Today, although "democracy" and "republic" are often used interchangeably, in ancient times they referred to distinct political systems. A democracy and a republic each had its own distinct institutional arrangements based on different ideas about what it meant for citizens to participate in the political process. Although the United States reflects the influence of both democracies and republics, these influences can at times be in tension with one another: While a democracy represents the principle of majority rule, a republic uses institutions to check and balance the power of majorities.

1 Origin Democracy was invented by the ancient Athenians in the sixth century B.C. It comes from the ancient Greek word "demos" or people and "kratos," meaning rule. Democracy was a political community in which the people, or the collective body of active citizens, exercised political power. In contrast, the term "republic" is Roman in origin and has traditionally been dated back to 509 B.C. It comes from the Latin word "res," meaning thing or matter, and "publica," meaning public or common. The republic, therefore, meant the public matter, the thing that is in common among the people.

2 Ancient Democratic Institutions One of the most important differences between ancient Greek democracy and ancient Roman Republicanism was institutional. Both ancient Greeks and Roman thinkers conceived of society as containing two permanently distinct and mutually antagonistic groups: the few (the rich) and the many (the poor). Greek democracy and Roman republicanism dealt with this fact in different ways. For Greek thinkers, democracy was simply the rule of the many over the few, whereas aristocracy or oligarchy was the rule of the few over the many. Power could only be held by the masses or by the elite.

3 Ancient Republican Institutions In contrast to Greek democracy, the Roman republic had a more complex institutional arrangement. Instead of a set of institutions through which one single group exercised power, the Roman republic contained multiple institutions that allowed both the few and the many to take part in political rule. In Rome, the few, or the patrician class, were represented by the senate, an exclusively aristocratic institution. The masses, or the plebeians, had their own institutional source of power in the councils and the popular assemblies. In this way, Roman political thinkers hoped to achieve stability by giving both the masses and the elites some institutional stake in political power.