r ththe incarnation of some trantranscendental truths

 Thinkers usually Russian in the 1920s in the years before the Bolshevik Revolution (1917) (before they were effectively silenced  by Stalin) 

a polemical group they rejected quasi mystical, the quasi theological, literature they deemed was not

pseudo religion, quasi mystical, the symbolist  doctrines or the incarnation of some transcendental truths