Counter-intuitivity and the method of analysis

Abstract

MR. LINsKIY rightly says that the sentences 3 and 4 are not logically equivalent. Thney are deducible from each other only if a further premise concerning the person X is added. This premise might state, for example, that X knows English and is aware of the logical equivalence of 1 and 2. This correction does not, of course, change the validity of my assertion that 2 and 4 have different contents. This assertion hardly needs to be supported by technical arguments; it is sufficient to point out that if the vessel contains alcohol but X has not observed it or heard about it, then 2 holds but 4 does not. Just as I did, so Linsky now supports a correct assertion by an incorrect argument. He shows correctly that 3 is not extensional. (This result is well known; Frege and Russell have shown that statements concerning propositional attitudes, like believing, knowing, and the like, are, in general, nonextensional.) This, however, is not a sufficient reason for asserting the nonderivability of 4 from 3, since 1 and 2 not only have the same truthvalue, but are logically equivalent. We must rather show that 3 is neither extensional nor intensional. This I have shown for the psychological statements of the kind mentioned in Meaning and Necessity (p. 54).