Within the depth-psychology corpus, ‘Line’ operates as a technical term of extraordinary precision, rooted almost entirely in the interpretive tradition of the I Ching. Across the commentarial lineages represented by Wilhelm, Huang, Wang Bi, and Liu I-ming, the line — yao in Chinese, originally signifying ‘crisscross’ and the intersecting of yin and yang — is the irreducible unit from which all divinatory meaning is constructed. Each hexagram’s six lines are not mere graphical marks but dynamic agents carrying positional significance: their quality (solid or broken, yang or yin), their place (first through sixth), their relationship to adjacent lines (riding, carrying, corresponding, holding together), and their consonance with the time all determine whether a situation augurs fortune or misfortune. The corpus reveals a persistent tension between the line as structural element and the line as living participant in a field of relational forces — the fifth-place line rules, the third-place line is imperiled, the top line signals completion or overreach. Wilhelm and Huang treat the line’s positional propriety as a moral analog: correct lines in correct places embody virtue. Wang Bi insists that the quality of the moment (shi) governs a line’s meaning more than its intrinsic nature. Thompson’s lone biological intrusion — the germ line versus somatic line — marks an outlier usage. The term thus concentrates divinatory, cosmological, ethical, and relational meanings into a single mobile symbol.