Despite being Proudhon one of the most important figures of nineteenth-century European socialism, the blazing success of his works and the diffusion and depth of his ideas, he is also one of the most misunderstood, perhaps the darkest of all before opinion. "Federalist Writings" offers the reader the revision of his work that was so necessary, not only to try to explain the true meaning of Proudhonian thought and thus definitively break with the numerous errors that over time have been installed among scholars , but also to clarify his political philosophy. Recognized as one of the leading theorists of federalism, Proudhon is one of the few critical thinkers who can be used against nationalisms large and small, state or sub-state, at a time like the present, in which uncertainty is gaining ground. everywhere.