Guises and Perspectives: An Intentional and Hyperintensional Sketch
This work provides a formal framework for philosophers and logicians interested in intentionality and hyperintensionality, but it is an incremental contribution that formalizes existing philosophical ideas without empirical validation.
The paper develops a formal logic for guises based on Castañeda's internalist viewpoint, integrating Leibnizian containment semantics, an intentional operator, and modal logic. It establishes soundness and completeness, and analyzes hyperintensional phenomena such as substitution failure and de se reference.
This paper develops a formal logic for guises based on the work of Héctor-Neri Castañeda, who understood relations from an internalist viewpoint, following Leibniz. We introduce a syntax, model theory, and proof theory for an intensional logic in which guises (taken as bundles of properties equipped with intention) serve as primary semantic objects. The system integrates (i) a Leibnizian containment semantics for singular truths, (ii) an intentional operator that captures internal relations among guises, and (iii) a modal layer for possibility and necessity modeled as maximally consistent closures. We establish core metatheoretic results (e.i. soundness and canonical-model completeness sketches) and analyze hyperintensional phenomena such as substitution failure in intentional contexts, quasi-indexicality, and de se reference. We compare the framework to classical intensional semantics (Montague), property theory (Bealer), hyperintensional logics (Fine), situation semantics (Barwise and Perry), and to the Leibniz program for a calculus of concepts. The result is a selfcontained formal framework that demonstrates that relations are not external causal links but intentional internal structures encoded in the guises through which agents and objects are conceived: i.e., they are perspectives.