Xuan Su(玄俗): The Taoist Who Healed in the Marketplace
Paul Peng
He lived in the marketplace. Every day, he laid out his medicines while the butchers shouted their prices and the grain merchants argued over weights. He did not hide on a mountain. He did not retreat to a cave. He stood among the crowds of Hejian—present-day Hebei Province—and sold healing to anyone who could pay. His name was Xuan Su (玄俗). The character xuan means “mysterious” or “dark”—the same xuan that appears in xuanxue, the Dark Learning of Laozi and Zhuangzi. The character su means “common” or “vulgar”—the ordinary life of ordinary people. His name united the mystery and the marketplace in a single word. The Comprehensive Mirror of True Immortals records his practice in a single compressed line: “He often took croton and yunying as medicine, practised the art of abstention from grains, sold medicines in the market, and was capable of curing all kinds of diseases.” He was not a hermit. He was not an alchemist. He was not a priest. He was a medicine seller—and his life is the earliest documented case of Taoist healing as a public, commercial practice.
The Two Medicines
Xuan Su took two substances. The Comprehensive Mirror names them: croton and yunying. Croton—badou (巴豆)—is a seed classified in Chinese pharmacology as one of the most powerful purgatives. It is hot, acrid, toxic in its raw state, and it drives everything downward and outward. When a patient is blocked—constipated, swollen, congested with the residues of disease—croton clears the obstruction with violent force. Yunying—yunying (云英)—is a form of mica, the shimmering mineral that flakes into translucent sheets. In Taoist alchemy, mica was classified among the highest grades of edible minerals. Pei Xuanren, the Pure and Empty Real Person, had consumed cloud-fungus—another name for mica—and had ascended from Mount Hua as an immortal. The two substances form a pair of opposites. Croton drives downward with heat and force, purging the body of its accumulated poisons. Yunying rises upward with coolness and clarity, nourishing the spirit and lightening the flesh. Taken together, they enact a complete cycle: first the expulsion of the old, then the absorption of the new. And Xuan Su took them both while abstaining from grain—the bigu practice normally associated with mountain hermits. Xuan Su practised it in the marketplace, surrounded by the smell of cooking food. He was fasting in the middle of a feast.
The Healer in the Crowd
Xuan Su sold his medicines. He did not give them away. This is a significant detail. Yin Gui, the priest of Louguan Tai, wore ten lacquered bamboo tubes of elixir around his waist and distributed them as alms. He did not charge. He walked through the villages, gave the sick what they needed, and walked on. Xuan Su stood in the market and sold his remedies. The market is a place of exchange, not of gifts. The medicine seller names a price. The buyer pays it. The transaction is complete, and neither party owes the other anything beyond the terms of the sale. This is a different model of Taoist healing. It is not the charismatic compassion of the wandering priest. It is the professional competence of the market physician. Xuan Su was not asking his patients to become disciples. He was healing them—for a price—and then they went home. The Comprehensive Mirror says he “was capable of curing all kinds of diseases.” This is the language of reputation, not of literal record. But a healer who cures enough diseases, across enough years, in a market where everyone can watch, develops a reputation that attracts the sick from surrounding towns. Xuan Su’s market stall was a clinic. His medicines were his practice. His reputation was his credential.
The Mystery and the Common
Xuan Su’s name is a philosophy in miniature. Xuan is the mystery—the dark, the hidden, the transcendent. It is the word that Laozi uses to describe the Tao: “Mystery upon mystery, the gate of all wonders.” Su is the common—the ordinary, the secular, the everyday. To be named Xuan Su is to be the mystery and the common in one person. To practise bigu in the marketplace, to consume cloud-minerals while standing in the dust of the butcher’s stall, to heal the sick for money while fasting toward immortality—all of this is contained in the name. Xuan Su is the proof that the Tao is not only on the mountain. It is in the market. It is in the transaction. It is in the hand that takes the coin and the hand that gives the medicine. The hermit in his cave and the medicine seller in his stall are practising the same art. They are simply standing in different places.
The Two Healers
Xuan Su and Yin Gui form a matched pair—the two faces of early Taoist medicine. Yin Gui gave his medicines freely, without price, without speech, without recognition. He was the healer as anonymous gift, walking through the world and leaving health behind him like a trail of footprints. Xuan Su sold his medicines openly, in the market, with a price, with a reputation, with a stall that anyone could find. He was the healer as public professional, integrated into the economy of the town. Both models survived. The Taoist temple pharmacy, where the priest dispenses herbal formulas to the faithful, is a descendant of Yin Gui’s bamboo tubes. The Taoist physician who runs a clinic and charges for services is a descendant of Xuan Su’s market stall. The tradition has always held both. The gift and the sale. The silence and the transaction. The bamboo tube and the market stall. The Tao is large enough to contain them both.
Why This Matters for the Living Tradition
From a Zhengyi perspective, Xuan Su represents the integration of Taoist healing into the fabric of everyday life. The Zhengyi priest is not primarily a physician. But many Zhengyi priests have practised medicine over the centuries, and the tradition has always maintained that spiritual and physical health are inseparable. The talisman that heals a fever and the ritual that dispels a haunting are applications of the same principle. Xuan Su, taking his croton and his yunying while the market crowd pressed around his stall, is the ancestor of every Taoist healer who has ever treated the sick without requiring them to convert, who has written a prescription without demanding a confession of faith. He was not a priest. He was not a hermit. He was a man with a stall and a reputation and a pair of medicines that worked. And in the Comprehensive Mirror of True Immortals, his name is written alongside the names of ascetics and alchemists, because the Tao that is spoken in silence on the mountain is the same Tao that is sold for coins in the market.
What the Medicine Seller Left Behind
Xuan Su left no writings. No disciples are recorded. His market stall decayed centuries ago, and the town of Hejian has forgotten his name. But his image survives in the Comprehensive Mirror: a man standing in the marketplace, a pile of croton seeds and a pouch of crushed mica on the table before him, the crowd pressing close, the coins changing hands, the sick departing in health. He was the mystery and the common. He was fasting and selling. He was the Tao in the marketplace, doing business, healing the sick, waiting for no one. The market is still there. The medicines have changed their names. But somewhere in the world, a Taoist healer is seeing patients today who do not know what tradition they are inheriting. Xuan Su was the first of them. The first medicine seller. The first proof that the Way could be bought and sold without being diminished. The coin and the cure. The mystery and the common. The man whose name said everything.
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