An unintentional omission that occurs in copying or transcription when a repeated letter sequence, word, phrase, or line that appears more than once in the source is written only once in the copy, producing loss of the intervening material.

Principle

When successive or non‑adjacent identical or near‑identical sequences appear in an exemplar, a scribe or copyist may reproduce the sequence once instead of repeating it, so omission follows from perceptual‑motor compression during copying.

Demonstration

(Illustrative scenario) Situation: A manuscript contains the lines “...and he went to the city. And he bought bread. And he returned to the city.” Recognition: A copyist recognizes the repeated phrase “to the city” in two adjacent clauses. Action: While copying, the eye or memory records a single instance and the copyist writes “...and he went to the city. And he bought bread.” Consequence: The copied text lacks the final clause; later readers encounter a lacuna that must be explained by editors as haplography.

Misapplication

Treating any omission as haplography. The error is to attribute every missing passage to repeated sequences; many omissions result from damage, deliberate excision, or airborne transmission rather than perceptual non‑repetition.

Consequence

Creates shorter readings in affected witnesses, produces variant traditions, and can mislead interpretation where omitted material carries factual or syntactic weight; it also influences stemmatic reconstruction by suggesting lost repetition in the exemplar.

Reversal

Does not apply when the copyist intentionally abbreviated or summarized material, when the sequences were non‑identical in form (so perceptual identity is absent), or when the missing text can be shown to be lost by physical damage rather than copying process.

Boundary

Clearly within: omission of an identical repeated word, phrase, or short line in a manual copy. Boundary case: omission where sequences are similar but not identical (orthographic variants, synonyms). Clearly outside: loss caused by ink corrosion, intentional editorial redaction, or the opposite error of duplication (dittography).

Semantic Tension

Tension between preserving the literal witness (faithfulness to a single copy) and applying conjectural emendation or conflation to restore plausibility when haplography is suspected.

Synthesis

Haplography is a specific perceptual‑motor omission tied to repeated material; identifying it depends on recognizing patterns of repetition across witnesses and distinguishing perceptual failure from other loss mechanisms.