Why might scribes deliberately alter a text while copying it?

In the field of textual criticism, scribes often introduced deliberate changes to manuscripts for several specific reasons:

• Glossing and Explanation: Scribes frequently inserted more common words to clarify rare or obscure terms, or they incorporated explanatory comments directly into the text to aid the reader’s understanding.1
• Conflation: When a scribe possessed two different manuscripts of the same work with conflicting readings and could not determine which was correct, they might incorporate both versions into the text, resulting in a "conflate" reading.1
• Correction and Emendation: Particularly during the Renaissance, scholars and copyists often felt empowered to "correct" texts to make them more readable or elegant. These changes were frequently subjective, based on a superficial sense of style rather than historical accuracy.2
• Theological or Ideological Motives: In religious or philosophical texts, scribes sometimes made alterations to align the text with specific interpretations or to resolve perceived difficulties, as evidenced by historical records of official "book correctors" and scribal emendations.3

These deliberate interventions are distinct from mechanical or accidental errors, such as those caused by fatigue or misreading, and represent a conscious effort to shape the text.43