nothing and everything. Lovers of Heidegger will be pleased to see that nothing is a quite coherent object. Indeed, it will play a significant role at crucial points in the book.We will see, moreover, that gluon theory provides a solution to Heidegger’s notorious Seinsfrage—the question of Being.

P.3 The One of Parmenides and Plato

The problem of the one and the many around which Part I turns has often been overlooked as a serious problem. Where it has been taken very seriously is in Ancient Greek philosophy. Aristotle and Plato, in particular, were much concernedwith it. Aristotle’s solution is discussed in Part I.There is muchmore to be said about Plato’s.This is the focus of Part II.

The behaviour of parts is intimately connected both with Parmenides’ partless One, and with Plato’s form of Oneness. Both come in for scrutiny in this part. In particular, both of these are involved in Plato’s Parmenides. This dialogue is one of his most important and influential. It is also one of the most tantalizing and obscure. Many commentators despair of a coherent interpretation. The centrepiece of Part II is an interpretation based on gluon theory. This, it seems to me, provides just such an interpretation.1

These are not the only issues traversed in Part II, however.This part concerns itself with the application of gluon theory to questions of meaning, truth, intentionality, and formal mereology. (An interlude after Chapter 6 provides an account of the mereology of nothing.) These are, of course, central issues in contemporary philosophy. However, I have chosen to approach them through the lens of Plato. This gives the material a unity it might otherwise lack. More importantly, it will remind readers that contemporary problems sink deep into the history of the subject.

P.4 All is One

The key to understanding what it means for all things to be one—or at least one way of doing so—is to understand the notion of identity in question. Chapter 11 shows how this may be done in terms of the notion of interpenetration to be found in the Buddhist Huayan tradition.This, in turn, depends on an analysis and endorsement of the Buddhist—and specifically Madhyamaka—notion of emptiness. This chapter is no mere historical exegesis, however. In particular, it deploys

1 A longer version of these chapters appears as Priest (2012). I am grateful to the editor of the International Journal of Plato Studies for permission to use this material here.

One: Being an Investigation into the Unity of Reality and of its Parts, including the Singular Object which is Nothingness by Graham Priest