The Ancient Theory of the Separation of Powers

   THE SEPARATION OF POWERS

The ancient theory of the separation of powers tries to combat tyranny by dividing the functions of government between groups with different interests so that no power centre can act without the co-operation of others.

There are different kinds of separation of powers. For example, the classical doctrine favoured by Aristotle would divide power according to the class interests of monarchy, aristocracy and democracy. This version of the separation of powers is reflected in the British institutions of monarchy, House of Lords and House of Commons. However, the most influential version of the separation of powers is that proposed by Montesquieu (De L’Esprit de Lois, 1748) who, broadly following Aristotle, argued that government powers are of three kinds: (i) the legislative power of enacting general laws; (ii) the executive power concerned with policy-making, foreign affairs and law enforcement; (iii) the judicial power concerned with the settlement of disputes arising out of the application of the law. If any two of these fall into the same hands there is a risk of tyranny.

Applied strictly, this version of the separation of powers would lead to weak and cumbersome government and in all countries there is some form of pragmatic compromise. Montesquieu believed that the British constitution of his time embodied the separation of powers but possibly did not take into account the extent to which conventions were beginning to blur the distinction between legislature and executive. The US constitution has been particularly influenced by Montesquieu. The president who forms the executive, and Congress the legislature, are elected separately and the same persons cannot be members of both. The US constitution is designed to encourage conflict between the two branches and regards weak government as desirable, whereas the UK system is more interested in ensuring that the will of the executive is carried out. The UK constitution is sometimes called a 'harmonious constitution' in that its efficient working depends not on checks and balances between contending forces as in the USA but requires the enlistment of different interests to form an all powerful government.