Active participant in zemstvo congresses, 1904–1905; one of the organizers of the Union of Liberation.
One of the founders and permanent member of the Central Committee of the Constitutional Democratic Party. Member and secretary of the Cadet group in the First State Duma.
In May–July 1917 he was Minister of Social Welfare in the Russian Provisional Government.
After the Bolshevik revolution he was active in Soviet cooperative institutions, 1930. He was arrested by the NKVD and executed on 15 April 1939.