 Eric Stencil has provided a general discussion of the disagreement between Leibniz and Arnauld about Modal Metaphysics. “Modal metaphysics,” Stencil says, “is the theory of possibility, necessity, essence and God’s relation to each” (Stencil. 2016, p. 2). Arnauld attacks Leibniz’s thesis that the individual concept of each person contains once for all everything that will ever happen to him, Leibniz’s claim that there are “purely possible” substances, and his associated view that God creates by choosing one from a multitude of possible worlds. Stencil argues that Arnauld’s criticisms are based on a positive view which Stencil describes as “a sophisticated essence-based modal actualism,” containing three theses: (1) Everything that exists is actual (ontological actualism). (2) The actual world is irreducibly modal; there is no reductive analysis of modality (modal actualism). (3) All true de re counterfactuals are grounded in the irreducibly modal essences of actually existing things (essence-based modal actualism) (Stencil, 2016, p. 2–3). Stencil says that Arnauld’s view “could be developed into a plausible view in its own right” and that,