This essay presents a philosophical and computational theory of the representation of de re, de dicto, nested, and quasi-indexical belief reports expressed in natural language. The propositional Semantic Network Processing System (SNePS) is used for representing and reasoning about these reports. In particular, quasi-indicators (indexical expressions occurring in intentional contexts and representing uses of indicators by another speaker) pose problems for natural-language representation and reasoning systems, because--unlike pure indicators--they cannot be replaced by coreferential NPs without changing the meaning of the (...) embedding sentence. Therefore, the referent of the quasi-indicator must be represented in such a way that no invalid coreferential claims are entailed. The importance of quasi-indicators is discussed, and it is shown that all four of the above categories of belief reports can be handled by a single representational technique using belief spaces containing intensional entities. Inference rules and belief-revision techniques for the system are also examined. (shrink)

Neo-Russellianism, which incorporates both Millianism (with regard to proper names) and the thesis of singular Russellian propositions, has widely been defended after the publication of Kripke's Naming and Necessity. The view, however, encounters various problems regarding empty names, names that do not have semantic referents. Nathan Salmon and Scott Soames have defended neo-Russellianism against such problems in a novel way; to account for various intuitions of competent and rational speakers regarding utterances of sentences containing empty names, Salmon and Soames appeal (...) neither to entities similar to Fregean senses, e.g. propositional guises or modes of presentation, nor to Gricean implicatures. In this paper, however, I argue that their view slips into neo-Meinongianism; it is committed to nonexistent objects, assigns various properties to them, and allows quantifiers range over such entities. This, I conclude, makes Salmon and Soames' view less appealing, if not implausible. (shrink)

The consistent formalization of Meinong's object theory in recent mathematical logic requires either plural modes of predication, or distinct categories of nuclear or constitutive and extranuclear or nonconstitutive properties. The plural modes of predication approach is rejected because it is reducible to the nuclear extranuclear property distinction, but not conversely, and because the nuclear extranuclear property distinction offers a more satisfactory solution to object theory paradoxes.

This essay describes computational semantic networks for a philosophical audience and surveys several approaches to semantic-network semantics. In particular, propositional semantic networks are discussed; it is argued that only a fully intensional, Meinongian semantics is appropriate for them; and several Meinongian systems are presented.