Knowledge or Conjecture

Abstract

This chapter shows how Ptolemy blends an Aristotelian form of empiricism with a Platonic concern for distinguishing knowledge and opinion, and thereby produces a new and subversive epistemology where mathematics is the only science that generates knowledge rather than conjecture. He argues that philosophers will never reach consensus on the nature of physical and theological objects, because these fields of inquiry are, on their own, conjectural. Mathematics, on the other hand, yields sure and incontrovertible knowledge, and its contributions to physics and theology are epistemically efficacious. Mathematics enables a good guess at the nature of the Prime Mover, and it reveals the nature of physical objects. In this way, Ptolemy bolsters the value of mathematics and co-opts the fields of inquiry traditionally studied by philosophers for mathematicians.