Much of the recent literature on political perfectionism has focused on dealing with objections to this view. This book adopts a different approach: It attempts to highlight the intuitive appeal of liberal perfectionism by presenting a positive prima facie argument in its favour. The book starts by clarifying the relation between political perfectionism — a conception of politics — and prudential perfectionism and ethical perfectionism — a conception of the good life, and a type of ethical theory. It is crucial to start by selecting a plausible form of ethical perfectionism, as it makes an important difference to the plausibility of the political conception based upon it. Once appropriate distinctions are drawn and a plausible form of liberal perfectionism is endorsed, many of the standard objections to perfectionism are shown to fail to reach their target. Different arguments in favour of liberal perfectionism are then proposed and critically examined, but the resilience of some pragmatic arguments against liberal perfectionism is conceded. The book ends by showing that perfectionism can be surprisingly relevant for discussions of social justice and proceeds to draw a sketch of the perfectionist implications for questions of distributive justice.