Socialism: Utopian and Scientific of thousands of copies. Throughout the decade of the 1860s, Karl Marx, close personal friend and political associate of Friedrich Engels, dedicated himself to the study of economics, culminating in the publication of the first volume of "Das Kapital" in 1867. Marx's lengthy and ponderous volume was extremely difficult for the average to penetrate, however, leading Engels to suggest to Marx in a letter of September 16, 1868 that a short popularized version of "Das Kapital" for a working class audience was urgently needed. "If it is not written, some Moses or other will come along and do it and
Circular flow of income economics, economic reproduction refers to recurrent (or cyclical) processes by which the initial conditions necessary for economic activity to occur are constantly re-created. Economic reproduction involves the physical "production" and "distribution" of goods and services, the "trade" (the circulation via exchanges and transactions) of goods and services, and the "consumption" of goods and services (both productive or intermediate consumption and final consumption). Karl Marx developed the original insights of Quesnay to model the circulation of capital, money, and commodities in the second volume of "Das Kapital" to show how the reproduction process that must occur in any type of society