In the sixth book of the Republic. Socrates begins leading his interlocutors down the 'longer road' that leads to the Form of the Good which is to complete the earlier account of virtue given in Book IV. The end of this road in the Republic is reached via the sketch of the Good portrayed in the famous Sun, Line, and Cave passages. In this paper, I wish to suggest that the road does not, in fact, end here, but extends to the account of the Good offered in one of Plato's latest dialogues, the Philebus . This account, like the one in the Republic before it, has ontological, epistemological and ethical dimensions, but in this paper, I shall concentrate on those aspects that have special relevance to the nature of the good life. Specifically, I shall focus my discussion on the role the Good as unity plays in the good life.
My argument shall run as follows. In the Republic the Good's role is ambiguous since its unity is depicted in two different ways: as an organic whole of interrelated parts or aspects, and as an absolute and transcendent One. Corresponding to each of these models of the Good's unity is a different picture of the good life. According to the first model, we should seek to integrate the diversity of our experience, but according to the second, we should strive to minimize or even eliminate all diversity. In the Philebus. it becomes clearer that the second model of unity is the one we should take as our ideal. Thus the good life is one in which various types of knowledge and pleasure are properly arranged in imitation of the universal order provided by the Forms. The Philebus. then, presents us with a fuller understanding of how we are to use the Good as the pattern for our lives.
Hampton, Cynthia, "The Good as Unity: Its Role in the Good Life in Plato's Later Thought" (1989). The Society for Ancient Greek Philosophy Newsletter. 257.