The relationship between schism, heresy and excommunication questioned the medieval canonists. The proximity of the three terms can be read from the Gratian's Decretum. Decretalists used and defined also them in the sense of close proximity, or even confusion. Regarding the treatment of heretics, schismatics and excommunicated by the Church and the faithful, two problems are developed in canon
... [Show full abstract] law : the validity of the sacraments they confer and the communication of the faithful with them. In the first case, ordination had generated the most discussion. Regarding the relationship of the faithful with these « excluded from the Church », the recurring problem is the knowledge of their status. The canonical reflection seems then to have been structured by the model of relations with excommunicated people.