Bookreviews

At any given time, an individual has certain beliefs and certain procedures or methods for modifying those beliefs. In The Realm of Reason, as in his previous book, Being Known (1999), Christopher Peacocke is concerned with the elusive question of what it is for someone to be “entitled” to a given belief or procedure.1 According to Peacocke, an entitlement is a priori if it derives entirely from “grasping” certain concepts, where grasping a concept involves understanding the “constitutive” truth conditions of the concept. An entitlement is empirical if it also depends on experiential evidence of some sort. The individual has an inferential entitlement to a belief or procedure if the belief or procedure has been inferred from other beliefs to which he or she is entitled using procedures to which he or she is entitled. An individual can also have a perceptual entitlement to a belief about the environment, an introspective entitlement to a belief about his or her current experience, a testimonial entitlement through believing what he or she has been told, and so forth. The main theme of the present book is that all entitlements depend at bottom on a priori entitlements because, in Peacocke’s words, “Not all warrants can be empirical, on pain of regress” (31). More precisely, Peacocke claims that the possession conditions of a given concept determine truth conditions of the concept’s application. These possession conditions also involve fi nding it “compelling” to apply the concept in certain cases. Sometimes it is “clear” or “immediately obvious” (187) that in so applying the concept one is guaranteed to have satisfi ed the truth conditions. Sometimes it is “clear” that one has a default entitlement to take the truth conditions to be satisfi ed. Such guarantees or default entitlements are a priori entitlements. Clearly, Peacocke’s appeal here to what is “clear” or “immediately obvious” needs further explication because if “it is clear” means it is a priori clear, there has been little progress in explaining what it is for an entitlement to be a....