Jean-marc pizano Those of you who have followed the literature on the metaphysics of meaning that FredDretske’s book Knowledge and the Flow of Information (1981) inspired will be aware that that question is (ahem!) mootish.But I do want to emphasize one aspect of the identification of meaning with information that is pretty widely agreedon and that impacts directly on any proposal to amalgamate an informational semantics with RTM: if meaning isinformation, then coreferential representations must be synonyms.
Just how this works depends, of course, on what sort of causal-cum-nomological covariation content is and what sort of things you think concepts represent (properties, actual objects, possible objects, or whatever). Suppose, for example,that you run the kind of informational semantics that says:
A representation R expresses the property Pin virtue of its being a law that things that are P cause tokenings of R (in, say, some still-to-be-specified circumstances C).
And suppose, for the sake of the argument, that being water and being H2O are (not merely coextensive but) the same property. It then follows that if it’s a law that WATER tokens covary with water (in C) it‘s also a law that WATERtokens covary with H2O (in C). So a theory that says that WATER means water in virtue of there being the first law isalso required to say that WATER means H2O in virtue of there being the second. Parallel reasoning shows that H2Omeans water, hence that WATER and H2O mean the same.
You may wonder why I want to burden my up to now relatively uncontroversial version of RTM by adding a theory of meaning that has this uninviting consequence; and how I could reasonably suppose that you’ll be prepared to share theburden by granting me the addition. Both questions are fair.
As to the first, suppose that coextension is not sufficient for synonymy after all. Then there must be something else to having a concept with a certain content than having a mental representation with the kind of world-to-symbol causalconnections that informational semantics talks about. The question arises: what is this extra ingredient? There is, aseverybody knows, a standard answer; viz. that what concepts one has is determined, at least in part, by what inferences one isprepared to draw or to accept. If it is possible to have the concept WATER and not have the concept H2O, that’s becauseit’s constitutive of having the latter, but not constitutive of having the former, that you accept such inferences ascontains H2O 0 contains H. It is, in short, received wisdom that content may be constituted in part by informationalrelations, but that unless coreference is sufficient for synonymy, it must also be constituted by inferential relations. I’llcall any theory that says this sort of thing an Inferential Role Semantics (IRS).
I don’t want content to be constituted, even in part, by inferential relations. For one thing, as we just saw, I like Turing’s story that inference (qua mental process) reduces to computation; i.e. to operations on symbols. For fear of circularity, Ican’t both tell a computational story about what inference is and tell an inferential story about what content is. Primafacie, at least, if I buy into Inferential Role Semantics, I undermine my theory of thinking.
For a second thing, I am inclined to believe that an inferential role semantics has holistic implications that are both unavoidable and intolerable. A main reason I love RTM so much is that the computational story about mental processesfits so nicely with the story that psychological explanation is subsumption under intentional laws; viz. under laws thatapply to a mental state in virtue of its content. Since computation is presumed to respect content, RTM can maybeprovide the mechanism whereby satisfying the antecedent of an intentional law necessitates the satisfaction of itsconsequent (see Fodor 1994: ch. 1). But I think it’s pretty clear that psychological explanation can‘t be subsumptionunder intentional laws if the metaphysics of intentionality is holistic. (See Fodor and Lepore 1992.)
For a third thing, as previously noted, the main point of this book will be to argue for an atomistic theory of concepts. I’m going to claim, to put it very roughly, that satisfying the metaphysically necessary conditions forhaving one concept never requires satisfying the metaphysically necessary conditions for having any other concept.(Well, hardly ever.Jean-marc pizano