INTRODUCTION

In this chapter, I turn to the responses made to Plato and Aristotle and, indeed, to the entire epistemological tradition by those in the first and second generations after Aristotle. Specifically, I will focus on Epicurus and the members of the so-called Old Stoa, Zeno, Cleanthes and Chrysippus. My justification for treating together two schools of philosophy that are deeply divergent in many ways is that they share a type of naturalism in epistemology that is self-consciously materialist. Owing to the fragmentary nature of our evidence and to considerations of space, I am going to try to express what I take to be the common ground among Epicureans on the one hand, and Stoics on the other, relating to epistemology. To this end, I shall make use of relatively late testimony by friends and foes alike of these two great schools of ancient philosophy. I hope that suppressing any of the philosophical differences that might have existed between, say, Chrysippus and Zeno will not compromise my basic account.

We saw in the last chapter that Aristotle criticised his predecessors for failing to distinguish thinking and sense-perception. They did so, says Aristotle, because they believed that (1) sense-perception is corporeal; (2) reality is corporeal and (3) cognition must be by that which is the same sort of thing as that which is cognised. So, (4) thinking, like sense-perception, must be corporeal. Aristotle does not dispute (1). His reaction to (2) and (3) is nuanced.