Origins
The noun 'plutocracy' entered English in the mid-seventeenth century from Greek 'ploutokratia' (government by the wealthy), a compound of 'ploutos' (wealth, riches) and 'kratos' (power, strength, rule), the latter from Proto-Indo-European *kret- (power, strength). The Greek 'ploutos' is possibly connected to PIE *plew- (to flow), suggesting an original concept of wealth as overflow, abundance, or flowing plenty.
The word 'plutocracy' names what many political thinkers have considered the most common form of actual government, as opposed to the forms governments claim to be. A state may call itself a democracy, an aristocracy, or a republic, but if wealth determines who holds power, who makes policy, and whose interests are served, the state is a plutocracy regardless of its official label. This tension between formal constitution and actual power structure has been a central concern of political theory since Aristotle.
Aristotle's analysis of oligarchy — rule by the few — was in practice an analysis of plutocracy, since the 'few' who ruled in Greek oligarchies were almost invariably the wealthy. Aristotle recognized that wealth tended to translate into political power through multiple mechanisms: the wealthy could afford leisure for politics, could fund armies and public works, could attract clients and dependents, and could use their economic power to influence or coerce others. The question was whether this concentration of power served the community or only the plutocrats themselves.
Latin Roots
In Rome, the Republic was formally governed by elected magistrates and the Senate, but in practice, political power was concentrated in the hands of wealthy patrician and equestrian families. The cost of running for office, maintaining a political network, and funding military campaigns meant that only the rich could compete for political positions. The 'cursus honorum' — the sequence of offices a Roman politician was expected to hold — was also a financial gauntlet. Crassus, reputedly the richest man in Rome, translated his wealth directly into political and military power; Cicero, who rose from a relatively modest background, was exceptional precisely because he succeeded in a plutocratic system without great personal wealth.
The term 'plutocracy' gained particular currency in the late nineteenth and early twentieth centuries, when the rapid industrialization of America and Europe produced concentrations of private wealth unprecedented in history. The Gilded Age in America (roughly 1870-1900) saw families like the Vanderbilts, Carnegies, Rockefellers, and Morgans accumulate fortunes that dwarfed the treasuries of most nations. Their influence over government — through lobbying, campaign contributions, ownership of newspapers, and direct political involvement — led critics to describe the United States as a plutocracy masquerading as a democracy.
The Progressive movement of the early twentieth century was largely a reaction against plutocratic power. Reforms like the direct election of senators (the Seventeenth Amendment, 1913), anti-trust legislation, income tax (the Sixteenth Amendment, 1913), and campaign finance regulation were all designed to reduce the influence of wealth on government. The New Deal further challenged plutocratic power through progressive taxation, labor rights, and financial regulation.
Greek Origins
The connection between wealth and the Greek god Pluto enriches the word's resonance. In Greek mythology, Hades — the god of the dead and ruler of the underworld — was given the euphemistic name 'Plouton' (the wealthy one) because the riches of the earth — gold, silver, precious stones — came from his domain beneath the ground. The Greeks considered it unlucky to say Hades' name directly, so they used the flattering substitute. 'Ploutokratia' thus carries a mythological undertone: the rule of wealth is also, etymologically, the rule of the underworld, the rule of the lord of the dead.
The element plutonium, named after the planet Pluto (discovered in 1930), extends the chain: Pluto the planet was named for Pluto the god because it was dark and distant, and plutonium the element was named for the planet because it was the next element after neptunium (named for Neptune, the next planet after Uranus/uranium). The connections are coincidental but suggestive: 'Pluto' links wealth, death, darkness, and nuclear power in a single etymological chain.
Modern political science has developed sophisticated methods for measuring plutocratic influence. Studies of campaign finance, lobbying expenditure, policy outcomes correlated with donor preferences, and the economic backgrounds of legislators consistently show that wealth translates into political influence in all democratic systems, though the mechanisms and degree vary. The question of whether contemporary democracies are plutocracies in practice — whether government 'of the people, by the people, for the people' actually serves the interests of the wealthy — remains one of the most vigorously debated questions in political science.