Xu Shen
Pre-"Shuowen" Chinese dictionaries like the "Erya" and the "Fangyan" were limited lists of synonyms loosely organized by semantic categories, which made it difficult to look up characters. Xu Shen analytically organized characters in the comprehensive "Shuowen Jiezi" through their shared graphic components, which Boltz (1993:431) calls "a major conceptual innovation in the understanding of the Chinese writing system."