44The issue of Plato's meaning and intent with this language is the problem at hand. Grube, in a footnote in his translation of the Republic, writes: "Because of the ambiguity of the verb einai ('to be'), Socrates could be asking any or all of the following questions: (1) 'Something that exists or something that does not exist?' (existential 'is'); (2) 'Something that is beautiful (say) or something that is not beautiful?' (predicative 'is'); (3) 'Something that is true or something that is not true?' (veridical 'is'). This ambiguity is the source of our difficulties."
45This itself is a controversial matter. Vlastos thinks, along with G.E.L. Owen and against John Ackrill and others, that "the method of analysis by paraphrase in the Sophist which isolated perfectly the 'is' of identity from its other uses was not pushed far enough to sort out in the same way the 'is' of existence from that of predication." (Vlastos "Metaphysical Paradox," 47.) Unfortunately, the space required for a sufficient treatment of this controversy, and the implications following from it, would far exceed the scope of this paper. Bringing in a discussion of the Sophist, and its treatment of the Forms of "being" and "non-being," while certainly relevant to Republic Bk. V, would basically involve a comprehensive assessment of Plato's ontology, which, needless to say, is far to ambitious for the current exposition.
46Vlastos puts forth Politicus 293e as showing this.
47Vlastos, "Metaphysical Paradox" 47.
48Vlastos, "Metaphysical Paradox" 48. This is the exact same conclusion reached by Owen in "Aristotle on the Snares of Ontology," 71: "he treats 'to be' and 'not to be' alike as incomplete or elliptical expressions which always call for some completion: to be is just to be something or other." The problem is, as we will see, that Plato does not 'complete' this expression in 478e. We can hardly infer the premise of predication only by appeal to his non-use of a predicate.
49R. 477a, 478c, 478d, 478e. Grube's translation.
50Vlastos justifies this expansion by referring to 479c 3-4 in conjunction with 479b 9-10. These further complications will not be dealt with here, except to say that we can still generate ontological problems. Cf. 478e: "what participates in both being and not being." It would be difficult to see in what way this could be rendered with a predicate that avoids ontological difficulty, since the noun 'being' can hardly be said to have the multiplicity of use that 'real' has. Vlastos also indicates that when Plato is using "to be" in an existential sense he supplements it with locatives like somewhere, or nowhere. Since he does not do this in the degrees of reality theory, Vlastos might argue that this further indicates the predicative use of "to be." There are complications
however. One could argue that locatives would be pointless in this context, since general issues of being are addressed, not instances of particular existence like the examples Vlastos gives us.
The Sophist is particularly relevant to these speculative questions, since it is there that Plato explicitly considers the Forms of "being" and "not-being," which, it may be argued, is directly applicable to the three formulations Plato offers us in Republic V: "is," "is and is not," and "is not." If Plato accepts Forms of "being" and "non-being," as is indicated in the Sophist, then this poses difficulties for the predicative position, since then the hypothesis that these formulations are merely ellipses for predicative expression would not seem to be as accurate as saying that Plato is setting up a serial gradation of distinct ontological categories. Again, Plato often uses the expression "participate" to refer to the relation of sensibles and Forms-or, in Aristotle's words, the relation of particulars and universals.
Given this, and taken together with R. 478e ("what participates in being and not-being"), it can be argued, contra the predicative position, that Plato is setting two distinct ontological classes (in short, two different Forms) in opposition, and not merely alluding to a hypothetical predicate F. In short, the existential interpretation, for all its apparent inconsistency, in the end, seems to be most in keeping with Plato's radical union of metaphysics and epistemology, wherein the degree to which something may be known, is directly related to its measure of "reality," and, vice-versa, the degree of reality of an object necessarily dictates the extent to which someone may have knowledge of that object, and ultimately defines the state of mind one adopts with respect to it (knowledge, opinion, or ignorance).
51R.E. Allen 46.
52He cites Timeas 52a. The citation, and Vlastos' use of it, is not contradicted here.
53Vlastos, "Metaphysical Paradox" 49.
59The same might be said of a thing's spatial location. It would be difficult to claim that a thing's spatial location has determinative bearing on its existence, while it is far easier to claim that time has bearing on a thing's existence. But the spatial dimension can be incorporated if it is merely for descriptive purposes, just as time, one could argue, may be mere description. In any event, temporality will be the focus of the analysis.