Passage Summary: If you think you can't change anything, you'll feel too discouraged to try. Therefore, if you actually want to make things better, you shouldn't believe that the world is controlled by big forces you can't influence.

Conclusion: Those aiming to better society ought to dismiss the idea that the future is dictated solely by unstoppable historical forces.

Reasoning: Believing that individuals are powerless leads to a sense of helplessness that prevents people from taking action to improve society.

Analysis: This argument moves from a psychological observation about how beliefs cause helplessness to a prescriptive recommendation about what people should believe. We need a principle that bridges the gap between a belief being a hindrance and the necessity of rejecting that belief. Look for a rule stating that one should avoid beliefs that interfere with achieving one's goals. It's a classic case of 'if the belief stops you from doing what you want, ditch the belief.'