Until 1905 Populist; 1903 emigrated. Formed close ties with German Social-Democrats and contributed to newspaper “Vorwärts”. 1904 appeared as expert in Koenigsberg trial of Russian Social-Democrats charged with smuggling Party literature
1905 sided with Bolsheviks and attended Tammerfors Conference. After 1917 October Revol head, Draft Bills Department, People's Commissariat of Justice. Member. Commission to Draft First Constitution.
Worked for People's Commissariat of Education. Taught at Red Army Military Academy.
Communist Party member from 1918.