ABSTRACT
THE CONCEPT THAT stands in the foreground of the medieval papal government was that of auctoritas. Originally employed in the Roman constitution, the concept expressed the final, supreme power to lay down binding rules of action. It was no doubt a charismatically inspired idea and gave birth to the principatus, that is, to a correctly understood monarchy. But the essential point about the (Roman and papal) auctoritas was that it was indivisible and could in its fullness be in only one man, whilst the correlative concept, that of potestas, could be divided. The elaboration of this twin concept of auctoritas and potestas by the papacy in the fifth century was historically conditioned.
