This article explores the evocations of the Synod of Pistoia (1786) at Vatican II, arguing that Pistoia was a “ghost” on the council floor, that is, a key moment in the Church’s collective memory which influenced drafting and debate. This is apparent in Bishop Carli’s evocation of Auctorem Fidei (the 1794 bull condemning Pistoia) during debates surrounding the theology of the episcopacy. This article concludes by arguing that the historical contextualization of Pistoia by figures like Cardinal Silva Henríquez was ultimately successful, as Auctorem Fidei did not exert a strong “controlling function” over Vatican II’s ecclesiological debates.