The Marx and Engels Collected Works is the a carefully compiled collection of translations into English of the most significant works of Karl Marx and Friederich Engels. Marx and Engels founded Marxist theory. In 1848 the co-authored The Communist Manifesto was published. Later, Engels supported Marx financially to do research and write Das Kapital. Marxism is a social, political, and economic philosophy named after Karl Marx. Engels developed what is now known as Marxism together with Karl Marx. Karl Marx The Communist Manifesto Karl Marx The Capital Karl Marx The Eighteenth Brumaire of Louis Bonaparte Karl Marx A Contribution to the Critique of Political Economy Friederich Engels Socialism: Utopian and Scientific Friederich Engels The Origin of the Family Private Property and the State Friederich Engels Feuerbach: The roots of the socialist philosophy

Das Kapital, also called Capital. A Critique of Political Economy, is the most cited book in the social sciences published before 1950. Marx aimed to reveal the economic patterns underpinning the capitalist mode of production in contrast to classical political economists such as Adam Smith, Jean-Baptiste Say, David Ricardo and John Stuart Mill. Marx proposes that the motivating force of capitalism is in the exploitation of labor, whose unpaid work is the ultimate source of surplus value. Das Kapital proposes an explanation of the "laws of motion" of the capitalist economic system from its origins to its future by describing the dynamics of the accumulation of capital, the growth of wage labour, the transformation of the workplace, the concentration of capital, commercial competition, the banking system, the decline of the profit rate, land-rents, et cetera.

The "forgotten" second volume of Capital, Marx's world-shaking analysis of economics, politics, and history, contains the vital discussion of commodity, the cornerstone to Marx's theories.