Source : Webster's Revised Unabridged Dictionary (1913)

Sacerdotalism \Sac`er*do"tal*ism\, m.
   The system, style, spirit, or character, of a priesthood, or
   sacerdotal order; devotion to the interests of the sacerdotal
   order.

Source : WordNet®

sacerdotalism
     n : a belief that priests can act as mediators between human
         beings and God