural beings is an old one. Students of magic and religion have identified innumerable varieties of them – gods, devils, pixies, fairies, you name it. A familiar motif is that they operate at the very fringes of perception. While the scullery maid sleeps, they are busy in the kitchen making the milk go sour. For a society with no concept of bacteria, this is, perhaps, a forgivable conceit. But for a modern university professor to take this idea seriously is, I think, mind-blowing.”
Thomas Nagel has responded to Fletcher, in a letter to the Times,
Sir, – Stephen Fletcher objects to my recommending Stephen C. Meyer’s Signature in the Cell in Books of the Year. Fletcher’s statement that “It is hard to imagine a worse book” suggests that he has read it. If he has, he knows that it includes a chapter on “The RNA World” which describes that hypothesis for the origin of DNA at least as fully as the Wikipedia article that Fletcher recommends. Meyer discusses this and other proposals about the chemical precursors of DNA, and argues that they all pose similar problems about how the process could have got started.
The tone of Fletcher’s letter exemplifies the widespread intolerance of any challenge to the dogma that everything in the world must be ultimately explainable by chemistry and physics. There are reasons to doubt this that have nothing to do with theism, beginning with the apparent physical irreducibility of consciousness. Doubts about reductive explanations of the origin of life also do not depend on theism. Since I am not tempted to believe in God, I do not draw Meyer’s conclusions, but the problems he poses lend support to the view that physics is not the theory of everything, and that more attention should be given to the possibility of an expanded conception of the natural order.
29 Washington Square, New York 10011.
But not all are critical of Nagel. Bradley Morton disagrees with Leiter and has more sympathy for Nagel’s comments. John Walton, a chemist and professor at the University of St Andrews has come to Nagel’s (and Meyer’s) defense. Walton, also writing to the Times:
Sir, – The resilience of the “prebiotic soup” myth, in spite of torrents of counter-evidence, is truly astonishing. Even professionals such as Stephen Fletcher (Letters, December 4), criticizing Thomas Nagel’s recommendation of Signature in the Cell by Stephen C. Meyer (Books of the Year, November 27), apparently still believe in it. Fletcher asserts that “Natural selection is in fact a chemical process as well as a biological process, and it was operating for about half a billion years before the earliest cellular life forms appear in the fossil record”.
Actually the operation of neoDarwinian natural selection depends on the prior existence of entities capable of self-replication. Variants are produced in their genetic material by mutations, the variants are copied by the organism’s biochemical machinery, and then natural selection ensures the most “fit” survive. Before the arrival of organisms capable of reproduction, this process could not operate. In the words of the renowned evolutionist Theodosius Dobzhansky: “Prebiological natural selection is a contradiction in terms”. It follows that, even in principle, some quite different explanation is required to account for the origin of life. Fletcher is pinning his hopes on a supposed RNA world. He tells us: “Indeed, before DNA there was another hereditary system at work, less biologically fit than DNA, most likely RNA (ribonucleic acid)”.
It is an amusing irony that while castigating students of religion for believing in the supernatural, he offers in its place an entirely imaginary “RNA world” the only support for which is speculation! Intense laboratory research has failed to produce even one nucleotide (RNA component) under geologically plausible conditions. As for the chains of nucleotides required for the RNA world, there are insuperable problems associated with their information content, as well as the chemical selectivity needed for their assembly. Furthermore, the earth’s oldest Precambrian rocks show very good evidence that life was present from the start, so the half-billion years Fletcher counts on were actually not available for chemical evolution.
Rather than just kowtowing to the creaky naturalist “prebiotic soup” scenario, Meyer engages with the whole range of origin of life problems. Anyone interested in discovering where the evidence leads will find this a fascinating book.
JOHN C. WALTON
School of Chemistry, University of St Andrews, North Haugh, St Andrews.