Some arguments for the objectivity of ethical claims have a 'companion in guilt' form. These arguments defend the objectivity of ethical claims by comparing them with other claims the objectivity of which is not in doubt, but which share the features of ethical claims that lead some toward scepticism about ethical objectivity. In this book, the most influential manifestations of this strategy are subjected to critical analysis for the first time. Topics discussed include: value and mental content, the normativity of instrumental reason, the fact/value distinction, values and secondary qualities, objectivity in ethics and science, and the normativity of ethics, logic and mathematics. This book will be a useful resource for anyone interested in questions of objectivity in ethics and elsewhere. As well as offering an original perspective on some of the most hotly debated questions in philosophy, this book also serves as a systematic introduction to central issues in metaethics.