The Origins of Sex: A History of the First Sexual Revolution, By Faramerz Dabhoiwala

In the 1970s, you could hardly open a magazine or pass a billboard without seeing the advertisement for Virginia Slims cigarettes that said, "You've come a long way, baby." It usually featured a flowing-haired, liberated modern woman alongside some drudge of a generation or two earlier, pegging out laundry. The implication (as well as that smoking was good for you) was that women had revolutionised their lives in unprecedented ways over a few decades, and that a great broad path of such freedoms still lay ahead, along with some fab new haircuts.

True, women's lives had changed rapidly and would continue to do so. But how dated this ad now sounds, not least for its Whiggish delight in human progress. This feels odd today, when prosperity and security are falling away and many fear losing freedoms too. We are drawn now more to circular than to progressive styles of history. We don't relish triumphalist narratives so much as books in which we see human beings spiralling on, repeating the same patterns and never getting any wiser.

Faramerz Dabhoiwala's The Origins of Sex, an enthralling history of changing ideas about sexual freedom and desire from 1600 to 1800, interestingly blends progressivist and circular approaches. He shows us a Western world (mainly England) emerging from medieval sexual morality and enjoying 200 years of relative freedom, but he also shows it sliding back into repression and denial in the 19th century. The future remains a question mark.

The overall narrative is broad and bold. In medieval and early modern Europe, Dabhoiwala writes, sexual behaviour was governed by the community and by God. To say that sex was an individual's private business would have sounded bizarre: although you didn't make love in public, you didn't exactly do it in privacy either.

Extramarital sex was punishable in public by whipping, banishment or death; homosexuality and prostitution were "filthiness", and no one expected free choice. Moreover, women were largely blamed for sexual misconduct, as they were thought too weak to control their lusts.

The Reformation opened things up by undercutting church authority and turning some matters over to personal conscience. By the mid-17th century, preacher Laurence Clarkson could argue that adultery was no sin so long as it was practised in a pure spiritual state, and Thomas Webbe, a "long-haired, music-loving antinomian" of Wiltshire, lived communally with his third wife, his mistress, and the mistress's husband. "There's no heaven but in women," he reportedly said, "nor no hell save marriage."

These were hardly mainstream cases, but the religious pluralism enshrined by England's 1689 Toleration Act brought broad sexual pluralism too. In the 18th century a new being appeared: the free-thinking sexual individualist. It seemed natural to say, as Samuel Johnson put it, that "every man should regulate his actions by his own conscience, without any regard to the opinions of the rest of the world." And it was now men who were seen as having the lion's share of sexual desire, to be managed by the individual rather than by church or state. By 1750 most forms of consensual extramarital sex had been legalised in Britain, with the notable exception of homosexuality, but here too, persecution had lost its deep moral justification.

When a William Brown was caught with another man's hand down his breeches in 1726, he retorted, "I think there is no harm in making what use I please of my own body." By the end of that century, Britain had an astonishingly radical Free Love movement. Alas, just around the corner lurked the Victorians, and that was the end of that until the 20th century.

Today, our situation is troubling. We cannot be sure our freedoms are unassailable, and parts of the world seem set in the other direction. "If, reader, you happen to be a member of the Iranian or Saudi Arabian moral police," Dabhoiwala remarks, you will find medieval Europe's justifications for sexual discipline very familiar. Societies that impose flogging, hanging or stoning as penalties for sexual licence share key qualities: "the theocratic authority of holy texts and holy men, intolerance of religious and social pluralism, fear of sexual freedom, the belief that men alone should govern." No one today could think such societies are things of the past.

This forms the great sweep of Dabhoiwala's narrative, but it is also filled with mystifying exceptions, ambiguous cases, reversals of direction, and rebellious characters who do not quite fit into their epochs. In such large-scale history, human complexity is bound to intrude. It is to the author's credit that, usually, he lets the exceptions speak.

The story ebbs and flows through its themes; the resulting tidal quality is pleasing, and Dabhoiwala is eloquent about why it must be written that way. Europe's 200-year journey through sexual freedom was "largely a jumbled, unconscious process". It happened in "a remarkably messy and inadvertent way". And, he says, "is that not how most ideas spread, and how most of us in practice make sense of the world around us?"

Yes, it is, and this thought makes his book inspiring as well as provocative. "The past is littered with alternative paths not taken," he warns; no single path lies ahead either. However far we may have come, it is never fully clear where we are or how long we will stay here. Let us just hope that we don't have to go all the way back again.

Sarah Bakewell's latest book is 'How to Live: a life of Montaigne in one question and 20 attempts at an answer' (Vintage)