karl marx was a famous communist philosopher from germany. he wrote a famous book called "the capital" (or "das kapital" in german). he said that capitalism would go away after workers decided to take over the government in a revolution because of the exploitation. there were violent communist revolutions in many countries. many people were killed because of this. but capitalism did not go away, and most of these communist systems have collapsed and do not exist today, or else they have become more capitalist. some people think that communism in those countries did not work because marx's ideas, though nice in thought, did not really work. others think that communist countries collapsed because of the attacks (military, political and economic) from capitalist countries.