Has worked at the IH UW since 1978; full professor since 2003. Deputy Director of the IH UW 1993-1996; Chair of the Department of 19th Century History; chair of the IH UW Advisory Board 2008-2012. Head of the Doctoral Studies School at the Faculty of History, University of Warsaw, 2005-2008. Member of the Advisory Board of the Institute of History, Polish Academy of Sciences, since 2007. Member of the Editorial Committee of Kwartalnik Historyczny since 2000 (deputy editor-in-chief in 2000-2003). Member of the Editorial Board of the Foundation for Polish Science since 2012. Member of the Polish PEN Club since 2012. Visiting professor at the University of Notre Dame in 1994-1995.
Research interests: history of social ideas in the 19th and 20th centuries.