In the Republic, Plato says some curious things by way of various constructions of the word einai"to be." For example: "what participates in being and not-being,"1 "more real,"2 "less real,"3 "the really real,"4 "completely real,"5 "purely real."6 How are we to understand what Plato is trying to say in these instances? Are we justified in interpreting these constructions in strict ontological terms (the existential use of "to be"), or do these passages express qualitative meaning (the predicative use of "to be")? More to the point, what does Plato mean by "real" and "reality" in these contexts?
We will attempt a brief exposition of the existential and predicative readings of Republic Bk. V (476a-478e).7 The questions are these: 1) How is Plato using einai in Republic Bk. V, and what is meant by "real" within this context? 2) Which of the interpretationsthe existential or predicativeis more coherent? 3) Are we justified in accepting either one of these interpretations?
It will be argued that, within the context of the degrees of reality theory presented in Republic Bk. V (476a-478e), it is not as easy to discriminate between Plato's "existential," ontological use of "to be" and its predicative use, as some scholars have represented.8 Moreover, since Plato does not provide an explicit characterization of sensibles and change (also known as flux), we cannot readily discard either reading. That is, both interpretations are consistent with the content and scope of Republic Bk. V. Because of this, we are not justified in favoring one reading over the other.
This is a difficult and controversial issue. The literature among noted scholars is considerable. Contradic-tory positions are the norm in this area. The usual approach has been to argue for the philosophically best interpretation of Bk. V that is consistent with the text. The problem is that, because of the ambiguity of the text, many different interpretations can consistently be ascribed to it. This gets us nowhere, as far as determining what Plato actually means. Indeed, the controversy should indicate that establishing Plato's "true" meaning is very likely impossible. Our ambitions here are merely to present an exposition of the problem and to advance the view that the problem is persistentnot try to present a definitive interpretation.
Republic Bk. V (476a-478e)
In the Republic Bk. V (476a-478e), Plato associates three classes of objectsthat which "is," that which "is not," and that which both "is and is not"with three corresponding states of mindknowledge, ignorance (or nescience9), and opinion (or belief10).11 Many scholars
have asserted that this account of the "grades" or "degrees of reality"12 constitutes a significant development of his theory of Forms.13 As G. Vlastos points out, Plato never actually uses the terms "grades" or "degrees." This ordering of reality is claimed to be expressed, as Vlastos says, by "the deliberate use in the comparative form of to be or to be real and their derivatives."14 The Forms, which are objects of knowledge, are taken to be "completely" and "perfectly" real, while their particular instances in the sensible world are "deficiently" real, "[falling] between the purely real and the wholly unreal,"15 because the status of their reality is such that "they both are and are not."16 The Forms are "more" real than objects of sensation, which are, in turn, "more" real than nothing, or that which is not (objects of ignorance). We are presented with a spectrum of reality with varying grades or degrees.17 According to Ross, this represents a "notable advance on Plato's earlier presentation of the theory of [Forms]."18
Hitherto he had maintained simply a complete opposition between the eternal, unchanging world of Forms and the temporal, changing world of individual things. He now still maintains that opposition, but he recognizes degrees within each of these worlds.19
Rather than completely opposed realities, Plato now advances a more complicated world-view recognizing the complexity of the universe.
The objects in the sensible world are held to be objects of opinion, since they are changing (in flux), imperfect, and not proper objects of knowledge.20 Thus, the Forms are "more" real than objects of sensation, since these can only be objects of opinion. Plato sums this up briefly, but cryptically: "what is completely knowable and what is in no way is in every way unknowable."21 We see that Plato has united metaphysics and epistemology,22 such that the way in which something is (or is not, or both) is directly related to its being known, not known, or believed (opined).23 Perhaps we are not making things any clearer. If we proceed with Plato's argument, we will at least be able to trace the development of such paradoxical language.
If knowledge is "by its nature set over what is"24 and knowledge is different than opinion, then opinion must be "set over" neither "what is" (since then it would be knowledge), or "what is not" (since that would be ignorance), but both "what is and what is not." Opinion is then "intermediate"25 between knowledge and ignorance. The logistics seem simple enough. Knowledge encompasses, or is "set over," what is, opinion (what is and is not), and ignorance (what is not). Since knowl