A conventional account of meaning for natural language does not work for mental representations.
@A mental representation is a system of symbols isomorphic to some aspect of the environment, used to make behavior-generating decisions that anticipate events and relations in that environment.@
@S represents that P = If optimal conditions obtain, S is tokened in x if and only if P and because P.@
Tye says explicitly that his proposal is only intended for perceptual representations.
@Obviously, this approach needs further amplification; but I have said enough to comment on the question of whether it can be used to understand mental representation generally. Clearly, there are difficulties. In particular, the account is not straightforwardly applicable to beliefs across the board. Take, for example, the belief that the Devil is an angel who fell from grace. What are the relevant optimal conditions here? And what about mathematical beliefs, the belief that 2 + 2 = 4, say?@
@According to conceptual role semantics (CRS), the meaning of a representation is the role of that representation in the cognitive life of the agent, for example, in perception, thought and decision-making. It is an extension of the well-known 'use' theory of meaning, according to which the meaning of a word is its use in communication and, more generally, in social interaction. CRS supplements external use by including the role of a symbol inside a computer or a brain.@
@For a large class of cases -- though not for all -- in which we employ the word "meaning" it can be defined thus: the meaning of a word is its use in the language.@
Peter jumped into a volcano.
⇒ Peter is dead.
⇒ Peter was crazy.
Peter is a bachelor.
⇒Peter is male.
⇒Peter is single.
⇒Peter is not a rock.
Conceptual role includes an internal and an external component.
@ In the famous "Twin Earth" thought experiment in Putnam (1975), we are asked to imagine that in 1750, there was a remote planet, Twin Earth, which was exactly like Earth except that instead of water (H2O), it had a different substance twin-water, say a different chemical compound XYZ. The macro properties of XYZ are supposed to be just like water : it looks and tastes like water, and it could be found in the rivers and oceans on Twin Earth, and so on. However, back in 1750 nobody on Earth or Twin Earth could distinguish between water and XYZ. Still, according to Putnam, an individual on Earth in 1750 who used the word "water" would have been referring to H2O and not XYZ. Of course, this person did not know that water is H2O. But according to the externalist, this should not have prevented him from referring to H2O when he used the term "water". If he had pointed to a sample of XYZ and said “That's water,” he would have said something false. Similarly, when an individual on Twin Earth in 1750 used the word "water", he would have been referring to XYZ and not H2O. stanford:externalism @
@"What we see at any given moment is in general a fully elaborated representation of a visual scene." From Churchland, Ramachandran, and Sejnowski (1994). A critique of pure vision. In Koch and Davis (Eds.) Large-Scale Neuronal Theories of the Brain Cambridge: MIT Press.@