ONMYŌDŌ is the collective Japanese name for various methods of divination, originally based on the Chinese theories of yin and yang (Jpn., onmyō, on'yō, or in'yō, the complementary forces seen in all phenomena), the "five elements" (Chin., wuxing ; Jpn. gogyō ; i.e., fire, wood, earth, metal, and water), their cyclical interactions, and the influence thereof in the natural and human spheres. The art of advising individuals and governments in the planning of all manner of activities and projects according to the movements of the sun and moon (representing yang and yin, respectively) and the stars, and the predicting of auspicious and inauspicious conditions as determined by the shifting relationships of the five elements and the sexagenary cycle (Chin. shigan shier zhi ; Jpn., jikkan jūnishi ) were highly developed and extensively documented in China by the beginning of the Han dynasty (206 bce–220 ce). Some of the major texts, such as the Yi jing (Jpn., Ekikyō ) date from much earlier.
From the time of the introduction of these texts and practices to Japan in the sixth century ce, onmyōdō encompassed not only yinyang and five-element divination per se but also the related fields of astronomy and astrology, geomancy, meteorology, calendar making (on Chinese models), and chrononomy (chiefly with Chinese water clocks). The word onmyōdō, meaning the "way (practice, art) of yinyang," labels these various arts and sciences and the beliefs and practices based on them in a manner similar to the way in which the term Butsudo may refer to the whole range of Buddhist ideas and practices; likewise, the term Shintō refers broadly to the many organized forms of indigenous Japanese religious tradition (as well as its imported accretions, including some rites and festivals originally associated with onmyōdō ). Similar nomenclature was also used for specific fields within onmyōdō, such as tenmondō for astronomy and rekidō for calendar studies. The word uranai ("augury") is another term used widely for the many forms of divination practiced by onmyōdō masters as well as by other types of seers and prognosticators. In early chronicles and works of literature, onmyōdō specifically identifies the divining arts as taught and performed in the official Bureau of Divination (Onmyōryō), which was established in the seventh century and which was responsible for providing the court with astronomical observations, astrological forecasts, calendars, accurate timekeeping, and the training of practitioners of these arts. However, onmyōdō skills were known and used by many persons outside the bureau, including scholars, physicians, and Buddhist priests, as well as by unschooled fortune-tellers and entertainers. Like many aspects of Japanese religion, onmyōdō has both an organized, institutional aspect and a popular, unsystematic aspect as well. Both are present in the history of onmyōdō from its beginnings, as is the tendency toward undifferentiated linkage with other religious traditions.
It is likely that some forms of onmyōdō thought and practice were known in Japan prior to what is recorded as their formal introduction. It has been observed, for instance, that the emphasis on duality in Japanese cosmogony (as narrated in the Kojiki, 712 ce) may reflect the influence of the yinyang concept. It would appear that yinyang and related elements of Chinese philosophy were fairly compatible with indigenous ideas of creation and causation, as well as with other beliefs. Although its origins were just as "alien," onmyōdō certainly did not meet with the kind of organized opposition that confronted the contemporaneous introduction of Buddhism.
According to the Nihonshoki (720), it was in 513 that Korean scholars introduced the "five texts"—a group of classic Chinese works, including the Yi jing —to the court of the (semihistorical) Emperor Keitai. In 554, Korean Yi jing professors (Eki hakase ) and calendar masters who had been serving at the court of Emperor Kinmei were replaced by new ones. In 602, the Korean Buddhist monk Kanroku presented himself to the court of Empress Suiko, along with up-to-date almanacs and books of astrology, geography and magic. Prince Shōtoku (574–622), Suiko's nephew and regent, is said to have chosen the colors of the caps used in his civil rank system on the basis of onmyōdō symbolism. The "Seventeen Article Constitution" attributed to him (although perhaps a later work) has also been said to reflect onmyōdō concepts of social order. When the scholars Minabuchi Shōgen and Takamuko Genri returned in 640 from a long period of study in China they introduced the latest in Chinese divining texts and practices. But even at this early stage, Japanese onmyōdō was distinguished from its Chinese models by the extent to which it incorporated other arts of divination, natural science, and what were probably native forms of magic. Nor was onmyōdō thought of as a discipline entirely separate from Buddhism or the other religions, philosophies, and forms of learning imported at the same time; the onmyōdō teacher Kanroku, for example, was also a high-ranking Buddhist monk.
Among the Taika reforms instituted in 645 was the adoption of a system of era names (Chin., nianhao ; Jpn., nengō ) consisting of two (or occasionally four) auspicious Chinese ideographs with symbolic significance based on onmyōdō teachings. The first era name chosen was Taika, literally "great change (or reform)." Eras were renamed at irregular intervals, usually when some especially good omen was reported, such as the discovery of rare metals, albino animals (particularly turtles, the color white and the creature both being deemed auspicious), or the sighting of a very favorable cloud formation. Several of the nengō of the late seventh and most of the eighth centuries include ideographs for metals, colors (white and red), "turtle," "cloud," and other auspicious signs. In the Heian period, nengō were changed more frequently, often in response to such inauspicious phenomena as solar eclipses, typhoons, droughts, and earthquakes.
