Plato on the Metaphysical Foundation of Meaning and Truth by Blake E. Hestir (review)

This study defends the view that Plato’s account of meaning and truth does not depend on strong Platonism. Strong Platonism is based, among other things, on the assumption that basic entities (forms) are pure and cannot mix with anything. In a semantic theory, such entities provide stability of reference to single terms and so keep the danger of fluctuating meanings at bay. Unfortunately, strong Platonism pays a heavy price for this stability in that it cannot explain how terms can be combined into sentences and how statements can be true if truth consists in correspondence between the statement and how things really are. The book under review offers an account of a more restricted ontology. By doing so, it provides a challenge to some recent accounts of Plato’s semantics as based on elements from strong Platonism, such as, for example, structural isomorphism (Paolo Crivelli). The argument runs through three parts: (i) stability; (ii) combination and (iii) truth. The author engages a number of key passages in the Cratylus, Theaetetus, and Parmenides, all of them leading up to a discussion of some loci classici from the Sophist.

The study is rich in detailed analyses of arguments but never loses sight of the main point: an account of Plato’s restricted ontology as the foundation for his thoughts about meaning and truth. To this end, the author introduces a grounding argument (GA), articulated most explicitly at Parmenides 135b–c. It is this: (1) Forms are necessary for the possibility of meaningful discourse; (2) meaningful discourse is possible; (3) so, there are forms. The author finds versions of GA at work also in the Cratylus, Theaetetus, and Sophist. In such an argument everything depends upon what (1) means and what warrant you have for it. So what the author has to show is that the forms mentioned in (1) are not the forms we find in strong Platonism. While it is uncontroversial to think that the Sophist offers an account of forms that is not strong Platonism, the author argues in the first and second parts of the volume that the Cratylus, Theaetetus, and Parmenides contain such accounts as well. To this reviewer the arguments for this seem problematic. At Cratylus 439d, Socrates is said to be committed to this: “If the f is always changing and not being [at least with respect to itself], it is not possible to refer to the f or predicate anything of the f” (author’s brackets, 48). Whereas it is clear enough that everything outside the bracketed sentence is found in the passage referred to, I see no evidence for the bracketed part here or in the author’s interpretation of 439d. This is serious, since the bracketed sentence gives a crucial qualification to how one should think about forms, that is, as entities that are one but not in all respects. Furthermore, this part of the dialogue (439d8–440a5) appears to contain either lacunae or a shortened version of longer arguments, as the Oxford editors point out in their 1995 edition. This calls for caution when interpreting the passage, caution not mentioned by the author. Later on, Cratylus is re-used to interpret GA as found in Parmenides 135b–c: “If one considers this passage . . . in context with the Cratylus . . . and the Theaetetus . . ., I suggest that Plato has provided a significant (albeit subtle) hint about how to solve the tension in Socrates’s position. All that Parmenides can reasonably require of a form in order to ground the possibility of dialegesthai is that it has the formal attributes of being one and always the same in at least one respect” (author’s italics, 93). The italicized qualification is neither explicitly in the Cratylus nor in the Theaetetus: “Plato’s answer is just below the surface text” (83). It is probably in Parmenides, as the author explains (94), but that does not mean that the context of the other dialogues...