that differentiated between those norms that have the authority of law and those that do not. Hart viewed the rule of recognition as an evolution from Hans Kelsen's "Grundnorm", or "basic norm". A posthumous reply to Ronald Dworkin, who criticized legal positivism in general and especially Hart's account of law in Taking Rights Seriously, A Matter of Principle, and Law's Empire. Persistent questions Hart begins The Concept of Law with a chapter titled "Persistent Questions." In the chapter, he lays out what he describes as "three recurrent issues." Hart asks the following recurring three questions for legal theory: "How does law differ from and how is it related to orders backed by threats? How does legal obligation differ from, and how is it related to, moral obligation? What are rules and to what extent is law an affair of rules?" Austin's "command theory" The starting point for the discussion is Hart's dissatisfaction with John Austin's "command theory": a jurisprudential concept that holds that law is command backed by threat and is meant to be ubiquitous in its application. Hart likens Austin's theory to the role of a gunman in a bank and tries to establish the differences between the gunman's orders and those made by law. (For instance, the gunman forces us to obey but we may not feel inclined to obey him. Presumably, obedience to the law comes with a different feeling.) Hart identifies three such important differences: content, origin, and range. In terms of content, not all laws are imperative or coercive. Some are facilitative, allowing us to create contracts and other legal relations. Austin believed that every legal system had to have a sovereign who creates the law (origin) while remaining unaffected by it (range), such as the bank scene's gunman, who is the only source of commands and who is not subject to other's commands. Hart argues that this is an inaccurate description of law, noting that laws may have several sources and legislators are very often subject to the laws they create. Hart lets us know that laws are much broader in scope than coercive orders, contrary to the "command theory" of Austin. Frequently laws are enabling and so allow citizens to carry out authoritative acts such as the making of wills or contracts which have legal effect. Social habits and rules Hart draws a distinction between a social habit (which people follow habitually but