Emperor Temmu (r. 672–686) is said to have been adept at the onmyōdō arts. An astronomical observatory was built early in his reign, and he probably used its findings in the surveying and construction of his capital at Kiyomihara, in what was believed to be a favorable location in relation to the topography and the deserted capitals of his predecessors. Generally, the north was regarded as a seat of power, while the northeast was viewed as the source of malevolence; the North Star, Polaris (Daigoku) was closely watched. As in China, Japanese capitals, including the permanent capitals Heijō (Nara) and Heian (Kyoto), were all constructed on carefully surveyed north-south axes, and official buildings and residences were placed where they might best receive favorable influences or be protected from evil ones, according to onmyōdō geomancy.
The Onmyōryō was organized soon after Temmu took the throne, and its structure remained unchanged for centuries. The chief of the bureau (onmyō no kami ) was a senior master responsible for reporting the observations of his subordinates to the emperor. The bureau employed six divination masters (onmyōji ), who performed the real work of observing and forecasting, and one professor of divination (onmyo hakase ), who supervised ten students (onmyōshō ). There was also one professor in each of the fields of calendar-making and astrology, each with ten students, as well as two professors of chrononomy. Onmyōji were also assigned to various provincial administrative centers. Famous masters of the eighth century include Kibi Makibi (693–775) and Abe Nakamaro (698–770), both of whom studied at length in China. Because divination could easily be used either in the interest of or against the government, efforts were made to limit divination activities to officially trained practitioners. The laws governing the activities of Buddhist monks and nuns (Sōniryō), enacted in 757 as part of the Yōrō Code, included specific punishments for those who falsely reported omens of disaster that might cause the people to lose confidence in the authority of the state.
The chronicles, diaries, and literary works of the Heian period (794–1185) are rich with information on the role of onmyōdō at court and in society. It is clear that it was at this time that onmyōdō reached the height of its importance. About fifty different onmyōdō rites are mentioned as having been observed at court. Among them were the Taizenfukunsai, honoring a Chinese deity who oversees the spirits of the dead; the Dokōsai, for Dokujin, or Tsuchi no Kami, the mischievous earth deity whose seasonal movements were closely watched; the Tensochifusai, performed once in each reign to honor war dead and to ward off disease; and the Shika-kushikyōsai, wherein the spirits that cause sickness were placated with offerings in each of the four corners of the ceremonial space and at each of the four borders of the state. The increase in the emphasis on these rites closely paralleled, and was sometimes linked to, the increase in the importance of Esoteric (Vajrayāna) ritual in Heian Buddhism. The monk Ennin (794–864), the third abbot of the Japanese Tendai school and the figure who introduced many Esoteric elements to it after his period of study in China, is also said to have introduced the worship of Taizenfukun.
Several works of the Heian period indicate that the onmyōdō masters stressed astronomical portents over other types of signs in their reports and forecasts. This may reflect the interest of two influential onmyō no kami, Shigeoka Kawahito (d. 874) and Yuge Koreo (bureau chief in the Kanpyō era, 889–898). Concern with overt astrological influences became obsessive, and plans for every type of public or private activity were first submitted to onmyōji for readings of the governing signs. Directional taboos (kataimi ), dictated by the rising and falling of one's birth sign (i.e., the two signs of the sexagenary cycle that were in convergence at the time of one's birth) and their relationship to others' signs, or by the association of those signs or of certain deities with certain directions, were strictly observed. In 865, Emperor Seiwa was advised that traveling from the crown prince's residence to the palace by a northwest-to-southeast route could have fatal consequences, and he duly altered his course. Such directional changes (katatagae ) were also made to avoid sectors favored at particular seasons by untrustworthy deities, especially Ten'ichijin, (usually called Nakagami), Dokujin, and Konjin, the "metal god." Nakagami's influences were particularly feared. He was believed to be active first in the northeast for six days, then for five days in the east, six in the southeast, five in the south and so on around the compass. The whole forty-four day period was termed a futagari ("obstacle"), because activity was blocked at almost every turn.
Travel to and from the dangerous northeast, called kimon ("demon's gateway") was also scrupulously avoided. This direction was believed to be favored by a deity called Daishogun, an active manifestation of the deity Taihakujin, identified in turn with the planet Venus. According to Venus's position, specific days in each sexagenary cycle, and certain hours on certain days, were judged especially unlucky. If an appointment required people to travel in a prohibited direction on a given day they might veer off in a safe direction on the day prior to it; after passing the night, they could proceed toward their destination without fear of adverse effect. Sei Shonagon, the author of Makura no sōshi (The pillow book), a journal and miscellany of court life, is among the Heian writers who describe this technique. Hikaru Genji, the hero of the great romance Genji monogatari, frequently cites directional taboos as a reason for absence from or neglect of one or another of his many lovers.
