BOOK REVIEW / Ahem, ahem - the rise and fall of morality: 'A History of Sin' - Oliver Thomson: Canongate, 17.99 pounds

MORAL codes rise and fall like hemlines. What is acceptable in one age is condemned in the next. For centuries slavery and child labour were accepted as part of the way of the world; and in Victorian times the British East India Company regarded it as ethical to promote the opium trade in China.

Even murder has, from time to time and in different cultures, been tolerated. The Thuggee tribe of India encouraged the strangling of foreigners, and a young Sioux was not considered an adult until he had taken someone else's life. In Nazi Germany the agents of genocide were decorated as heroes.

Within any era there is a wide variation in what is deemed acceptable behaviour. While the Victorians were busy covering their bodies with neck to ankle bathing costumes, Tahitians were happy to go about naked as long as they were tattooed. Alaskan females felt undressed unless they were sporting lip plugs. Muslim women today shield their faces, Chinese their feet and Sumatrans their knees.

Oliver Thomson records these and a whole host of other examples of the changing face of morals in his often breathless and entertaining survey. As he hurries through the history of the darker side of civilisation, there is a temptation to tut-tut at the depravity or hypocrisy of past ages without taking on board the implications for more recent times. Each century, the book shows, thinks it knows better than its predecessors.

It is only when Thomson starts to draw the threads together in a final essay that such contemporary self-confidence is questioned. Judged by the lessons of history, many of today's moral assumptions seem less than crystal clear. Most of the man-made suffering in the world has not been created by isolated individuals who have rejected the norms of their society, but by officialdom - by leaders who were in their lifetime seen as good and just. It was men of the cloth, regarded by their flocks as beyond reproach and with a direct line to heaven, who inspired and orchestrated the witch-burning frenzy of the sixteenth century.

Down the ages the establishment, Thomson argues, has demonstrated an alarming capacity to rationalise its cruelties. And if we are tempted to think that such a theory no longer applies, we only have to recall Norman Lamont's description of mass unemployment as 'a price worth paying'.

The danger Thomson highlights for the 1990s is the tendency to claim the moral high ground. How are we to know if the current drive to turn the globe's population into one vast commercially-conformist middle class is not itself an error? The text of A History of Sin offers little comfort for the true believers in the new world order.

The other strong theme here is the extent of the sadistic streak that leads some human beings, nearly always men, to murder, torture or terrorise as a way of gaining power. Sadism then becomes part of the culture - as when people were sacrificed to the gods, servants thrown on the funeral pyres of their dead masters, or Christians cast into the lions' den.

As befits an academic who now runs an advertising agency, Thomson has a touch that is scholarly but light. He raises questions without always feeling a vocation to answer them. The cast of characters, from Adam and Eve on the front cover breaking the code by eating the apple, through Attila the Hun, Genghis Khan, Caligula, the Borgias, the Marquis de Sade, Adolf Hitler, Stalin and Idi Amin is as comprehensive as it is chilling.

Above all, his timing could not be better. With moral standards so large a part of today's political rhetoric, this should be required reading in Whitehall and Westminster.