Concepts of property are used to describe the legal and ethical entitlements that particular people or groups have to use to mage particular resources. Beyond that most general definition of 'property' however, philosophical controversy reigns. Political and legal philosophers disagree on what types of entitlements are essential elements of property, and on the shape and ture of the resultant property entitlements. Indeed, philosophers even disagree on whether it makes sense to talk, in abstraction from a specific legal context, of concepts of property at all. These theoretical controversies are mirrored in practice and law. Cases are determined and conflicts are resolved - or fomented, as the case may be - by the different ideas of property that claimants, judges, legislators and ordiry people recognise and deploy. This article surveys the major types of contemporary property theories, and the philosophical arguments offered in support of them.