Two Swords for Two Powers

The doctrine of the two swords takes its name and its central image from the Gospel of Luke, in which the disciples tell Jesus, here are two swords, and he replies, it is enough, a passage medieval theologians read allegorically as representing spiritual and temporal authority, the two powers a rightly ordered Christian society requires.

Medieval popes, most forcefully Boniface VIII in the 1302 bull Unam Sanctam, used the image to argue that both swords belonged in principle to the church, which held the spiritual sword directly and delegated the temporal sword to secular rulers for exercise on the church's behalf, subject ultimately to spiritual authority and correction. This reading placed the papacy at the summit of a single integrated hierarchy of both spiritual and temporal power, a strong claim that secular rulers, especially the Holy Roman Emperors, contested vigorously across the medieval period in a series of conflicts historians group under the broader heading of church and state controversy, including the eleventh century Investiture Controversy over who had the right to appoint bishops. Later medieval and early modern political writers continued to cite the passage on both sides of church and state disputes, each finding in the same brief gospel exchange support for whichever balance of the two powers their own argument required.