Pierre-Joseph Proudhon was a French economist and socialist philosopher who was the first individual to call himself an "anarchist" and is considered among the first anarchist thinkers. He was a workingman (a printer) who taught himself to read Latin so as to print books in that language well. Proudhon is most famous for his assertion of "Property is theft!", in his missive "What is Property?"] Or, an Inquiry into the Principle of Right and Government" (1840) which was his first major work. The publication of "What is Property?" attracted the attention of the French authorities, and also of Karl Marx who started up a correspondence with Proudhon. The two men influenced each other's work, particularly during Marx's time in exile in Paris. Their friendship ended completely when Marx wrote a response to Proudhon's "The Philosophy of Poverty" entitled "The Poverty of Philosophy". Their dispute was one of the origins to the split between the anarchists and the Marxists in the International Working Men's Association.