Suan Zao Ren Tang by Will Ceurvels

Suan Zao Ren Tang

The following is another guest post by Will Ceurvels about Suan Zao Ren Tang:

Suan Zao Ren Tang, the Brain, Qiao Pathology and Insomnia

In perhaps the most well-known discussion of insomnia in the Inner Canon, SP71 describes how an external pathogen lodging in the organs and bowels prevents yang qi (wei qi) from circulating inward, leading to repletion and distension in the yang qiao vessel, which “prevents the eyes from closing” and leads to insomnia.
As I describe in the Archaeology of the Qiao Vessels, the actual mechanism of insomnia in this case is that wei qi is blocked from effusing outwards by an external pathogen lodged in the membrane source surrounding the organs and bowels. Only after wei qi fully effuses to reach the surface of the body and brain can it circulate inward via the channels and submerge into the yin phase. Thus, SP81 states,

“Qi emerges from the middle burner like mist and suffuses through the interstices before seeping into the tertiary collateral channels.”

In the SP71 case, wei qi is blocked by an external pathogen and thus fails to fully effuse. Failing to fully effuse, it cannot cycle back inwards via the channels and thus a global stagnation in the membranes, interstices and notably, the brain, ensues.

The yang qiao vessel becomes replete when wei qi stagnates in and fails to descend from the brain, the high node and site of accumulation of wei qi. The qiao vessel is bound up with the eye complex inside the brain as in:
Spiritual Pivot Ch. 21: The Foot Greater Yang channel enters into the brain at the root of the eye in the nape of the neck through what is called the “eye complex”. Entering into the brain, it splits off into the Yang Qiao vessel which interpenetrates and connects at the inner canthus.

In the SP 71 understanding, when the brain is replete with wei qi (because it has stagnated and can’t circulate down), the yang qiao vessel distends and suffuses the eye, which then fails to close.
Two treatment methodologies are given for this pathology. The first is to drain yang qiao (by bleeding at BL62) and supplement yin qiao (by needling at KI6). By draining yang qiao, the yang qiao collateral is unblocked and stuck wei qi in the brain can drain from it into the channel circulation and downward into the bowels. Supplementing yin qiao draws channel qi downward. (we will comment more on this below) The second treatment is to use Banxia Shumi Tang. Much like in Xiao Chaihu Tang, Banxia unblocks stagnant weiqi caught in the membranes and interstices allowing it to effuse out into the exterior where it can circulate inward. (This is why the formula stipulates there should be sweating) Shumi and worked water also course the waterways, restoring flow through the interstices and membranes.

Later iterations of Banxia Shumi Tang such as Liushui Tang (流水湯) and the unnamed formula in Handbook of Prescriptions for Emergencies also were used to treat insomnia, but with two key differences. First, both formulas added fuling and, second, both were indicated for “post-illness” vacuity vexation. The term insomnia with vacuity vexation might sound familiar: it is the same phrase used in Suanzao Ren Tang, which is indicated for “taxation with vacuity vexation and insomnia.” Indeed, as this essay will argue, the mechanism governing Suanzao Ren Tang bears striking similarities to the banxia shumi tang formula family and comparing their formula architectures and etiologies provides profound insights into the nature of insomnia and its relation to yin/yang qiao pathology.
The character for taxation (勞) combines two fire (火) radicals above a character for strength or effort (力), a lovely illustration of the mechanism of taxation in the body. As the body undergoes physical strain, yang qi carried in ying and wei effuses outwards to supply the muscles and to cool the body down. Likewise, in mental taxation, yang is spirited up into the brain to fuel the activities of the spirit. As yang effuses outwards, the organs and bowels, the membranes of the interior become relatively cold, and thus the processes of transformation and transportation that the inner organs govern becomes impaired. This process is reflected in the big empty pulse of taxation described in the Golden Cabinet. As Zhang Zhicong states:

Yang qi [normally] conceals in the yin viscera. When yang outbears, yin-cold attacks the yin viscera, yang qi is increasingly deficient and [the yin viscera] cannot seep ying qi into the channels.

Invariably, a process much like the one in Banxia Shumi Tang ensues. Circulation through the membranes and interstices slows, and, failing to effuse completely outward, yang (weiqi) stagnates in the yang phase, in the interstices and the high collecting site of the brain and fails to circulate inwards, leading to insomnia.
Just as the taxation-induced mechanism of insomnia bears similarities to the pathogen-induced model described in the Inner Canon, Suanzao Ren Tang bears certain structural similarities to Banxia Shumi Tang. However, Suanzao Ren Tang features certain innovations that, as I argue, incorporate an Inner Canon understanding of how Qiao Vessel pathology relates to insomnia and represent another solution to the predicament of yang failing to descend that Banxia Shumi tang fails to address.

