In this lively and engaging book, Margaret Jacob, one of the most distinguished scholars of the Enlightenment, navigates a complex topic, over which there has been much debate and considerable confusion in recent years. She does so with great clarity and aplomb. Her book is a refreshingly straightforward defence and even celebration of the Enlightenment and its secular values.

There is at present a disconnect between what the general public hears about the Enlightenment and what is said in academic circles. In mainstream thought, the Enlightenment is commonly perceived as a heroic campaign for secularisation and emancipation led by great thinkers known as philosophes. Voltaire and Hume are often seen as the standard-bearers. For a simplified version of the argument, one need only consult Steven Pinker’s bestseller Enlightenment Now, an unambiguous celebration of the movement’s supposed embrace of science and rejection of faith.

For many years, however, more serious scholars have been busy problematising this view, arguing over the basic meaning of such terms as the Enlightenment and secularisation, and questioning how emancipating they really were. Jacob takes positions on these scholarly debates without letting them weigh down her narrative, producing a book that is both informative and enjoyable to read.

Years ago, there was a consensus among scholars that the very essence of the Enlightenment was its battle against religion. The dominant view was that the Enlightenment was, by its very nature, anti-Christian, anti-Church and anti-religious. Thanks to the influence of science and a newly acquired capacity for critical thinking, Europeans suddenly discarded their faith and became enlightened and ‘modern’.

More recent scholarship has taught us that the relationship between religion and the Enlightenment is more complex than that. First, the Enlightenment was not a unified and homogeneous movement, but one with many regional and national variations (this is why many scholars today prefer to speak of multiple Enlightenments). Second, it was by no means a straightforwardly secularising movement. Outside France especially, Enlightenment thinkers did not necessarily treat reason and religion as opposites. Many, if not most, felt that you could be religious and enlightened at the same time. In Scotland, the Enlightenment took place within the churches themselves: many clerics preached a world-affirming theology that celebrated the advance of liberal ideas. Across Europe, enlightened clergy worked to reconcile their faith with the new sciences. They advocated reasonableness in all things and a simpler, more tolerant and morally efficacious religion. It is also clear that ‘Bible-talk’ and ‘God-talk’ did not decline in the 18th century. The Bible was reconstituted as an important element of the West’s cultural heritage. It was not discarded, but read differently. God’s attributes and providence were described in new ways.

In a related trend, the concept of secularisation is increasingly seen less as a process of gradual and consistent religious decline and more as a nonlinear process in which religion recedes and then returns again. Some therefore prefer to use the term laicisation, because it does not presume a decline in religious sentiment. A few scholars have even argued that a resacralisation took place alongside secularisation during the 18th century.

Jacob is obviously well aware of all this. In this regard, her title, The Secular Enlightenment, can even be read as a bit of a provocation. Hers is a strong defence of the notion that the Enlightenment was, at its core, a secular movement. When she writes of people becoming more secular, Jacob means that they acquired a new kind of worldliness, an attachment to the here and now as opposed to the afterlife. They less frequently invoked God and the Devil and many lost their belief in hell. Miracles and the doctrine of original sin became less important; space and time lost their Christian meanings; saints disappeared from almanacs.

She recognises that religion wasn’t abruptly cast away. She is also sensitive to ironies and incongruities. The great scientist Isaac Newton, for instance, was profoundly religious. Enlightened men and women coexisted in 18th-century France with Jansenists, who emphasised original sin and the need for divine grace to avoid damnation. In Paris, convulsionnaires congregated at a cemetery, where they became possessed with seemingly miraculous powers and went into ecstatic spasms. The 18th century also produced prophets who predicted that the world would soon come to a cataclysmic end. But even theologians, Jacob notes, now spent less time on dogma and ceremonies than on temporal issues. They encouraged the pursuit of happiness on earth. They placed less emphasis on the truth or falsity of their beliefs and could even explain religion in secular terms.

The great thinkers we usually associate with the Enlightenment play a role in Jacob’s book, but much of its originality lies in its inclusion of lesser-known figures and use of untapped archival materials. We hear of the contributions of Voltaire and Hume, Rousseau and Lessing, among others, but also of the gentleman tourist Henry Penruddocke Wyndham and of the wife of a professor, Luise Gottsched, who began to display enlightened ideas. And then there is the fascinating Dutch freethinker Isabella de Moerloose, who started life as a Catholic, married a Protestant clergyman, became disillusioned with organised religion and ended up writing an autobiography designed to teach women about sex. Jacob is mostly interested in ordinary yet reasonably educated people, so we learn about Freemasons, travellers and the readers of novels as well. We hear about Picart and Bernard’s Religious Ceremonies and Customs of the World, a book that came out in 1723 and was reprinted in multiple editions, translated and widely disseminated across Europe. It sought to treat all the religions of the world even-handedly, focusing on culture rather than belief. Jacob admits that she has chosen these examples ‘somewhat randomly’, but explains that enlightened men and women ‘could turn up anywhere’ across Europe, from London and Amsterdam to Berlin, Vienna, Turin and Naples. In this way, she conveys admirably the richness, diversity and reach of the Enlightenment.

Jacob is an unabashed admirer of the Enlightenment and has no doubts about what it was: an ‘explosion of innovative thinking’ that prepared the ground for democracy. In a period of just a hundred years, three generations of Europeans and Americans came to question all inherited orthodoxies. They became curious, tolerant and cosmopolitan. Many were led to oppose torture and slavery. They still have much to teach us.

The Secular Enlightenment will no doubt be criticised by some. They will accuse Jacob of painting the Enlightenment too favourably. Postmodernists and their sympathisers, who prefer to attack the Enlightenment for its darker side, will not like it. There are those today for whom ‘secularisation’ is just another word for Western cultural imperialism. They will say that the Enlightenment’s faith in science resulted in forms of oppression at least as bad as what came before. Nevertheless, in today’s troubled times, Margaret Jacob’s fine book should be able to hold its own against such critiques.