Thinker: Francis Crick
Matt Ridley unravels the humanist code of Francis Crick
Briefly, in the 1960s Francis Crick was as famous for his atheism as he was for his scientific achievements. The leading light of the Cambridge Humanists, he resigned from a fellowship of Churchill College in protest at the building of a new chapel, donated £100 for an essay competition on “What should be done with the college chapels?” and told Varsity magazine: “I do not respect Christian beliefs. I think they are ridiculous.” Some of this made the national newspapers.
It was not until 1968 that most of the world discovered just what else this opinionated don had achieved, when James Watson's book The Double Helix came out, with its extraordinary story of how the unappreciated middle-aged Crick and the brash prodigy Watson had snatched the very secret of life from under the noses of more diligent scientists in London by their discovery of the structure of DNA in 1953. The book's famous opening sentence was “I have never seen Francis Crick in a modest mood” and it included the story of Crick announcing to fellow drinkers in the Eagle on the last day of February 1953: “We've discovered the secret of life”.
But in the long view Francis Crick, who died in 2004 and whose biography I have just written, deserves his place in history for neither of these reasons. His role in the double helix story, though vital, was only auxiliary – it was Watson who made the running and the moment when arguments about atheism reached the national news soon passed. No, in my opinion Francis Crick was one of the great scientists not just of his time but of all time and this reputation rests on what he did after the double helix.
Consider what was known in 1950 about the nature of life, and then what was known 20 years later in 1970. In 1950 scientists knew that living creatures were made of organic polymers, of which proteins seemed the most varied, and that creatures had objects in them whose properties could be very specifically copied – genes. But how genes copied themselves and how proteins were made were two separate, baffling enigmas.
The first question was answered by the double helical structure of DNA – a structure so obviously designed to carry a linear code and copy itself that the conclusion virtually spoke for itself. It none the less took several years and numerous experiments before biochemists and geneticists were convinced, but to true believers like Crick there was never any doubt that they would be.
The second question was the one on which Crick's great reputation is based. It is all very well saying that a gene can copy itself. But what does it do? What's a gene's job? To make proteins, said Crick and set out to prove how. That code running down the DNA backbone must be a code spelling out the sequence of amino acids in a protein, written in three-letter words and translated at ribosomes by a mechanism involving an “adaptor”, a molecule that can both read in DNA-ish and write in protein-ish. Crick set all this out in 1957 in a paper of sublime deduction and proved some of it himself with experiments of surpassing ingenuity. By 1966 it was all proved correct and the code itself had been cracked and set out in a format devised by Crick himself.
Why do I say this was such a great scientific moment? Because it answered a really big question – what is life? – with a simple, beautiful and unexpected answer. Life is the use of linear digital codes to construct machinery that can cause eddies in the entropy stream. There is a universal genetic code, common to all living things, and what Crick called a central dogma (that nucleic acid sequences determine protein sequences, not vice versa).
And with that, all vitalism – the metaphysical notion that life is animated by some kind of extra physical “life force” – becomes unnecessary. Superstition had always hung about the subject of life like fog over a lake: life would surely prove to contain an enigma that could never be explained by physics, chemistry or even philosophy. Life was an essentially spiritual thing, not accessible to reductionism. Until 1950 that was at least a tenable idea. By 1970 it was utterly perverse to think in such a way. The mysterians fell back on the mysteries of consciousness, hotly pursued by Crick, who switched to neuroscience in the 1980s. Apart from the farther reaches of the organic farming movement, vitalism became essentially extinct. Indeed, Michael Crick, son of Francis, points out that the word is unrecognised in Microsoft's spellchecker – “Score one for Francis!”, he cried at his father’s memorial “service”.
So Crick’s great achievement was of a piece with his humanism. He set out deliberately to topple a citadel of spiritual thinking, claiming its hinterland for rational inquiry, and succeeded beyond his wildest dreams. His science both caused his atheism and was caused by it. “If some of the Bible is manifestly wrong,” he wrote in his memoirs, “Why should any of the rest of it be accepted automatically?” And “What would be more important than to find our true place in the universe by removing one of these unfortunate vestiges of early belief?” ■