Can Aristotle's theory of truth for assertions be regarded as a correspondence theory of truth? Section 1 argues that on certain conceptions of truth as correspondence it cannot, but on at least one other it can. Specifically, Aristotle's theory of truth can be regarded as a correspondence theory of truth in that it can be regarded as taking the truth of an assertion to amount to a relation of isomorphism to reality. In particular: it relies on a classification of assertions, with each class it associates some characteristic that can hold of the items an assertion is about, and it claims that an assertion is true when and only when the characteristic associated with its class holds of the items it is about.

Section 2 addresses Aristotle's reaction to the Liar, which creates a puzzle for correspondence theories of truth like Aristotle's. It is not clear whether Aristotle addressed the Liar, and, in case he did, what version of it he confronted. On the somewhat optimistic assumption that he did address a robust version of the paradox, his solution is that the assertion on which the paradox turns (an utterance of the sentence-type ‘I am speaking falsely’) is sometimes neither true nor false.

A CORRESPONDENCE THEORY OF TRUTH?

Focusing on truth for assertions. The theory of truth we are in the best position to attribute to Aristotle is a theory of truth for assertions (utterances) (it was described in chapters 2 and 3).

In chapter 9 of de Interpretatione (henceforth ‘Int. 9’) Aristotle claims that some future-tense singular assertions are sometimes neither true nor false, and therefore refute Bivalence, the principle stating that every assertion is always either true or false. Aristotle's argument goes as follows:

Int. 9 divides into four parts: the first (18a28–33) is introductory (it briefly states Aristotle's position); the second (18a34–18b25) contains two arguments from Bivalence to Determinism; the third (18b26–19a22) argues that Determinism is absurd; the fourth (19a23–19b4) contains Aristotle's solution to the problems raised by Bivalence and Determinism.

In section 1 of the present chapter I present the most important modal attributes and theses at play in Int. 9: the attribute of necessity as ineluctability (a diachronic modality, with two ‘slots for dates’), the thesis of the necessity of the present and the past (the thesis that for whatever obtains at any time it is both then and later necessary to obtain then), and Determinism (the thesis that for whatever obtains at any time it is always antecedently necessary to obtain then). Aristotle endorses the necessity of the present and the past, but rejects Determinism.

The study of truth is a central part of the philosophical tradition we have inherited from classical Greece. Aristotle played an important role in developing and sharpening the debate in this area and on many issues that are connected with it. I have two primary goals: to offer a precise reconstruction of all of Aristotle’s most significant views on truth and falsehood and to gain a philosophical understanding of them. In this introduction I first offer an overview of Aristotle’s theory of truth and then discuss the methodology I adopt in pursuing my primary goals.

AN OVERVIEW OF ARISTOTLE’S THEORY OF TRUTH

Why an overview? Aristotle speaks about truth and falsehood in passages from several works, mainly the Categories (chapters 4, 5, 10, and 12), de Interpretatione (chapters 1–9), Sophistici Elenchi (chapter 25), de Anima (chapter 3.6), and the Metaphysics (chapters Γ 7, Δ 7, Δ 29, Ε 4, and Θ 10). Truth and falsehood are not the main topic of these works: their discussions of truth and falsehood are asides. Reconstructing an Aristotelian theory of truth and falsehood on the basis of such asides poses complicated problems of various sorts. To help readers to keep their orientation through the many bifurcations of the arguments addressing these problems, I decided to offer a concise but precise map of the territory – an overview of Aristotle’s theory of truth.

The evidence. At 1051b2–3 various readings are available. E and J have

1. τοῦτο δ'ἐπὶ τῶν πραγμάτων ἐστὶ τὸ συγκ∊ῖσθαι ἢ διῃρῆσθαι.

This reading, also presupposed by William of Moerbeke's translation, is printed by some early editors (the Aldine edition, Brandis, and Weise).

Ab has instead

1. τοῦτο δὴ ἔτι τῶν πραγμάτων ἐστὶ τῷ συγκεῖσθαι ἢ διῃρῆσθαι.

No editor prints this.

Most modern editors (Bekker, Schwegler, Bonitz, Dübner, Christ, Ross, Tredennick, and Jaeger) print

1. τοῦτο δ' ἐπὶ τῶν πραγμάτων ἐστὶ τῷ συγκ∊ῖσθαι ἢ διῃρῆσθαι, a text obtained by combining readings [a] and [b].

Evaluation. Reading [b] makes no sense and must be discarded. Reading [a] has the edge on [c] because of the parallel with 1051b11–13, 1051b19–20, and 1051b33–5. I therefore opt for reading [a].

In chapter 2 I sketched a theory of the truth conditions for predicative assertions which can be plausibly attributed to Aristotle. The goal of the present chapter is to attain the corresponding result for existential assertions: to outline a theory of the truth conditions for existential assertions which captures Aristotle's views concerning this subject. Aristotle concentrates on existential beliefs and assertions of two types: those concerning simple items, which are essences and incorporeal substances (i.e. God and, perhaps, the intellects that move the heavenly spheres), and those concerning material substances.

The first two sections of the chapter focus on existential beliefs and assertions concerning simple items. The main witnesses are the middle part of Metaphysics Θ 10 and the beginning and the end of de Anima 3.6. Section 1 offers truth conditions for existential beliefs and assertions concerning simple items. Simple items are essences and incorporeal substances, all of which are everlasting, i.e. exist always. It follows that every existential affirmative belief, or assertion, concerning a simple item is always true, and every existential negative belief, or assertion, concerning a simple item is always false. Section 2 addresses a scholarly issue: what does Aristotle have in mind when in Metaphysics Θ 10 he speaks of ‘non-composite substances’? I defend the traditional interpretation, according to which Aristotle has incorporeal substances in mind.

