A HISTORY of SKEPTICISM in the MIDDLE AGES Henrik Lagerlund

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A HISTORY OF SKEPTICISM IN THE MIDDLE AGES

Henrik Lagerlund

Introduction

For a long time the history of skepticism did not include the Middle Ages. We knew about Ancient skepticism, but then foremost due to the domination of Aristotle it was assumed that skepticism was not a problem in the Middle Ages, and then the Renaissance saw a resur- gence of skepticism due to the rediscovery of Sextus Empiricus in the late fi ft eenth century. We now know that this is wrong and that the history of skepticism must be rewritten. Th ere is a concern with epis- temological and skeptical problems throughout the Middle Ages, but from the late thirteenth and early fourteenth centuries epistemology and as a consequence skeptical problems becomes the main focus of philosophy. How this is related to and had an impact on Renaissance and Early Modern skepticism is not known yet, but must be a future area of research. Th ere are several reasons for why skepticism became such an impor- tant issue in the fourteenth century. One is the declining infl uence of Aristotelian philosophy and the subsequent criticisms of Aristotelian epistemology introduce questions about the status of science. Another reason is the change in modal theory with John Duns Scotus and the introduction of logical possibility, which dramatically changes the view about what God can and cannot do. God’s absolute power suddenly becomes a threat to human knowledge. A third reason is the introduction of new texts and the increased importance of already known texts. All this creates a climate that pushes skeptical problems to the forefront in the early fourteenth century.1 Th is book contains new articles on medieval skepticism and tries to shed light on the discussions from Al-Ghazālī to early sixteenth century Paris. It will bring into focus new aspects of already known discussions and it will also introduce some new discussions. In this introduction

1 For overviews of medieval skepticism see Perler (2006) and Bolyard (2009). 2 henrik lagerlund

I will try to give a short overview of medieval skepticism and I will try to place the articles of the book in their proper historical context.

The Ancient Background: Cicero and Sextus

Although it is true to say that Plato was skeptical about knowledge gained through the senses and that atomists like Democritus and Epicurus had to accept the conclusion that our senses do not give us the truth about the world, neither of these thinkers were skeptics. Th e fi rst skeptic was instead, according to Sextus Empiricus (c. 200) and Diogenes Laertius (he lived somewhat later than Sextus), Pyrrho of Elis (c. 365–270 BC).2 Pyrrho was the founder of a school of thought oft en referred to as Pyrrhonism. Sextus was a member of this school and it is only the members of this school that call themselves skeptics. Th e Greek ‘skeptikos’ means ‘inquirer’ and, according to Sextus, a skeptic is someone who is still seeking the truth. He also contrasts the skeptic with the dogmatists which are those that think they know the truth.3 Pyrrho seems not to have written anything, but his follower Timon of Phlius (c. 325–235 BC) supposedly wrote a biography of him. Pyr- rhonism seems to have died out a generation or two aft er Timon. In the mean time, Plato’s Academy had turned skeptical under the leadership of Arcesilaus (c. 315–241 BC). Under his and his successor’s, Carneades (c. 219–129 BC), rule the so-called Academic skepticism fl ourished well into the fi rst century BC. Around that time a new skeptical movement again inspired by Pyrrho was started by Aenesidemus of Cnossos (fi rst century BC). He broke away from the Academy. It is this renewed Pyr- rhonism that Sextus was part of.4

2 Th ere seems to have been a group of thinkers infl uenced by Democritus who denied the possibility of knowledge. Pyrrho is said to have belonged to this group. In his book On Nature, Democritus’s pupil, Metrodorus of Chios says that “none of us know anything, not even whether we know anything or not.” He also argued in a way very similar to the later Hellenistic skeptics. See Sedley (1983). 3 Th is aspect of Ancient skepticism sets it apart from today’s skeptics. When skepticism and relativism about truth, which oft en go hand in hand, are proposed today, the conclusion is oft en drawn that since all opinions are equal one can believe anything. Instead of implying an opposition to dogmatism, as it did in Antiquity, dogmatists of today get a helping hand from skepticism. Ancient skepticism is also, contrary to today’s skepticism, quite compatible with the possibility of knowledge. 4 For a more detailed account and further references see Groarke (2008).