Interpolation (manuscripts)

Interpolation (textual criticism)

Codex Manesse showing typical scribal notes
Field	Textual criticism, Philology
Origin	Latin interpolare (to refurbish or alter)
Key people	Richard Bentley, Karl Lachmann, Brooke Foss Westcott, Fenton John Anthony Hort
Purpose	Addition of non-authorial material to a text during transmission

Interpolation in manuscript traditions is the addition of non-authorial wording to a text after its initial composition. The added material can be a single gloss, a phrase, a verse, or a larger passage. Interpolations arise through marginal notes that migrate into the text, through harmonization across parallels, through doctrinal or ideological expansion, or through deliberate literary revision.

Identifying and evaluating interpolation is a core task of textual criticism in classical, biblical, rabbinic, Islamic, and medieval corpora. The presence or absence of secondary text affects editions, translations, and interpretation, so editors document decisions about probable interpolations with transparent criteria and source-based argumentation.

Works that illustrate the phenomenon range from the gloss at John 5:3b–4 and the longer ending of Mark to the pericope adulterae and the Comma Johanneum, each traced by editors through manuscript distribution and stylistic seams. Beyond the New Testament, scholars debate the expanded Ignatian long recension, stratified layers in the Babylonian Talmud, and cumulative growth in the Mahābhārata, examples that show how interpolation reshapes religious, legal, and literary canons across cultures.

Overview

Leaf from a vellum manuscript of Tobit, c. 1240

Interpolations originally may be inserted as an authentic explanatory note (for example, [sic]), but may also be included for fraudulent purposes. The forged passages and works attributed to the Pseudo-Isidore are an example of the latter. Similarly, the letters of Ignatius of Antioch were interpolated by Apollinarian heretics, three centuries after the originals were written. Charters and legal texts are also subject to forgery of this kind. In the 13th century, a medieval romance, the Prose Tristan, inserted another prose romance, the Vulgate Cycle's Queste del Saint Graal, in its entirety in order to reinterpret the Quest for the Holy Grail through the optics of the Tristan story.

However, most interpolations result from the errors and inaccuracies which tend to arise during hand-copying, especially over long periods of time. For example, if a scribe made an error when copying a text and omitted some lines, he would have tended to include the omitted material in the margin. However, margin notes made by readers are present in almost all manuscripts. Therefore, a different scribe seeking to produce a copy of the manuscript perhaps many years later could find it very difficult to determine whether a margin note was an omission made by the previous scribe (which should be included in the text) or simply a note made by a reader (which should be ignored or kept in the margin).

Conscientious scribes tended to copy everything which appeared in a manuscript, but in all cases scribes needed to exercise personal judgement. Explanatory notes would tend to find their way into the body of a text as a natural result of this subjective process.

Textual critics combine internal evidence, examining whether disputed wording matches an author's characteristic vocabulary, style, and meter, with external evidence from manuscript families to identify interpolations, using principles like lectio brevior potior (the shorter reading is preferable) and lectio difficilior potior (the more difficult reading is preferable) as helpful guidelines rather than absolute rules, while tracing how readings spread geographically and chronologically to distinguish original text from later additions that often reveal themselves through conflation of earlier alternatives or through patterns that suggest scribal harmonization rather than authorial composition.

History

A page from Codex Sinaiticus showing Matthew 6:4–32. Ancient manuscripts like this one provide crucial evidence for identifying interpolations through comparison of textual variants across different manuscript traditions.

Ancient literary culture depended on hand-copying. Copyists added glosses and scholia to explain rare words, to align parallel passages, or to guide performance and teaching. Over time, some notes entered the body of the text. Classical philologists developed internal tests for detecting secondary strata, for example inconsistency with an author's vocabulary or metrical practice, and external tests, for example the distribution of readings among early witnesses. Alexandrian scholars marked suspicious lines with critical signs, for example the obelus, to flag wording thought non-authorial in Homeric poems.

Late antique and medieval manuscripts are rich in marginal and interlinear annotation. The line between paratext and text was porous in classroom and liturgical settings, which increased the risk that glosses would pass into the main text in later copies. For the Hebrew Bible, Israeli textual critic Emanuel Tov describes pluses, harmonizing additions, and glosses in the Masoretic, Greek, and Latin traditions, and emphasizes the need to distinguish explanatory notes from authorial text.

Renaissance and early modern critics developed systematic tools to sift primary from secondary text. English classicist Richard Bentley and German philologist Karl Lachmann advanced stemmatic methods that reconstruct family relationships among manuscripts, which help locate conflations and expansions in later branches. Debates over stemmatics continued in the twentieth century, with Italian classical philologist Sebastiano Timpanaro defending analytic stemma-building and urging attention to historical plausibility.

Examples

Classical Greek and Latin literature

Homeric scholarship debates secondary lines and book-level growth. British classical philologist Martin Litchfield West used diction and formulaic systems to identify lines that resist Homeric usage and may be secondary. In Latin epic, the so-called Helen episode at Aeneid 2.567–588 has been judged by many editors to be non-Virgilian on stylistic and manuscript grounds, though the case remains debated.

Old Testament

Notable examples among the body of texts known as Old Testament pseudepigrapha include the disputed authenticity of Similitudes of Enoch and 4 Ezra which in the form transmitted by Christian scribal traditions contain arguably later Christian understanding of terms such as Son of Man. Other texts with significant Christian interpolation include the Testaments of the Twelve Patriarchs and the Sibylline Oracles.

