conceptual-role semantics, (also known as “inferential-role semantics,” “causal-role semantics,” “computational-role semantics,” and “functional- role semantics”) an attempt to explain the INTENTIONALITY or CONTENT of a mental STATE in terms of relations (such as inferential relations [see INFERENCE]) a mental state bears to other mental states. For example, the content of my mental state concerning dogs may be constituted by relations to other mental states, such as those concerning mammals, those concerning domestication, and those concerning barking. Thus, any mental state has the content dog if it is a mental state that a person would be in as a result of drawing an inference from premises concerning domesticated barking mammals. Such an account of mental content seems especially compatible with the LANGUAGE OF THOUGHT hypothesis. For the same reasons that make conceptual-role semantics fit with the hypothesis of a language of thought, conceptual-role semantics is sometimes regarded as an account of the meaning of public language items. (See also USE THEORY OF MEANING.)
A key early proponent of conceptual-role semantics was Wilfrid SELLARS.
Conceptual-role semantics is widely regarded as most plausible as an account of logical concepts and terms such as “and.” Plausibly, the meaning of the truth-functional connective “and” is exhausted by the role it plays in truth- preserving inferences such as inferring from “John has slacks and Mary has a skirt” to “John has slacks.” One appealing reason for extending conceptual- role semantics beyond logical items is that it promises to account for the sorts of phenomena that support the postulation of Fregean SENSE. For example, there seems to be a difference in thinking that the Morning Star is bright and that Venus is bright even though the Morning Star and Venus are one and the same astronomical body. This difference is accounted for in conceptual- role semantics by positing different conceptual roles for the MENTAL REPRESENTATION of the Morning Star and the mental representation of Venus.
Conceptual-role semantics has a certain compatibility with FUNCTIONALISM given the emphases both theories place on the roles played by mental states. Certain versions of conceptual-role semantics, in emphasizing relations between mental states and de-emphasizing relations borne to states of the external world, have been appealing to adherents of INTERNALISM and METHODOLOGICAL SOLIPSISM. Other philosophers, more impressed with the insights of EXTERNALISM, have adapted conceptual-role semantics to involve content-constituting rela- tions to the external world in addition to relations between internal states, thus giving rise to accounts such as two-factor conceptual-role semantics. Many detractors of conceptual-role semantics have held that it gives rise to intolerable versions of HOLISM. See also CONTENT, THEORIES OF.