My reply was first published in a series of articles in the Leipzig "Vorwärts," the chief organ of the Socialist party, and later on as a book: "Herrn Eugen Dühring's Umwälzung der Wissenschaft" (Mr. E. Dühring's "Revolution in Science"), a second edition of which appeared in Zürich, 1886. At the request of my friend, Paul Lafargue, now representative of Lille in the French Chamber of Deputies, I arranged three chapters of this book as a pamphlet, which he translated and published in 1880, under the title: "_Socialisme utopique et Socialisme scientifique_." From this French text a Polish and a Spanish edition were prepared. In 1883, our German friends brought out the pamphlet in the original language. Italian, Russian, Danish, Dutch, and Roumanian translations, based upon the German text, have since been published. Thus, with the present English edition, this little book circulates in ten languages. I am not aware that any other Socialist work, not even our "Communist Manifesto" of 1848 or Marx's "Capital," has been so often translated. In Germany it has had four editions of about 20,000 copies in all. The economic terms used in this work, as far as they are new, agree with those used in the English edition of Marx's "Capital." We call "production of commodities" that economic phase where articles are produced not only for the use of the producers, but also for purposes of exchange; that is, as _commodities_, not as use-values. This phase extends from the first beginnings of production for exchange down to our present time; it attains its full development under capitalist production only, that is, under conditions where the capitalist, the owner of the means of production, employs, for wages, laborers, people deprived of all means of production except their own labor-power, and pockets the excess of the selling price of the products over his outlay. We divide the history of industrial production since the Middle Ages into three periods: (1) handicraft, small master craftsmen with a few journeymen and apprentices, where each laborer produces the complete article; (2) manufacture, where greater numbers of workmen, grouped in one large establishment, produce the complete article on the principle of division of labor, each workman performing only one partial operation, so that the product is complete only after having passed successively through the hands of all; (3) modern industry, where the product is produced by machinery driven by power, and where the work of the laborer is limited to superintending and correcting the performances of the mechanical agent.