The article considers the division of the word in Varro’s linguistic doctrine into two constituent parts, referred to as principia (“primary elements”). Those components (material and figura), being inextricably linked, cannot exist separately. Varro comes to such a conclusion while studying the process of word modification (declinatio). The principia of the word identified by Varro allow him to derive his own conditions for the correctness of analogy. An examination of the concepts material and figura reveals their similarity to the opposition ὕλη – σχῆμα in the Stoic theory of πάθος. In theory, πάθος primary matter (ὕλη) under the influence of an active principle – namely, the λόγος inherent in matter – acquires a definite form (σχῆμα). In Varro, the original categories of the word (materia), under the influence of the universal law of language (ratio), through changing components (casus, exitus eius) acquire the form (figura) necessary to reflect the interconnection of things and phenomena. A comparative analysis demonstrates that the similarity is not coincidental but stems from the tradition of studying the linguistic phenomena in that period, as well as from Varro’s own purposes and objectives who sought to establish a comprehensive doctrine of the Latin language.