Marr introduced into linguistics another and also incorrect and non-Marxist formula, regarding the ‘class character’ of language, and got himself into a muddle and put linguistics into a muddle. Soviet linguistics cannot be advanced on the basis of an incorrect formula which is contrary to the whole course of the history of peoples and languages." Since then, the Japhetic theory has been seen as deeply flawed, both inside and outside the former Soviet Union, but some of Marr’s surviving students continued to defend and develop it into the late 1960s.[citation needed]