Wilfrid Sellars' theory of language and the problem of intentionality

The controversy between the scientific realism of Wilfrid Sellars and the Brentano-Chisholm psychological thesis of intentionality is evaluated in terms of their explication of the notion of meaning in the context “‘…’ means ___.” The intentionality thesis holds that the language we use to describe or express mental phenomena such as beliefs, wishes, hopes, desires, etc., cannot be reduced to or translated into a nonmental or physicalist language. Thus there are certain criteria which language used to express or describe mental phenomena, but which language used to describe nonmental phenomena fails to meet. These criteria then, constitute reliable standards for distinguishing the mental from the nonmental.. The intentionality thesis is therefore construed as a defense of mind-body dualism and, while conceiving language to be primarily the expression of thought, as providing no causal account of thought. The scientific realism of Wilfrid Sellars is construed as an attempt to provide a causal account of thought. Thus Sellars' argument is not directed against the criteria established by the intentionality thesis, but towards suggesting nonmental sources for the intentionality of thought. Sellars does not deny that an intentional language is proper for describing or expressing mental phenomena, but claims that once the semantical nature of this language is understood, it will be seen to be compatible with a metalinguistic vocabulary that pertains fundamentally to overt verbal behavior. Such compatibility would help explain both the phenomena of mental acts and mental actions and the propriety of an intentional language in behaviorism.