This book is a contribution both to analytical philosophy of mind and to Marxist philosophy. Marxists see pervasive irrationality in the conduct of human affairs, and claim that people in a class-divided society are prone to a variety of misconceptions. They say that we can suffer from `false consciousness' in our views about what inspires our behaviour and in our judgements about what is good for us. Denise Meyerson uses the techniques of analytic philosophy to investigate this picture. She argues that Marxism is committed to the idea of motivated belief, and that the idea is philosophically defensible. She shows that there are other philosophically defensible claims which are congenial to Marxism: that there are facts about interests that are not based on wants; that a desire can be contaminated by its history; that our judgements about our interests do not automatically motivate us; and that beliefs can survive the evidence that they are false. In doing so she throws light on certain puzzling psychological phenomena which confront everyone in their everyday political experience.