Quia propter (Latin: "Wherefore by…") was a document issued by the Fourth Lateran Council in 1215 on the subject of papal elections.[1] It recognized three processes for unanimous agreement: "acclamation", "scrutiny" (balloting), and "compromissum" (compromise committee).[1]
Acclamation was rare, and often driven more by crowd dynamics than discussion among the electors.[1] Compromise committees were also rare, as they required unanimous agreement to be initiated (although, once formed, only two-thirds of the commission would be required).[1] The requisite majority by balloting was considered a process for determining divine unanimity, that is, sanior et maior pars (Latin: sounder and greater part).[1] The requirement of a two-thirds supermajority had been in place since the Third Lateran Council (1179), which followed the disputed election of Pope Alexander III.[1]