Increase, Line 4

The fourth line of Increase (King Wen 42) is drawn as yin, the numeral six in the old divination manuals. James Legge's translation renders the line as pursuing the due course, his advice to the prince is followed, and he can be relied on to advise even the moving of the capital. The image sits inside a hexagram whose judgment as a whole concerns advantage in every movement undertaken, even advantage in crossing the great stream, 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 Zhen, thunder in the same traditional set of images. The Great Symbolism of the hexagram reads wind and thunder together; the superior man, seeing what is good, moves toward it, and seeing his errors, turns away from them, and the fourth line takes its place inside that combined picture of Zhen 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, Pursuing the Due Course, 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 Increase reads within the hexagram's overall concern with advantage in every movement undertaken, even advantage in crossing the great stream. 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 pursuing the due course, his advice to the prince is followed, and he can be relied on to advise even the moving of the capital, 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 Increase turns Xun into Qian while the other trigram, Zhen, stays as it is, which yields Increase's changing partner, Innocence (King Wen 25), the hexagram this line is recorded as transforming into.