A quote from "The Authority of Empiricism and the Empiricism of Authority: Medicine and Buddhism in Tibet on the Eve of Modernity" by Janet Gyatso
"When Systems Collide: The Channels of the Body
Empirical evidence in its most overtly physicalistic sense posed on several occasions an estimable challenge to Buddhist revelation. How this challenge was mounted, and then fielded, is illustrated well by the debate around the anatomy of the channels. The Four Tantras describes four kinds of channels that transmit substances and energies through the body: 1) initial “growth channels,” which give rise to the fetus’s body; 2) “channels of being,” matrices of channels at the brain, heart, navel, and genitals responsible for perception, memory, and reproduction; 3) “connecting channels,“ which consist in two main “soul channels,” one white and one black, that control the nervous and the cardiovascular systems, along with the smaller channels branching out from them; and 4) “life channels” through which a life force moves around the body. There was considerable debate in the commentaries about what these categories actually refer to, and exactly where in the body they are. But the discussion took a new turn entirely when, in the fifteenth century, a medical writer casually remarked that the life channels follow along the path of lalana and rasana.
This writer was referring to the tantric conception of the “central channel,” a straight tube that runs between the crown of the head and the genitals, and two others, lalana and rasana, that run along its sides; the three are well known in Indic and Tibetan Buddhist tantras as the basis for yogic cultivation. In the centuries that followed there developed a sustained effort to locate this tantric system within the medical system of channels in the Four Tantras. Towards the end of the fifteenth century Byang-pa bKra-shis-dpal-bzang found the tantric channels not only in the life channels, which in any case had always been viewed as derivative of tantric system, but also in the more properly medical growth channels, and especially now in the connecting channels. Byang-pa called the medical white soul channel, often understood to be the spinal column, the “outer” lalana, while he labeled the black soul channel, which is something like the vena cava, the “outer” rasana. This seems to be the first time a medical writer equated the nervous and cardio-vascular systems with the two side tantric channels, but we already see a device to make it palatable—a distinc-tion between an outer version and an inner one, which presumably would be the actual yogic channels de-scribed in the tantras. This device mirrors a larger ten-dency to distinguish the average human body—in this case, the medical body—from the body of the medita-tor or indeed a Buddha. And it serves to avoid a very large problem: the central channel, lalana, and rasana are simply not visible in the average body in the way they are described in the tantras. Clearly, people had been looking inside corpses to find them, and the discrepancy had already been noted several centuries before by Buddhist writers. What is new now is the increasing attention to the problem on the part of the medical community. And yet it has not really been solved: in Byang-pa’s solution, the real, or correct—the inner—lalana and rasana are still invisible, although by sleight of hand it may look like they have been accounted for in the empirical.
In the spate of increasingly detailed Four Tantras commentaries written from the fifteenth century on-ward, different writers try different schemes. The bril-liant sKyem-pa is more interested in locating the most important tantric channel, the central one, than the two on its sides. He finds it in the channel matrices around the brain and the genitals, but he also, controversially, locates it in the spinal column itself. This would seem promising, since like the central channel, the spinal column is a single straight channel running from the top of the torso to the bottom. It took the master commentator Zur-mkhar-ba Blo-gros-rgyal-po (b. 1509) to disqualify this attractive solution—largely because it fails to respect the signal characteristics of the central channel on its own tantric terms. The deft solution he proposes instead is emblematic of where medicine was headed by the latter part of the sixteenth century.
Like other participants in this fray, Zur-mkhar-ba lets the embryonic growth channels be the tantric channels. In a way, this is a safe solution; those initial channels disappear once the child’s body is fully formed, so, although he does not say this, there is no chance to disprove their existence later by investigation. But apparently, finding the tantric channels in the first weeks of life did not satisfy the quest to locate them in the adult body. So Zur-mkhar-ba also has recourse to the earlier suggestion that lined up the two side tantric channels with the white soul channel (the spinal column) and the black soul channel (the vena cava) in the adult body. However, a close reading of his language reveals that he doesn’t actually equate them. At one point, he says that rasana “gives rise” to the black soul channel, but this seems to have only the general sense that, as he says elsewhere, all of the wind channels in the body are the central channel, all of the blood channels in the body are rasana, and all of the liquid channels are lalana. As for the central channel itself, he does seem to display his agreement with a variety of tantric passages that de-scribe it, but he does so in the context of the growth channels. The upshot is that he actually locates the cen-tral channel only in the general channel (srog-rtsa) that grows in the embryo’s body; he rejects the views of those who argue that the central channel “always exists,” i.e., in the adult body. He certainly never pinpoints any of the tantric channels the way he does the medical channels, whose location with respect to the spine, for example, he can specify by digit.
Zur-mkhar-ba is quite conscious of larger questions of incommensurability. But when he raises the possi-bility that it could be inappropriate to introduce material into medicine from what is clearly another system—that of the tantras—he doesn’t jump at the chance to disqualify the effort to find the tantric channels once and for all. He almost sounds like a modern historian when he argues instead that in fact it is appropriate to bring in tantric ideas into medical description, for the medical system has always had multiple sources, which included the Vedas and disparate Buddhist sources like the Vinaya, the Suvarnaprabhasottama, and the Kalacakra. But the signature of his complex polemics is all too evident when he maintains that while the Four Tantras system “roughly accords” with the tantric one, it is important to separate the terminology, for the Four Tantras is not talking about the same thing, i.e., the fruits of meditation. Whatever is tantric about the anatomy of the Four Tantras is “hidden.” Note that in the process Zur-mkhar-ba has sustained his allegiance to tantric truths.
Indeed, Zur-mkhar-ba rejects as “invalid” the argu-ment of previous writers that the tantric channels are merely matters of meditation, existing in the imagina-tion but not present in the average body, since if they were, they would be visible in corpses. Others came up with the theory that the tantric channels do exist concretely in the body but evaporate at death, just as the mind does. Zur-mkhar-ba’s reason for rejecting these views is telling: If the tantric channels were only a matter of the imagination, the fruits of tantric yoga would not be obtained. The next major Four Tantras commentator, sDe-srid Sangs-rgyas-rgya-mtsho (b. 1653), makes a similar argument for the physicality of the tantric channels: yogis can attain immortality by holding the winds in the central channel.
In arguing for the concrete efficacy of exercises in-volving the tantric channels, Zur-mkhar-ba and sDe-srid would probably say (if they were reading this essay) that they were taking recourse in another kind of empirical truth: the evident efficacy of tantric practice. It is significant that they are committed to this efficacy being physically based. That already says a lot about the ambitions of the period to establish tantric ideology in some sort of physical reality, and I will return to this below. Note for now that while the influential sDe-srid repeats most of Zur-mkhar-ba’s solution verbatim, the subtlety of the ambiguation is such that the question continues to dog the medical commentators, and we find major nineteenth- and twentieth-century writers still at pains to demonstrate that what Zur-mkhar-ba and sDe-srid established was the validity of the tantric system. But that perduring ambiguity also meant that the door had been opened for dissent. Gling-sman bKra-shis (b. 1726), close student of the polymath Situ Chos-kyi-‘byung-gnas at the outlying medical center at sPal-spungs, might have been far enough from the dominion of sDe-srid’s lCags-po-ri to offer a more rigorously empirical account. He is willing to concede that the soul channel is sometimes called an “outer” central channel and so on; this distinction lines up with his general approach to treat the human body differently from that of a Buddha. But regarding that human body, Gling-sman has little patience for anything that is not directly observable. He can declare categorically that that the tantric channels are out of court in an anatomy of the medical, i.e., “material,” body; the tantric system is meant solely as a map for meditation."