Proudhon, Pierre Joseph Syllabification: (Prou·dhon, Pierre Joseph)Pronunciation: /pro͞oˈdôN/Definition of Proudhon, Pierre Joseph (1809–65), French social philosopher and journalist. His pamphlet What is Property? (1840) argues that property, in the sense of the exploitation of one person’s labor by another, is theft. Proudhon, Pierre Joseph in other Oxford dictionaries Definition of Proudhon, Pierre Joseph in the British & World English dictionary