Section 3 addresses the truth conditions for existential beliefs and assertions concerning material substances.

The evidence. At 17b16–20 Aristotle discusses contradictory pairs where one member is a universal predicative assertion. Here is the text handed down by the main manuscripts and printed by the majority of recent editors (Bekker, Waitz, Dübner, Cooke, Minio-Paluello, and Zadro):

Ammonius (in Int. 109, 24–5) reports that according to Porphyry at 17b17 some manuscripts instead of ‘ἀντιφατικῶς’ read ‘ἀποφαντικῶς’ (some manuscripts of Ammonius have ‘ἀποφατικῶς’, the reading we find also in some manuscripts of de Interpretatione, e.g. in Laur. 72, 17). In n ‘τῷ’ (17b17) is added above the line. Bekker claims that at 17b17–18 B reads ‘τὴν τὸ καθόλου σημαίνουσαν τῇ τὸ οὐ καθόλου’, but he is wrong: B's reading is the same as that of the other main manuscripts. (Was this reading attested in some other manuscript?) At 17b18 Laur. 72, 4 omits the first ‘οὐ’. In Vat. Palat. Gr. 74 a later hand added ‘τῇ τὸ αὐτὸ’ above ‘τῷ αὐτῷ’.

The evidence. At 1051b1 the main witnesses present a variety of readings: Ab and (probably) ps.-Alexander (in Metaph. 598, 1–2) have ‘κυριώταταὂν’; the first hand of E has ‘κυριώτατον εἰ’; J and the second hand of E have ‘κυριώταταεἰ’; William of Moerbeke's translation presupposes ‘κυριώτατα ἢ’.

Brandis, Bekker, Weise, Schwegler, Bonitz, Dübner, Christ, and Jaeger print ‘κυριώτατα ὂν’. Ross (followed by Tredennick and various commentators) excises ‘κυριώτατα ὂν’ (he also contemplates the possibility of transposing it after ‘τὸ μὲν’ at 1051a34). Jaeger suspects a lacuna between ‘κυριώτατα ὂν’ and ἀληθὲς ἢ ψεῦδος’: he suggests ‘κυριώτατα ὂν <ἡ οὐσία, λείπεται δὲ ἐπισκοπεῖν τὸ ὂν> ἀληθὲς ἢ ψεῦδος’.

An inconsistency? Many editors and commentators find the reading ‘κυριώτατα ὂν’ of Ab at 1051b1 hard to accept because in Metaphysics E 4 (= T7), at 1027b31, Aristotle says that what ‘is’ in the sense of being true ‘is a different thing that “is” from the things that “are” in the strict sense [κυρίως]’: were the reading ‘κυριώτατα ὂν’ genuine, in Metaphysics Θ 10 Aristotle would be committing himself to the incompatible claim that what ‘is’ in the sense of being true is what ‘is’ in the strictest sense. The fact that E 4, at 1027b28–9, contains a forward reference to Θ 10 makes it particularly implausible to assume that Aristotle should entertain such incompatible views about what ‘is’ in the sense of being true.

As we saw in chapter 4, Aristotle's theory of truth for assertions can be regarded as a correspondence-as-isomorphism theory of truth: Aristotle takes an assertion's truth to consist in a certain isomorphism obtaining between the assertion and reality. We also saw that Aristotle's correspondence-as-isomorphism theory of truth presents itself in two formats. In the first, the components of reality with respect to which a true assertion's isomorphism holds are objects that correspond to assertions as wholes (one object corresponding to one complete assertion). In the second format, which concerns mainly predicative assertions, the components of reality with respect to which a true predicative assertion's isomorphism holds correspond to parts of the assertion: they are objects, i.e. universals or individuals, signified by the assertion's predicate and subject. A well-known difficulty faced by correspondence-as-isomorphism theories of truth of the second format is the problem of ‘vacuous’ terms. What happens if either the subject or the predicate of an assertion is ‘vacuous’, i.e. fails to signify an item of the appropriate kind? A correspondence-as-isomorphism theory of truth of the second format loses one of its toeholds.

Section 1 contains four arguments for the thesis that Aristotle's reply to the problem of ‘vacuous’ terms is that in every predicative assertion both the predicate and the subject are ‘non-vacuous’ in that they signify items of the appropriate kinds.

This chapter addresses the relationship of truth to time and change. According to Aristotle, any bearer of truth or falsehood can, at least in principle, be true at one time and false at another. This is somewhat hard to square with his view that the linguistic items that are bearers of truth or falsehood are utterances (expression-tokens). On reflection, however, the position turns out to be consistent: utterances (expression-tokens) can be true at one time and false at another.

Aristotle also claims that if an assertion or a belief is true at one time and false at another, it does not follow that it undergoes a change. This is probably due to the idea that truth (being correspondence to the world) is something like a relative and therefore, like relatives, is involved at most in a ‘mere Cambridge change’ that does not count as a genuine change. Now, properties involved in a ‘mere Cambridge change’ are not genuine properties. It follows that truth is not a genuine property.

DIFFERENT TRUTH-VALUES AT DIFFERENT TIMES

Truth and falsehood at times. Aristotle thinks that the bearers of truth or falsehood are true, or false, at times. He does not formulate this view explicitly: nowhere does he use a sentence like ‘States of affairs, beliefs, and assertions are true or false not absolutely, but at times.’