Much like later iterations of banxia Shumi Tang, Suan Zao Ren Tang includes fuling. In both formulas, fuling acts to clear the waterways of the triple burner membrane of turbid and stagnant fluid allowing wei qi to effuse outwards and then inwards. Thus Zou Run-an states:

“When [fuling transforms the yin of the upper burner], then, as the saying goes, “the dregs and foulness recede and the clear light emerges”, blockages naturally open and all counterflow descends.”

Zhimu continues along this trajectory outwards, targeting the fluid at the surface of the body. Zhimu is used in the Golden Cabinet to treat hot, swollen joints, as in the formula Guizhi Shaoyao Zhimu tang. When fluid at the surface fails to circulate back inward via the channels, it blocks the flow of ying and wei qi, causing a buildup of yang at the surface that manifests as swelling and heat. Notice here, again, yang is caught at the surface and cannot cycle inwards. The cold bitterness of Zhimu drains fluid from the surface into the channels, descending heat/yang in the process. Thus, Lu Zhiyi says of Zhimu:

[Zhimu is used for when] lung metal qi (referring to qi/fluid at surface) cannot seep out and cycle back into the [channels].

These two herbs work in a very similar way to the Banxia Shumi formula family, coursing the flow of wei qi outward to allow for complete effusion to the surface and circulation of yang back inward via the channels. The second two herbs, however, represent a substantial architectural innovation and a unique solution to the floating yang pathology:

While modern commentaries tend to focus on Chuanqiong’s connection to the gall bladder, early writings focused on its ability to penetrate and course the brain. For instance, the Divine Farmer’s Materia Medica wrote, “Treats wind-strike entering the brain and causing headache.” Similarly, the Miscellaneous Record of Famous Physicians wrote: “Chuanqiong Expels cold from the brain.” Indeed, as Lu Zhiyi points out, even the name hints at this capability, with the 穹 character meaning “high”, “heavenly” and it’s homonym 窮 meaning “pursing or moving out to the furthest point/extreme”. The brain is the high collecting point of wei qi, the far extreme, after which the only place to go is down. As such, it is an important pivot point, like the surface of the body, for the transition of wei qi into the channels and down into the interior of the body. In taxation, as in external pathogen pathologies, wei qi stagnates in the extra-channel spaces, like the brain, and cannot circulate back into the channels and inwards. As Zhang Xichun notes, “Chuanqiong upbears light, clear qi into the brain” thereby freeing congestion and stagnation. In this sense, Chuanqiong functions like Yang Qiao BL62, restoring flow through the brain to guide yang downward via the channels.

Just as Chuanqiong functions like Yang Qiao in the Suanzao Ren Tang formula architecture, Suanzao Ren arguably functions like yin qiao KI6. As stated in the Zhang Zhicong quote above, when yang rushes outwards, yin-cold attacks the yin viscera. This leads to accretions and repletion in the yin phase which block the penetration of yang downwards via the channels. The Divine Farmer states that Suanzao Ren is indicated for: “evil qi bound (below the heart) and in the abdomen.” Commenting on this line, Zhang Zhicong wrote, “[Suanzao Ren] guides heart qi to penetrate downwards… thus unblocking bound evil qi below the heart and abdomen… When fire returns to the center earth, spirit qi stores within.” Much like KI6, which is needled to draw yang downwards, Suan Zao Ren penetrates heart qi downwards, breaking up yin accretions below and allowing yang to descend.
The addition of Suanzao Ren to this formula architecture constitutes an important innovation in this taxation induced floating yang pathology. Unlike the Banxia formula family which mainly focuses on freeing up the Shaoyang membrane to allow wei qi to flow completely outward and circle inward, Suanzao Ren penetrates heart qi downward, breaking up accretions and thereby creating a vacuum to draw yang inward. Not surprisingly later iterations of the banxia shumi formulas, like Sun Simiao’s Liu Shui Tang and a version of Wen Dan Tang in Discussion of Illnesses, Patterns, and Formulas Related to the Unification of the Three Etiologies, both incorporate Suan Zao Ren, ostensibly for this purpose.

To learn more about Banxia Shumi Tang and the greater BXSMT formula family including Wen Dan Tang, as well as how these formulas relate to Qiao pathologies including insomnia, see Archaeology of the Qiao Vessels in our bookshop.