Abstract: In this paper, an example of the kind of essentialist argument that is supposed to generate difficulties for quantified modal logic is shown to be invalid on one interpretation, and valid but unable to generate categorical necessities without the ad hoc addition of essentialist premises, on another. The paper specifies how attributes figure in quantified modal logic, and also gives a formal characterization of essential properties.

Keywords: essentialism, quantified modal logic, Quine,