An alternative semantics for quantified modal logic

This paper proposes an alternative, alien-free semantics for quantified modal logic grounded on a radical being-constraint principle. The authors argue that only actual entities can appear in the extension of non-modal formulas, including their negations, and they formalize this constraint through a novel model-theoretic framework. Philosophical motivations and implications are discussed, especially regarding actualism, contingentism, and essentialism.