Fascism evolved as a heresy within Marxism into a competitor and mortal enemy. As such, anti-Fascism was initially strongly associated with Marxism, both in its Revolutionary Socialist and Communist forms. Anti-Fascism was based on its divergence from and betrayal of Marxism. As mentioned in the previous part, Stalin attacked Fascism on the same ground as Social Democracy. It undermined the class struggle by humanizing the Capitalist system and making it acceptable for the lower classes.