Since ancient times Taoist learning has been considered mixed and many-sided (see scroll 225 of the Comprehensive Examination of Literature), and the outline of this can be seen in the composition of the present Taoist Canon (Daozang), that is, in the kinds of books it contains.
The Ming-dynasty Zhengtong Taoist Canon contains 1,476 Taoist works, arranged in the Three Caverns and Four Supplements, in 5,485 scrolls (this number of scrolls is the one handed down by tradition; the surviving Canon is much damaged and actually contains fewer than five thousand scrolls). It includes books on Taoist scriptures and precepts, liturgy, talismans and diagrams, and refinement and nourishment, as well as books of Taoist philosophy and of the related Confucian, Mohist, Logician, Legalist, Yin-Yang, military, medical, Eclectic, and other schools. Its sheer size bears comparison with the Buddhist Canon. For this reason scholars past and present have, on the one hand, regarded it as a treasure house of the nation's culture and, on the other, judged its contents to be mixed rather than pure.
In fact, the gathering of Taoist books into a vast collection had already begun in the early days of the Taoist religion. The Baopuzi says: “Few of the Taoist books come from the Yellow Emperor and Laozi; most were enlarged by later enthusiasts, each according to what he knew and saw, until the scrolls piled up like mountains.” (Inner Chapters, “Resolving Hindrances”) This shows that as early as the time of Ge Hong (284–363), the ancient Taoist scriptures had already been compiled rather freely and had grown to a very large number. This habit seems to have continued unchanged in the later compilation of the Taoist Canon. The modern scholar Ding Fubao therefore held that “many of the books listed in the whole Canon were gathered merely to fill out the number of scrolls. Some, though refined in language, are not what the Taoist Canon should contain. Liu Mu's Diagrams Hooking Out the Hidden in the Numbers of the Changes and Nine Leftover Discussions, Zhang Li's Illustrated Explanations of the Images of the Changes, Inner and Outer Chapters, Yu Yan's Separate Transmission Outside the Changes, and Lei Siqi's Comprehensive Changes of Yarrow Divination and Comprehensive Changes of the Diagrams of the Changes all belong in the category of the Changes; the Account of King Mu, Son of Heaven belongs among the court diaries; the Classic of Mountains and Seas belongs in geography; Yang Xiong's Classic of Great Mystery, Master Shao's Supreme Principles Governing the World, and Bao Yunlong's Revealing the Subtleties of the Origin of Heaven were all formerly classed as Confucian; the Mozi belongs among the Mohists; the Plain Questions, the Numinous Pivot, the Classic of Eighty-One Difficult Issues, Sun Simiao's Prescriptions Worth a Thousand in Gold, Ge Hong's Handbook of Prescriptions for Emergencies, the Emergency Prescriptions of the Immortals, the Secret Surgical Prescriptions Transmitted by the Immortals, and Kou Zongshi's Extended Meaning of the Materia Medica all belong among the physicians; the Gongsun Longzi and Yin Wenzi belong among the Logicians; the Hanfeizi belongs among the Legalists; the Sunzi belongs among the military writers; the Guiguzi belongs among the Diplomatists; and the Yuzi, Heguanzi, Huainanzi, Zihuazi, Liuzi, and Forest of Ideas all belong among the Eclectics…. To include them all indiscriminately now is quite forced.” (Essentials of the Taoist Canon, Introduction)
Yet the Taoist Canon's inclusion of so many kinds of scholarly works, as above, has its historical roots and grounds. As early as the Former Han dynasty, Taoism was already regarded as a school that embraced the learning of all the others. The Grand Historian Sima Tan (second century BCE) held that “Taoism makes people's spirits concentrated and unified, moves in harmony with the formless, and provides amply for all things. As a method, it follows the great order of the yin-yang school, adopts the best of the Confucians and Mohists, and takes the essentials of the Logicians and Legalists; it shifts with the times and changes in response to things, and in establishing customs and managing affairs there is nothing for which it is not suited.” (Records of the Grand Historian (Shiji), “Postface of the Grand Historian”) Sima Tan's son Sima Qian seems to have inherited this view, saying that Taoist learning could bridge the yin-yang, Confucian, Mohist, Logician, and Legalist schools popular at the time and take the strengths of each. This laid the groundwork for the later Taoist Canon's inclusion of the teachings of the pre-Qin and later masters.
This is because Taoism originated with Laozi, who “believed in and loved antiquity.” The book Laozi quotes some old Confucian sayings, and its dialectical thought—on loss and gain, being and nonbeing, and other opposites that complete each other, similar to the Zhouyi—comes close to Confucian teaching. Confucian books also contain ideas similar to Taoist thought. All this is enough to prove that Confucianism and Taoism have points in common. In addition, the traditions in many books that Confucius asked Laozi about the rites, and that Confucius sighed that Laozi was “like a dragon,” also show the relationship between Laozi and Confucius in certain respects.
Next, Mohist thought was not originally far from Taoism. The chapters of the Mozi on “Universal Love,” “Against Offensive War,” “Moderation in Expenditure,” and “Understanding Ghosts” come close to the Taoist ideals of compassion and frugality.
