BOOK REVIEW / Tatty genes, and the grace of God: Scientists only interpret the world . . . the point is to change it. Tom Wilkie on a modern religion: The Doctrine of DNA - R C Lewontin: Penguin, pounds 5.99

THIS slim volume is the most subversive book to be published in English this year.

Before anyone, scientist, sociologist, philosopher, journalist or man- in-the-street presumes to discuss politics, economics, and society, they should first be expected to master this book. It should be required reading for every civil servant or politician who requires scientifically based information to decide policy - and in our modern age what aspect of government is untouched by science?

It should be mandatory for every student in the country; for in around 130 pages it will tell them more home-truths about science - and a surprising amount of information about society and politics - than they will ever get from their professors in three years of tuition.

One despairs of publishers when Penguin, which has this superlative book on its list, has slipped it out without fanfare and without drawing attention to a work of such rare value. It is a series of essays which the author developed from the Massey Lectures which he delivered on Canadian radio in 1990. I wonder if anyone at Penguin actually read it before publication.

The publishers have helpfully printed on the back that it is part of 'Penguin Science'. Well, yes, it is true that the book has been written by one of the world's foremost population geneticists, and that its pages are peppered with references to DNA and modern molecular biology, but this book is about ideology and politics and society, it is not a technical exposition of DNA.

The theme is set out immediately in the first essay where Lewontin discusses 'the institutions of social legitimation'. There is inequity in all societies: they tend to create institutions which persuade the dispossessed that the uneven distribution of power, status and material comfort is part of the natural scheme of things; they imply that things are improving, and that social progress will right immemorial wrongs. 'For almost the entire history of European society since the empire of Charlemagne, the chief institution of social legitimation was the Christian Church', Lewontin notes. 'It was by the grace of God that each person had an appointed place in society. Kings ruled Dei gratia.'

Science is the source of legitimacy in our atheistic age. But its ideological influence is subtler than many suppose. Before the 18th century, Lewontin recalls, society placed no importance on the individual, except as a representative of his or her social group. But now the ideology of modern science is reductionist, and social organisation reflects this: the atom or individual is the causal source of all the properties of larger collections. There is, as the former research chemist Margaret Thatcher once told us, no such thing as society, only individuals and their families.

Lewontin's counter-argument is hugely provocative and utterly persuasive. What should we teach our medical students is the cause of tuberculosis? The textbooks say Mycobacterium tuberculosis, but Lewontin says: 'We are much closer to the truth when we say that it was the conditions of unregulated 19th century competitive capitalism unmodulated by the demands of labour unions and the state that was the cause of tuberculosis.'

If we look to see what eradicated tuberculosis, we should not turn to medicine. 'The death rates from the major killers fell rather regularly during the 19th century. There was no observable effect on the death rate after the germ theory of disease was announced in 1876 by Robert Koch. By the time chemical therapy was introduced for tuberculosis in the earlier part of this century, more than 90 per cent of the decrease in the death rate from that disease had already ocurred.' Declining mortality from tuberculosis 'is related to an increase in the real wage'. Let's hear it for the Trades Union Congress as the cure for tuberculosis.

But of course, we don't. Our medical students are indoctrinated with concern for the agents of disease (the mycobacterium) and are blinded to the causes of the disease (depressed real wages). Thus does benificent medical science tacitly support and reinforce a particular form of social and economic organisation: science has become an institution of social legitimation.

Lewontin devotes his most withering criticism for the latest manifestation of science as ideology: the claim that all or most of human existence is controlled by our DNA and that we should therefore pursue the Human Genome Project to analyse the details of all our DNA. As he points out, whether they realise it or not, molecular biologists are manufacturing the raw material for politics. (There is a rich irony here, because the ideology which arises as a natural consequence of modern molecular biology is a reactionary one whereas, in the UK certainly, many of the cleverest researchers are lifelong left-wing radicals.)

Several muddled anti-science tracts have been published in recent years. What makes this book worth reading is that it is written by a front-line practitioner in the science that is being criticised. But Lewontin, professor of zoology at Harvard, does not intend to be 'antiscientific or to suggest that we should give up science in favour of, say, astrology or thinking beautiful thoughts'. The intention is to promote a reasonable scepticism, not a worldweary cynicism - 'for the former can lead to action and the latter only to passivity'.