Journal of the History of Ideas

Ancient skepticism was more influential in the sixteenth and seventeenth centuries than it had ever been before. Thanks to the groundwork of Charles B. Schmitt and Richard H. Popkin on the influence of ancient skepticism in early modern philosophy and to the extensive research that followed their lead, skepticism is now recognized as having played a major role in the rise of modern thought. ¹

There were two ancient skeptical schools, Academic skepticism and Pyrrhon-ism. Were both equally influential? Until the sixteenth century, Pyrrhonism was scarcely known. Only a few copies of Sextus’s books (the only surviving primary source of ancient Pyrrhonism) have been discovered in medieval libraries. By contrast the main source of Academic skepticism, Cicero’s Aca-demica, was occasionally referred to by medieval authors and was the object of some commentaries and criticism in the Renaissance. ² Academic skepticism was preserved from the Middle Ages to the Renaissance not only through Cicero’s Academica, but also through Lactantius’s Divinae Institutiones and [End Page 199] Augustine’s Contra Academicos. ³ This situation changed when Sextus’s works were translated to latin and published in 1562 and 1569. Sextus presents a much more complete and detailed account and defense of ancient skepticism than that of Cicero’s Academica. Sextus presents Pyrrhonism as a coherent form of skepticism and Academic skepticism as a kind of negative dogmatism. ⁴ It was thus natural that the ancient skepticism that fascinated some (and troubled so many) early modern thinkers was mostly Pyrrhonian. Because of the publication of Sextus’s works, according to Schmitt, the increasing influence of Cicero’s Academica in the Renaissance was halted. Sextus’s Hypotyposes and Adversus Mathematicos took the place of Cicero’s Academica and drastically increased the influence of ancient skepticism. ⁵ The skeptical crisis at the dawn of modern philosophy is called “pyrrhonienne” not “academicienne.”

While the appearance of Sextus’s works in Latin turned him and Pyrrhonism into the main source and influence of ancient skepticism in early modern philosophy, further research on the history of skepticism in the period has shown that the role of Cicero’s Academica and of Academic skepticism in general continued to be considerable. First, Cicero’s works were important items in the university curricula. Although Cicero’s works of rhetoric and morals were those more read, the students could certainly learn about Academic skepticism through at least some of them. Second, many editions of De Natura Deorum, a work of Cicero’s in which Academic skepticism is quite central, were published during the seventeenth century. Third, features of Academic skepticism, exhibited above all in Cicero’s Academica, are basic to the skepticism revived in the late Renaissance by Montaigne and Charron; were related to the new science in the first half of the seventeenth century by Gassendi; were used in the anti-Cartesian reaction of the late seventeenth century by Rapin, Huet, Bayle, and above all Foucher; and were radicalized in the eighteenth century by Hume. Despite the Academic features of Montaigne’s, Charron’s, and Gassendi’s skepticisms, it does seem that from the publication of Sextus’s works to the mid-seventeenth century, Academic skepticism was secondary to Pyrrhonism. But the appearance of Descartes and the development of Cartesianism in the second half of the seventeenth century set conditions for a complete revamping of Academic skepticism, bringing about what Schmitt thought was precluded by the appearance of Sextus in the modern scene, namely, a “full flowering of the Academica as a work to inspire new directions of philosophical thought.” ⁶ [End Page 200]

Montaigne’s Apologie pour Raimond Sebond is rightly considered the first major result of the revival of ancient Pyrrhonism in modern thought. ⁷ Montaigne never cites the name of Sextus nor acknowledges his source and, by contrast, fills his Apology with passages from Cicero on the Academic skeptics. It is clear, however, that Montaigne follows closely Sextus’s Outlines of Pyrrhonism in the central part of the Apology where he gives a detailed and sympathetic exposition of ancient skepticism.

After dwelling on the evils and problems arising from knowledge and science, Montaigne...