From his earliest to some of his last writings, Hart has discussed the concept and justification of rights (Hart 1948a; EJP, chaps. 8,9). His work has inspired many detailed analyses and justifications of rights. Hart’s discussions are often in the context of other issues, such as the ascriptive use of language or the analysis of Bentham’s views. Moreover, although we here separate the analysis of the concept of rights from their justification, some of Hart’s writings address both issues. Regrettably, no paper presents his definitive views, which have changed over time.