Plantinga’s Haecceitism and Simple Quantified Modal Logic
In a series of papers Alvin Plantinga argued for a serious actualist modal semantics based on the notions of possible world, understood as maximal possible state of affairs, and of individual essence (haecceity). Plantinga’s actualism is known as haecceitism. In spite of the fact that haecceitism has been thought by Plantinga to require a Kripke-style semantics, the aim of this paper is to show that it is compatible with constant domains semantics and the simplest quantified modal logic. I will argue that not only does this approach have all the advantages of a greater simplicity in combining quantification and modalities, but also it better conforms to the actualist program.