Aristocracy (Greek aristokratía, from ? aristos 'excellent', and , kratos 'rule') is a form of government that places strength in the hands of a small, privileged ruling class. The term derives from the Greek aristokratia, meaning 'rule of the best'.
In practice, aristocracy often leads to hereditary government, after which the hereditary monarch appoints officers as they see fit. However, the term was first used by ancient Greeks such as Aristotle and Plato, who used it to describe a system where only the best of the citizens, chosen through a careful process of selection, would become rulers, and hereditary rule would actually have been forbidden, unless the rulers' children performed best and were better endowed with the attributes that make a person fit to rule compared with every other citizen in the polity. Hereditary rule is more related to Oligarchy, a corrupted form of Aristocracy where there is rule by a few, but not by the best. Plato, Socrates, Aristotle, Xenophon and the Spartans considered Aristocracy (the ideal form of rule by the few) to be inherently better than the ideal form of rule by the many (Democracy), but they also considered the corrupted form of Aristocracy (Oligarchy) to be worse than the corrupted form of Democracy (Mob Rule). This belief was rooted in the assumption that the masses could only produce average policy, while the best of men could produce the best policy, if they were indeed the best of men. At the time of the word's origins in ancient Greece, the Greeks conceived it as rule by the best qualified citizens--and often contrasted it favourably with monarchy, rule by an individual. In later times, aristocracy was usually seen as rule by a privileged group, the aristocratic class, and has since been contrasted with democracy. The idea of hybrid forms which have aspects of both aristocracy and democracy are in use in the parliamentary form of government and in republics. There are no pure democracies in the world today, nor have there been since the fall of Athens. There are some governments that have elements of Direct Democracy, but all of those governments are mixed governments, like the Spartan, Roman, British, Swiss, German, French and American governments, which all have elements of Democracy, Aristocracy and Monarchy, with a system of checks and balances, where each element checks the excesses of the other, as described by Polybius in his analysis of the Roman Constitution. Therefore, varying degrees of aristocracy are prevalent throughout nearly all modern governments.
The concept evolved in Ancient Greece, whereby a council of leading citizens was commonly empowered and contrasted with representative democracy, in which a council of citizens was appointed as the "senate" of a city state or other political unit. The Greeks did not like the concept of monarchy, and as their democratic system fell, aristocracy was upheld. In the 1651 book Leviathan, Thomas Hobbes describes an aristocracy as a commonwealth in which the representative of the citizens is an assembly by part only. It is a system in which only a small part of the population represents the government; "certain men distinguished from the rest". Modern depictions of aristocracy tend to regard it not as the ancient Greek concept of rule by the best, but more as an oligarchy or plutocracy--rule by the few or the wealthy.
The concept of aristocracy per Plato, has an ideal state ruled by the philosopher king. Plato describes these "philosopher kings" as "those who love the sight of truth" (Republic 475c) and supports the idea with the analogy of a captain and his ship or a doctor and his medicine. According to him, sailing and health are not things that everyone is qualified to practice by nature. A large part of the Republic then addresses how the educational system should be set up to produce these philosopher kings.