Karl Marx publishes the first volume of his famous work, Das Kapital, Kritik der politischen Ökonomie (Capital: Critique of Political Economy). This book analyzes the capitalist means of production as it has developed in the modern industrialized society. Marx develops his ideas of the labor theory of value and the ways in which workers are exploited by capitalists who extract surplus value from the workers.
In his summation of Das Kapital, Friedrich Engels writes:
"Capital has evolved into command over labour, and sees to it that work is done regularly and intensively. Moreover, it compels the workers to do more work than is necessary for their sustenance; and, in pumping out surplus-labour, it surpasses all earlier production systems based upon direct compulsory labour. ...
The means of production become means of absorbing the labour of others. It is no longer the labourer who employs the means of production, but the means of production that employ the labourer.
Instead of being consumed by him...they consume him, as the ferment necessary to their own life-process, and the life-process of capital consists only in its movement as value constantly multiplying itself. ...
The simple transformation of money into means of production transforms the latter into a title and a right to the labour and surplus-labour of others."
At this time the second and third volumes of Das Kapital are still in manuscript form, and Karl Marx will continue to refine them for the rest of his life. They will only be published after his death by Friedrich Engles, who has been acting as Marx's editor.