The scientific classification of governmental forms originated with Aristotle in his classical treatise Politics. Aristotle formulated a twofold matrix based on: (1) the number of persons holding sovereign authority (One, Few, Many), and (2) the moral purpose of governance (Normal/Pure for the common welfare vs. Perverted/Corrupt for the rulers' selfish gain):
| Number of Rulers | Pure / Normal Form (Common Good) | Perverted / Corrupt Form (Selfish Interest) |
|---|---|---|
| Rule by One | Monarchy (Royalty): Virtuous rule of a single benevolent king. | Tyranny: Despotic, oppressive rule by a lawless autocrat. |
| Rule by Few | Aristocracy: Rule of the best and wisest citizens. | Oligarchy: Rule of the wealthy few for self-enrichment. |
| Rule by Many | Polity (Constitutional Rule): Moderate rule of the middle class. | Democracy (Mobocracy): Lawless mob rule by the impoverished majority. |
Modern political science categorizes sovereign states through institutional taxonomies:
1. Despotic vs. Democratic: Based on whether sovereign power rests with an unaccountable dictator or the sovereign citizenry.
2. Monarchical vs. Republican: Based on whether the Head of State is hereditary (UK, Japan) or democratically elected (India, USA).
3. Unitary vs. Federal: Based on the territorial concentration or constitutional division of governmental powers.
4. Parliamentary vs. Presidential: Based on the structural relationship and accountability between the executive and legislative branches.