He was the leading representative of the positivist and democratic current in Polish politics. He was born on 18 January 1849 in Stoczek Łukowski (near Łuków). From 1866 to 1870, he studied at the Faculty of Philology and History of the Warsaw Main School; four years later, he moved to Leipzig, where he attended university lectures for a year and a half. In 1875, he obtained a doctoral degree for his dissertation Ein Versuch die Entstehung der Moralgesetze zu erklären. Eine ethische Analyse (published in Polish as O powstawaniu praw moralnych [“On the emergence of moral laws”], 1877). From Leipzig, he moved to Kraków where he unsuccessfully applied for employment at the Jagiellonian University. In 1876, he returned to Warsaw and started work at the positivist Przegląd Tygodniowy [“Weekly Review”]. In that paper, he published a text that was important for the self-awareness and development of Polish positivist thought: My i Wy [“We and You”] (1877) and also a series of articles that described the condition of the Polish nation after the fall of the January Uprising; this was meaningfully entitled Dumanie pesymisty [“Ponderings of a pessimist”]. In 1881, he became editor-in-chief of the new positivist newspaper Prawda [“Truth”], in which he had a political column entitled Liberum Veto until 1900. From 1900 to 1914, he was engaged in intensive social and political activity. He became a member of many associations, including the Society for Rural Education, gave lectures at the Society for Promoting Education and at the People’s University of the Society for the Promotion of Education in Łódź. During the Russo-Japanese War and the related crisis in Russia, he was among the founders of a party which promoted the liberal tradition: the Progressive Democracy Union. During that period, he wrote his most famous works: Utopie w rozwoju historycznym [“Historical development of utopias”] (1910), Źródła moralności [“Sources of morality”] (1912) and Genealogia teraźniejszości [“Genealogy of the present”] (1914), and also started work on Historia chłopów w zarysie [“Outline history of peasants”]. He died in Gołotczyzna near Ciechanów on 25 April 1938.