 In 1961, Hart’s book The Concept of Law raised issues that have occupied legal philosophers ever since. He borrowed J.L. Austin’s method of ‘using a sharpened awareness of words to sharpen our perception of the phenomena’ (Hart 2012, v, 14). Hart’s observations about the use of language in law were elements in an innovative approach to explaining the normativity of law—that is, the fact that law presents itself as conferring rights and powers and as imposing obligations and liabilities. Hart argued that we can understand that feature of law more clearly, if we understand where Bentham and his nineteenth-century disciple  John Austin  (not to be confused with J.L.Austin) went wrong in explaining the meaning and use of normative language. Hart’s new approach to the issue has been a starting point for discussions of the normativity of law since the 1960s (see section 6.2 below).