German philosopher Karl Marx is considered to one of the most influential thinkers of all time. Marx wrote in the 19th century, a time of tremendous upheaval in the social and political fabric of Europe. Marx wrote at a time during which the excesses of the new Industrial Revolution were most prominent, and his ideas revolutionized thinking about capitalism and its relation to business, individuals, states and the environment.


The motivating idea behind Marx's philosophy was the idea of materialism. Materialists believe that it is the material conditions of the world, for instance, the structure of the economy and the distribution of wealth, that give rise to ideas such as who "should" lead and "deserves" to earn what they earn. This idea is contrary to idealism, which states that it is ideas that give rise to material reality.


Marx believed that the real danger of capitalism was that it exploited workers. Marxists have since developed his theory to explore how capitalism also exploits the planet and its natural resources. According to Marx, capitalists exploit laborers by paying them less than they are worth -- the excess labor of the laborer is what becomes the capitalists' profits. This "surplus labor" is exploited by the capitalist who also forces the laborer into unfitting and unfair working conditions -- something that was much more obvious and severe during the 19th century Marx was writing.


Marx believed that workers were alienated in several ways. Marx highlighted four elements from which the worker is alienated: the product, the act of producing, himself and others. The main idea behind alienation is that one of the effects of the worker's exploitation by the capitalist is that he is not able to live as he otherwise naturally would. This alienation is a kind of separation or removal from how life "naturally" should be. Capitalism, for Marx, is a perversion that separates man from what he makes and how he makes it as well as he would otherwise "naturally" be as a human and how he would relate to others.


Marx believed that, eventually, workers would unite and overthrow the capitalist ruling class. He thought that the bourgeois-capitalist ruling structure would give way to a revolution led by workers who would replace the order with a more fair system. Marx did not exactly call this "communism," and the "communist" states that emerged after Marx -- the Soviet Union, North Korea, the People's Republic of China -- in no way resembled what Marx was talking about. Marx sought a radically democratic order based on collective decision-making and the shared used of the means of production -- that is, the land, labor, and capital that goes in to producing things.