The concept of what justice is and what constitutes a good life vary from jurist to jurist and thinker to thinker. HLA Hart is one of the most well known jurists to come up with a concept of law that was widely acclaimed but was aggressively challenged as well. In hid masterpiece, The Concept of Law, Hart recognizes the legal system as the "combination of primary rules of obligation with the secondary rules of recognition, change and adjudication" (Hart, p. 98). Hart maintains that law is a combination of primary and secondary rules which serve as "not only the heart of a legal system but a most powerful tool for the analysis of much that has puzzled both the jurist and the political theorist" (Hart, p. 98). Hart is of the view that law as we exercise it is the sum or the system of rules. He takes a rather linguistic approach towards the explanation of the rules, laws, legal system and the concept of justice. He believes that the various sets of rules represent the term law and these rules are understood and practiced and represented by words. The specific usage of language determines the kind of social functions that these rules are suppose to perform. Some rules that are though legal in nature perform the social function of imposing duty or demand rigid accountability of acts whereas some rules perform the social function of conferring power. Hart explains his concept of the legal style with reference to rule-based versus case-based law. The author believes that one way to differentiate between the rule-based law and the case-based law is that though the rules utilize greater power of the words and their meanings, they are not as "open textured" as case laws. .

             The concept is further explained by the author with the help of the difference of language and procedures and rules of the two kinds of law. Rule-based laws are based on rules that are in turn based on the medium of communication, in our case the language of English.