Born into an assimilated Jewish family, he graduated in
sociology from the
University of Warsaw in 1952. In 1989, he was granted the title of a Humanities Professor. He worked at the Institute of History of the
Polish Academy of Sciences (PAN). He specialized in the history of the culture of the 18th-20th centuries as well as
social history. He was also a member of the Warsaw-based
Collegium Invisibile. Since 1948, he was a member of the
Union of Youth Struggle and later the
Polish Youth Union (ZMP). Between 1952 and 1968 he was a member of the communist
Polish United Workers' Party (Polish:
Polska Zjednoczona Partia Robotnicza, PZPR) which he left as a sign of protest against the so-called
March events of 1968. He was the only member of the Institute of History of PAN who decided to resign from the membership of the ruling communist party in Poland at that time. He took part in the discussions at the
Crooked Circle Club and was a signatory of the 101 Memorial, an initiative of Polish intellectuals aimed against changes to the
Constitution of Poland of 1952. Since 1977, he dealt with organizing meetings of the
Flying University. He was the founder, lecturer and member of the Scientific Training Association. He collaborated with the
Student Committee of Solidarity and participated in the Doświadczenie i Przyszłość ("Experience and Future") discussion group. In 1980, he became a member of the
Solidarity movement. After the imposition of the
Martial law in Poland he was interned since December 1981 until July 1982. He published articles in opposition magazines such as
Tygodnik Mazowsze. After the
fall of communism in Poland, he became involved in the activities of
PEN Club. He was appointed a member of the supervisory board of the Polish Information Agency and chairman of the "Open Res Publica" Association Against Anti-Seminitsm and Xenophobia. In 2009, he was awarded (together with Maciej Janowski and Magdalena Micińska) the
Jerzy Giedroyc Prize for their collaborative work entitled
Dzieje inteligencji polskiej do roku 1918 ("The History of the Polish Intelligentsia until 1918"). In 2011,
President Bronisław Komorowski awarded him with the Commander's Cross of the
Order of Polonia Restituta. In 2015, he received the
Prize of the Foundation for Polish Science in the humanities and social sciences category for his "fundamental studies on the phenomenon of the
intelligentsia as a social stratum and its role in modernization processes in
Central and
Eastern Europe". He died on 31 January 2018 and was buried at the
Powązki Military Cemetery in Warsaw. ==Selected publications==