Acclamation was formerly one of the methods of papal election.
The method of electing the Roman Pontiff is contained in the constitutions of Gregory XV Æterni Patris Filius and Decet Romanum Pontificem, Urban VIII's constitution Ad Romani Pontificis Providentiam, and John Paul II's Universi Dominici Gregis, issued in 1996. Prior to the issuance of Universi Dominici Gregis, three methods of election were valid. These were, namely, by scrutiny, by compromise, and by acclamation (or "quasi-inspiration"). This last form of election consisted in all the electors present unanimously proclaiming one of the candidates Supreme Pontiff, without the formality of casting votes. As this was required to be done without previous consultation or negotiation it was looked on as proceeding from the Holy Spirit and hence was also designated "quasi-inspiration".
An example of this mode of election in more recent times is found in the case of Clement X (1670-76), formerly Emilio Cardinal Altieri, whose election is said to have been determined by the sudden cry of the people outside the conclave, "Altieri Papa", which was confirmed by the cardinals. Innocent XI (1676-89) is another example. The cardinals surrounded him in the chapel of the conclave and in spite of his resistance every one of them kissed his hand, proclaiming him Pope.
Universi Dominici Gregis specifically disallowed both election by acclamation and by compromise - as a result the secret ballot is the sole valid method of electing a Pope. Originally, Universi Dominici Gregis allowed for a Pope to be elected with a simple majority if the usual requirement of a two-thirds super majority could not be reached after thirty-four ballots. On June 11, 2007 Pope Benedict XVI issued a Motu Proprio which requires a two-thirds majority regardless of the number of ballots it takes to elect a new Pope.[1]
In the 1968 film The Shoes of the Fisherman, the Cardinal electors had acclaimed Kiril Cardinal Lakota as Pope after repeated balloting failed to produce the required majority.
This article incorporates text from the public-domain Catholic Encyclopedia of 1913.