Plato’s Theory of Forms: Analogy and Metaphor in Plato’s Republic

Abstract

It would be impossible to understand Plato’s writings on the nature of justice, beauty, or the good without first understanding Plato’s theory of Forms. Plato gives us a variety of different arguments in favor of his theory; most, if not all, of these arguments are analogical. I will explicate two such arguments, the sun analogy and the argument for the Forms found in book X, evaluating each as they are discussed. The evaluation will be geared toward cogency and consistency. First, though, I briefly explain Plato’s theory of Forms in general before examining these arguments. Ultimately, I will conclude that they illustrate both the relationship between the Forms and their instantiations, and among the Forms themselves, namely, the relationship between the good and the other Forms, but the arguments do not prove Plato’s ontology. From examining only these two arguments, it is clear how the Forms would function if they did exist, but the arguments themselves do not establish this existence, and, as a consequence, the arguments have limited persuasive power.