M. Proudhon has the misfortune of being peculiarly misunderstood in Europe. In France, he has the right to be a bad economist, because he is reputed to be a good German philosopher. In Germany, he has the right to be a bad philosopher, because he is reputed to be one of the ablest French economists. Being both German and economist at the same time, we desire to protest against this double error.

The reader will understand that in this thankless task we have often had to abandon our criticism of M. Proudhon in order to criticize German philosophy, and at the same time to give some observations on political economy.

Karl Marx Brussels, June 15, 1847

M. Proudhon's work is not just a treatise on political economy, an ordinary book; it is a bible. "mysteries", "Secrets Wrested from the Bosom of God", "Revelations" -- it lacks nothing. But as prophets are discussed nowadays more conscientiously than profane writers, the reader must resign himself to going with us through the arid and gloomy eruditions of "Genesis", in order to ascend later, with M. Proudhon, into the ethereal and fertile realm of super-socialism. (See Proudhon, Philosophy of Poverty, Prologue, p.III, line 20.)