“Movies can envision the need for social change, but it is unclear that they can help bring it about. They are better at pointing the way to a different, happier, more fulfilling life. Not the least interesting thing about the hopeless love dramatized in ‘Brokeback Mountain,’ which garnered eight Oscar nominations last week, is how many social hopes it has inspired.” Still, those hopes might not translate. “Movies can take on the great social problems of their time, but they may be the least effective — or appropriate — medium for solving them.”