Charles Constantin Pecqueur (26 October 1801 – 17 December 1887) was a French economist, socialist theoretician and politician. He participated in the Revolution of 1848 and influenced Karl Marx. Life and Thought Charles Constantin Pecqueur was born into a wealthy upper-middle-class family in the Department du Nord; his town of birth is variously given as Arleux or Douai. He studied engineering and mathematics. He worked for a time as a geometer. In the 1820s he entered the Military Teaching Hospital in Lille, where he completed a treatise on education and became interested in utopian socialist theories. In 1830 he moved to Paris. At first he joined the followers of Saint-Simon. He contributed to Le Globe and other Saint-Simonian papers, but left the Saint-Simonian school in 1832, dissatisfied with the religious direction in which Prosper Enfantin was taking it. Until 1836 he belonged to the school of Fourier and joined a phalanstère or Fourierist community. He wrote a biography of Fourier in 1835 and contributed to various Fourierist journals. In 1836 he left the Fourierists, publishing a critique of their system, and developed his own theories. He remained close, however, to some of his friends from the Saint-Simonian and Fourierist schools, such as Pierre Leroux and Victor Considerant. In contrast to these theorists, Pecqueur was one of the earliest French socialists to advocate collective ownership of the means of production, distribution and exchange. He is sometimes called the 'father of French collectivist socialism.' In the 1830s Pecqueur made his name as a highly respected socialist economist. His writings included Intérêt du commerce et de l'industrie (1836), Améliorations matérielles (1839), La réforme électorale (1840), Théories nouvelles d'économie sociale et politique (1842), De la paix, de son principe et de sa réalisation (1842), Des armées dans leurs rapports avec l'industrie (1842) and La République de Dieu (1844). Among other works, particular notice accrued to his two-volume opus Economie sociale des intérêts du commerce, de l'industrie, de l'agriculture et de la civilisation en général, sous l'influence de l'application de la vapeur (1839). In this work, Pecqueur tried to show that changes in material conditions, such as the introduction of steam power, produce changes in intellectual development. The French Academy of Moral and Political Sciences awarded him a prize. Karl Marx also praised Pecqueur's materialist method. Marx later frequently cited Pecqueur as an authority in Capital and other economic writings. In contrast to many of