It is virtually impossible to overestimate the historical contributions of the Roman Empire to modern society. The legacy of Roman art, architecture, literature and philosophy is visible today throughout much of Europe and the rest of the world. In the area of political theory, the Romans made two long-standing contributions: secular law and citizenship.

Separation of Law and Religion

Before the Roman Republic, religion and law were deeply intertwined. Priests and other religious officials served as both spiritual leaders and rulers. Monarchs were seen as enforcers or executors of divine law rather than as lawmakers. The Roman legal system changed that. According to Professor John Mathai of the University of Calicut, the Roman state actually made its own laws separate from and independent of religious law. Secular law became the foundation of European legal systems for generations to come.

The Roman Concept of Citizenship

A second essential Roman contribution to political theory was the concept of citizenship. Before the Roman Empire, early states tended to view all people under their control as essentially equivalent. The Romans changed that by establishing multiple legal codes. One set of laws applied only to Roman citizens. It guaranteed rights and privileges that were unavailable to people in conquered territories under Roman control, according to the Stanford Encyclopedia of Philosophy. The distinction between citizens and outsiders endures in our modern society.