The Gelasian Decree (Latin: Decretum Gelasianum) is a Latin text traditionally thought to be a Decretal of the prolific Pope Gelasius I, bishop of Rome from 492-496. The work reached its final form in a five-chapter text written by an anonymous scholar between 519 and 553, the second chapter of which is a list of books of Scripture presented as having been made part of the biblical canon by a Council of Rome under Pope Damasus I, the bishop of Rome from 366-383. This list, known as the Damasine List, represents the same canon as shown in the Council of Carthage Canon 24, 419 AD. The fifth segment of the work includes a list of distrusted and rejected works not encouraged for church use.
The Decretum has five parts. The second part is a canon catalogue. The Deuterocanonical Books (other than Baruch and the Letter of Jeremiah) are accepted by the catalogue, and are still found in the Roman Catholic Bible, though not in the Protestant canon. The canon catalogue gives 27 books of the New Testament. In the list of gospels, the order is given as Matthew, Mark, Luke, John. Fourteen epistles are credited to Paul including Philemon and Hebrews. Of the General Epistles seven are accepted: two of Peter (First Epistle of Peter, Second Epistle of Peter), one of James (Epistle of James), one of the apostle John (First Epistle of John), two of "the other John the elder" (presbyter) (Second Epistle of John, Third Epistle of John), and one of "Judas the Zealot" (Epistle of Jude).
The fifth part is a catalogue of the "apocryphal books" and other writings which are to be rejected, presented as adjudged apocryphal "by Pope Gelasius and seventy most erudite bishops". Though the ascription is generally agreed to be apocryphal itself, except among the most traditional of apologists, it perhaps makes allusion to the seventy translators of the Septuagint and the seventy disciples sent out in the Gospel of Luke. This list de libris recipiendis et non recipiendis ("of books to be admitted and not to be admitted"), probably originating in the 6th century, represents a tradition that can be traced back to Pope Damasus I and reflects Roman practice in the development of the Biblical canon. These apocrypha are not the same as the deuterocanonical books (which would acquire the label "apocrypha" in the Protestant tradition only a millennia later, in the 1500s), but rather are other writings that parts of the early Church revered, but declared invalid during the doctrinal debates of the 3rd, 4th, and 5th centuries. It includes works such as the Acts of Andrew, the Acts of Paul and Thecla, the Gospel of James, and others.
The other parts are generally of less interest to modern audiences and historians. Part 1 is a poem to the many facets of God. Part 3 is a short endorsement of the supremacy of the Bishop of Rome over the other bishops as "first among equals", citing the authority of Peter. Part 4 is a description of accepted synods that includes the Council of Nicea, the Council of Ephesus, and the Council of Chalcedon. It then lists accepted Church Fathers. It also enumerates lesser recognized ecclesiastical writers varying from famous to obscure (for example Sedulius and Juvencus). Notably, it suggests that while Origen of Alexandria's work can be read, he personally should be rejected as a "schismatic".
The complete text is preserved in the mid-eighth-century Ragyndrudis Codex, fols. 57r-61v, which is the earliest manuscript copy containing the complete text. The earliest manuscript copy was produced c. 700, Brussels 9850-2.
Versions of the work appear in multiple surviving manuscripts, some of which are titled as a Decretal of Pope Gelasius, others as a work of a Roman Council under the earlier Pope Damasus. However, all versions show signs of being derived from the full five-part text, which contains a quotation from Augustine, writing about 416 after Damasus, which is evidence for the document being later than that.