The Polish version of the article was published in “Roczniki Humanistyczne,” vol. 59 (2011), issue 2. The article discusses the origins of public penance for heresy in the early Christian tradition as well as examining its application in the penitential practice of the medieval Church. It demonstrates how public penance for mortal sins, which took shape in Late Antiquity, was later adopted and developed within the system of Medieval Inquisition. In the medieval collections of canon law, heresy was qualified as a religious crime which required special public penance. Following the guidelines set up in the ancient Church, any heretic who declared his or her intention to renounce their wrongs was to be interrogated by a bishop, who would grant...