This chapter frames this book’s inquiry by discussing the question of what fixes the scope of consent and the methods to use in order to answer this question. The question of the scope of consent is a question about which moral changes are brought about by consent. When someone’s consent is valid, it releases the consent-receiver from duties. This book sets to one side the questions of which duties we have and which conditions must be met for consent to be valid. Instead, this book asks a downstream question. Phrased in terms of duties, this question is: of all the duties from which the consent-giver can release the consent-receiver, what determines the duties from which the consent-receiver is released by the consent-giver’s valid consent? To answer that question, this book will use four methods. First, this book will adopt the comparative method in moral philosophy by comparing the pros and cons of three rival accounts. Each account is made up of a view of consent, a principle for consent’s scope, and an argument that supports this view and principle. Second, this book will develop and evaluate these accounts by adopting the method of cases, which involves considering accounts’ implications for various cases. Third, this book will look at bigger-picture arguments. Fourth, this book will inform our discussion by drawing on work in the philosophy of mind, the philosophy of language, and epistemology.