The theory of sovereignty is Budan's greatest contribution to western political thought. Budan inherited the concept of "national rationality" put forward by Machiavelli, further developed the concept of sovereignty that existed in ancient times, and finally made it the mainstream discourse of modern European political science theory.

Jean bodin (-1596) is the most famous constitutional expert in the modern west, and his Six Theories on the State is also regarded as the most important theoretical treatise on state sovereignty in the west. Born in France, Boudin studied law at the university when he was young, stayed as a lecturer after graduation, then worked as a lawyer in Paris, served as a royal prosecutor in the 1970s from 65438 to 2006, and was hired as a court legal adviser in Henry III. 1576, Boudin published Six Theories on the State. He was the first person to systematically discuss the theory of state sovereignty in the history of western political and legal thought.

Budan believes that sovereignty is the main symbol of the country and the supreme power over citizens and subjects without legal restrictions. Sovereignty means having supreme power at home and independent and equal power abroad. The form and appearance of supreme power is essentially a sign that the state is different from all social organizations and other groups, including families. Therefore, Budan defined the acquisition of citizenship as obedience to the sovereign, and clearly defined the concept of the state as the sovereign and subject. Sovereignty is the supreme power to rule citizens and subjects without legal restrictions.