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.
Originally, yao meant 'crisscross'; it represented the intersecting of the yin and the yang… Yin yao are represented by two broken lines (--), yang yao by a solid line (—).
Huang establishes the foundational ontology of the line (yao) as the intersection of yin and yang forces, making explicit that the graphic distinction between broken and solid encodes a complete cosmological polarity.
, The Complete I Ching: The Definitive Translation, 1998thesis
The places occupied by the lines are differentiated as superior and inferior, according to their relative elevation… the fifth place is that of the ruler, and the fourth that of the minister who is close to the ruler.
Wilhelm articulates the positional hierarchy of lines, demonstrating that each of the six places carries a fixed sociopolitical analogue that conditions the meaning of any line occupying it.
, The I Ching or Book of Changes, 1950thesis
The places occupied by the lines are differentiated as superior and inferior, according to their relative elevation… the fifth place is that of the ruler, and the fourth that of the minister.
This parallel passage from the companion Wilhelm edition confirms the hierarchical positional doctrine of lines as the structural grammar of hexagram interpretation.
, The I Ching or Book of Changes, 1950thesis
When a yin line carries a yang line, this indicates congruity… When a line is far from trouble, this indicates ease, but when a line is close to trouble, this indicates danger.
Wang Bi's commentary articulates the relational logic of lines — their relative positioning to one another and to structural danger determines auspiciousness independent of their intrinsic quality.
, The Classic of Changes: A New Translation of the I Ching as Interpreted by Wang Bi, 1994thesis
The hexagram Ch'ien… is uniformly composed of firm lines all having a certain relation to one another. They form a sequence of stages, so that a genetic development in time can be observed.
Wilhelm demonstrates that when a hexagram's lines are of uniform quality, their sequential positional relations rather than yin-yang contrast govern the interpretive logic, revealing lines as markers of temporal development.
, The I Ching or Book of Changes, 1950thesis
The relationship of holding together occurs also between the fifth and the top line. Here it pictures a ruler placing himself under a sage; in such a case it is usually a humble ruler (a weak line in the fifth place) who reveres a strong sage.
Wilhelm maps the relational dynamic of 'holding together' between specific line positions onto social and ethical archetypes, showing lines as carriers of interpersonal meaning.
, The I Ching or Book of Changes, 1950supporting
The holding together of a strong, i.e., an incorrect line in the fourth place with a yielding ruler is generally unfavorable… it is favorable in certain hexagrams in which the strong fourth line is the ruler.
This passage details how the correctness of a line — its consonance of quality with its positional parity — modulates the auspiciousness of relational bonds between lines.
, The I Ching or Book of Changes, 1950supporting
Each six-yao gua also has a host which represents the central theme of the gua. Being the host of a gua, the yao should be virtuous and appropriate at the right time and the right position.
Huang introduces the concept of the 'host' line — a single line whose virtuous consonance with time and position determines the central meaning of the entire hexagram.
, The Complete I Ching: The Definitive Translation, 1998supporting
The third usually has misfortune, the fifth usually has merit, because they are graded according to rank. The weaker is endangered, the stronger has victory.
Wilhelm establishes the normative moral gradation of line positions, wherein structural rank directly correlates with expected outcome, encoding a proto-ethical hierarchy in the hexagram's vertical axis.
, The I Ching or Book of Changes, 1950supporting
Two other trigrams, called nuclear trigrams, can be formed from lines 2 3 4 and 3 4 5. In the hexagram T'ai, which shows heaven below and earth above, the two nuclear trigrams are Tui…
Hellmut Wilhelm explains how individual lines participate in multiple simultaneous trigram configurations, multiplying a single line's significance beyond its primary positional role.
, Change: Eight Lectures on the I Ching, 1960supporting
The individual lines denote the respective parts of the body: the three lower lines are the legs, including toe, calf, and thigh; the three upper lines are the trunk, with the heart, the back of the neck, and the organs of speech.
Wilhelm maps the six lines onto a somatic register, demonstrating that the vertical axis of the hexagram can function as an image of the human body from lowest to highest.
, The I Ching or Book of Changes, 1950supporting
The individual lines denote the respective parts of the body: the three lower lines are the legs… the three upper lines are the trunk, with the heart, the back of the neck, and the organs of speech.
This parallel passage reinforces the somatic mapping of lines, anchoring the hexagram's vertical structure in an embodied phenomenology of self from ground to expression.
, The I Ching or Book of Changes, 1950supporting
The line is the ruler of the hexagram. It is this line that must lead the resolute struggle against the six at the top, which symbolizes the inferior man.
Wilhelm illustrates how a specific line's positional authority confers on it a directive role within the hexagram's internal drama of forces, functioning as a moral protagonist.
, The I Ching or Book of Changes, 1950supporting
The line can be resolute. It is on the one hand the ruler of the hexagram, and moreover ruler in the most distinguished place; on the other hand it is the top line of the vigorous upper nuclear trigram Ch'ien.
This passage demonstrates the compounded significance of a ruling line that simultaneously holds positional authority and functions as the apex of a nuclear trigram.
, The I Ching or Book of Changes, 1950supporting
A standstill is imposed upon the lowest line, weak in itself, by the nuclear trigram K'ean forming above it. Hence it is stopped in its tendency to progress.
Wilhelm shows how a line's tendency is constrained not only by its own quality but by the nuclear trigram superstructure — demonstrating the multi-layered determinism acting on each individual line.
, The I Ching or Book of Changes, 1950supporting
A standstill is imposed upon the lowest line, weak in itself, by the nuclear trigram K'ean forming above it. Hence it is stopped in its tendency to progress.
This passage reinforces how nuclear trigram formation constrains individual line movement, illustrating the relational entrapment of the weakest positional element.
, The I Ching or Book of Changes, 1950supporting
The nine at the beginning is still far from danger; hence if one holds to lasting things, one can avoid mistakes. The nine in the second place is approaching closer to danger…
Wilhelm traces a narrative of progressive temporal proximity to danger through successive line positions, rendering the hexagram's vertical axis as a timeline of developing crisis.
, The I Ching or Book of Changes, 1950supporting
Receiving a hexagram without any changing lines can sometimes be confusing. In such cases I think that we are simply meant to reflect on the hexagram as a whole.
Anthony foregrounds the role of changing lines as activators of interpretive movement, noting that their absence shifts the reader's attention from particular line dynamics to the hexagram's gestalt meaning.
, A Guide to the I Ching, 1988supporting
The nine in the third place is a firm line in a firm place, which gives too much firmness for an exceptional time, hence the misfortune of bending and breaking threatens.
Wilhelm articulates the paradox of overcorrection: a line that is correct in both quality and position may nonetheless produce misfortune when the time demands flexibility rather than firmness.
, The I Ching or Book of Changes, 1950supporting
The trigram is composed of three lines, traditionally representing heaven, humanity, and earth. The heavenly, or celestial, is associated in humans with the spiritual, or reason or the ideal.
Liu I-ming situates the three-line trigram within a cosmological anthropology, reading each line as a register of being — celestial, human, and terrestrial — that frames the hexagram's six positions.
, The Taoist I Ching, 1986aside
The division between germ line and somatic line does not exist in all animals and is not applicable to plants… In somatic embryogenesis, there is no distinct germ line: all cells are capable of participating in the development of the body.
Thompson imports the biological meaning of 'line' as hereditary lineage versus somatic tissue, an outlier usage in this corpus that shares with the I Ching tradition only the notion of differentiated functional roles within a developing whole.
, Mind in Life: Biology, Phenomenology, and the Sciences of Mind, 2007aside