Critical Examination of the Distinction Between Analytical and Natural Law Schools

Introduction

Jurisprudence, at its heart, grapples with the fundamental question of "what is law?". The statement presented in the question draws a classic dividing line between two of the oldest and most influential schools of thought: the Analytical school, more commonly known as legal positivism, and the natural law school. The distinction suggests a neat separation of labour: positivists are like scientists, objectively describing the phenomenon of law as it exists in society, while natural lawyers are more like philosophers or moralists, concerned with evaluating law against a higher standard of what is right and just. This essay will argue that while this distinction provides a useful starting point for understanding the different focuses of these two theories, it is ultimately an oversimplification. By critically examining the core ideas of key thinkers like H.L.A. Hart and Lon Fuller, this essay will show that both schools are engaged, in different ways, with both the 'is' and the 'ought' of law. The real difference between them lies not in a simple choice between description and evaluation, but in their understanding of the relationship between law and morality.

The Analytical School: Describing Law 'as it is'

The central claim of the Analytical school, or legal positivism, is the 'separation thesis'. This is the idea that there is no necessary or conceptual connection between law and morality. Whether a rule is a valid law depends on its source—how it was made—not on its moral content. As John Austin, an early positivist, starkly put it, "The existence of law is one thing; its merit or demerit is another" (Austin, 1832). For Austin, law was simply the command of a sovereign, backed by the threat of a sanction. This approach is purely descriptive; it seeks to identify law by observing empirical facts: who holds power (the sovereign) and whether their commands are habitually obeyed. There is no room here for what the law 'ought to be'. A morally bad command from the sovereign is still, in Austin's view, a valid law.

This rather crude version of positivism was refined significantly by H.L.A. Hart in The Concept of Law. Hart moved away from commands and sanctions, instead describing law as a system of rules. He saw a legal system as a union of 'primary rules' (which impose duties, like the criminal law) and 'secondary rules' (which confer powers, such as rules about how to make contracts or how Parliament can legislate) (Hart, 2012). The most important of these secondary rules is the 'rule of recognition', which is the ultimate criterion used by officials in a legal system to identify valid law. For example, in the UK, the rule of recognition might be simplified as 'what the Queen in Parliament enacts is law'.

Hart’s project is very much in the spirit of describing law 'as it is'. Identifying the rule of recognition in a given society is an empirical task. One looks at what legal officials, like judges and MPs, actually do and accept as the standard for creating valid law. The morality of the rules they create is a separate question. Hart would argue that a law passed by Parliament according to the correct procedure is a valid UK law, even if we consider it profoundly unjust. We can, and should, use morality to critique the law, but this moral critique does not invalidate it as law. This maintains the core positivist commitment to separating the question of 'what is law?' from 'what ought the law to be?'.

The Natural Law School: Evaluating Law 'as it ought to be'

In direct contrast, the natural law school argues that law and morality are fundamentally intertwined. The core thesis is that for a rule to be a valid law, it must conform to a higher moral standard. This standard might be seen as deriving from God, human reason, or the inherent nature of humanity. The classic expression of this view is lex injusta non est lex—an unjust law is not a true law at all. This is not just a call for moral critique; it is a claim about legal validity itself. From this perspective, a rule that violates fundamental moral principles simply fails to qualify as law.

A modern and influential version of this theory comes from Lon Fuller. In The Morality of Law, Fuller introduces the concept of the "inner morality of law" (Fuller, 1969). He argues that for a system of rules to be properly called a 'legal system', it must meet eight key procedural requirements. These are principles of legality, such as that laws must be general, publicly promulgated, clear, non-contradictory, and prospective (not retrospective). Fuller uses the famous allegory of a hapless King Rex, who fails to make law because he violates every one of these principles.

