The author revisits the issue of religious "non-conformism" by focusing attention on the passage, between the 12th and 13th centuries, in which the overlap between Christian heresies and other religions was determined. Compared to the conciliar and papal pronouncements regarding orthodoxy and heresy, the author favors the analysis of canon law to reconstruct the delimitations that delimited the space of dissent and repression: a coherent semantic development emerges, from a legal perspective, around the libertas religionis and libertas Ecclesiae and in relation to two other key words: tolerantia and iurisdictio. In this way the Church came to identify in the sacrament of baptism the unequivocal act of belonging to Christian society and the 'duty' repression of dissent.