It is usual to divide the activities of a modern government in three parts, viz., legislative, executive and judicial. Corresponding to these three functions there are three organs of the government, i.e., legislature, executive and judiciary. The function of the legislature is to make, amend and repeal laws.

The executive is entrusted with the the theory of separation of powers function of enforcing these laws. The judiciary interprets and applies them to specific cases arising out of breach of laws.

Now these three functions may be given to one authority or to different authorities. The theory of separation of powers in its simplest form implies that all these three functions should be entrusted to three different authorities. The three organs of the government should be kept separate and distinct. One organ should be independent of the control of others.

Each organ should be supreme in its own sphere of authority. The theory further states that combination of any two or all the three powers in a single person may result in tyranny and loss of individual liberty.


The theory was the direct outcome of reaction against despotism of Middle Ages when kings combined in their person all three powers of the gov­ernment and enjoyed the authority of life and death over their subjects.

Development of the Theory:

The idea of threefold division of state functions may be traced back to the writings of Aristotle and Cicero. According to Aristotle, a state should have three functions—deliberative, magisterial and judicial. Bodin, a French philosopher, further emphasized the necessity of separating these three powers.

He was especially in favour of separation of the judicial functions from the other two func­tions. The powerful exponent of this theory was Montesquieu (1689- 1755). He developed this theory in his book The Spirit of Laws published in 1748. Montesquieu lived in France during the tyrannical rule of Louis XVI, who was an absolute monarch having authority over the life and death of the people.

He combined in him all the legislative, executive, and judicial powers. In other words, he was the source of laws, the seat of executive authority and the fountain of justice. In the opinion of Mon­tesquieu people in France did not enjoy any liberty because of a combi­nation of all the three powers in the monarch.


In or about the year 1730 Montesquieu visited England and was highly impressed by individual liberty enjoyed by the English people. He concluded that liberty of the English people was safe because their constitution was based on the Principle of separation of powers.

He proclaimed “there would be an end of everything, were the same man, or the same body whether of the nobles  ‘he people, to exercise these three powers …”

According to Montesquieu, ‘when the legislative and executive Powers are united in the same person or in the same body of persons, there can be no liberty, because they make tyrannical laws and execute them tyrannical manner.

Again, if judicial authority is combined with legislative, the life and liberty of the subjects would be subject to arbitrary control. If judiciary is joined with executive, the judge might behave with violence and oppression’.


The theory was also defended by Blackstone in his book Commen­taries on the Laws of England published in 1776. He insisted that “Whenever the right of making and enforcing the law is vested in the same man or one and the same body of men, there can be no public liberty.

” The American constitutionalist Madison held that, “the accumu­lation of all powers, legislative, executive and judicial in the same hands may justly be pronounced the very definition of tyranny.”

Influence of the Theory : The theory exercised a profound influence on political thought in the eighteenth century. The American Federal Constitution of 1789 was clearly based on the theory of separa­tion of powers with slight modifications.

Some of the states of the U.S.A. also enacted their constitutions on the basis of this theory. The Consti­tution of the first Republic of France was again based on this theory. The French Constituent Assembly of 1789 declared in unequivocal terms that, “every society in which the separation of powers is not determined, has no constitution.”