The Knowledge Machine: How Irrationality Created Modern Science

by Michael Strevens

EUROPE, once Luther’s “Ninety-Five Theses” went out, was forever to be spiritually divided—the new Protestant versus the old Catholic faith; citizens, rulers, and territories of opposing religions living uneasily side by side. Violence followed soon enough: popular revolt in Germany in the 1520s; English dissidents burned at the stake in the 1550s; the desecration of churches in the Low Countries in the 1560s; full-scale war in France from then through the end of the century. It was to get worse. In 1618, the Protestant nobles of Bohemia, rightly fearing for their religious freedom, spurned their Catholic king Ferdinand—famously by ejecting his representatives from an upper-floor window of Hradčany Castle in Prague—and appointed a Calvinist prince in his place. The deposed Ferdinand soon after assumed the station of Holy Roman Emperor, thereby becoming the ruler of a motley but powerful confederacy of Central European states, some Catholic and some Protestant. He marched on Bohemia to take his revenge. These were the opening moves of the Thirty Years’ War, the conflict that launched Descartes’s short, uneventful military career and devastated Europe. Although the war began over a matter of religious toleration, it soon grew into far more than that: a war between the Bourbon dynasty that ruled France and the Habsburg dynasty that ruled Spain and the Holy Roman Empire; a war by which the German princes asserted their rights against the Holy Roman Emperor; a war of territoria...