This seems to be a simple subject-predicate sentence of the form "S is P like, for instance, the sentence "The Moon is round".
Another step of the same kind is what Quine calls eternal predications, subject-predicate sentences true or false once for all, such as "Fido is a dog".
Accordingly, in discussing Jones in relation to Frege and Russell, I will construe The Law of Significant Assertion as a doctrine concerning identity sentences sentences of the form a is b (where a and b are names, demonstratives or descriptions and is functions accordingly as the is of identity, not predication)—and not as a claim about subject-predicate sentences generally.
First, in subject-predicate sentences, an analytic sentence is one in which the concept of the predicate is contained in that of the subject.
And it could be used to advance a traditional nominalist agenda because, as Quine saw it, ordinary subject-predicate sentences carry no ontological commitment to properties or universals.
Instead, kind terms designate properties and simple seeming subject-predicate sentences like 'Foxes are carnivores' are claimed to possess a more complicated logical form, ∀x(Fx→ Cx), where Cx translates the predicate 'is a carnivore'.
The analysis in the Sophist appears incomplete as it stands, though, since it only applies to subject-predicate sentences, where the subject succeeds in referring to something (262e, 263c): it is unclear how he would handle other types of statements, much less negative existentials.
This shows that Lγ is actually a language containing its own truth predicate: Any sentence φ is true (false) if and only if the sentence expressing its truth, T<φ>, is true (false).
Indeed, substitutional quantification is often used to mimic quantification into predicate and sentence position of the kinds discussed later in this entry.
In particular, where It is easy to verify that, in each of the above cases, replacing one coextensional term, predicate, or sentence for another has no effect on the truth values rendered by the above clauses, thus guaranteeing the validity of the classical substitutivity principles and, hence, the extensionality of first-order logic with a Tarskian semantics.
We follow the usual custom in logic of treating this as a predicate of sentences.
