This classic collection of essays, first published in 1979, has had an enduring influence on philosophical work on the nature of law and its relation to morality. Raz begins by presenting an analysis of the concept of authority and what is involved in law's claim to moral authority. He then develops a detailed explanation of the nature of law and legal systems, presenting a seminal argument for legal positivism. Within this framework Raz then examines the areas of legal thought that have been viewed as impregnated with moral values - namely the social functions of law, the ideal of the rule of law, and the adjudicative role of the courts. The final part of the book is given to understanding the proper moral attitude of a citizen towards the law. Raz examines whether the citizen is under a moral obligation to obey the law and whether there is a right to dissent. Two appendices, added for the revised edition, develop Raz's views on the nature of law, offering a further dialogue with the work of Hans Kelsen, and a reply to Robert Alexy's criticisms of legal positivism. This revised edition makes accessible one of the classic works of modern legal philosophy, and represents an ideal companion to Raz's new collection, Between Authority and Interpretation.

约瑟夫．拉兹（Joseph Raz），牛津大学法哲学教授、巴利奥尔学院（Balliol College）研究员，哥伦比亚大学法学院法理学访问教授。主要从事法律、道德和政治哲学教学与研究工作，在法理学、政治哲学、道德与实践理性领域颇有建树。拉兹是当代道德、法律与政治领域最杰出的学者之一。

拉兹1963年毕业于耶路撒冷希伯来大学；1967年获牛津大学哲学博士学位；1972年成为牛津大学巴利奥尔学院法学研究员和导师；自1977年在哲学系工作，1985年牛津大学为了表彰拉兹在法哲学领域的杰出贡献，专门为他新设了一个学术职位：法哲学教授。拉兹曾先后在多所著名大学做过访问教授，如洛克菲勒大学，加利福尼亚大学，耶鲁大学，普林斯顿大学，密歇根大学，澳大利亚国家学院，等。

拉兹是英国研究院研究员、美国人文与自然科学院名誉会员。主要著作有：《法律体系的概念——一种法律体系理论的介绍》、《法律、道德和社会》、《实践理性》、《法律的权威——关于法律与道德论文集》、《自由的道德》等。