Christopher Peacocke

In their searching contributions to this Symposium, Gideon Rosen, Timothy Williamson and Crispin Wright identify a set of issues crucial for assessing the principle-based treatment of modality I presented in Chapter Four of Being Known. I thank them for such focused and thoughtful discussions. This response is organized as a series of questions and proposed answers that aim to address the issues they raise. I hope their contributions will be as helpful to the reader as they have been to me in understanding what is, and what is not, involved in the principle-based conception. My response will not consist only in defense and elaboration. On some issues, I will argue that the position formulated in Being Known needs supplementation. On others, especially those concerned with actualism and possibilia, it needs revision and a new positive theory.