Automated Topic Analysis of the Voynich Manuscript

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I’ve been running paragraph-level topic models on the text. The first passes (NMF/LDA) made it clear that a lot of variance is explained by style-language A/B and scribal hands. However, the plots also showed sharp colour changes exactly at section boundaries (e.g., Herbal → Pharma), suggesting that genuine themes coexist with stylistic effects.

To separate the two, I cleaned the text (removed single-character tokens and a small, empirically derived list of near-ubiquitous “stop-forms”) and switched to DMR (Dirichlet-Multinomial Regression). In DMR the topic word distributions are global, while the topic mixture for each paragraph depends on covariates (here: language, writing hand, Currier). In practice this lets style influence how much of each topic appears without redefining the topics themselves. I compared several K topic numbers and selected K=6 (highest AMI between topics and editorial sections). Here are the topic distributions through the folia and separated by section, language, writting hand and currier hand:


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The six topics align as follows:

• T0 – Marginal stars: qok-… with -ain/-ey; dominant on the marginal-stars pages.
  
• T1 – Astronomical/Zodiac: frequent -iin/-ar/-ey; peaks in Astronomical and Zodiac.
  
• T2 – Pharmaceutical: ch/che- + -ol/-or (e.g., chol, cheol, cheor), plus qok+-ol; strong in Pharma.
  
• T3 – Text/Cosmological: general high-frequency forms (ar, or, aiin…); Text-only and parts of Cosmological.
  
• T4 – Biological (balneological): distinctive -edy/-dy with qo-/qoke-/oke-; the balneological block.
  
• T5 – Herbal: ch/sh + o/l patterns; Herbal pages, especially in Language A.
  

Distribution. Heatmaps and stacked timelines show near-pure blocks per section: Zodiac/Astro→T1, Pharma→T2, Biological→T4, Herbal→T5, Marginal→T0, Text/Cosmo→T3. Where sections change, the dominant topic usually flips at the same boundary.



Language and hands. Language and hands still influence prevalence. Language A leans Herbal (T5); Language B spreads over T0/T1/T3/T4. Some hands show long runs dominated by one topic, yet topic shifts track section changes. This points to thematic structure that is not merely scribal style.



A cautious reading is that this patterning is inconsistent with pure gibberish: the DMR analysis (K=6) uncovers stable, section-aligned topics whose vocabularies persist across scribes and languages, suggesting the text carries systematic content rather than random noise.

I would appreciate any comment.