Decrease, Line 4

The fourth line of Decrease (King Wen 41) is drawn as yin, the numeral six in the old divination manuals. James Legge's translation renders the line as decreasing the ailment, causing it to be dealt with quickly, occasion for joy, no error. The image sits inside a hexagram whose judgment as a whole concerns sincerity in one who practices decrease brings great good fortune, freedom from error, firmness and correctness maintained, advantage in every movement, and even in the use of two small dishes for sacrifice, 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 Gen, mountain 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 a marsh beneath a mountain; the superior man restrains his wrath and represses his desires, and the fourth line takes its place inside that combined picture of Dui below and Gen above.

Read on its own the line neither opens nor closes the hexagram's argument. It marks the point where Gen is either forming (in the lower trigram) or completing itself (in the upper), and later interpreters treat its image, Decreasing the Ailment, 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 Decrease reads within the hexagram's overall concern with sincerity in one who practices decrease brings great good fortune, freedom from error, firmness and correctness maintained, advantage in every movement, and even in the use of two small dishes for sacrifice. 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 decreasing the ailment, causing it to be dealt with quickly, occasion for joy, 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, Gen 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 Decrease turns Gen into Li while the other trigram, Dui, stays as it is, which yields Decrease's changing partner, Opposition (King Wen 38), the hexagram this line is recorded as transforming into.