THE PRINCIPLE OF SEPARATION OF POWER
First of all, what is SEPARATION OF POWER?
According to Wikipedia,
Separation of powers is a model for the governance of a state. Under this model, a state’s government is divided into branches, each with separate and independent powers and areas of responsibility so that the powers of one branch are not in conflict with the powers associated with the other branches.
That principle was fathered by Montesquieu, a Frenchman, in the mid eighteenth century. According to Montesquieu, the executive, the legislative and judicial functions of government should be performed by different bodies. He did not notice that there could be overlapping or fusion of powers between the three main arms of government .Montesquieu based his argument on what he thought obtained in Britain. There, he thought, civil liberty was based on separation of powers.
In Brain, Montesquieu thought he saw the independence of the judges guaranteed by Act of Settlement of 1701.The two houses of Parliament enjoyed an authority independent of the executive with the Monarchy also enjoyed independent executive authority. The Conclusion was then that there existed complete separation of powers in Britain.
Merits or Advantages of separation of powers
If there is no separation of powers, there will be confusion and occasional misunderstanding between the arm of government as to which does what. Separation of power prevents unnecessary scramble or struggle for powers by the arms of government .It ensures that too many powers or functions are not concentrated on one organ of government.
Weaknesses of separation of powers
If there is absolute or too much separation, an arm that abuses its power cannot to be checked. Absolute separation does not allow people from different arms to learn from one another. Separation of powers may mean more people in governance and that may also mean high cost governing.
DIVISION OF POWER OR FUNCTIONS
Power or Functions are distributed among the central (federal) government and other units in a federation .The unit could be states, regions et cetera, as the case may be.
The Executive list: This shows areas in which only the central (federal) government can operate/legislate and in many countries, they include: arms and ammunition, census, citizenship, currency, deportation, prisons, export duties, external affairs, et cetera.
Concurrent list: This shows matters in which both the Centre and units can function. The idea is to enable the federal government intervene and help. For example, in Nigeria, the Federal government started paying primary school teachers, a matter that belonged to the Local Government. Such type of intervention by the Federal Government can be if the unit requests or without any such request and probable areas are; electricity generation, education, agriculture, et cetera. But one thing should be clear. If there is a clash between federal and state laws, federal law usually prevails.
Residual list: This refers to matter that crop up after the constitution has been prepared or matters that have not been taken care of in the constitution. Such matters are neither in the exclusive nor in the concurrent list. The states, most often, handle them.
In conclusion, ’’TRIAS POLITICA’’ or ‘’SEPARATION OF POWER’’ is necessary because the system divides the task of the state into three branches: Legislative, Executive and Judicial. These tasks are assigned to different institutions in such a way that each of them can check the others. As a result, no one institution can become as powerful in a democracy as to destroy this system. History has time and again shown that unlimited power in the hands of one person or group in most cases means that others are suppressed or their powers curtailed. The separation of powers in a democracy is to prevent abuse of power and to safeguard freedom for all.

Ibekwe Arinze I., HAOF
300L DEPT OF ELECTRICAL/ELECTRONICS ENGINEERING
CHUKWUEMEKA ODUMEGWU OJUKWU UNIVERSITY,ULI CAMPUS.