Published online by Cambridge University Press: 14 March 2022
This paper argues that if a person's beliefs are idealized as a set of sentences (theoretical, observational, and mixed) then the device of Ramsey sentences provides a treatment, of the mind-brain problem, that has at least four noteworthy characteristics. First, sentences asserting correlations between one's own brain state and one's own “private” experiences are, on such treatment, reconstrued as neither causal, coreferential, nor as meaning postulates, but as clauses in an overall hypothesis (Ramsey sentence) whose only nonlogical constants have “private” meanings. Second, sentences asserting psycho-physical correlations in general, or in other individuals, remain theoretical and susceptible to scientific reduction, though not prejudged to be so. Third, communication between persons having mutually exclusive, “private,” observational vocabularies can be made intelligible. Fourth, it becomes possible in principle (though not necessary) that the world could ultimately be given a total description in a scientific language, Lφ, without mental primitives. However, such a language would be susceptible to interpretation by a given individual using a metalanguage whose primitives (not among those of Lφ) were privately observational to that individual. His procedure in accomplishing such an interpretation would be to construct a Tarskian truth definition in a metalanguage MLφ and then to incorporate it, by Ramsifying its descriptive terms, in his own overall Ramsey sentence. The physical language, Lφ, while not containing a person's primitives, would, of course, be able to define their physical correlates, thus providing a certain sort of mutual mirroring, and a certain sort of relativity.
This paper is in almost exactly the form in which it was presented to a Philosophy Colloquium at Michigan State University in May, 1973. As a consequence, it sometimes reviews well-known matters, and at other times it makes use of challengeable simplifications with little or no acknowledgment of their problems. A more defensive treatment of their problematic would, I think, have obscured the idea itself. The idea itself may best be viewed as an application of the Ramsey sentence approach to the analysis of language urged in my [1] and [2].