How Many Sciences is Semantics?
I often wonder to what extent different theories and approaches in philosophy of language are conflicting theories about the same matter, or rather different theories about different matters. For example, some theories try to describe the cognitive processes involved in human speaking and understanding; Others try to find systematic rules for how semantic properties (like truth value or truth conditions) of complex expressions are determined by semantic properties (like reference or intension) of their components; Others try to spell out what mental and behavioural conditions somebody must meet in order to understand an expression (or a language); Others try to find physical relations that hold between expression tokens and other things iff these other things are in some intuitive sense the semantic values of the expression tokens; Others try to discover social rules that govern linguistic behaviour; and so on. How are all these projects related to each other?
There are certainly many interconnections between all of them. For example, the project of formal compositional semantics has to match the actual usage of the relevant language. It won't do to assign to every sentence the meaning that God is great, even if this is the result of very elegant and systematic rules. But how about, say, the cognitive processes involved in linguistic competence? Are these relevant to formal semantics? And if so, in what way? (Personally, the more I've studied neurobiology, the more I believe that any correct theory of these processes will be hopelessly inadequate to deal with questions discussed in semantics and philosophy of language.)
This situation makes it quite difficult for me to discuss theories in philosophy of language. If someone suggests that the meaning of an expression is its conceptual role, or that the meaning of a proper name is exhausted by its referent, or that meaning ain't in the head, or that reference is inscrutable, I always want to say: Well yes, I can see that in the context of your project this statement is correct, but I can see other projects where its negation would be correct, and I'm not so sure about whether your project is better than these, and whether they are even in conflict with each other.