Treatise 115: Yin-Yang Studies I

¶In remote antiquity, people and affairs were simple and unadorned, and wisdom and talent had not yet developed. For that reason, we have not heard that methods of calendrical reckoning, divination, or measurement already existed in those times.

¶When the Three Han kingdoms came into allegiance, the Chinese theories of pitch-pipes and the calendar, and the arts of astronomy and the Five Phases, were probably first transmitted to our realm around this time. However, according to what the earlier histories record, from the Great Founder (Emperor Jinmu) onward the first month was set at the month of the Tiger, and years, months, and sexagenary day-and-year designations are recorded in the greatest detail; yet which calendrical system was actually in use cannot be known. One theory holds that "later people fixed a calendrical system and then calculated backward into the past." Even so, for events more than a thousand years old, to compile the years, link the months and days, and set them down in books without error—how could that have been done without any basis?

¶When one observes the marvelous principle of Heaven, the four seasons do not go astray, cold and heat come and go, and yin and yang flourish in turn. The sages of old who fixed the reckoning of years may well have counted the days and months by some simple method. Methods such as the futomani (the great divination) are said to have been handed down from the Age of the Gods. And in the case of the portent in the reign of Emperor Ingyō, when ice formed on a bowl of soup, the words of the diviners were quite similar to the legends of the Five Phases expounded by Chinese Confucian scholars. One may suppose that, with regard to calamities, auspicious signs, and good and ill fortune, our country also had its own theories, which were not transmitted to later ages.

¶From the reign of Empress Suiko onward, the study of calendrical science, astronomy, and the occult arts all became the duty of specialist hereditary officials (chūkan). Anomalies of the sun, moon, and stars, manifestations of inauspicious vapors, and omens and disasters of an uncanny kind are recorded in the histories without interruption. When the Taihō Code was established, in general the study of astronomy and calendrical texts, and divination by wind, clouds, and the colors of the sky, all came under the charge of the Bureau of Yin and Yang (Onmyōryō). In later ages, astronomy became solely the profession of the yin-yang practitioners; scholars no longer exerted themselves in observation and in calculating the movements of the heavens, but idly lectured on the theories of yin-yang and the Five Phases, clung to trivial numerical schemes, recklessly put forward arbitrary doctrines of their own, and in the end threw the way of the calendar into disorder. This may truly be called an extreme delusion.

¶Now, measuring the shadow of the sun with the gnomon is done in order to assist what is fitting for all things and to bring out the harmonious vapor. Rectifying the calendar days is done in order to draw near to and follow the forms of Heaven and to respectfully bestow the seasons upon the people; that is why kings held it in such regard. When the sages of old compiled histories, they recorded anomalies but did not write down their reasons or explanations. As for what retribution calamities and auspicious signs bring, those of insight, it would seem, do not discuss it at length.

¶In former times, Emperor Sujin met with the calamity of an epidemic, and in fear and reverence he begged pardon of the gods for his faults. He strove with vigor in government and was able to revive the achievements of his predecessors, and so he was styled Hatsukuni-shirasu-sumeramikoto (the Emperor who First Ruled the Land). By contrast, in later ages some rulers disliked speaking of calamities and anomalies, and at the slightest auspicious sign would cite theories of omens to patch things over for the moment; yet no instance is seen of this having aided government. In sum, calamities and auspicious signs arise from the unfathomable workings of yin and yang, but good and ill fortune most likely depend on whether people's conduct is right or wrong. That the historians record these matters with reverence is likewise in order to leave a warning for later generations.

¶Now, our realm began to follow a calendar only after foreign calendrical learning was transmitted, and by the Jōgan era (859–877) its calendrical system had been changed five times. These are the so-called Genka, Gihō, Taien, Goki, and Senmyō calendars. All of these, however, were old calendrical systems of the Song and Tang, and were not independently revised or created. Moreover, the theories of astronomy and the Five Phases transmitted by the specialist officials mostly came from China, so they will not be described again here in detail. Only the order in which these calendars were adopted and the discussions of the scholars (hakase) of the time are recorded.

¶And in setting forth the origins of the calendrical arts, those celestial calamities and earthly prodigies that already appear in the Imperial Annals have been omitted or abbreviated. Those not yet recorded have all been investigated and gathered, and this Treatise on Yin and Yang has been made.