To many a courtier, official, teacher, lawyer, physician, and churchman, philosophy and philosophers seemed to have burst upon the European scene in the late seventeenth century with terrifying force. Countless books reflect the unprecedented and, for some, intoxicating, intellectual and spiritual upheaval of those decades, a vast turbulence in every sphere of knowledge and belief which shook European civilization to its foundations. A sense of shock and acute danger penetrated even the most remote and best defended fastnesses of the west. The Spanish physician Diego Matheo Zapata, writing in 1690—before his own conversion to Cartesianism— implored the cohorts of Cartesians and Malebranchistas besieging every citadel of traditional learning in Spain to desist, warning that it was not just received philosophy and science which was at stake but also, ultimately, the beliefs of the people, the authority of Church and Inquisition, the very foundations of Spanish society.1 A Spanish professor of medicine claimed, in 1716, that Descartes' philosophy had thrown all Europe into the greatest intellectual and spiritual perplexity seen for centuries.2 In less isolated regions the agitation was no less. A Zeeland preacher, writing in 1712, appalled by the impact of Descartes, Spinoza, and Bayle, despairingly compared the Netherlands of his time to the ancient Athens of the warring Hellenistic philosophy schools, a land racked by intellectual controversy where rival schools of thought battled ceaselessly, philosophy divided the ruling élite, and even the common people were proving susceptible to new ideas, letting themselves be 'led like children through the whirlwinds of thought', the helpless prey of philosophical seducers and, through new ideas, becoming entrapped in the 'Devil's snares'.3 Parts of this tide of new concepts, moreover, were of a distinctly radical character, that is, totally incompatible with the fundamentals of traditional authority, thought, and belief.
During the later Middle Ages and the early modern age down to around 1650, western civilization was based on a largely shared core of faith, tradition, and authority. By contrast, after 1650, everything, no matter how fundamental or deeply rooted, was questioned in the light of philosophical reason and frequently challenged or replaced by startlingly different concepts generated by the New Philosophy and what may still
1 Zapata, Verdadera Apologia, 40–5, 49, 64.
2 Boixy Moliner, Hippocrates aclarado, prólogo x.
3 Tuinman, Johan Kalvijn's Onderrichting, 1, 3–4.