Actualism, serious actualism, and quantified modal logic (Q1750301)

The paper navigates in the waters between metaphysical doctrine and formal logical representation. The goal is to build a first-order modal logic that accommodates both ``actualism'' (the view there are no merely possible things, that is, things that do not exist but have some alternative kind of being) and ``serious actualism'' (that all sentences attributing properties using non-designating constant terms are necessarily false) in a manner that preserves both logical truth under uniform substitution of complex predicate abstracts for simple ones and plain truth under replacement of logically equivalent subformulas, as well as admitting a sound and complete proof system.