Mathematical reasoning in Plato’s Epistemology
According to Plato, we live in a substitute world. The things we see around us are shadows of reality, imperfect imitations of perfect originals. Beyond the world of the senses, there is another, changeless world, more real and more beautiful than our own. But how can we get at this world, or attain knowledge of it, when our senses are unreliable and the perfect philosophical method remains out of reach? In the Divided Line passage of the Republic, Plato is clear that mathematics has a role to play, but the debate about the exact nature of that role remains unresolved. My reading of the Divided Line might provide the answer. I propose that the ‘mathematical’ passages of the Meno and Phaedo contain evidence that we can use to construct the method by which Plato means us to ascend to knowledge of the Forms. In this dissertation, I shall set out my reading of Plato’s Divided Line, and show how Plato’s use of mathematics in the Meno and Phaedo supports this view. The mathematical method, adapted to philosophy, is a central part of the Line’s ‘way up’ to the definitions of Forms that pure philosophy requires. I shall argue that this method is not, as some scholars think, the geometric method of analysis and synthesis, but apagōgē, or reduction. On this reading, mathematics is pivotal on our journey into the world of the Forms.