A Comparative Structural Hypothesis: Voynich Manuscript and Linear A as Functionally Layered Writing Systems

The Voynich Manuscript and Linear A represent two of the most studied yet undeciphered writing systems in historical scholarship. While Linear A is widely recognized as a hybrid administrative system combining textual signs with numerical and metrological notation, the Voynich Manuscript is still predominantly approached as a purely alphabetic or linguistic cipher. This paper proposes a comparative structural hypothesis: that the Voynich Manuscript belongs to the same functional class of writing systems as Linear A—namely, systems in which textual elements coexist with an independent numerical or cyclical notation layer. The study does not attempt semantic decipherment. Instead, it applies a strictly structural methodology based on functional segregation of signs, positional rigidity, repetition patterns, and cycle termination markers. A control experiment using Linear A tablets demonstrates that functional segregation correctly identifies numerical and administrative structures (~85% conformity). Applying the same methodology to the Voynich Manuscript yields comparable structural regularities (~70% conformity) in specific sections, particularly astronomical and diagrammatic folios. These results suggest that the persistent failure to decipher the Voynich Manuscript may stem from a methodological assumption rather than from the absence of structure. The hypothesis is explicitly falsifiable and is offered as a comparative and methodological contribution to future research.