Within the Heian bureaucracy, the Onmyōryō became the virtually exclusive domain of the Abe and Kamo clans. For generations beginning in the mid-tenth century, onmyōdō practices were divided between the two clans, the Kamo being the masters of the art of the calendar and the Abe controlling astronomical studies. The twenty-fourth volume of Konjaku monogatari shū contains a series of stories about the exploits of illustrious members of these clans as well as those of their predecessors and of some anonymous practitioners, including Buddhist monks. The emphasis in these stories is on the use of special insights to perceive life-threatening dangers and the secret techniques used to outwit them. Abe Yasuchika, a particularly accomplished onmyō no kami, is said to have relied on three texts—Konkikyō, Suikyō, and Jinsūryōkyō —which he referred to as "the three onmyōdō classics." A Sui dynasty manual, Wuxing taiyi (Jpn., Gogyō taigi ), attributed to Xiao Ji was also used by many masters. In 1210, the onmyō hakase Abe Takashige was asked by Retired Emperor Go-Toba to prepare a new manual based on classical texts. The result, a work known as Onmyōdō hakase Abe Takashige kanjinki, prescribes divination for the undertaking of construction projects and official excursions, with many examples from Heian practice.
After the twelfth century, as political power passed from the Heian court to a series of military dictators, the heyday of official onmyōdō came to an end. Calendar studies fell into decline, while interest shifted to numerology, sukuyōdō, a form of astrology strongly influenced by Esoteric Buddhism, and folk astrologies. When the Kamo line of rekidō masters died out in about 1400, the Abe clan reclaimed the calendar legacy and, as a reward for helpful predictions, were granted the surname Tsuchimikado and the hereditary onmyōdō monopoly by Emperor Gokomatsu. The Tsuchimikado name remains closely linked with the remainder of onmyōdō history. Tsuchimikado Shintō, also known as Abe Shintō, is a sect that combines onmyōdō elements with Shintō. It traces its origins to Tsuchimikado Yasutomi (1655–1717). When the shogun Tokugawa Yoshimune (1652–1751) wanted to adopt a Western calendar he was defied by Tsuchimikado Yasukuni, who asserted the right of his family—and of the Kyōto establishment over the Edo shogunate—to exercise control of the calendar. He prepared a new one, the Hōreki calendar, which was promulgated in 1754.
Meanwhile, a class of professional conjurers, the shōmonji, had appropriated many onmyōdō functions, which they combined with sūtra chanting, dancing and theatricals. Although licensed to perform such entertainments, the shōmonji were a despised class. The word onmyōji, which previously had denoted a learned master, came to refer to itinerant magicians who roamed the country selling charms, almanacs and advice. Eventually, in the Edo period (1603–1867), both shōmonji and onmyōji were labeled outcasts and were forced to reside in ghettos. In some of these, their descendants still practice the ancient arts of their ancestors. Many modern fortune-tellers and astrologers continue to rely on basic onmyōdō methods, while many Japanese still refuse to live in a house with northeastern exposure or to position their beds in a way that might invite the malignant effects that come from that quarter.
The first major work of modern scholarship on onmyōdō was Saitō Tsutomu's Ōchō jidai no onmyōdō (Tokyo, 1915). More recently, Murayama Shūichi has devoted much of his career to the study of onmyōdō' s history, treating it most comprehensively in his Nihon onmyōdōshi sōsetsu (Tokyo, 1981). His work is complemented by that of Yoshino Hiroko, whose Nihon kodai jujutsu: onmyō gogyō to Nihon genshi shinkō (Tokyo, 1974) and Onmyō gogyō shisō kara mita Nihon no matsuri (Tokyo, 1978) document the role of onmyōdō in various early cults and rites, with many diagrams and illustrations. See also Classical Learning and Daoist Practices in Early Japan: Engishiki, translated by Felicia G. Bock (Tempe, Ariz., 1985). A helpful table, explaining the various applications of the sexagenary cycle, forms part of the article by Fujita Tomio, "Jikkan jūnishi" (in English), in the Encyclopedia of Japan (Tokyo, 1983), vol. 4, pp. 55–57. The most comprehensive history of calendar study in Japan is Satō Masatsugu's Nihon rekigaku shi (Tokyo, 1968). On era names, see Takigawa Masajirō's Nengō kōshō (Tokyo, 1974). A highly regarded study of directional taboos is Bernard Frank's Kataimi et katatagae: Étude sur les interdits de direction à l'époque Heian (Tokyo, 1958). Nakamura Shōhachi has transcribed and edited Gogyō taigi (Tokyo, 1973) and has also produced a study, Gogyō taigi no kisoteki kenkyū (Tokyo, 1976). A translation of the early legal codes, giving the structure of the Onmyōryō as well as a translation of the Sōniryō, may be found in Sir George Sansom's "Early Japanese Law and Administration," Transactions of the Asiatic Society of Japan, 2d ser., 9 (1932): 67–109 and 11 (1935): 117–149. There is extensive material on shōmonji and the later onmyōji in Hori Ichirō's Wagakuni minkan shinkōshi no kenkyū, 2 vols. (Tokyo, 1953–1955), some of which is incorporated in his Folk Religion in Japan, edited and translated by Joseph M. Kitagawa and Alan L. Miller (Chicago, 1968).
Edward Kamens (1987)