Farewell to Semantics (part one)

Some entries earlier I described the old and famous intensionality paradox my philosophy teachers were fascinated about. (do not forget to click)

Here is another example:


(1) Cicero believed that Rome was a great town

But Rome is also the capital of Italy, so Rome and the capital of Italy are the same thing.

(2) Rome = capital of Italy,

so by way of substitution, the following should be true

(3) Cicero believed that the capital of Italy was a great town.

But this is false. Cicero did not have the faintest idea about Italy, not in the modern sense, and what its capital was.


Why is this paradox disquieting? This is connected with three names

1’) Frege and compositional semantics
2’) Tarski and definition of truth
3’) Davidson and truth-conditional theory of meaning


Re 1') The compositionality principle says that the meaning of a complex expression is determined by the meanings of its constituent expressions and the rules used to combine them. In particular, it depends on what entities are assigned to constituent words. The town of Rome is assigned to the word “Rome”. But the meaning of (1') and (3') does not depend only on the reference of words, but also what words are actually used (“Rome” or “capital of Italy”). And this seems to be unpredicable.

Re 2') This is similar. Once you assign meaning to basic proper names, variables and predicates (or put more simply to basic constituents of language), you can determine by automatic rules the truth of complex sentences which involve logical connectives (and quantifiers). But this apparently cannot be done if we admit verbs expressing propositional attitudes like "believe" or "know". "Rome" and "capital of Italy" refer to the same town. So whether we use the word "Rome" or "capital of Italy" should have no bearing on the truth of the sentences.

(1) Cicero believed that Rome was a great town.
(3) Cicero believed that the capital of Italy was a great town.

But the first is true and the second untrue.

Re 3') Donad Davidson and some other philosophers suggested that the meaning of natural language sentences should be their truth conditions. But for this this you need a Tarski-style semantics, which with belief sentences you apparently are not going to get.

In the next entry I will try to give a solution to the intensionality paradox. I am still a little sketchy about the details and I am sure that it cannot be faultless, because in my experience no one has yet succeeded to solve this problem. But for now my solution seems quite intuitive and, moreover, is rooted in philosophy of mind.

See you soon,

Marco