The Concept of Law is one of the most influential texts in English-language jurisprudence. 50 years after its first publication its relevance has not diminished and in this third edition, Leslie Green adds an introduction that places the book in a contemporary context, highlighting key questions about Hart's arguments and outlining the main debates it has prompted in the field. The complete text of the second edition is replicated here, including Hart's Postscript, with fully updated notes to include modern references and further reading.