guise theory a system developed by Castañeda to resolve a number of issues concerning the content of thought and experience, including reference, identity statements, intensional contexts, predication, existential claims, perception, and fictional discourse. For example, since (i) Oedipus believed that he killed the man at the crossroads, and (ii) the man at the crossroads was his (Oedipus’s) father, it might seem that (iii) Oedipus believed that he killed his father. Guise theory blocks this derivation by taking ‘was’ in (ii) to express, not genuine identity, but a contingent sameness relation betweeen the distinct referents of the descriptions. Definite descriptions are typically treated as referential, contrary to Russell’s theory of descriptions, and their referents are identical in both direct and indirect discourse, contrary to Frege’s semantics. To support this solution, guise theory offers unique accounts of predication and singular referents. The latter are individual guises, which, like Fregean senses and Meinong’s incomplete objects, are thinly individuated aspects or ‘slices’ of ordinary objects at best. Every guise is a structure c{F1 . . . , Fn} where c is an operator expressed by ‘the’ in English – transforming a set of properties {F1, . . . , Fn} into a distinct concrete individual, each property being an internal property of the guise. Guises have external properties by standing in various sameness relations to other guises that have these properties internally. There are four such relations, besides genuine identity, each an equivalence relation in its field. If the oldest philosopher happens to be wise, e.g., wisdom is factually predicated of the guise ‘the oldest philosopher’ because it is consubstantiated with ‘the oldest wise philosopher’. Other sameness relations account for fictional predication (consociation) and necessary external predication (conflation). Existence is self-consubstantiation. An ordinary physical object is, at any moment, a cluster of consubstantiated (hence, existing) guises, while continuants are formed through the transubstantiation of guises within temporally distinct clusters. There are no substrates, and while every guise ‘subsists,’ not all exist, e.g., the Norse God of Thunder. The position thus permits a unified account of singular reference.
One task for guise theory is to explain how a ‘concretized’ set of properties differs internally from a mere set. Perhaps guises are façons de penser whose core sets are concretized if their component properties are conceived as coinstantiated, with non-existents analyzable in terms of the failure of the conceived properties to actually be coinstantiated. However, it is questionable whether this approach can achieve all that Castañeda demands of guise theory. See also CASTAÑEDA, PRACTITIO. T.K.
