In just 264 pages this book effectively conveys the essence of the philosophy of the founder of modern anarchism. Writing in the mid-nineteenth century, Proudhon's views still have relevance today.His mutualism or anarcho-syndicalist style of anarchism attempts to fit into the realities of the industrial age rather than submerge itself in dreams of the pastoral agrarian past.During the Spanish Civil War (1936-1939) the followers of Proudhon's style of anarcho-syndicalism were a major political party which controlled the city goverment of Barcelona and the Catelonian province in Spain. From this base they fought against Franco's fascists on the side of the Spanish Republic.