• Charles E.Cheadle

A Basic Introduction to Jurisprudence



Jurisprudence is the theory of Law. To understand the basic principles behind the law helps guide a lawyer in the correct direction as to what the law actually says when there is a grey area, answering the question: what happens when the law runs out? Unhelpfully, however, the discipline is not an exact science and there are differences of opinion when considering which principles should underpin the law. Perhaps Jurisprudence doesn’t fulfil its job quite so succinctly, as different people will arrive at different outcomes as to what the law should say depending on which principles they follow. This article will take a look at the four main theories which will give the reader a chance to consider which they think is the most convincing.


There is a spectrum on which each of the theories lie. The farthest left side of the spectrum is a theory known as ‘strong’ natural law, which claims there to be a strong, if not intrinsic link, between morality and the law. Conversely, the farthest right side of the spectrum is home to ‘exclusive’ legal positivism, which claims there to be no link whatsoever between the law and morality. The theories in between these two on the spectrum are guided by the overarching principles on either side, but allow some exceptions.


Thomas Aquinas is the founder of strong natural law. He claims that an ‘unjust law is no law at all’. This is because Aquinas believed there to be a close relationship between the rationality of the law and its morality. Society generally believes that the law has a right to impose restrictions on your person. One must not go out and kill someone, otherwise they face the charge of murder. However, Aquinas argues that there must be a moral justification to impose such restrictions. Morally, society believes murdering people is bad. Nevertheless, Aquinas continues to say that in order for the law to be moral, it must be rational – based on reason or logic – or there would be no justification to order you to do something. The logic and reason behind murder laws is that it prevents anarchy and chaos. Hence, Aquinas calls law an ‘ordinance (authoritative order) of reason’.[1]


On the other hand, an immediate critique of strong natural law is a literary one when the statement ‘an unjust law is no law at all’ is looked at in its contrapositive form it is transformed into: ‘if it is law then it must be just’. Put simplistically, Aquinas' claim is saying that any laws passed are just. Following this claim, the set of laws that we have today must be just, otherwise they are not law. There are two issues here. Firstly, the fact that ‘laws are made that could be unjust disproves strong natural law’, for example, former laws permitting slavery. [2] Secondly, a quietism may be promoted if one believes the fact that any laws passed must be absolutely moral. They are less likely to question and critique the law and, ironically, the less criticism the government receives over its laws may simply promote an abuse of power for more immoral laws to be passed to benefit themselves.


Mark Murphey (2005), however, argues that it is linguistically possible to argue that an unjust law is not a law. He uses the example of a glass diamond. Whilst it is a diamond in its shape, it does not have the chemical composition of a real diamond – the four carbon, covalent, bonds; it is simply ‘diamond-like’. Placing this idea in a legal context, unjust laws can become law but they may be considered to be ‘fake’, ‘defective’ or ‘counterfeit’. It is law, but not real law. Nonetheless, the distinction that Mark Murphey gives rise to suggests that an unjust law isn’t completely removed from the category of being law. This idea is called ‘weak natural law’; an unjust law is a defective law. This view moves slightly over to the right of the spectrum. The law and its connection to morality is placed on a higher level. Moral laws are ranked higher than those considered unjust.


However, the principles so far rely on the assumption that the law's job is to do something moral. If one is to move away from this assumption, they enter the realm of legal positivism. Here, there is a different way to assess whether the law is defective; it is within its legality. To use the example of Dr Ken Enhrenberg, if a law was promulgated to increase the orderliness of society that stipulated everyone had to wear straight jackets every time they went out, it would certainly achieve its function in increasing orderliness. The law has achieved its function and aim – hence it’s not defective in its legality as it can do its job - but at the consequence of being immoral. If one considers the most important thing for the law to achieve is to fulfil a function, then it has done just this, regardless of its morality.


It is this view that John Austin purports in his slogan: ‘the existence of law is one thing; its merit and demerit another’. Austin argues that legal positivism and its disconnection of morality and the law are important in order to be able to properly critique the law. To determine what the law says first and then critique it from a moral view; this segregates the idea of an intrinsic relationship between the law and morality. It is almost in direct refute to Aquinas’ claim which, as mentioned, arguably promotes an air of quietism regarding the critiquing of the law. Austin points out a major flaw in Aquinas’ claim by saying that if all law is just, the law cannot be improved because it is already just.[3] Why would one need to improve just law? Instead, Austin argues through his Command Theory that ‘Law is the command of a sovereign backed by a threat of force’, which is the classical legal positivist view. One is incentivised not to break the law otherwise they will face a punishment.


However, isn’t the law itself and not the threat of the punishment meant to be the reason to follow the law? The law and its content itself should carry some reason, respect and authority that society follows regardless of the threat or punishment that breaking the law carries. It is a negative view to believe that the only reason we have an orderly society that doesn’t descend into anarchy is totally due to the coercive nature of the law. Surely, to some extent, society respects the law because humans are sentimental beings that like the order, continuity and reasonableness that it provides. Whilst coercion and threats are certainly a factor in people following the law, Austin’s theory doesn’t fully take into account of how the law presents itself as a reason for following it.


H.L.A Hart responds to Austin’s Command Theory in his famous book ‘The Concept of Law’. His theory is that the law is a union of primary and secondary rules. The primary rules are duty imposing which tell you to do or not to do something. Secondary rules, however, are rules about the primary rules. ‘These are rules about how to change the primary rules: who has the power to make the primary rules and how they are made. This isn’t about government and the courts, but includes things like how to make a will. By making a will, you are creating new primary rules for other people’.[4] Hart recognises that the law doesn’t solely concern itself with rules backed by threats like Austin suggests. He notices that the law goes deeper than this through its secondary rules. For example, it sets outs the precedents of how to write a legally valid will and the need for two independent witnesses, but doesn’t force one to create a will. Hart was integral to developing the legal positivist outlook by creating a more nuanced view of the legality and function of the law. Both Hart and Austin, however, believed the law to be a social fact and its validity to have no connection to morality.


Nevertheless, in more recent years there has been a growing divide amongst legal positivists. Those who believe that certain systems can choose to base legal validity on morality are coined ‘inclusive legal positivists’. Arguably, the USAs system is set up to facilitate inclusive legal positivists with their constitution regulating certain moral conditions and criteria that the law must meet for it to become legally valid. However, ‘exclusive legal positivists’ believe that by making morality a criterion for officials to adjudicate, its legal validity transfers them too much discretion and the decision becomes too subjective for an individual/s opinion.


In summary, there are four theories on the relation of the law to morality. Strong natural law claims that a law must be moral for it to be legally valid. Weak natural law claims that an immoral or unjust law can be legally valid but is defective. Inclusive legal positivism argues that a system can choose for morality to be a criterion for legal validity but by no means is a system bound to this. Finally, exclusive legal positivism believes that no system should include morality as a factor to base legal legitimacy. It is down to the reader to decide where they lie.









[1] https://www.futurelearn.com/courses/general-jurisprudence/1/steps/1214800 - Jurisprudence: Introduction to the Philosophy of Law, University of Surrey, FutureLearn [2] Quote by Dr Ken Ehrenberg, Reader in Public Law and Legal Theory at the University of Surrey. [3] Classical Legal Positivism, 1.17, FutureLearn, An Introduction to Jurisprudence, Surrey University [4] Hart’s response to command theory: law as the union of primary and secondary rules, An Introduction to Jurisprudence, 1.22, Surrey University - https://www.futurelearn.com/courses/general-jurisprudence/1/steps/1215016