A brief definition of two very important doctrines in UK Law - The Rule of Law and The Separation of Powers
What are the principles of separation of powers and the rule of law
The doctrines of separation of powers and the rule of law are heavily important principles of the uncodified constitutional wiring of the United Kingdom.
Montesquieu created the doctrine of separation of powers, stating that this separation is in place to ensure that there are substantial checks and balances so that no branches of government have too much power concentrated within them. In the tripartite system he developed, the branches are; the legislature (Parliament) the executive (Government) and the judiciary (Supreme Court). Whilst the USA is an example of a State that operates a strict separation of powers, the UK is said to have relatively weak separation of powers as there are several overlaps between the various branches. The most recognised example stems from the Prime Minister and Government coming directly out of Parliament. States with stricter separation would require their members to leave one branch before joining another. However, it can be disputed that the creation of the UK Supreme Court in 2009, removing the Law Lords form the House of Lords into a completely independent branch, weakened the overlap between the Judiciary and Parliament.
The rule of law on the other hand, is a more complex doctrine. Although there have been many different opinions in regards to how the rule of line can be defined, its simplest description stems from Dicey as “no one being above the law”. This again is in place to ensure that power is not too heavily concentrated and ensures that those in power are not tyrannical or abusive. However, it is to be recognised that Dicey’s approach has been heavily criticised. A factor includes his neglecting of the need of discretionary powers (authority given to the government to act in their own discretion at times) as he felt it harmed the rule of law.
Montesquieu, The Spirit of the Laws, 1748
AV Dicey, The Rule of Law