A Discussion of the Names of Two Yijing Hexagrams

Why is Xiaochu 'xiao,' and Dachu, 'da?' While a number of significant differences between Xiaochu (??, hexagram 9) and Dachu (??, hexagram 26) may be highlighted, as well as some striking commonalities, ultimately it seems that the most persuasive, single trait that distinguishes the two hexagrams is the different number of yin lines in each upper trigram. Nonetheless, an exploratory survey of some of the hexagrams' other qualities is not without merit, and may contribute to understanding the relationship of the two.

One of the most outstanding similarities is the theme of refinement of one's character found in the images of both hexagrams. Xiaochu says:

The wind drives across heaven:

The image of THE TAMING POWER OF THE SMALL.
Thus the superior man
Refines the outward aspect of his nature. (Wilhelm & Baynes p. 432)
And Dachu:
Heaven within the mountain:
The image of THE TAMING POWER OF THE GREAT.
Thus the superior man acquaints himself with many sayings of antiquity
And many deeds of the past,
In order to strengthen his character thereby. (Wilhelm & Baynes p. 516)

The refinement of character in Xiaochu, like the wind, is subtle and rarefied. The strengthening in Dachu, however, is substantial, like the mountain. Heaven, that is, the trigram Qian (?) represents the character of the perfecting person, Wilhelm's "superior man" (Junzi ??), who constantly strives to improve his nature, though it is already like Heaven.
The presence of Qian as the lower trigram in both Xiaochu and Dachu is another similarity. In both hexagrams, Qian's three yang lines are the main body of strong lines that the yin line(s) are trying to tame or domesticate (chu ?). From the perspective of trigrams, Qian is also the solid strong force that the upper trigram seeks to tame. If we read Qian as related to the character of Junzi, then the taming or domestication of Qian is the process of taming or domesticating, that is, refining and strengthening, one's character. And indeed, the gentle refinement in Xiaochu does seem small compared to the big character-strengthening in Dachu. Yet, this is only a reiteration that Xiaochu is small and Dachu is big; nothing much is said about why.

Other similarities are apparent, but suggest even less about smallness and bigness. Both hexagrams, for example, have some water-related imagery in their judgments (?). In Xiaochu, there are "Dense clouds, [but] no rain from our western region" (Wilhelm & Baynes p. 431), and in Dachu, "It furthers one to cross the great water." (Wilhelm & Baynes p. 515). It might be said that the dense clouds that are not quite raining are a small amount of water, while "the great water" is, of course, a large amount, but this is a little strained at best, and once again only affirms that one is small and the other, big.
Since our inquiry is primarily concerned with differences - the difference, that is, between small and big - examining differences between the two hexagrams may shed clearer light on the answer we seek. The first difference that comes to our attention is structural: the hexagrams are made up of different trigrams, of course. Sun (?) representing wind, is above in Xiaochu, and Gen (?), the mountain, is above in Dachu. The massive weight of the mountain in Dachu does suggest weighing down or restraining, while the wind in Xiaochu is not so able to restrain. Since domestication or taming requires restraint, the mountain of Gen may be thought of as better able to hold down the strong Qian. Thus, the "taming power," as Wilhelm calls it, is indeed greater in Dachu than in Xiaochu. While this begins to get at the essential reason behind Xiaochu's smallness and Dachu's bigness, it still does not quite get past simply reaffirming those qualities.

As with the minor similarities above, minor differences do not discover much to us. Take, for example, the familial status of the trigrams in each hexagram. In Xiaochu, we have Qian and Sun, the father and the first daughter; in Dachu, the father and Gen, the third son. Perhaps the father and a daughter, even the eldest, are not able to accomplish much domestication (that is, of their livestock) because the daughter is simply not suited to such tasks. The father and a son, even the youngest, on the other hand, may more easily accomplish domestication because the son can use his youthful energy and vigorous strength to better assist his father. Needless to say, such a reading is definitely a bit of a stretch. Ironically, though, despite this reading itself being somewhat untenable, it does suggest the right direction somewhat: namely, that in Xiaochu, there is one able to do the taming, while in Dachu, there are two.

The number of yin lines in each hexagram, of course, is meant. This difference, more than any other detail examined above, holds the key to why Xiaochu is 'xiao' and Dachu is 'da,' which all the others details have been pointing to. It does seem almost too obvious, too easy to say that the smallness of Xiaochu comes from there being only one yin line to tame five yang lines, and that the bigness of Dachu comes from there being two yin lines to tame four yang lines. Nevertheless, one must admit that two against four are much better odds than one against five. This can be seen in the hexagrams themselves, if considered in a pictorial fashion: the lone yin line in Xiaochu is utterly surrounded, and looks overwhelmed, but manages to prevail by being in an appropriate place (the fourth place, that is, a yin position) and subtle gentleness, like the wind. In Dachu, on the other hand, while the two yin lines are still outnumbered, they have banded together and divided the yang somewhat, and are gaining an advantage.

Wilhelm identifies this same key difference in his commentary: "There [in Xiaochu] one weak line must tame five strong lines, but here [in Dachu] four strong lines are restrained by two weak lines; in addition to a minister, there is a prince, and the restraining power [?] therefore is far stronger." (Wilhelm & Baynes p. 104) This same difference of lines is what separates another pair of big and small hexagrams, Daguo (??, hexagram 28) and Xiaoguo (??, hexagram 62), in which the former has two more yang lines than the latter, while both essentially share the same pattern or structural arrangement.

The similarities and differences examined above all hint at this same conclusion: Dachu has the greater strengthening of character, the better capability to restrain Qian, the more able father and son pair, even the bigger body of water. All these traits have only pointed toward the essential advantage of Dachu, its band of two yin lines, which make its "taming power" greater than that of Xiaochu's single yin line.