=The Development of Plato’s Metaphysics――The Development of Plato’s Ideas in the Two Drafts.= The twofold world with its new evaluation of the Socratic conception and of the Protagorean perception was, after all, only Plato’s point of departure for his constructive work. It was his first and undeveloped apprehension of a theory of Ideas. It appeared first in the _Meno_ in his doctrine of recollection and immortality, which was written in his second period just after his series of splendid polemics against the Sophists. From this time for a full half-century Plato developed the conception of a twofold world into a Theory of Ideas. In the course of time he found himself confronted with three problems: (1) How many Ideas are there? (2) What is the relation between Ideas and physical things? (3) What is the relation of the Ideas to one another? Plato’s answers to these three questions compose what is known as his Theory of Ideas. However, he answers these three questions differently when he first considered them than later, when his grasp upon the significance of his problem became more mature. Plato’s Theory of Ideas, therefore, may be said to have had a development in two stages. These two stages are called his “two drafts” (Windelband) of the Ideas. We shall now present, first in summary form and then in more detail, his answers to these three questions in the two drafts, and thereby show how his theory developed to its final formulation. =Brief Comparison of the Two Drafts of the Ideas.= =1. The Earlier Draft of Ideas.= (a) _The Number of Ideas_ is infinite. (b) _The Relation of Ideas to Physical Things_ is similarity. The Ideas on their side are spoken of as having a “presence” in physical things, but never fully appearing in them; the physical phenomena on their side are spoken of as “participating” in the Ideas. (c) _The Ideas are Related to One Another_ logically, as genera to species, but they are only roughly classified by Plato. =2. The Later Draft of Ideas――Plato’s Final Statement.= (a) _The Number of Ideas_ is limited to those of worth, mathematical relations, and nature-products, but Plato never arrived at any definite selection. (b) _The Relation of Ideas to Physical Things_ is teleological. The Ideas are the ideal or purposeful ends of physical objects. (c) _The Ideas are Related to One Another_ teleologically. The Idea of the Good stands at the head, and is the purposeful end of all the other Ideas. =Comparison of the Two Drafts of Ideas in More Detail.=