Nikolai Fëdorovich Fëdorov was a Russian religious philosopher. From 1854 to 1868 he taught history and geography at district schools in Russia. From 1869 to 1872 he worked at the Chertkovskaia Library in Moscow, and from 1874 to 1898 he worked at the libraries of the Moscow Public and Rumiantsev Museums. For a quarter of a century he defined the spiritual atmosphere of this latter library, infusing it, in the words of his contemporaries, with the traditions of the "philosophical school." Many talented men of Russian science and culture used to gather in the catalogue room of the library where Fëdorov served to converse with the "Moscow Socrates." In the 1880s and 1890s Fëdorov met with Vladimir Sergeevich Solov'ëv, who called Fëdorov's teaching "the first progress the human spirit has...