Socialism developed from political movements in the 18th and 19th centuries that sought to alter the traditional capitalist order where workers had few rights and equally few means of lobbying for more. There has never been one clear-cut definition for socialism. Even Karl Marx, after whom Marxism was named, had severe differences with some of his fellow radicals. Today, the socialist movement has splintered into dozens of varying political philosophies -- from Maoism to social democracy to Communism -- some of which, on close inspection, bear faint resemblance to socialism.

The World Socialist Movement defines socialism as a political system allowing for "common ownership," in which people have free access to what they need, everyone is allowed to participate in the society's governance and industry is dedicated only to producing what people need, rather than to commerce and profit [source: World Socialist Movement].

In his "Critique of the Gotha Programme," Karl Marx coined a phrase that has since been frequently cited in relation to the tenets of socialism: "From each according to his ability, to each according to his needs" [source: Marx]. His formulation captures part of the essence of socialism: an economic and political system in which citizens take what they need and contribute what they can, but in neither case to excess or to the detriment of others.

In his 1928 essay "What is Socialism?", Charles Rappoport, a French communist, defined socialism as "based on the recognition of interests common to all citizens" in order to promote "a free individual in a free society" [source: Rappoport]. In this sense, while the United States is far from a socialist country, we do "socialize" certain services for the common good. This is done primarily through taxation, which supports socialized services like public schools, the military, fire departments, libraries and so forth.