This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Karl Marx and Pierre-Joseph Proudhon corresponded cordially at first, two radical critics of capital circling the same set of problems from different angles, but the friendship did not survive Proudhon's 1846 book The System of Economic Contradictions, or The Philosophy of Poverty, which laid out his mutualist alternative to both liberal political economy and the revolutionary socialism Marx was beginning to develop. Marx's reply came a year later as a book-length rebuttal with a title built to sting, The Poverty of Philosophy, which dismissed Proudhon's economics as amateur, his Hegelian gestures as borrowed and misunderstood, and his gradualist, cooperative program as a plan to reform capitalism into something gentler rather than a plan to overthrow it.
The disagreement was not merely personal, though it became personal. Marx wanted a revolution that seized the means of production and, in his own account, would require a transitional period of proletarian state power before a stateless, classless society could follow. Proudhon wanted no such transitional state at all, arguing that any state, however revolutionary its birth, would concentrate power in the hands of whoever administered it and reproduce the same domination it claimed to abolish, only under new management. Where Marx located the coming transformation in the organized seizure of state power by a revolutionary class, Proudhon located it in the patient, voluntary construction of cooperative and mutual credit institutions that would make the capitalist and the state administrator equally unnecessary, built up from below rather than imposed from above.
The argument did not end with Proudhon's death in 1865. It reopened, sharper and with higher stakes, when Mikhail Bakunin, who took Proudhon's rejection of state power further than Proudhon himself had, led the anarchist wing of the First International against Marx's own faction in the early 1870s, a fight that split the International in two and set anarchism and Marxism on separate, often hostile courses for the rest of the nineteenth century and beyond. Proudhon did not live to see that later battle, but the terms he set in his exchange with Marx, whether the road away from capitalism runs through the state or around it, are the terms it was fought on.