New Testament

A folio from Papyrus 46, one of the oldest extant New Testament manuscripts

According to textual criticism scholarship, the New Testament contains two major later additions: Mark 16:9–20 and the Pericope Adulterae (John 7:53–8:11). Modern critical editions also identify approximately fifteen to twenty shorter interpolations at the verse level, which are typically bracketed or relegated to footnotes. Examples include John 5:4, Acts 8:37, and the Comma Johanneum (1 John 5:7–8). The Hebrew Bible shows evidence of extensive redactional development, particularly visible in the Book of Jeremiah, where the Septuagint version is approximately one-seventh shorter than the Masoretic Text and arranged differently.

The longer ending of Mark, Mark 16:9–20, is absent from the earliest Greek codices. The pericope adulterae, John 7:53–8:11, appears in different locations or is missing from early witnesses. American New Testament scholar Bruce M. Metzger summarized the committee's view that the pericope's "non-Johannine origin" is likely, based on internal and external evidence. The Comma Johanneum, 1 John 5:7–8, entered the printed Greek tradition from the Latin Vulgate. Dutch New Testament scholar H. J. de Jonge reports Erasmus's later inclusion to "avoid slander", a strategic concession during controversy.

The explanatory note at John 5:3b–4 describes the stirring of the water at the Pool of Bethesda. The wording is absent from the earliest Greek manuscripts and is believed to have originated from marginal or lectionary notes that were later incorporated into the main text.

Printed editions stabilized certain interpolations by spreading them widely. The Comma Johanneum entered Erasmus's third edition in 1522 after controversy over its omission, then circulated through the Textus Receptus and early vernacular Bibles.

Notable disputed examples in the works of Josephus include Josephus' sections on John the Baptist and James the Just which is widely accepted, and the Testimonium Flavianum, which is widely regarded as at best damaged.

Patristic and rabbinic writings

Sometimes interpolation crosses the line into outright forgery. This happens when someone takes an authentic work, adds substantial new material, and then presents the expanded version as if it were entirely original. The letters of Ignatius of Antioch offer a clear example: alongside the seven authentic letters, there exists a much longer collection that includes additional correspondence and greatly expanded versions of the originals. Scholars universally recognize this "long recension" as a later fabrication. As William R. Schoedel puts it, we're dealing with an "expanded version of the seven letters" that someone created to advance their own theological agenda under Ignatius's borrowed authority.

In the Babylonian Talmud, American Talmudist David Weiss Halivni argued that an anonymous stammaitic layer organizes and expands Amoraic material, a thesis refined by American Jewish studies scholar Jeffrey L. Rubenstein. They identify stylistic and structural markers that signal later intervention.

Roman law and Justinian's Digest

Roman law scholarship debates whether sixth-century compilers altered classical juristic writings by inserting explanatory or harmonizing material. British legal historian Barry Nicholas introduces the issue for students of Roman law, while English legal scholar Tony Honoré analyzes the compilers' techniques and the character of the anthology. German-born legal historian Fritz Schulz provides a broader history of Roman legal science that contextualizes the debate. Critics of aggressive interpolation-hunting warn against overdiagnosis and prefer limited, source-based claims.

Islamic hadith

In the study of hadith transmission, Arabic idrāj names the insertion of non-prophetic wording by a transmitter or scribe into a report. American Islamic studies scholar Jonathan A. C. Brown surveys how hadith critics diagnose such additions and mark them in editions.

Medieval texts

Old French epic shows extensive expansion across branches with the Chanson de Roland surviving both in an Oxford manuscript and in later rhymed redactions such as Châteauroux and Venice 7. The CV7 version introduces new episodes and substantial expansions that reframe the narrative arc, which provides a dossier for analyzing growth across witnesses.

Sanskrit epics

The long oral and written transmission of the Mahābhārata and Rāmāyaṇa shows a history of expansion and interpolation. Indian textual critic V. S. Sukthankar's Prolegomena to the Bhandarkar Critical Edition outlines principles for distinguishing archetypal readings from later growth. British Indologist John Brockington surveys these processes and their implications for interpretation.

Debates

From Origen and Jerome to Bentley and Lachmann, critics worked out methods for recognizing secondary material. Lachmannian stemmatics privileged shared error and genealogical reconstruction. American New Testament scholar Eldon Jay Epp later urged caution about the very idea of a single "original text" and recommended attention to textual plurality.

Some medievalists, notably French literary historian Joseph Bédier, criticized what he called "abominable genealogical trees" and argued that complex traditions resist neat stemmata. Others refined stemmatics and combined it with local judgment and an awareness of authorial revision.

Interpolation analysis influences editorial practice, translation policy, and interpretation. Editors may exclude material identified as secondary to present what they consider the author's original text, while recording suspected interpolations in critical apparatus or notes to preserve reception history. Editorial decisions typically balance internal and external evidence, with editors documenting their reasoning to allow readers to evaluate disputed cases. When analyzing passages in religious or culturally significant texts, scholars employ neutral terminology and careful documentation of sources.

American New Testament scholar Bart D. Ehrman revived debate about theological motivation, while other editors attribute many pluses to routine scribal habits. British New Testament scholar Michael W. Holmes highlights that claims of "theological corruption" must be weighed against ordinary harmonization and explanatory glossing. Modern genealogical modeling and digital collation tools have transformed how scholars understand textual transmission, shifting focus from seeking single archetypes to mapping the complex networks through which expansions and interpolations gradually entered living traditions.

See also

• Textual criticism
• Contamination (textual criticism)
• Archive
• Deuteronomist
• Elohist
• Exegesis
• Hermeneutics
• Marginalia
• Media preservation
• Priestly source
• Western non-interpolations