Cum ex apostolatus officio is the name of a papal bull issued by Pope Paul IV in 1559; it states that only Catholics can be elected Popes, to the exclusion of non-Catholics, including former Catholics who have become public and manifest heretics.[1]


  1. ^ Bonora, Elena (2015). "Il sospetto d'eresia e i 'frati diplomatici' tra Cinque e Seicento". In Tallon, Alain; Gigliola, Fragnito (eds.). Hétérodoxies croisées. Catholicismes pluriels entre France et Italie, XVIe-XVIIe siècles. doi:10.4000/books.efr.2823 – via OpenEdition Books.