Venus in Japanese Astrology

by H. Shuseh Kokubu, Q.H.P.

Venus Occulted by the Moon

Strange as it may sound to the Western astrologers, both Venus and the general of army are classified into the element Kin (gold or metal) in the Chinese theory of yin-yang and five elements. Therefore On'myoji - ancient Japanese astrologers - predicted that there would be some change in the general or the army when they observed something unusual happening to Venus. If Venus was occulted by the Moon, for instance, the general had to stay in his house on On'myoji's advice in order to avoid a misfortune or accident.

Abe-no-Yasuchika, a famous twelfth-century On'myoji, observed an occultation of Venus by the Moon on August 26th, 1155, and delineated it to suggest the death of Toba, the emperor's father at the moment. This sounds strange and arouses our curiosity because On'myoji regarded Venus as the significator of the general, and Jupiter as the emperor. Why did Yasuchika predict the death of Toba? Kuniji Saito, an astronomer at the Tokyo Observatory, calculated the planetary positions and says the occultation started at 2:59 a.m. and Venus reappeared at 3:42 a.m. JST. If we erect a chart for the middle time of the occultation, like William Lilly did when judging eclipse charts, we can conjecture Yasuchika's reasoning.

Chart 1 (Aug. 26, 1155 03:21 AM JST 135E46 35N01)

Venus is the ruler of the tenth house of the power. At that time, Go-Shirakawa had taken the throne in succession to Toba. However, Toba replaced emperors and also regents as the supreme political figures at the central government, full utilizing and expanding upon the private base of power for the imperial house - Toba exercised his power at will yet. So I suspect that Yasuchika considered Venus as the accidental significator of Toba and its occultation as his death. Actually Toba died in July 1156.

Daylight Venus

Being an inferior planet, Venus can never be more than 48 degrees from the Sun, and it is brightest, magnitude -4.8, when its elongation is 40 degrees. Its brightness is one thousandth that of a full moon, but it is 100 times brighter than first magnitude fixed stars like Spica and Regulus, and then Venus sometimes can be seen in the daytime. On'myoji called the phenomenon Taihaku-chu-ken (Venus-daytime-visible) and considered it as an omen of coup d'etat. It is because that the ancient Chinese and Japanese said a planet 'competing in brightness' with the Sun when it was seen in the daytime, and that they considered the Sun as the lord and the inferior planets as chamberlains, and besides Venus was the significator of the general. But Chinese texts say it is a fortunate sign if the Moon is seen at the same time: this is called san-kou (three lights) - their theory is rather complex.

In 740 AD, Fujiwara-no-Hirotsugu impeached the brain trust of the Emperor for their poor administration, and proposed to discharge them. The central government rejected his proposal, then Hirotsugu rebelled against the Emperor and the central government. The rebel army was suppressed by the Emperor, and Hirotsugu was killed in the battle two months after his uprising. Although Hirotsugu could not get an important position in the government, he was well-educated and conversant with astrology. In his letter to the central government he says, "On December 31st, 739, Venus appeared in Shin (the lunar mansion including Antares), glaring in the south-west sky at the noon." Therefore he thought the Emperor would be assassinated by the brain trust. In reality, however, it was Hirotsugu who rebelled against the Emperor.

Chart 2 (Dec. 31, 739 Noon LMT 130E30 33N30)

Chart 2 confirms Hirotsugu's observation - Venus is in the eighth house (south-west sky) and 4 degrees from Antares (Scorpio 2203') the main star of Shin. The emperor's own men and the military in those days are represented by the eleventh house and its ruler. The ruler of the eleventh Saturn is in its detriment and retrograde in motion but it also symbolizes the emperor, as Saturn rules both tenth and eleventh. The Moon is translating the light of Mars, the natural significator of uprising, to Jupiter that On'myoji considered as the significator of the emperor. On the other hand, the accidental significator of the emperor Saturn is in mutual reception with the Sun, meaning an escape. If I were Hirotsugu, I would not predict the assassination of the emperor. These make me think that Hirotsugu mentioned the daylight Venus to justify his proposal. And it is interesting to note that Mercury conjuncts Altair (Capricorn 1416'), as Ebertin says, "If Mercury and Moon are posited here, this will make people as bold as brass and foolhardy, in order to assert themselves."

Supplementary Note

"He that goes about to destroy Art, is far worse than he that is unskilled in it, for his mind is full of malice and idleness as well as ignorance." - Jerome Cardan

One of the reasons that On'myoji observed the sky was to compensate errors in their ephemeris. They were able to calculate the planetary positions precisely, but errors in the range of 0.3 degrees were unavoidable in some cases. Astrologers today enjoy the benefits of the progress of astronomy and computer science - astronomical observations and complicated calculation are no longer needed, so that we can make better use of our lives than On'myoji. The benefits, however, made astrologers shortsighted at the same time - some of us cannot say the names of stars when looking up the night sky, and some are absorbed in fumbling for the horoscopee's character with a chart on the desk.

Astrology is originally the art for the purpose of finding coincidence between the events on the Earth and the movement of heavenly bodies. Some say astrology must change with the times. This reminds me the Law of Changes mentioned in the ancient Chinese text Yi Jing (Book of Changes), which is still studied by the practitioners of I-ching - "Everything must change. But the Law of Changes never changes." People's motive to visit astrologer may change, but astrology must not change. If we lose the spirit of astrology and modify the art, we don't deserve to be an astrologer and it is not proper to call the art astrology, but horoscopology.


"Kotenmongaku no Michi (The Way to Ancient Astronomy)" Kuniji Saito. Kodansha Pub. 1990
"Annus Tenebrosus" William Lilly. Ascella. 1997
"Tetrabiblos" Ptolemy. Loeb.
"Fixed Stars and Their Interpretation" Ebertin-Hoffmann, A.F.A.
"Anima Astrologiae" Ed. by William Lilly. Regulus.


1998 H. Shuseh Kokubu. All rights reserved.