Onmyodo - The Way of Yin and Yang

Onmyodo (literally ‘The Way of Yin and Yang’) is a traditional Japanese esoteric cosmology, a mixture of natural science and occultism. It is based on the Chinese philosophies of Wu Xing (five elements) and Yin and yang, introduced into Japan at the beginning of the 6th century. It was accepted as a practical system of divination. These practices were influenced further by Taoism, Buddhism and Shintoism, and evolved into the system of onmyodo around the late 7th century. Onmyodo was under the control of the imperial government, and later its courtiers, the Tsuchimikado family until the middle of the 19th century, at which point it became prohibited as superstition.

In the 5th and 6th centuries, the principles of yin-yang and the Five Elements were transmitted to Japan from China along with Buddhism and Confucianism. Yin-yang and the Five Elements, as well as the divisions of learning to which they were linked – astronomy, calendar-making, the reckoning of time, divination, and studies based on observation of nature – were amalgamated into fortune telling. This process of judging auspicious or harmful signs present in the natural world was accepted into Japanese society as a technique for predicting good or bad fortune in the human world. Such techniques were known mostly by Buddhist monks from mainland Asia who were knowledgeable in reading and writing Chinese. Over time demand from members of the imperial court who believed that onmyodo divination would be helpful in decision-making made it necessary for the laity to perform the art, and onmyoji began to appear around the middle of the 7th century.

With the implementation of the ritsuryo system law codes in the 7th and 8th centuries, yin-yang techniques were put under the jurisdiction of the Bureau of Onmyo in the Nakatsukasa-sho of the Imperial bureaucracy. The Bureau of Onmyo was responsible for overseeing the divinations of Onmyodo, astrological observations, and the creation of calendars. Also, by law the Buddhist clergy was forbidden to practice astrology and fortune-telling; hence, government-controlled onmyoji came to monopolize the practice.

From the Heian period onward, as the ritsuryo system relaxed and the Fujiwara family rose to power, the society of the Imperial court took on a more formal shape, and adherence to rituals to placate the souls of the dead to combat the creation of vengeful ghosts burgeoned. Because onmyoji displayed methods that were believed to avert disasters with their skills of divination and magic, the practice afforded onmyoji influence over the personal lives of the Emperor and the nobility of the court. Consequently, popular awareness of onmyodo gradually spread from court society to Japanese society as a whole, strengthening its development into a characteristically Japanese art.

Onmyodo merged with other beliefs and occultism, and evolved from imported Chinese thought into a syncretism found only in Japan. Japanese onmyodo took in elements from Taoism, which was transmitted to Japan at the same time as onmyodo, including magical elements such as katatagae, monoimi, henbai, and ceremonies to Taoistic gods such as the Taizan Fukunsai. Elements of feng shui and the medical art of jukondo were incorporated as well, and as onmyodo and Japanese Shinto mutually influenced each other, onmyodo grew more distinctive. From the end of the 8th century onward, it was influenced by the magical elements of esoteric Buddhism and the Indian-derived astrology (Sukuyodo) that were transmitted with it.

During the Heian period the nobility organized their lives around practices recommended by onmyoji. The practice of "lucky and unlucky directions" provides an example. Depending on the season, time of day, and other circumstances, a particular direction might be bad luck for an individual. If one's house was located in that direction, such an individual was advised not to go back directly to his house but had to "change direction" (katatagae), by going in a different direction and lodging there. Such a person would not dare to go in the forbidden direction, but stayed where they were, even if that resulted in absence from the court, or passing up invitations from influential people.

In the 10th century Kamo no Tadayuki and his son Kamo no Yasunori made great advancements in onmyodo, astronomy and calendar science, and from among their students emerged Abe no Seimei, who displayed superior skills in the divining arts of onmyodo, by which he gained an uncommon amount of trust from the court society. Tadayuki and Yasunori passed on their skills in astronomy to Seimei while their advances in calendar-making went to Yasunori's son. From the end of the Heian period into the Middle Ages, astronomy and calendar science were completely subsumed into onmyodo, and the Abe and Kamo families came to dominate the art.

Onmyoji was one of the classifications of civil servants belonging to the Bureau of Onmyo in ancient Japan's ritsuryo system. People with this title were professional practitioners of onmyodo. Onmyoji were specialists in magic and divination. Their court responsibilities ranged from tasks such as keeping track of the calendar, to mystical duties such as divination and protection of the capital from evil spirits. They could divine auspicious or harmful influences in the earth, and were instrumental in the moving of capitals. It is said that an onmyoji could also summon and control shikigami.

Famous onmyoji include Kamo no Yasunori and Abe no Seimei (921–1005). After Seimei's death the emperor had a shrine erected at his home in Kyoto.

Onmyoji had political clout during the Heian period, but in later times when the imperial court fell into decline, their state patronage was lost completely. In modern-day Japan onmyoji are defined as a type of Shinto priest, and although there are many that claim to be mediums and spiritualists, the onmyoji continues to be a hallmark occult figure.