Abstract
The canonists’ determination of the sphere of sanction provides an insight into the foundations of ecclesiastical tolerance. There is indeed an ecclesiastical tolerance that leads the magisterium to limit the scope of penal normativity for theological and pastoral reasons. The distinction between sin and crime, well known to canonists, is justified less by recourse to decretals or decisions of councils than by a return to the discourses of the Church Fathers. The definition of the notion of crime in canon law and beyond owes a debt to Augustine’s meditation on the Donatist quarrel: according to this approach, it is a question of tolerating the tares.