Legitimacy in political science refers to the right and acceptability of an authoritative person, often a governing legislation or a system. Whereas authority refers to a specific position in an established government, legitimacy refers to a system of government—where government refers to a "sphere of influence." Legitimacy is therefore the quality or state of being legitimate, while authority is the power to establish or grant legitimacy.
In modern politics, the terms are used interchangeably with the word "government". However, they can also apply to more informal systems where there is no official leader who receives votes or is voted into office, such as in certain Native American tribes or small countries. In these cases, someone or something else is legitimately exercising authority over others.
It is difficult to define exactly what constitutes legitimacy, but it usually involves a belief that the person or body in question is able to make decisions for others, by reason of their position within the hierarchy of authority. For example, in a monarchy, legitimacy depends on the belief that the monarch is capable of making good decisions for the country.
The term "legitimate authority" may be used in place of the word "government" to describe any organization or individual who has been authorized to exercise some form of control over another entity.
In political science and sociology, legitimacy is typically described as the conviction that a rule, institution, or leader has the authority to govern. It is an individual's assessment of the legitimacy of a hierarchy between a rule or ruler and its subject, as well as the subordinate's duty to the rule or ruler. The concept of legitimacy is important in understanding how individuals relate to governments, why some countries are more likely than others to use military force, and what role ideology plays in shaping government behavior.
In ancient Greece, a ruler's authority was based on his/her position within the social hierarchy. Thus, their legitimacy depended on their class status. A king could not escape this constraint by claiming to be a god or by other means. As long as he remained among men he would be judged by them according to his class status. His rank would determine both his rights and duties. If he rose above his station, he would lose his privilege of governing and be subjected to him who ruled over him.
In modern democracies, legislative bodies play a key role in establishing authority by voting on issues before them. However, even though they are democratically elected, legislators cannot unilaterally revoke their citizens' constitutional rights. They can only propose changes to the constitution and call for an election if they feel it is necessary. In order for them to be deemed legitimate, they must also act in accordance with democratic principles. For example, they can't grant themselves extra-legal powers or discriminate against certain groups of people.
The popular approval of a government, political regime, or system of administration is referred to as legitimacy. The term legitimacy can be understood in two ways: normatively or positively (see positivism). The first meaning is political philosophy, and it deals with issues such as: what are the appropriate sources of legitimacy? How should legitimate authority be defined? What conditions must exist for an entity to have legal authority? The second meaning is related to law enforcement and includes questions like: how do we know when a government has achieved legitimacy? How can governments gain legitimacy?
Legitimacy is based on beliefs about the proper relationship between individuals or groups and their leaders. These beliefs are often reflected in laws or customs that are assumed to represent the will of the people. However many countries have no written constitution, so their institutions are not clearly defined. In such cases, experts can give advice on proper relationships between rulers and ruled; this advice can then become part of a country's customary law. For example, in ancient Greece, appropriate relations between rulers and ruled were suggested by philosophers and other experts who lived in states where there were no kings or queens. These experts gave their opinions in writing and through speech given at public gatherings known as "law courts". They also said which actions brought out the worst in humans and thus were most likely to get you punished. These actions included killing someone without just cause, stealing, sexual misconduct, and taking bribes. By contrast, doing good acts would usually bring rewards.