As for the pre-Qin Logicians, Hui Shi, Gongsun Long, and Yin Wenzi all advocated laying down arms and ending war. Hui Shi proclaimed “Love all things universally; heaven and earth are one body,” and Yin Wen advocated “having few and shallow desires” and “not feeling disgraced when insulted.” Their methods of argument could also serve to support Taoist teachings, so they too had much in common with Taoism.
As for the Legalist learning of Shen Buhai and Han Fei, all of it was “rooted in the Yellow Emperor and Laozi.” The Hanfeizi also contains the chapters “Explaining Laozi” and “Illustrating Laozi,” clearly showing its esteem for Laozi.
As for the Yin-Yang school, it was founded by Zou Yan, who “discoursed on heaven.” His theory of yin and yang and the Five Phases was studied and transmitted by the fangshi (masters of esoteric arts) of Yan and Qi, gradually became attached to Taoism, and became a component of later Taoist doctrine.
These are the points that Taoism has in common with the Confucian, Mohist, Logician, Legalist, and Yin-Yang schools.
Sima Tan and his son held that pre-Qin learning comprised these six schools, and that Taoism could take in the strengths of the other five. This seems to rest on the view that the Tao can encompass everything, as the Laozi says: “The Tao is empty, yet in use it is never filled; deep, it seems to be the ancestor of the myriad things.” The later idea that Taoism can embrace the teachings of all the schools may be based on this.
Building on the “six schools,” Ban Gu's “Treatise on Literature” in the Book of Han and later historical treatises also list the Diplomatist, military, medical, immortality, and Eclectic schools, whose teachings were likewise absorbed by Taoism from ancient times.
As for the relationship between the Diplomatists and Taoism, the Laozi says: “The softest thing under heaven gallops over the hardest thing under heaven”; and also: “What you would shrink, you must first stretch; what you would weaken, you must first strengthen; what you would abolish, you must first raise up; what you would take, you must first give.” This is clear proof that Diplomatist doctrines were used within Taoism.
The points of contact between the military writers and Taoism appear in such sayings in the Laozi as “Use the unorthodox in waging war”; “Being compassionate, one can be brave; being frugal, one can be generous”; and “One who is good at warfare is not angry; one who is good at defeating the enemy does not engage him.” In addition, the “Military Books” section of the treatise in the Book of Han records Taoist works on war attributed to the Yellow Emperor, Li Mu, and others. All of this proves the relationship between Taoism and the military writers.
Medicine and Taoism also have much in common. The Laozi's “giving life to life,” “safeguarding life,” and “the way of long life and lasting vision” all show that Taoism contains elements of medical thought. In particular, medicine traces its origin to the Yellow Emperor and does not stray outside the learning of the Yellow Emperor and Laozi; thus Taoist learning also extends to medicine.
The school of the immortals traces its lineage to the Yellow Emperor. The treatise in the Book of Han lists several works such as the Miscellaneous Masters of the Yellow Emperor. In self-cultivation it forms the outside to the inside of the theory of Laozi and Zhuangzi, and afterward it came under the scope of Taoism.
The Eclectics—such as the Yuzi, Heguanzi, Zihuazi, Lüshi Chunqiu, and Huainanzi—all have teachings close to the Yellow Emperor and Laozi, and the Yuzi, Heguanzi, and others were originally listed under Taoism in the treatise of the Book of Han, so naturally they fall within the scope of Taoism.
This is probably why the teachings of the schools above were also included in the Taoist Canon.
As for the historical fact of the books of the Zhou and Qin masters being included in the Taoist Canon, it seems already to have appeared in the sixth century, at the Xuandu Abbey in Chang'an under the Northern Zhou. In the fifth year of the Tianhe era of Emperor Wu of the Northern Zhou (570), Zhen Luan submitted his Treatise Laughing at the Tao, which says: “On the masters being counted as Taoist books: the scripture catalog of the Xuandu (Abbey) says: Taoist scriptures, commentaries, records, talismans, diagrams, and treatises total 6,363 scrolls, of which 2,040 scrolls exist in copies, requiring 40,054 sheets of paper; of these, over 1,100 scrolls are scriptures, commentaries, talismans, and diagrams, and 884 scrolls are masters and treatises. For 4,323 scrolls, Lu Xiujing's catalog records the numbers, but no copies have been obtained. Your servant Luan laughs and says: In the scripture catalog submitted by the Taoist priests, Lu Xiujing's catalog shows only 1,228 scrolls of scriptures, medical prescriptions, talismans, and diagrams, with no names of miscellaneous books or masters at all; yet the Taoist priests now list more than 2,000 scrolls, taking 884 scrolls from the catalog of the Han Treatise on Literature as Taoist scriptures and treatises. Such being the case, there is reason for doubt. Why? Han Fei, Mencius, the Huainanzi, and their like do not speak of Taoist matters at all. And if the Eight Lords' recipes for gold and silver, Tao Zhu's arts of transformation, the talismans for overturning heaven and earth, and medical prescriptions and spells can count as Taoist books and may be brought in, then I do not know why the Lianshan, the Guicang, the Forest of Changes, the Classic of Great Mystery, the Yellow Emperor's Golden Casket, and the Grand Duke's Six Secret Teachings are not counted among the Taoist books. Lu Xiujing's catalog originally contained no masters; now they have been arbitrarily added—on what basis, I do not know.” This shows that the catalog of Taoist scriptures in the time of Lu Xiujing (406–477) contained only some 1,100 scrolls of scriptures, commentaries, records, medical prescriptions, talismans, diagrams, and treatises, and that only in the Northern Zhou did the Taoist scriptures recorded by the Xuandu Abbey add more than 800 scrolls of masters and treatises from the Zhou and Qin onward, making a total of more than 2,000 scrolls. This may be called the union of the masters with Taoism, which thus formed a general catalog of Taoist scriptures. Naturally, this was something that Buddhists such as Zhen Luan could not understand.
