Unam Sanctam

Unam Sanctam is a short document carrying a long argument. Boniface VIII begins from the unity of the church, one body with one head, and reasons from that unity to a single governing authority. He takes up the image of the two swords, drawn from a passage in Luke and read allegorically since Bernard of Clairvaux, and gives it the hardest available reading: both swords, the spiritual and the temporal, belong to the church, and the temporal sword is wielded for the church by kings and soldiers at the direction of the priest. Where the two conflict, the spiritual power judges the temporal, and the spiritual power itself can be judged by God alone.

The closing sentence is the one that mattered afterwards. It declares, defines and pronounces that it is altogether necessary for salvation for every human creature to be subject to the Roman Pontiff. Later Catholic theology treats that clause as the definition and the rest of the bull as the argument leading to it, which is why the document still appears in doctrinal collections while its political claim is read as a product of its moment.

Almost nothing in the reasoning was new. Canonists had been assembling the case for papal superiority over secular rulers for two centuries, and most of the phrases Boniface uses are quotations from that literature. What was new was the decision to state the case at full strength, in a formal bull, in the middle of a quarrel with the strongest king in Europe, at the point when the papacy could no longer make the claim good.

The bull belongs to a dispute about money and jurisdiction rather than about theology. Philip IV of France had been taxing the clergy of his kingdom to pay for war with England, and had then arrested and tried a French bishop, Bernard Saisset, on a charge of treason. Both acts touched claims the papacy regarded as its own: the immunity of church property from lay taxation, and the right of the church to try its own clergy. Boniface had already answered the taxation in 1296 with Clericis Laicos and had been forced to soften it. Unam Sanctam, issued on 18 November 1302, restated the underlying principle at its widest.

Philip's answer was not argument. His counsellors accused the pope of heresy and simony and called for a council to judge him. In September 1303 a force under Guillaume de Nogaret and members of the Colonna family seized Boniface at Anagni. He was released within days but died on 11 October, and within a decade the papal court had moved to Avignon. In 1306 Clement V issued the brief Meruit, which stated that France stood in no worse position with respect to the church than before the bull, withdrawing its political edge without touching a word of its text.

That sequence is why the document is read two ways. As a statement about communion with Rome it was never withdrawn and is still quoted. As a claim to direct authority over kings it was defeated within a year of being made, and the medieval papacy never recovered the ground it had staked.