By: Nathan Bell
Legal philosophy is the analytical study of fundamental questions on the nature of law. It provides the foundations for justice, rights, and morality. The nature of human action and intention also finds roots within legal philosophy, as does the nature of truth and knowledge. The philosophy of law provides a platform by which to question the law’s authority and reach, and by tracking the development of legal philosophy it provides clarity in determining where contemporary legal theories and practices have arisen from.
Law has been discussed since humans could govern each other, however, its abstract nature was not truly discussed until Ancient Greece. Firstly by Homer (BCE c. 700) in his poems and Herodotus (BCE c.484) in his Histories; the discussion was furthered by Sophocles in his tragedy Antigone, which first linked questions on law and its potential conflict with morality, and in which the protagonist disobeys the laws of a tyrant for her own legal beliefs.
However, it is Plato (c.428-328 BCE) who first advances claims on the nature of law. In Crito, through his teacher Socrates, Plato discusses the nature by which one must follow the law. Particularly, breaking or disobeying the law. Charged with impiety and the corruption of the youth of Athens, and having failed to convince the state of his innocence, Socrates elects to not break the law, but instead follow it, accepting his death sentence. Socrates reasons this argument that as he has availed of and been protected by these laws throughout his life, he must obey them as others have. Plato’s works proposed the idea that due to the law’s authority over people, this gives rise to an almost unquestioning obedience
Aristotle (c.384–322 BCE) gave true expression to Plato’s ideas. Defining man as a “political animal”, naturally organising themselves into distinct communities of the largest being the cities or polis. The cities are defined by their politeia, commonly meaning “constitution” but in actuality referring to the way a polis organises itself.  For these polis “law is order”, constituting a society that provides comprehensive rules and institutions, by which it may be governed. To Aristotle the law is universal, it is general and a standard of conduct that can be applied anywhere. Aristotle maintained that, should this fail, a correction he called “equity” is required, which entails considering the novel case where the law has failed, and applying it, then adapting the law to fit a new purpose.
Aristotle was also the first to articulate the rule of law. Aristotle shared the Grecian opinion that law was the means by which to regulate political power, especially tyrannical power. On whether the best people or laws should rule the aforementioned polis, Aristotle stated:
“[he] who bids the law rule may be deemed to bid God and Reason alone rule, but he who bids man rule adds an element of the beast; for desire is a wild beast, and passion perverts the minds of rulers, even when they are the best of men. The law is reason unaffected by desire”.
Despite taking great influence from Greek society, Rome established its own legal institutions, along with the first lawyers. Their practice of legal writing culminated in Justinian I’s (c.527-565 CE) Digesta, which serves as fundamental for many contemporary judicial systems. Roman legal philosophy endured for several years, through to the Middle Ages, where it was refined wholly, particularly within Christian theology and tradition.
Roman philosopher and jurist Cicero (c.106-43 BCE) developed the most definitive “natural law” conception. Cicero sought to situate human-enacted Roman law in relation to objective moral truths. In his dialogue De Republica he echoed Sophocles:
“True law is the right reason in agreement with nature with universal application, unchanging and everlasting … It is a sin to try to alter this law, nor is it allowable to attempt to repeal any part of it, and it is impossible to abolish it entirely…We cannot be freed from its obligations by senate or people… And there will not be different laws at Rome and at Athens, or different laws now and in the future, but one eternal and unchangeable law will be valid for all nations and all time”
Cicero set strict moral conditions on human-enacted law that must be met to be considered valid; “Those who formulated wicked and unjust statutes for nations, thereby breaking their promises and agreements, put into effect anything but”. St Augustine of Hippo’s claim that “a law that is not just, is not actually a law” represents well the natural-law position.
Natural moral law theory was systematically developed by St Thomas Aquinas (1224-74). He developed the Aristotelian principles of what value and nature are (alongside politics), but modified them to be something new entirely – this also included his treatment of law. He defined law as an “ordinance of reason”, meaning that it was produced by and responded to through reason, something distinctly human. He claimed that law had a purpose. For Aquinas, this was to benefit a political community.