From then on, the successive catalogs of the Taoist Canon in the Tang and Song dynasties seem to have been further expanded on this basis. Although the actual titles contained in each canon of that time are no longer known in detail, the “Taoist” books recorded in the “Treatise on Literature” of the Comprehensive Treatises by Zheng Qiao (1103–1160) of the Song fall into twenty-five categories: Laozi, Zhuangzi, the masters, the Yellow Emperor's Classic of the Hidden Talisman (Yinfu Jing), the Scripture of the Yellow Court (Huangting Jing), The Seal of the Unity of the Three (Cantong Qi), catalogs, commentaries, records, treatises, letters, scriptures, liturgy, talismans and registers, breathing exercises (tuna), embryonic breathing, inner vision, daoyin (guiding and pulling exercises), grain avoidance (bigu), inner alchemy (neidan), outer alchemy (waidan), metal and mineral drugs, ingestion of drugs, the arts of the bedchamber, and self-cultivation. From this we can see that the Taoist scriptural collections of the time contained both the works of the masters relating to Taoist philosophy and the religious texts of scriptures and precepts, talismans, and diagrams.
Song Lian of the Ming dynasty, in his Discussion of Laozi, held that what the Laozi says is, on the whole, to draw in and keep to oneself, to withdraw and hide, not to put oneself before things, and to return wholly to naturalness; and because what it covers is so broad, later generations have mostly revered and practiced it. “Looked at but not seen, it is called the invisible; listened to but not heard, it is called the inaudible; grasped at but not obtained, it is called the subtle.” The Taoists took this as their ancestor. “The spirit of the valley never dies; it is called the mysterious female. The gate of the mysterious female is called the root of heaven and earth.” The school of the immortals took this as its ancestor. “I dare not play the host but play the guest; I dare not advance an inch but retreat a foot. This is called marching without ranks, rolling up sleeves without bare arms, repelling without an enemy, holding without weapons. There is no disaster greater than underestimating the enemy; underestimating the enemy nearly cost me my treasures. So when opposing armies meet, the one that grieves will win.” The military writers took this as their ancestor. “The Tao is empty, yet in use it is never filled; deep, it seems to be the ancestor of the myriad things. It blunts sharpness, untangles knots, softens glare, and merges with the dust. Profound, it seems to exist. I do not know whose child it is; it seems to precede the Lord.” Zhuangzi and Liezi took this as their ancestor. “What you would shrink, you must first stretch; what you would weaken, you must first strengthen; what you would abolish, you must first raise up; what you would take, you must first give.” Shen Buhai and Han Fei took this as their ancestor. “Govern the state with the orthodox, wage war with the unorthodox, and win the world by not meddling.” Zhang Liang took this as his ancestor. “I have no strength, and the people transform themselves; I love stillness, and the people become upright of themselves; I do not meddle, and the people prosper of themselves; I have no desires, and the people become simple of themselves.” Cao Can took this as his ancestor. This too represents the later view that Taoism can encompass the teachings of all the schools.
The “Taoist Category” of the Annotated Catalog of the Complete Library of the Four Treasuries by Ji Yun and others of the Qing dynasty also says: “Its (Taoism's) original essence lies in keeping oneself pure and still, helped by the power of firm endurance, using the soft to overcome the hard and retreating in order to advance. Therefore the followers of Shen Buhai and Han Fei flowed into the learning of forms and names, and the Hidden Talisman could be applied to warfare. Later the doctrine of long life merged with that of the immortals, and ingestion of drugs and daoyin entered it; … when there was a book of the Vast Treasure, the refining of elixirs entered it; when Zhang Lu founded his teaching, talismans and registers entered it; and Kou Qianzhi of the Northern Wei and others brought in fasts and offerings (zhaijiao), memorials, and incantations.” This may be said to explain how, after Taoism became a religion through the Han, Jin, and Northern and Southern dynasties, a great many books of scriptures and precepts, liturgy, talismans and registers, ingestion of drugs, and refinement and nourishment were added, forming the contents and origins of the Taoist Canon as it exists today.