Penitential

thumb|Incipit of the Paenitentiale Vinniani A penitential is a book or set of church rules concerning the Christian sacrament of penance, used for regular private confession with a confessor-priest, a "new manner of reconciliation with God" that was promoted by Celtic monks in Ireland in the sixth century AD, under the Egyptian monastic influence of St John Cassian. It consisted of a list of sins and the appropriate penances prescribed for them, and served as a type of manual for confessors.

==Origin== The earliest important penitentials were those by the Irish abbots Cummean (who based his work on a sixth-century Celtic monastic text known as the Paenitentiale Ambrosianum) and Columbanus, and the Archbishop of Canterbury, Theodore of Tarsus. Most later penitentials are based on theirs, rather than on earlier Roman texts. The number of Irish penitentials and their importance is cited as evidence of the particular strictness of the Irish spirituality of the seventh century. Walter J. Woods holds that "over time the penitential books helped suppress homicide, personal violence, theft, and other offences that damaged the community and made the offender a target for revenge."