Cum ex apostolatus officio
Cum ex apostolatus officio is the name of a papal bull issued by Pope Paul IV on 15 February 1559 as a codification or explicitation of the ancient Catholic law that only Catholics can be elected Popes , to the exclusion of non-Catholics , including former Catholics who have become public and manifest heretics . 
<triplet> Cum ex apostolatus officio <subj> papal bull <obj> instance of <subj> Pope Paul IV <obj> author