A third thesis is that secularising modernity itself has a marked record of ruthlessness and violence. Thus Renaissance humanists like Thomas More were more approving of European colonisation than Dominicans like Francisco de Vitoria. The French Revolution was merciless in its extirpation of the ancien régime, before launching a "holy war" to spread the Gospel of liberté, égalité, fraternité throughout Europe. Secular nationalism has been energetic in justifying aggressive war on ethnic grounds and on an increasingly massive scale. And Western imperialism has forced the pace of modernisation on bewildered and unwilling societies, provoking violent reaction, often articulated in religious terms. This is what today's global jihadism is really about: "Licking its wounds in the desert, the scapegoat, with its festering resentment, has rebounded on the city that drove it out."

Armstrong's corrective, complicating history includes a number of nicely water-muddying, stereotype-confounding details. For example, in the so-called Wars of Religion, Protestants and Catholics not infrequently fought on the same side against imperial forces: in its final phase, during the Thirty Years War, Catholic France came to the rescue of Protestant Sweden. Second, whereas that famous son of the Enlightenment, Thomas Jefferson, owned slaves, the inspiration for the abolitionist movement was originally and predominantly Christian. Third, the first genocide of the 20th century was committed by zealous secularists, the Young Turks, against (Christian) Armenians. Fourth, it was the Tamil Tigers, a non-religious, nationalist movement, which pioneered suicide bombing, and most suicide bombing in Lebanon during the 1980s was performed by secularists. Fifth, so deep-rooted were the habits of coexistence between Christians and Muslims in Bosnia that, during the 1990s, it took the Communist Slobodan Milošević three years of relentless nationalist propaganda to turn the former against the latter. Sixth, James Warren Jones, the instigator of the infamous Jonestown massacre in 1978, was not a religious zealot but a self-confessed atheist, who ridiculed conventional Christianity. Next, Ayatollah Khomeini's critique of the regime of Shah Reza Pahlavi in the 1960s has much in common with Pope John XXIII's contemporaneous critique of unfettered capitalism. And finally, what is striking about the 9/11 bombers is not how much they knew about Islam, but how little.

In the end, notwithstanding the ambivalent history, Armstrong commends religious traditions for helping us face up to the tragic necessity of political violence, while offering us pacific spiritual practices and alternative, non-violent patterns of community. To this I would add that just war thinking in the Latin Christian West, which has its counterparts in Confucian and neo-Confucian China and in the Islamic world, has developed moral norms that constrain violence from hatred and vengeance and discipline it towards peace. Since Augustine of Hippo is its patriarch, it is not quite fair to say of him, as Armstrong does, that he "gave the most authoritative blessing to . . . Christian state violence". Augustine did not simply bless political violence: he agonised over its tragic necessity and sought to forge it into the left hand of love. And insofar as just war thinking has found partial expression in the international laws of war and, more recently, in the emerging doctrine of the Responsibility to Protect, the Augustinian project to integrate justice, violence, and peace has met with success.