the French Huguenot Wars (1562–94), the Dutch Wars of Independence, also known as the Eighty Years’ War (1568–1648), the Thirty Years’ War (1618–48), the English Civil War (1642–48), the wars of Elizabeth I in Ireland, Scotland, and Spain (1586–1603), the War of the Holy League (1508–16), and Charles V’s wars in Mexico, Peru, France, and the Ottoman Empire (1521–52).39 The rates of death in these wars were staggering. During the Thirty Years’ War soldiers laid waste to much of present-day Germany, reducing its population by around a third. Rummel puts the death toll at 5.75 million, which as a proportion of the world’s population at the time was more than double the death rate of World War I and was in the range of World War II in Europe.40 The historian Simon Schama estimates that the English Civil War killed almost half a million people, a loss that is proportionally greater than that in World War I.41
It wasn’t until the second half of the 17th century that Europeans finally began to lose their zeal for killing people with the wrong supernatural beliefs. The Peace of Westphalia, which ended the Thirty Years’ War in 1648, confirmed the principle that each local prince could decide whether his state would be Protestant or Catholic and that the minority denomination in each one could more or less live in peace. (Pope Innocent X was not a good sport about this: he declared the Peace “null, void, invalid, unjust, damnable, reprobate, inane, empty of meaning and effect for all time.”)42 The Spanish and Portuguese Inquisitions began to run out of steam in the 17th century, declined further in the 18th, and were shut down in 1834 and 1821, respectively.43 England put religious killing behind it after the Glorious Revolution of 1688. Though the divisions of Christianity have sporadically continued to skirmish right up to the present (Protestants and Catholics in Northern Ireland, and Catholics and Orthodox Christians in the Balkans), today the disputes are more ethnic and political than theological. Beginning in the 1790s, Jews were granted legal equality in the West, first in the United States, France, and the Netherlands, and then, over the following century, in most of the rest of Europe.
What made Europeans finally decide that it was all right to let their dissenting compatriots risk eternal damnation and, by their bad example, lure others to that fate? Perhaps they were exhausted by the Wars of Religion, but it’s not clear why it took thirty years to exhaust them rather than ten or twenty. One gets a sense that people started to place a higher value on human life. Part of this newfound appreciation was an emotional change: a habit of identifying with the pains and pleasures of others. And another part was an intellectual and moral change: a shift from valuing souls to valuing lives. The doctrine of the sacredness of the soul sounds vaguely uplifting, but in fact is highly malignant. It discounts life on earth as just a temporary phase that people pass through, indeed, an infinitesimal fraction of their existence. Death becomes a mere rite of passage, like puberty or a midlife crisis.
The gradual replacement of lives for souls as the locus of moral value was helped along by the ascendancy of skepticism and reason. No one can deny the difference between life and death or the existence of suffering, but it takes indoctrination to hold beliefs about what becomes of an immortal soul after it has parted company from the body. The 17th century is called the Age of Reason, an age when writers began to insist that beliefs be justified by experience and logic. That undermines dogmas about souls and salvation, and it undermines the policy of forcing people to believe unbelievable things at the point of a sword (or a Judas’s Cradle).
Erasmus and other skeptical philosophers noted that human knowledge was inherently fragile. If our eyes can be fooled by a visual illusion (such as an oar that appears to be broken at the water’s surface, or a cylindrical tower in the distance that appears to be square), why should we trust our beliefs about more vaporous objects?44 Calvin’s burning of Michael Servetus in 1553 prompted a widespread scrutiny of the very idea of religious persecution.45 The French scholar Sebastian Castellio led the charge by calling attention to the absurdity of different people being unshakably certain of the truth of their mutually incompatible beliefs. He also noted the horrific moral consequences of acting on these