Inner Truth, Line 4

The fourth line of Inner Truth (King Wen 61) is drawn as yin, the numeral six in the old divination manuals. James Legge's translation renders the line as like the moon nearly full, or a horse that loses its fellow, no error. The image sits inside a hexagram whose judgment as a whole concerns reaching even pigs and fish, good fortune, advantage in crossing the great stream, advantage in being firm and correct, and this line supplies one stage of that larger reading rather than a complete statement on its own.

Structurally the line stands at the lowest place of the upper trigram Xun, wind in Legge's readings of the eight trigrams, while the lower trigram of the hexagram is Dui, lake in the same traditional set of images. The Great Symbolism of the hexagram reads wind above the waters of a marsh; the superior man deliberates carefully over criminal cases and delays the infliction of death, and the fourth line takes its place inside that combined picture of Dui below and Xun above.

Read on its own the line neither opens nor closes the hexagram's argument. It marks the point where Xun is either forming (in the lower trigram) or completing itself (in the upper), and later interpreters treat its image, Like the Moon Nearly Full, as the concrete case through which the hexagram's abstract judgment becomes visible in a single situation rather than a general principle.

As a divinatory line, six at the fourth place of Inner Truth reads within the hexagram's overall concern with reaching even pigs and fish, good fortune, advantage in crossing the great stream, advantage in being firm and correct. The line occupies a place proper to its own nature in the classical doctrine that odd places favour a firm, yang line and even places favour a yielding, yin line. Its own text, that like the moon nearly full, or a horse that loses its fellow, no error, is the particular fortune assigned to this one stage of the situation, not to the hexagram as a whole.

The fourth line corresponds by classical convention with the first line, and the two correspond here, since one line is yin and the other yang. Read together with the trigram it belongs to, Xun in the upper position of the figure, the line marks the first word of the upper trigram, close enough to the ruling fifth line to be shaped by it, one stage in the six stage movement the hexagram traces from its first line to its last.

A change at this line, from yin to its opposite, is the mechanism the tradition uses to move from one hexagram to another. Flipping the fourth line of Inner Truth turns Xun into Qian while the other trigram, Dui, stays as it is, which yields Inner Truth's changing partner, Treading (King Wen 10), the hexagram this line is recorded as transforming into.