Abstract

In his _Being Known_ Peacocke sets himself the task of answering how we come to know about metaphysical necessities. He proposes a semantic principle-based conception consisting of, first, his Principles of Possibility which provide necessary and sufficient conditions for a new concept ‘admissibility’, and second, characterizations of possibility and of necessity in terms of that new concept. I focus on one structural feature; viz. the recursive application involved in the specification of ‘admissibility’. After sketching Peacocke’s proposal, I introduce a fictional protagonist, Cautious Peacocke, whose coherence I claim shows that Peacocke’s proposal cannot be made good. I conclude with the conjecture that similar failure will attend any such semantic-based attempts to ground the epistemology of metaphysical necessity.