Davidson is proposing that we might develop on the work of Frege, who formalised quantification, and Tarski, who formalised truth and meaning. While logicians explore and develop formal languages, then look to see how these might be applied to natural language, linguists look at natural languages and seek a theory that encompasses and explains them. Davidson’s proposal is a project that brings these together, applying formal logical methods to natural languages, by interpreting natural language in a formal language.
The theory would, give some sentence in say English, provide us with a T-sentence for that sentence, setting out in formal terms the conditions under which the sentence is true. Given a sentence “s” it would provide us with a truth conditional sentence “p” such that “s” is true ≡ p.
If there is an ambiguity in a natural language, an interpretation of that ambiguity in a formal language does not need to remove the ambiguity; indeed if it is to be accurate to the task of interpretation, it ought bring that ambiguity into the formalisation.
At p.316 of the text, explicitly, the place of such a theory of meaning is to exhibit the structure of the sentences of a natural language by exhibiting their logical form. Over the next few pages Davidson sets out the requirements for such a theory, for a series of special cases. He first turns to the problematic case of belief sentences, and extensionally opaque sentences more generally. He considers Carnap’s approach to such sentences in order to characterise the answer given as analysing the concept of belief rather than the structure of statements of belief. He applies this to normative sentences. If our theory of meaning takes “Bardot is good” and generates some formally equivalent sentence “p”, such that p is true if and only if “Bardot is good” is true, it will have set out the truth conditions for “Bardot is good”; and this whether or not it has provided an analysis of “…is good”.
…the mystery is transferred from the word ‘good’ in the object-language to its translation in the metalanguage.
It might be worth dwelling on what is proposed here. It would not suffice that “p” in such a sentence stand alone; the structure of “p” must be shared across other sentences of the metalanguage, so that the similarity between “Bardot is good” and “Bogart is good” is also seen in that metalanguage. Hence the requirement that there be some shared structural elements between formal interpretations of “Bardot is a good actress” and “Fido is a good companion dog”. Crucially, the interpretation must be in truth-conditional terms - and here we might read this as the requirement that the interpretation be extensional, and so allowing for substitution preserving truth. To do otherwise is to “…lapse into (or create) language for which we have no coherent semantical account” (top p. 318).
In a similar vein, the theory doesn’t separate analytic sentences. They are to be treated by the theory just as are other sentences.
The approach would be the same with demonstrative, and indeed with indexicals generally. Hence the same treatment must be applied to “I am wise” as to “Socrates is wise”. (Top p. 319)
These restrictions are dealt with by another innovation. We have up until now been talking of “s” as a sentence. Davidson now suggests that we need to instead consider “s” as instead an instance of language use, say an utterance, by some individual, with a given time and place. Hence the theory would not treat of the sentence “I am tired” but of ‘I am tired’ spoken by p at t; not “That book was stolen” but “That book was stolen” spoken by p at t. After all,
…sentences are true, and held true, only relative to a speaker and a time. The real task is therefore to translate each sentence by another that is true for the same speakers at the same times.