Chapter 4 of Being Known outlines an integrated metaphysics and epistemology for the metaphysical—absolute—notions of necessity and possibility. The leading idea is to view the modal status of a proposition as the deliverance of a set of fundamental Principles of Possibility, and our ability to recognise modal status as issuing from an implicit knowledge of these principles. Peacocke aims at a middle way between the extremes of Lewis-style realism about modality and the various—conventionalist, expressivist, Wittgensteinian—forms of non-cognitivism that were prominent (...) in the last century. An attraction of his account is its unified treatment both of a priori logical—more generally, conceptual—necessity and possibility and of a posteriori necessities of essence, identity, origin and constitution, etc. The treatment is ambitious and rich in invention and original detail, but Peacocke professes himself more wedded to the general approach than to the particular development. I shall correspondingly confine my remarks, more or less, to the general approach. (shrink)