Writer, poet, publicist, translator; one of the ideologues of Judaism in Russia. After serving in the Russian army he settled in Poland. From the beginning of the First World War he lived in Russia. He was associated with left-leaning, pro-Communist political and literary groups. In 1928 he travelled to the USSR and visited Jewish kolkhozes. One of the Jewish settlements in Ukraine was named after him. Later he dissociated himself from left-radical organisations and Communist ideology. He is regarded as a classic of Jewish literature in the USA.