With regards to the Papacy, I think it's very important to remember something: there is ONLY one head of Christ's Chruch and that is Christ Himself. In Acts 15, at the council of Jerusalem, Peter did not dictate to the others how things were going to be. Actually, he wasn't even the bishop in charge at that point, it was James. Even in the early church, when all the leaders of the Church came together, when it was time for the vote at the councils, each had but one vote. The Pope was given the title, "greater among equals," a title which now belongs to the Ecumenical Patriarch (the Patriarch of Constantinople). This by means implied that the Pope could ward supreme authority as he tried to. I hope this could shed a little light on the topic.