Aquinas’ idea was that human-created law is necessarily drawn from objective truths and that it is actualised in two ways. The first is that law can be a derivative from morality; for example, the ethical principle that taking a life is an offence. From this principle arises the prohibited act of murder. Secondly, law may be ethically derived through a process Aquinas named determinatio – the evaluation of how ethical principles applied in different circumstances with the goal being to help humans work better together. An example can be found in traffic laws - it is not morally vital that humans drive on a particular side of the road, but a determination from a legislative authority due to its indirect connection to ethical principles, will bind its citizens. Aquinas suggested if human-enacted law is not determined from ethics, then such laws are “unjust”, and as Augustine stated, will fail to be “law”. If they are not “just” then they have no authority over the citizens that have an obligation to follow them. Aquinas’ discussion on law and morality is developed further in his view on suitable rulers. If a ruler can legislate to serve the common good, he should not only rule, but should be obligated to. He believed that legitimate political authorities are people motivated through caring about their community, and that any law created from selfishness constitutes injustice and invalidates human-enacted law.
The Renaissance was a period of artistic and developmental revolution in Europe, particularly in philosophy, and nowhere is this fact clearer than in legal philosophy. Thinking became diversified, building upon the theories of Aquinas, that laws should be understood in a command model, from superior to subordinate. With the issuance of this command, certain actions were made clear to the rational man – that he had an obligation to fulfil this now-given purpose. In the 1620s, there emerged a custom-based legal idea, giving rise to what is now Common Law in England. This is one of the most important developments in western legal thinking, having a significant impact on most if not all anglophone judicial systems.
The command law theory finds its roots in the works of the philosopher Hugo Grotius (1583-1645), who developed ideas of what characteristics a person must embody to be capable of imposing, and being imposed upon, by the law. There were some distinctions in theories between philosophers. For example, it was accepted that law is directed regarding those that are free agents —those who have the ability to choose from a variety of options — that are autonomous and intelligent. People who have the ability to identify law as a form of command directed at them, who can comprehend that these commands are a reason to act or think, and in specific means to fulfil the ends of these means on the acknowledgement of the given commands.
The creation of law involves a person’s will, this explains why and how the law makes its subjects act. It is a symbiotic relationship. Through their will, the legislator commands, by creating and enacting laws, to ensure a particular type of behaviour is carried out. The behaviour of said subject is also carried out by an act of will. The philosopher Francisco Suarez (1548-1617) postulated that the will of the subjects and of the legislator must come into direct contact. The common law model substantiated the view that the law is to provide the rationality and decisiveness basis for how people ought to act.
In Enlightenment-era England legal professionals stated that law is derived from “customs immemorially current in the nation”. Coke (1552-1634), Hale (1609-1676) and Blackstone (1723-1780) significantly contributed to this theory. Hale explained that laws are common law if they “have acquired their binding Power and the Force of Laws by a long and immemorial Usage, and by the Strength of Custom and Reception in this Kingdom”. This longevity is what gives law its legitimate authority. If practices extend further back in time than people can remember, this reinforces a community’s understanding and acknowledgement that those practices reasonably should be followed.
The role and nature of the history of a specific practice was debated. Coke determined that the law had not substantially changed since Roman or Saxon times, and it is that history which forms English law’s legitimacy. Hale disagreed, determining that current common law need not be the same, but only continuous with the law of the past. Hale decided that what was most important was that the community believed that the current laws were appropriate and reasonable.
Common law marked a significant change from command law theory. It removed statute from the significant operator of law and focused instead on the operation of the judicial system, and their relation to the people that said system was judging. The roles of judges, lawyers and other jurists were considered in legal philosophy and the theory of law for the first time.
The theory of adjudication advanced the philosophy of law. This theory concerned what judges do and what they ought to do. As common law was derived from immemorial custom, transcending an individual’s set of beliefs or attitude, a judge could not make the rules when resolving citizens’ disputes. Instead, the judge discerned and interpreted from common law tradition, the most significant past cases, statutes, and conventions. Coke determined that a judge is an expert at stating what law preceded and giving instructions as a result. Therefore, a judge is an agent of the law, but not its source. Coke’s claim coincides with the doctrine of precedent – when a judicial decision is reached, it is the new case that advances the law, not the judge.