Fuller’s theory is clearly concerned with what law 'ought to be'. He is not just describing any system of social control, but setting out the necessary moral conditions for a system to be worthy of the name 'law'. A system of rules that is secret, retrospective, and contradictory is not just a bad legal system; for Fuller, it is not a legal system at all. It is a failure in the enterprise of "subjecting human conduct to the governance of rules" (Fuller, 1969, p. 106). This directly connects the existence of law ('is') to its moral and procedural qualities ('ought').

A Critical Examination of the 'Is/Ought' Distinction

While the 'is/ought' distinction is a helpful initial guide, it breaks down under closer inspection. It wrongly suggests that positivists are uninterested in morality and that natural lawyers are uninterested in the reality of existing legal systems.

Firstly, sophisticated positivists like Hart do not ignore the 'ought'. Hart fully accepts that morality heavily influences the content of the law. Many laws, particularly in the criminal sphere, reflect prevailing moral views. Furthermore, he acknowledges that when judges are faced with 'penumbral' or hard cases where the existing rules are unclear, they may have to exercise discretion and draw on moral or policy considerations to reach a decision (Hart, 2012). The positivist claim is not that morality has no place in law, but that its presence is a contingent social fact, not a necessary condition for legal validity. Positivists separate the 'is' of valid law from the external 'ought' of moral critique, but they do not deny the importance of the latter. Indeed, Hart argued that by clearly identifying what the law 'is', we are in a better position to decide whether we 'ought' to obey or reform it.

Secondly, and perhaps more significantly, the work of natural lawyers is not purely evaluative. It is also descriptive. When Fuller sets out his eight principles of legality, he is making a claim about the very nature of law. He is attempting to describe the essential features that any system must possess to be a legal system. His theory is a description of the 'is' of law, but one where the 'is' is defined in a way that includes moral and procedural criteria. The Hart-Fuller debate over the validity of Nazi law illustrates this perfectly. Hart took the positivist view that, however evil, Nazi decrees were law because they were made according to the rules of the then-existing German legal system. Fuller argued that the Nazi regime so perverted the legal process, using secret and retrospective 'laws', that it failed to create a genuine legal system at all (Hart, 1958; Fuller, 1958). Both thinkers were trying to describe and make sense of a real-world situation ('what was the status of Nazi law?'), but their different starting assumptions about the relationship between law and morality led them to different conclusions.

Therefore, the distinction is not as clear-cut as the question suggests. It is not that one school describes and the other evaluates. Rather, both schools describe, but they have different ideas about what is essential to the concept of law being described. For the positivist, the essential feature is its source or 'pedigree'. For the natural lawyer, the essential features include a minimal moral content or procedural integrity.

Conclusion

In conclusion, the statement that "The Analytical school describes law as it is, whereas the natural law school evaluates law according to what it ought to be" captures a genuine difference in emphasis between the two great traditions of jurisprudence. Legal positivism prioritises a descriptive, sociological account of law, focusing on its sources and structure, while natural law theory insists on an evaluative dimension, linking legal validity to moral standards. However, to treat this as a rigid, binary opposition is to misunderstand both theories. Positivists do not deny the importance of morally evaluating the law, and natural lawyers are deeply concerned with describing the essential nature of what a legal system truly is. The 'is/ought' distinction is not a wall separating the two schools, but a lens that highlights their different starting points. The ultimate debate is not over whether to describe or to evaluate, but over whether a complete description of law can ever be truly separated from the moral and procedural ideals it ought to serve.

References

Austin, J. (1832) The Province of Jurisprudence Determined. John Murray.

Fuller, L. (1958) 'Positivism and Fidelity to Law: A Reply to Professor Hart', Harvard Law Review, 71(4), pp. 630-672.

Fuller, L. (1969) The Morality of Law, Revised edn. Yale University Press.

Hart, H.L.A. (1958) 'Positivism and the Separation of Law and Morals', Harvard Law Review, 71(4), pp. 593-629.

Hart, H.L.A. (2012) The Concept of Law, 3rd edn. Oxford University Press.