The Rule of Law as Political Theory
In recent years, the use of the term “rule of law" has become more prevalent. The concept of rule of law is currently one of the most important political ideas. The notion of the rule of law can be traced back to at least the time of Aristotle who observed that given the choice between a king who ruled by discretion and a king who ruled by law, the later was clearly superior to the former.
In more recent times, it is AV Dicey who is credited with providing the logical foundation upon which the modern notion of the rule of law is based. He laid out his three principles of the rule of law in his book named An Introduction to the Study of the Law of the Constitution.
Dicey’s rule of law consisted of three aspects or principles  :
No man is punishable or can be lawfully made to suffer in body or in goods except for a distinct breach of law established in the ordinary legal manner before the ordinary courts of the land. Dicey went on and stated that no one should have too wide and arbitrary or discretionary powers.
No man is above the law; every man and woman, whatever may be his or her rank or position from the prime minister right down to the tax collector, is subject to the ordinary law of the realm and amenable to the jurisdiction of the ordinary tribunals.
Each man’s individual rights are best protected under Common Law rather than a formal Bill of Rights.
The first element requires that no one is punishable except for a distinct breach of law of the land. It involves the absence of arbitrary power on the part of the government and prevents it from making retrospective penal law. In order to comply fully with this requirement, laws should be open and accessible, clear and certain. As Dicey said, “with discretion comes arbitrariness  ".
Dicey’s second postulate emphasises equality before the law. This means that not only government is subject to law, but everyone, irrespective of rank and status, whether official or individual, shall be subjected to the same law and the same courts of the land. But the idea of equality before the law is subject to many exceptions. So far as equal powers are concerned, it is understood that King enjoys royal prerogative, government when implementing government policies may abuse their powers, diplomats enjoy immunities and so on. In the words of Sir Ivor Jennings, 'No two citizens are entirely equal  .'
The third aspect shows Dicey’s preference for common law protection of rights and freedoms and this reveals his faith in judiciary. He believed that people’s right are best protected under Common Law rather than a formal Bill of Rights.
Professor Joseph Raz
Professor Joseph Raz, the leading legal positivist, claims that the rule of law is a precondition of individual liberty. He recognised the need for the government of men as well as laws, and that the pursuit of social goals may require the enactment of particular, as well as general, laws. At the same time, Raz also saw the rule of law as essentially a negative value, acting to minimise the danger that could follow the exercise of discretionary power in an arbitrary way  . Raz’s principles emerged from the ground that the law must be capable of guiding the individual’s behaviour. Some of Raz’s principles are as follows  :
Laws should be prospective rather than retroactive. People cannot be guided by or expected to obey laws that have not as yet been introduced.
Laws should also be open and clear to enable people to understand them and guide their actions in line with them.
Laws should be stable and should not be changed too frequently as this might lead to confusion as to what was actually covered by the law.
There should be clear rules and procedures for making laws.
The independence of the judiciary has to be guaranteed to ensure that they are free to decide cases in line with the law and not in response to any external pressure.
The principles of natural justice should be observed, requiring an open and fair hearing to be given to all parties to proceedings.
The courts should have the power to review the way in which the other principles are implemented to ensure that they are being operated as demanded by the rule of law.
The courts should be easily accessible as they remain at the heart of the idea of making discretion subject to legal control.
The discretion of the crime preventing agencies should not be allowed to pervert the law.
Friedrich von Hayek
Friedrich von Hayek, one of the most masterful and insightful economists and philosophers, is a latter day exponent of Dicey’s viewpoint. Hayek followed Dicey in demanding that all citizens must have access to an independent judiciary before they can challenge the legality of government action. Hayek described the function of rule of law is to ensure that ‘government in all its action is bound by rules fixed and announced beforehand  ’. Hayek believed that society’s interest are best served by reducing the size and power of government to a minimum, thus gives freedom to individual citizens to organise their social and economic affairs  . He also recognised that there will be great inequalities of wealth in a society. He considered such inequality to be a lesser evil than the intrusion upon individual freedom. Hayek denies that the legislature can perform a balancing act between economic equality and rule of law; ‘any policy aiming directly at a substantive ideal of distributive justice must lead to the destruction of the rule of law  ’.
Professor Lon Fuller
On the other hand, Professor Lon Fuller rejected legal positivism, the idea that law is no higher than a particular authority, that is, a sovereign state or a rule of recognition, is morally neutral, and is merely an instrument of external ends such as utility  . In his book The Morality of Law, Fuller presents eight routes of failure for any legal system, which are listed below  .
The lack of rules or law, which leads to ad-hoc and inconsistent adjudication.
Failure to publicize or make known the rules of law.
Unclear or obscure legislation that is impossible to understand.
Contradictions in the law.
Demands that are beyond the power of the subjects and the ruled.
Unstable legislation (when laws changed frequently)
Divergence between adjudication or administration and legislation.
In Fuller's perspective, a legal system which fails to observe his eight principles of procedural law is not regarded as a legal system.