Oligarchy occupies a curious place in the political vocabulary. While oligarchies are largely predominant economic, social, and political life, few ruling groups would publicly use this word to describe themselves. Furthermore, unlike the word "democratic," few ruling groups would claim to be oligarchical as a way of justifying their rule as proper and legitimate. Conversely, if a political party, a political interest group, or a political regime is described as oligarchical, one invariably wants to refer to the fact that a small class or group is in charge and the vast majority of the party, group, or regime has been excluded from decision making.

The concept of oligarchy has its roots in Greek political vocabulary and literally means rule or political power of the few. The few, as the term was originally used, could be the wealthy, the powerful, or the nobility. In The Politics, Aristotle (384–322 B.C...