According to Law in Legal Languagengocthanh
This approach is not only simpler; it fills the void left by Hart in his theory. According to Hart, the meaning of normative language differs in morality and law. But in fact, Hart had nothing to say about the meaning of normative expressions like “should” and “must” or “obligation” or “right” (except that their meaning differs in law and morality). He only pointed out that people show an attitude when they use such language. A full-time lawyer employed by the federal courts to legally defend defendants who cannot afford a lawyer. The judiciary administers the Federal Defence Lawyers Programme in accordance with the Criminal Justice Act. Hart argued that a legal system is a system of rules that confer power and impose obligations that are validated by a “recognition rule.” This rule is not valid by any other rule; This is a “social rule”. To explain this crucial notion of social rule, Hart turned to the use of words to explain the normativity of the law. He asserted that a social rule is a pattern of regular behavior accompanied by a “distinctive normative attitude” that “consists in the constant readiness of the individual to take such patterns of behavior both as a guide for his own future behavior and as norms of criticism” (Hart, 2012, 255). In explaining this disposition, or “inner attitude,” Hart focused on acts of speech — the use participants make in practice of normative language.
In 1961, Hart`s book The Concept of Law raised questions that have occupied legal philosophers ever since. He borrowed J.L. Austin`s method of “using an increased awareness of words to sharpen our perception of phenomena” (Hart 2012, V, 14). Hart`s observations on the use of language in law were part of an innovative approach to explaining the normativity of law – that is, the fact that the law presents itself as a delegation of rights and powers and as the imposition of obligations and responsibilities. Hart argued that we can understand this feature of the law more clearly if we understand where Bentham and his nineteenth-century student John Austin (not to be confused with J.L. Austin) erred in explaining the meaning and use of normative language. Hart`s new approach to the issue has been a starting point for discussions on the normativity of the law since the 1960s (see section 6.2 below). Some legal philosophers have responded to this problem by asserting that judges never (or almost never) have such a choice and that there is almost always a correct answer to a question of legal rights (Dworkin, 1986a, 1991). Others have responded to the problem by stating that the law gives judges the discretion, in all or some borderline cases, to decide issues that the law does not establish (Hart, 2012, Chapter VII.1). That is, the standards of the system give judges the choice of how to decide the issue. Then, judges must treat the parties to the dispute as if they had responsibilities or obligations or claims that were not definitively theirs at the time the dispute arose.
This power of judges seems to run counter to a certain requirement of the rule of law: that laws (or at least these legal burdens) not be imposed retroactively. It may seem that judges only have to make such judgments in cases that are limited to the application of legal language – and that they have a margin of appreciation in these cases (i.e. the judge must make a decision that is not established by law). This, one might say, would confirm the source`s thesis. But a clear case of a vehicle is considered a “vehicle” within the meaning of the Road Traffic Act simply because the evaluative considerations justifying the use of the word “vehicle” in this context clearly support its application. The source`s thesis seems to be contradicted even in the clearest cases of application of a law mentioned in descriptive language, where the content of those laws depends on how the purposes of the law are to be understood. This form of evaluation, one might say, can only be achieved by the same form of argumentation that excludes the law in Raz`s theory. As an example of a controversy over the effects of the use of language in law, we consider Garner v. Burr  1 KB 31.