On 18 November 1302, Pope Boniface VIII issued the Papal bull Unam sanctam which some historians consider one of the most extreme statements of Papal spiritual supremacy ever made. The original document is lost but a version of the text can be found in the registers of Boniface VIII in the Vatican Archives. The Bull lays down dogmatic propositions on the unity of the Catholic Church, the necessity of belonging to it for eternal salvation, the position of the pope as supreme head of the Church, and the duty thence arising of submission to the pope in order to belong to the Church and thus to attain salvation. The pope further emphasizes the higher position of the spiritual in comparison with the secular order.
The main propositions of the Bull are the following: First, the unity of the Church and its necessity for salvation are declared and established by various passages from the Bible and by reference to the one Ark of the Flood, and to the seamless garment of Christ. The pope then affirms that, as the unity of the body of the Church so is the unity of its head established in Saint Peter and his successors. Consequently, all who wish to belong to the fold of Christ are placed under the dominion of Peter and his successors.