Abstract

The paper focuses on the issue of Plato’s so called “unwritten doctrine” and on the position of “ideas” in it. First, the basic features of classical interpretation of ideas in Plato’s dialogues Phaedo and Republic will be introduced. Further, it will explain “protology”, the theory of principles. Author suggests the protological interpretation of the Idea of the Good that stands out above all existence, as Plato claimed explicitly in Republic. In the end of the paper is discussed the nature of ideal numbers and the mathematical being in the dialogue Philebus.