The history of moral philosophy has been dominated by attempts to find and defend the correct moral principle or set of principles. However, over the last two decades the assumption that morality can and should be understood in terms of principles has come under attack from several quarters. The most radical attack has come from so-called moral particularists according to whom principles are at best useless and at worst a hindrance to successful moral reasoning and action. Why should - and how can - morality be based on principles? These are the leading questions of this book. Moral Principles offers a historically informed, in-depth examination of the current particularist/generalist debate and presents a novel account of the place of principles in our moral thought and action.