The term “artificial reason” refers to the expertise of legal professionals, particularly the ability to amalgamate the practices of a people into a common-law basis for assistance with adjudication. Coke stated that “reason is the life of the law”, and that the law requires “long study and experience” before being able to “attain… cognizance of it”. 
The increase of economic and socio-political might in common-law jurisdictions found in states such as the USA and the UK, justifies the significance of common law, and just how influential it is. International law itself, being based upon common law, has steadily evolved since the mid-20th Century, demonstrating the influence of this theory.
Thomas Hobbes (1588-1679) is considered amongst the most influential theorists of legal philosophy. Hobbes created a substantive view of law from the standing of both command-law and natural-law positions. He also heavily criticised the common law tradition. Hobbes saw law as an instrument of the sovereign to serve the aims of a government – those aims being peace and security for its people. Hobbes developed the idea that the only defence against anarchy was an effective ruling government, an idea extremely appropriate for the time in which he wrote - the English Civil Wars (1642-51). Hobbesian legal philosophy prescribes what elements the law should be composed of to carry out its function in society. Hobbes can be seen as the originator of legal positivism. He discussed that law, as a concept, centres around being contingent with society’s moral standards and practices. In Hobbes’ view, what one might consider immoral could be legally prescribed and vice-versa; this was due to his adherence to the command-law theory. In Leviathan, Hobbes stated that “law in general, is not counsel, but command”, suggesting human-enacted law to be “rules which the common-wealth hath commanded by… sufficient sign of the will”. Hobbes emphasised that these “signs” were required to be public and lucid.
Hobbes’ criticism of immemorial custom was that it was not always discernible to a community, and what claimed to be the foundations of law could be seriously controversial. Therefore, it failed to be authoritative, offering no reason for why its subjects ought to act. Coke’s suggestion that knowing the law had the prerequisite of “artificial reason” was rejected by Hobbes. He argued that if the law was contingent on legal professionals being intermediaries between the King or Queen and their subjects, then the law would be insufficient to inform the actions of the people.
Whilst there are positivist elements in Hobbesian legal philosophy, he also determined a connection between natural moral law and civil law, claiming “The law of nature, and the civil law, contain each other, and are of equal extent. For the laws of nature, which consist in equity, justice, gratitude, and other moral virtues on these depending, in the condition of mere nature are not properly law, but qualities that dispose men to peace, and to obedience”. Hobbes believed that there were ethical restrictions for a ruler, on what could legitimately be requested of the people. Hobbes utilised the example of a law violating self-preservation, a principle that was fundamental to the purpose of government. A law requiring actions leading to one’s death would be vitiated by one's moral duty and obligation to the natural law of self-preservation. Therefore, this would fail to be a valid law.
Hobbes' synthesis of natural moral and command law traditions was novel at the time; however, in a post-Enlightenment era, it holds very little weight in legal philosophy. Instead, this has been replaced by debate on whether legal realism or positivism should helm the legal systems of the anglophone world.
Bibliography / Works Cited:
 Aristotle, B. Jowett (tr), Politics, (1976) bk 1 pt 2 5.  Ibid bk 2 pt 1 22.  Ibid bk 7 pt 4 159.  Aristotle, J. Thomson (tr), Ethics, (1976) s1137a32–1138a3.  Politics (n.1) bk 3 pt 16 77.  Cicero, De Re Publica, bk 3 pt 22.  Ibid bk 2 pt 5.  The Encyclopedia of Language and Linguistics (1st Edition, 1994) vol 4 2058.  John Austin, Lectures on Jurisprudence or the Philosophy of Positive Law, 5th ed. (London 1885), vol 2 539.  Hale, The History of the Common Law of England (1713) ch 2 para 3.  Co, Inst (1628) bk 2 ch 6 s138.  Case of Prohibitions  EWHC J23 (KB).  Thomas Hobbes, Leviathan (first published 1651, Penguin 1985) ch 26 para 2.  Ibid para 8.