sentences:  The book was written as a reaction and criticism to the three-volume work "Empiriomonism" (1904–1906) by Alexander Bogdanov, his political opponent within the Party.In June 1909, Bogdanov was defeated at a Bolshevik mini-conference in Paris and expelled from the Central Committee, but he still retained a relevant role in the Party's left wing.He participated in the Russian Revolution and after 1917, he was appointed director of the Socialist Academy of Social Sciences.