In this book, Joshua Gert puts forward a distinctive and original combination of proposals for how to understand our basic normative concepts, including practical (ir)rationality, practical reasons, and (personal) harm. The broader aim of the book is to ‘demystify’ the normative by explaining how there can be irreducibly normative facts and properties in a world that is also truly described by natural science. Normative Bedrock follows on from Gert's 2004 book Brute Rationality , in which he describes the structural features of basic normative concepts. The bulk of Normative Bedrock has previously appeared in article form since 2007. This may account for the somewhat scattered way in which the different parts of his account are presented in this new book. Conscientious readers will find the index useful. According to Gert, our basic normative concepts are response dependent. Response-dependent concepts are ones the extension of which is in crucial ways dependent on how those who apply them are disposed to respond to their environment in particular circumstances. Basic response-dependent concepts are associated with a distinctive set of primitive responses, such as the visual experiences that (on Gert's view) partly fix the extension of colour concepts. The social function of these concepts, and the need for conformity in response that this entails, implies that their extension is fixed independently of the actual responses of any individual user. All response-dependent concepts are governed by a minimal norm of ‘accuracy’ that serves to isolate a set of responses as favourable for picking out the relevant property. They therefore enjoy a substantial degree of objectivity that distinguishes them, first, from concepts that fail to meet all these criteria (such as idiosyncratic expressions of subjective taste) and, secondly, from concepts that meet these criteria but for which there is some further story to be told (e.g., in terms of natural constitution or essence) about the nature of the relevant property. In Normative Bedrock , Gert develops response-dependent accounts of two normative concepts in particular, namely practical (ir)rationality and (personal) harm. He associates both concepts with a distinct set of primitive responses to the behaviour of oneself or others (a reaction of puzzlement in the case of irrationality, and reactions of aversion in the case of harm). Gert thinks that there is a necessary connection between behaviour we respond to as irrational and behaviour we respond to as harmful. This is a synthetic a priori connection that is knowable by means of armchair reflection on our basic normative dispositions and the features of the world to which they respond. Our knowledge of these connections constitutes our ‘faculty’ of normative intuition.