This is an account of some of the most bizarre areas of human psychology, ranging from extraordinary states of mind such as love, faith and anger to full-blown psychosis. It examines disorders such as schizophrenia or Tourette's syndrome and bizarre mental states that lead to dancing mania, demonic possession, hypocondria or self-mutilation. The author discusses the unusual mental make-ups of criminals, saints, paedophiles and mediums and the extraordinary mental states most of us experience - self delusion as a defense mechanism.