Carnap's theory of descriptions was restricted in two ways. First, the descriptive conditions had to be non-modal. Second, only primitive predicates or the identity predicate could be used to predicate something of the descriptum . The motivating reasons for these two restrictions that can be found in the literature will be critically discussed. Both restrictions can be relaxed, but Carnap's theory can still be blamed for not dealing adequately with improper descriptions.

Fregean theories of descriptions as terms have to deal with improper descriptions. To save bivalence various proposals have been made that involve assigning referents to improper descriptions. While bivalence is indeed saved, there is a price to be paid. Instantiations of the same general scheme, viz. the one and only individual that is F and G is G, are not only allowed but even required to have different truth values.

This paper examines and discusses an argument for the collapse of modal distincions offered by Quine in "Reference and Modality" and in Word and Object that relies exclusively on a version of the Principle of Substitution. It is argued that the argument does not affect its historical targets: Carnap's treatment of modality, presented in Meaning and Necessity, and Church's Logic of Sense and Denotation, developed by Kaplan; nor does it affect a treatment of modality inspired in Frege's treatment of oblique (...) contexts. It is argued, nevertheless, that the immunity of those systems to Quine's argument depends on the success of their rejection of the Principle of Substitution presupposed by Quine. (shrink)

This note is a friendly amendment to Marti's analysis of the failure of Føllesdal's argument that modal distinctions collapse in Carnap's logic S2. Føllesdal's argument turns on the treatment of descriptions. Marti considers how modal descriptions, which Carnap banned, might be handled; she adopts an approach which blocks Føllesdal's argument, but requires a separate treatment of non-modal descriptions. I point out that a more general treatment of descriptions in S2 is possible, and indeed is implicit in Marti's informal discussion, and (...) that this treatment also blocks Føllesdal's argument. Further, I show by a semantic argument that no revised version of Føllesdal's argument could establish a collapse of modal distinctions. (shrink)

It is shown that de re formulas are eliminable in the modal logic S5 extended with the axiom scheme □∃xφ ⊃ ∃x□φ.