Thought-Contents and the Formal Ontology of Sense

摘要

This paper articulates a formal theory of belief incorporating three key theses: (1) belief is a dyadic relation between an agent and a property; (2) this property is not the belief's truth condition (i.e., the intuitively self-ascribed property which the agent must exemplify for the belief to be true) but is instead a certain abstract property (a thought-content) which contains a way of thinking of that truth condition; (3) for an agent a to have a belief about such-and-such items it is necessary that a possesses a language of thought, M _a , and that a (is disposed as one who) inwardly affirms a sentence of M _a in which there are terms that denote those objects.Employing an extended version of E. Zalta's system ILAO, the proffered theory locates thought-contents within a typed hierarchy of senses and their modes of presentation, the provisional definitions of which (suppressing complications added later to accommodate the contents of beliefs about beliefs) are as follows. A mode of presentation of e is a ternary relation of the sort [xyz z is a name in M _y that denotes x, and D _e yz] in which D _e is an e-determiner – a relation between agents and their mental expressions imposing a syntactico-semantic condition sufficient for such an expression to denote e therein. A sense of an entity e is an abstract property that contains a mode of presentation R _e of e by dint of encoding its property-reduct [x(y)(z)R _e xyz]. In particular, a thought-content is a sense T of an ordinary first-order property P containing a mode of presentation whose P-determiner D _P is such that, for any y and z, D _P yz entails that z is a -abstract [ v S] of M _y in which S is a sentence whose non-logical parts stand in appropriate semantic relations to the constituents of T's (some of which may themselves be senses).