Inter-relation of Power, Authority and Legitimacy :

Power, authority and legitimacy are important concepts of political science. These are inter-connected. When legitimacy adds to power, then it is called authority. Factually legitimate power is authority. 

This interrelationship can be understood with the help of the following points : 

(i) Role in formation of State-Governance : 

The factor/element of power provides a base to the governance of a state. Authority gives legal base to it and legitimacy provides moral base. These have separate roles to play, but their joining gives perfection to the governance of a state. 

(ii) Role in Management of State-Governance : 

In the management of a state, authority is real subject, i.e., operator. It provides legitimate personality to the governance.

Power and legitimacy are respectively means and objectives. In the form of valid power, the authority uses power as a tool to get certain or decided by legitimacy. Hence, in a government, the legitimacy plays the role of an objective. 

(iii) In view of Human Nature :

Power, authority and legitimacy are closely related with different human tendencies. Human has natural attraction towards power. This tendency gives rise to the struggle among individuals and institutes. This power struggle is controlled and regulated by social nature of human. The developed form of this social tendency is authority. This authority makes the power a tool to systematise the society and keeps valid control over the society. But there is an another human tendency which is not satisified by social system only. It wants to see the system in sensible and justful state. This tendency comes out in the form of legitimacy. In this way power and legitimacy are not related directly. These are interrelated by authority. Legitimacy makes the power and authority justful. When authority and legitimacy are very close then the authority uses less power. But, when authority and legitimacy lack combination with each other then authority uses more power. In absence of legitimacy, both power and authority are immoral. 

Legitimacy is link between power and authority. Any ruler can control the outer form of an individual or society with power but it cannot rule over the heart of public in absence of legitimacy. Hence, it is clear that power, authority and legitimacy are interrelated. Without power, we cannot establish peace, discipline, justice and happiness but the role of power is more effective when it works in combination with legitimacy.