* Exploitation: Marx refers to the exploitation of an entire segment or class of society by another. He sees it as being an inherent feature and key element of capitalism and free markets. Marx emphasises that exploitation takes place in capitalist production, not in circulation. He distinguishes between labour (the activity) and labour-power - a person's ability to labor. The worker's labour-power is, under capitalism, a commodity, which can be bought and sold. When the capitalist hires the worker, the capitalist pays not for a certain labor but rather for the worker's labor-power, because anything the worker produces during the time under contract belongs to the employer. Marx argued that the wage - the price of the labor-power - should reflect the price of the commodity produced when sold on the market. However, the price of the commodity produced, and the price of commodified labor, is determined by two different markets (e.g. the market for sweaters and the market for labor). Since Marx believed that capitalists will always invest in mechanization, capitalists will always depend on unskilled labor. Moreover, Marx felt that the supply of unskilled labor will almost always far exceed the demand for unskilled labor, thus leaving the price of labor low. Observing the conditions of industrial workers at the time he wrote, Marx concluded that capitalists will pay workers only what workers need to survive and reproduce. Marx is at pains to emphasize that capitalism does not cheat the worker. The capitalist pays the worker for the commodity labour-power at its market price. The capitalist's profit comes from the fact that the worker will labour for more hours than are needed to produce the commodities used to reproduce the worker. Marx calls this 'surplus labour' and, when embodied in a commodity 'surplus-value'. This surplus value is what becomes the capitalist's profit.
* Alienation: Marx refers to the alienation of people from aspects of their "human nature" ("Gattungswesen", usually translated as 'species-essence' or 'species-being'). He believes that alienation is a systematic result of capitalism. Under capitalism, the fruits of production belong to the employers, who expropriate the surplus created by others and in so doing generate alienated labour.[5] Alienation describes objective features of a person's situation in capitalism - it isn't necessary for them to believe or feel that they are alienated.
* Base and superstructure: Marx and Engels use the “base-structure” metaphor to explain the idea that the totality of relations among people with regard to “the social production of their existence” forms the economic basis, on which arises a superstructure of political and legal institutions. To the base corresponds the social consciousness which includes religious, philosophical, and other main ideas. The base conditions both the superstructure and the social consciousness. A conflict between the development of material productive forces and the relations of production causes social revolutions, and the resulting change in the economic basis will sooner or later lead to the transformation of the superstructure.[6] For Marx, though, this relationship is not a one way process - it is reflexive; the base determines the superstructure in the first instance and remains the foundation of a form of social organization which then can act again upon both parts of the base-structure metaphor.[citation needed] The relationship between superstructure and base is considered to be a dialectical one, not a distinction between actual entities "in the world".[citation needed]
* Class consciousness: Class consciousness refers to the awareness, both of itself and of the social world around it, that a social class possess, and its capacity to act in its own rational interests based on this awareness. Thus class consciousness must be attained before the class may mount a successful revolution. Other methods of revolutionary action have been developed however, such as vanguardism.
* Ideology: Without offering a general definition for ideology[7], Marx on several instances has used the term to designate the production of images of social reality. According to Engels, “ideology is a process accomplished by the so-called thinker consciously, it is true, but with a false consciousness. The real motive forces impelling him remain unknown to him; otherwise it simply would not be an ideological process. Hence he imagines false or seeming motive forces”.[8] Because the ruling class controls the society's means of production, the superstructure of society, as well as its ruling ideas, will be determined according to what is in the ruling class's best interests. As Marx said famously in The German Ideology, “the ideas of the ruling class are in every epoch the ruling ideas, i.e. the class which is the ruling material force of society, is at the same time its ruling intellectual force”.[9] Therefore the ideology of a society is of enormous importance since it confuses the alienated groups and can create false consciousness such as commodity fetishism (perceiving labor as capital ~ a degradation of human life).[citation needed]
* Historical materialism: Historical materialism was first articulated by Marx, although he himself never used the term. It looks for the causes of developments and changes in human societies in the way in which humans collectively make the means to live, thus giving an emphasis, through economic analysis, to everything that co-exists with the economic base of society (e.g. social classes, political structures, ideologies).
* Political economy: The term "political economy" originally meant the study of the conditions under which production was organized in the nation-states of the new-born capitalist system. Political economy, then, studies the mechanism of human activity in organizing material, and the mechanism of distributing the surplus or deficit that is the result of that activity. Political economy studies the means of production, specifically capital, and how this manifests itself in economic activity.
