Following the First Zionist Congress in Basel in 1897, he became an ardent Zionist and helped establish the radical student Zionist organization, Molodoy Izrail (Young Israel), and also participated in the 1902 Minsk Zionist Conference.
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In August 1925, along with Max Weinreich and Elias Tcherikover, he helped establish in Vilna the Yiddish Scientific Institute, commonly called YIVO.