Liberalism makes it a matter of moral principle not to use coercive means, threats, and inducements to impede the spread of ideas we reject, even when they seem not only wrong but dangerous. In Bayle’s time many Christians believed that God himself had commanded the use of such means to prevent the spread of religious error, but even apart from this theological opinion it will seem natural to many people to block the spread of dangerous ideas by force, if that is the most effective way. Coercive methods may often be ineffective, but the liberal believes that even when they are effective, or might be, they are wrong. The earliest and still perhaps the most persuasive argument in favor of this basic tenet of liberalism is Pierre Bayle’s Philosophical Commentary on these words of the gospel (Luke 14.23), “Compel them to come in, that my House may be full.”

      Bayle’s Life

      Pierre Bayle, the second son of a Protestant pastor, was born on 18 June 1647 in Le Carla (now Carla-Bayle) in the Compté de Foix, at the foot of the Pyrenees. With his brothers, Jacob and Joseph, he learned to read and write in the town’s only school, and furthered his education with the help of his father, who introduced him to Latin and Greek as well as to the various books found in his own library and those of his colleagues living nearby. Jean Bayle’s modest circumstances made it impossible for him to send his younger son to secondary school until Jacob had finished his theological studies, and Pierre was twenty-one when he set out for the academy at Puylaurens. Already in love with books and learning but disappointed by the school’s low standards, Pierre left three months later for Toulouse and was accepted as a day-pupil in a Jesuit college, where he was instructed in Aristotelian philosophy and logic. Unable, as a young country scholar, to defend his Protestant faith against the arguments of his teachers, on 19 March 1669 he converted to Catholicism, to the dismay of his Huguenot family.

      Bayle’s conversion did not last long. By the time he stood to defend his Master’s thesis in August 1670 he had become thoroughly disaffected with Catholic practice and was no longer satisfied intellectually by its doctrine. But if abandoning his Protestant faith had taken considerable moral courage, abjuring Catholicism—even for the religion of one’s birth—was positively dangerous, since under French law “relapsed heretics” incurred heavy penalties. Nonetheless, Bayle converted again and fled to Geneva, never to see his parents or younger brother again.

      In Geneva Bayle also abandoned his Aristotelian views and, under the influence of his fellow students at the Academy, Jacques Basnage (1653–1723) and Vincent Minutoli (1640–1710), became a follower of Descartes’s philosophy. After two years as tutor in a noble family near Geneva, Bayle returned to France to other tutorships, going under the name Bèle to avoid being identified as a lapsed Catholic. In 1675 he competed for and won the chair in philosophy at the Protestant Academy of Sedan.

      At the Academy Bayle formed a close friendship with the professor of theology and Hebrew, Pierre Jurieu (1637–1713), and enjoyed the benefits of his patronage and of his extensive library. In Sedan he read Malebranche (1638–1715) and Spinoza (1632–77), and began to produce writings of his own. This academic life was disrupted by political developments. The religious toleration the Huguenots had enjoyed since the 1598 Edict of Nantes was slowly eroded during the reign of Louis XIV (1638–1715). In 1681 the Academy at Sedan was abolished by royal decree, and Bayle and Jurieu moved to the École Illustre in Rotterdam to take up chairs in philosophy and theology respectively, Bayle carrying with him the manuscript of Various Thoughts on the Occasion of a Comet.