The moral debate over paternalism concerns, roughly, the conditions under which it is permissible to intervene in a person’s affairs for that person’s own good. This debate raises a set of questions – for instance, about the limits of government authority, the significance of personal autonomy, and the norms appropriate to various interpersonal relationships – that have been widely debated among both scholars and the general public. This introduction to The Routledge Handbook of the Philosophy of Paternalism briefly surveys several of these issues. It first discusses difficulties in the definition or characterization of paternalism. It then considers several questions relevant to the moral permissibility of paternalism and discusses how these questions arise in contexts such as medical ethics, public policy, and interpersonal relationships. In doing so, it paves the way for a fuller discussion in the chapters to follow. It concludes that the philosophical debate over paternalism will likely continue to attract interest, because of the theoretical and practical importance of the issues it raises.