The decrees of Trent fall into two kinds, doctrine and reform, and it issued them in pairs at almost every session. On doctrine it fixed the canon of scripture to include the books the Reformers set aside as apocryphal, declared the Latin Vulgate the authentic text for public use, and ruled that the gospel is contained both in written books and in unwritten traditions. Its decree on justification, the longest and most carefully argued document it produced, held that a person is genuinely made righteous rather than only accounted so, and that free will co-operates with grace without earning it. It confirmed seven sacraments, defined transubstantiation, and upheld the sacrifice of the Mass, communion under one kind for the laity, purgatory, indulgences and the invocation of saints.
On reform it required bishops to reside in their dioceses, ended the holding of several benefices at once, and ordered every diocese to establish a seminary, which is the single measure with the widest practical effect. The liturgical books issued afterwards under papal authority, the catechism, the breviary and the missal, standardised worship across the Latin church for four centuries and gave the Tridentine Mass its name. That rite, and the question of who may celebrate it and by whose permission, remains a live division within Catholicism sixty years after the Second Vatican Council revised the liturgy.