John Austin famously claimed that the idea of sanctions is “the key to the science[] of jurisprudence.” Thus, he held legal rules to be threats backed by sanctions and statements of legal obligations as predictions that the threatened sanctions will be carried out. And before The Concept of Law was published in 1961, the concept of sanctions was central to every other positivistic theory of law as well. Although Hans Kelsen sought to explain legal rules and obligations in terms of norms, he understood these norms to be directives to courts requiring that sanctions be applied. Splitting the difference between Austin and Kelsen, Alf Ross conceived of legal rules as norms addressed to courts directing the use of sanctions and statements of legal validity as predictions that these norms will be followed