Federalist #10

Madison begins perhaps the most famous of the Federalist papers by stating that one of the strongest arguments in favor of the Constitution is the fact that it establishes a government capable of controlling the violence and damage caused by factions. Madison defines that factions are groups of people who gather together to protect and promote their special economic interests and political opinions. Although these factions are at odds with each other, they frequently work against the public interests, and infringe upon the rights of others.
Both supporters and opponents of the plan are concerned with the political instability produced by rival factions. The state governments have not succeeded in solving this problem; in fact the situation is so problematic that people are disillusioned with all politicians and blame government for their problems. Consequently, a form of popular government that can deal successfully with this problem has a great deal to recommend it.
Given the nature of man, factions are inevitable. As long as men hold different opinions, have different amounts of wealth, and own different amount of property, they will continue to fraternize with people who are most similar to them. Both serious and trivial reasons account for the formation of factions but the most important source of faction is the unequal distribution of property. Men of greater ability and talent tend to possess more property than those of lesser ability, and since the first object of government is to protect and encourage ability, it follows that the rights of property owners must be protected. Property is divided unequally, and, in addition, there are many different kinds of property; men have different interests depending upon the kind of property they own. For example, the interests of landowners differ from those who own businesses. Government must not only protect the conflicting interests of property owners, it must, at the same time, successfully regulate the conflicts that result from those who own, and those who do not own, property.
To Madison, there are only two ways to control a faction: one, to remove its causes and the second to control its effects. The first is impossible. There are only two ways to remove the causes of a faction: destroy liberty or give every citizen the same opinions, passions, and interests. Destroying liberty is a "cure worse then the disease itself," and the second is impracticable. The causes of factions are thus part of the nature of man and we must deal with their effects and accept their existence.