From Vajrayana Tara to Bengali Baul: A Computational Study of Lexical Transmission Across Buddhist, Shakta, and Vaishnava Traditions in Bengal

Technical Summary: From Vajrayana Tara to Bengali Baul

Problem Statement
The historical relationship between Buddhist Vajrayana and Shakta Tantra traditions in Bengal has long been a subject of philological and iconographic debate. Scholars such as Bharati, Dasgupta, and Lorenzen have argued that following the collapse of the Pala dynasty (8th–12th centuries), Buddhist vocabulary and practices were absorbed into the Shakta tradition. However, this hypothesis has remained largely qualitative. A critical gap exists in quantifying whether the observed vocabulary overlap is a specific historical signal of transmission or merely a generic property of Sanskrit devotional literature from that era. Furthermore, the specific pathways through which Buddhist vocabulary survived into modern Bengali devotional culture (Baul tradition) remain unmeasured.

Methodology
The study employs a computational corpus analysis of 75 texts spanning eight tradition layers from the 8th to the 19th centuries, covering Sanskrit and Bengali scripts. The corpus includes Pure Vajrayana Buddhist texts, the Charyapada (Old Bengali), "Bridge Tara" texts (Buddhist-Shakta transitional), Vaishnava Sanskrit texts (specifically the Gitagovinda), Shakta Kali and Durga texts, and Vaishnava and Baul Bengali texts.

• Vectorization: Documents are represented as TF-IDF vectors using character n-grams of length 3 to 5. This approach was selected to handle the high inflection of Sanskrit and the complex consonant clusters of Bengali without requiring full morphological resolution or sandhi splitting. The method is robust to OCR noise, which was present in the 18th-century Ramprasad Sen corpus.
• Similarity Metric: Pairwise cosine similarity is computed between all document vectors. Cross-tradition averages are calculated as the mean similarity between documents of different traditions.
• Control Condition: The Vaishnava Sanskrit tradition (centered on Jayadeva's Gitagovinda) serves as a primary control. It shares the same language, script, period, and broad category of devotional poetry as the Buddhist-Shakta texts but represents a distinct lineage with no claimed Buddhist-Shakta inheritance.
• Term Density Analysis: In parallel with vector analysis, the study counts occurrences of curated Buddhist and Shakta term lists (normalized per 1,000 tokens) to measure vocabulary orientation and migration ratios.

Key Results

1. Specificity of the Buddhist-Shakta Connection: The study identifies a stark contrast in lexical similarity. Bridge Tara texts (12th century) show a cosine similarity of 0.54 to Shakta Kali texts. In contrast, the Gitagovinda (Vaishnava Sanskrit, 12th century) shows 0.00 similarity to Shakta Kali texts. This 8.5-fold difference demonstrates that the vocabulary overlap is specific to the Buddhist-Shakta transmission chain and not a generic feature of Sanskrit devotional literature.
2. Measurable Vocabulary Gradient: A smooth lexical migration is observed across the Sanskrit chain:
   • Buddhist Tara texts show a Shakta/Buddhist term ratio of 0.3.
   • Bridge Tara texts sit at near-parity (ratio 0.9).
   • Shakta Kali texts show a ratio of 1.5.
   • Specific Bridge Tara texts from the Brihannilatantra show Shakta-to-Buddhist ratios ranging from 2.0 to 4.0, providing measurable evidence of lexical transition within specific tantric lineages.
3. Late Survival of Buddhist Vocabulary: In the 18th-century Bengali corpus of Ramprasad Sen, Buddhist vocabulary persists. The corpus contains 56 occurrences of "Tara" alongside 103 occurrences of "Kali," with a Shakta/Buddhist ratio of 3.0. Terms like Shunyata (emptiness) and Sahaja also appear, indicating the survival of Buddhist residues six centuries after the destruction of Pala monasteries.
4. Three-Channel Transmission to Baul: The study identifies three distinct channels contributing to modern Baul vocabulary, with broadly similar strength:
   • Shakta Padavali Chain: Similarity of 0.40.
   • Buddhist Sahajiya Chain: Charyapada to Baul similarity of 0.31.
   • Vaishnava Bengali Chain: Vaishnava texts to Baul similarity of 0.29.
     The results suggest the Baul tradition draws from all three streams, with the Buddhist Sahajiya channel being marginally stronger than the Vaishnava one.

Significance and Claims
The paper claims to provide the first quantitative, multi-tradition corroboration of the historically argued Buddhist-Shakta syncretism in Bengal. By introducing a control group (Vaishnava Sanskrit), the study isolates the Buddhist-Shakta vocabulary overlap as a specific historical signal rather than a background literary property.

The findings support a nuanced, bidirectional model of transmission (consistent with scholars like Sanderson and Davidson) rather than a simple unidirectional absorption. The computational gradient confirms that "Bridge" texts occupy a measurable intermediate position, acting as the site of "reflux" where Buddhist vocabulary was absorbed into a Shakta framework. Additionally, the study validates the hypothesis that modern Baul vocabulary is a synthesis of Shakta, Buddhist, and Vaishnava streams, with the Buddhist contribution operating primarily through the Sahajiya practice layer (vocabulary of sahaja, shunyata) and the Vaishnava contribution through shared devotional symbols.

The authors note limitations, including the small size of the Charyapada corpus, the orthographic barrier between Devanagari and Bengali scripts (which prevents direct cross-script similarity calculation), and the reliance on point estimates without bootstrap significance testing. However, sensitivity analyses confirm that the core gradient findings are robust to definitional choices regarding shared tantric terms.