text: The Bishops of the Church are the only individuals with clear Apostolic Authority. Their's is the  Sacred responsibility to to uphold the teachings of Christ. Why would they consult an ethicist if they are authority? (see section 25 of Lumen Gentium) Pope Pius XI define artificial contraception as intrinsically evil in the encyclical letter Casti Connubii (Reponse to the Anglican Lambeth Conference in 1930).  Note that intrinsically evil is a fancy way of saying there is no moral gradation. It requires an all or nothing response, as the action, or support of, is always a moral error. 
  
  Of course, this all means nothing if you dispute the authority of the Church's Magisterium. (See Council of Constance, Council of Basle and Vatican I)