/lit/ - Literature

How does one break through to someone who is ideologically possessed? So many of my friends have bought into the musings of communism and find capitalism to be the worst system ever created. They further think social issues are so important, that any traditional notions are abhorrent and should be dismantled to make way for a more progressive outlook. How does one penetrate through their excuses, defense mechanisms and strike down the snake that's infested their mind?