The Civil Partnership Act 2004 is a groundbreaking piece of legislation, giving legal recognition to same-sex relationships and providing equality of treatment in regard to inheritance and other financial matters with that enjoyed by married couples. The legislation was opposed by certain religious communities for a variety of reasons. This article is the text of an address delivered by Lord Falconer of Thoroton to the annual conference of the Ecclesiastical Law Society on 1 April 2006. It provides a personal reflection on the nature of the legislation and the necessity for its enactment, and seeks to demonstrate that the concept of civil partnership does not undermine the nature of marriage. It also discusses the Act in the context of law and social attitudes with particular reference to the Hart/Devlin debate of the 1950s and 1960s.