Who has classified political institutions into republic, aristocracy, monarchy and autocracy?

Montesquieu has classified political institutions into republic, aristocracy, monarchy, and autocracy. Important Points

• Montesquieu was a French political philosopher of the Enlightenment period who played a very important role in the French Revolution. 
• His political theory was based on the idea of separation of powers which shaped modern democratic societies. 
• Thus in modern democracies, we have the executive, legislature, and judiciary as separate entities of government. 
• He has classified political institutions into republic, aristocracy, monarchy, and autocracy. 

Additional Information

• Robert Michels was a German-born Italian political sociologist who was famous for the formulation of the Iron Law of Oligarchy. 
• The Iron Law of Oligarchy states that all political systems however democratic will eventually develop into oligarchies. 
• Harold Gould is an American anthropologist who specialized in Indian society and civilization. 
• He has studied the caste system, religion, politics, etc of India. 
• Rajni Kothari was a famous Indian political scientist. 
• He was a great activist who was involved in continuous research on the intellectual and ethical dimensions of Indian politics.