Scepticism and Metaphysics

Abstract

Medieval philosophers saw that sceptical arguments need to be taken seriously and paid close attention to their consequences. Yet, they also realized that these arguments are to be discussed in a metaphysical context and attempted to dissolve skeptical arguments by showing that they are in conflict with a number of basic metaphysical principles. This article discusses this close connection between epistemological and metaphysical issues by presenting two case studies, namely Thomas Aquinas's analysis of the demon hypothesis and John Buridan's reaction to the argument appealing to divine omnipotence. It suggests that one cannot understand how and why radical doubts were rejected or neutralized by medieval authors unless one pays attention to their explicit and implicit assumptions about the nature of knowledge claims and the methods for evaluating them.