text: On the other hand you readily admit your opinions are not identical with the magisterium.
  
  The "case that I know of" turned out to be a non-magisterial opinion.
  
  While simple agreement with the magisterium is not what makes one Catholic, claiming to be Catholic while disputing with the magisterium is no more effective.
  
  And, be it slavery or otherwise, the ordinary magisterium properly understood does not err.