Two Different Decan Rulers
If you’re studying astrology and tarot, you are familiar with the planet and sign combinations that correspond to the Minor Arcana numbered cards. But if you’ve started exploring where those correlations come from, you very well may have hit a snag. It seems that some astrologers assign different rulers to the decans than we learn in tarot. Why are there two different decan rulers? And which one is the tarot one?
The Question: Which of the Two Different Decan Rulers is Correct?
A friend contacted me the other day after researching the decans. Here’s her question:
I hope this is an easy question. I’ve tried to figure this out but think I don’t know enough to know what I should be looking for. Two different sources gave me different information about what planet rules what decan. Which of these are correct (if either)?
Joy’s Answer: Tarot Readers Use the Chaldean Decans
Yes, there are indeed two sets of rulerships for the decans. The first is the Chaldean order of the planets, and that’s the one the tarot uses. The other is the rulership of the decans according to triplicity. Astrologers more often use this system.
The Chaldean Decans
The first is based on the Chaldean order of the planets. This is the order of the seven traditional planets according to speed. Saturn is the slowest, then Jupiter is a bit faster, Mars faster yet, followed by the Sun, Venus, Mercury, and the Moon zips through the zodiac the fastest. This is the system the Golden Dawn uses. (Notice that the same order applies to the planets as assigned to the sephiroth of the Tree of Life, from Binah/Saturn through Yesod/Moon.)
To assign these planets to the decans, we start with the first decan of Leo. This is the time when the rising of the star Sirius announced the inundation of the Nile to the ancient Egyptians. When a star can be seen rising prior to sunrise — i.e., the star is visible in the pre-dawn sky while the Sun is still below the horizon — it’s called the heliacal rising. Sirius’s heliacal rising indicated that the growing season was coming, around the beginning of Leo. So the Golden Dawn kicked off the sequence of the pips with the Five of Wands, Saturn ruling the first decan of Leo. After Saturn comes Jupiter, so that planet rules the second decan of Leo, the Six of Wands; Mars next for the third decan of Leo, and so on.
There’s a hiccup with Mars ruling both the last decan of Pisces (Ten of Cups) and then the first decan of Aries (Two of Wands). This marks the traditional start of the zodiac year, the spring equinox. The common explanation is that as winter pushes into spring and the energy of germination underground sprouts into life above ground, nature needs extra energy, the domain of Mars.
Decans by Triplicity
On the other hand, there is also the traditional decans system, or decans according to triplicity. The triplicities are the four groups of three signs of the same element. For example, the three fire signs, Aries, Leo, and Sagittarius, form the fire triplicity. Using this system, the rulers of each decan form a microcosm that reflects the macrocosm of the signs that share the same element.
So, for instance, Aries is a fire sign, ruled by Mars. The other two fire signs are Leo, which the Sun rules, and Sagittarius, with Jupiter as the ruler. That’s the macrocosm. In the Aries microcosm, Mars rules the first decan, referencing Aries, the Sun rules the second decan, encapsulating Leo, and the third decan reflects the Sagittarius ruler, Jupiter.
Likewise, when you get to Leo, the first decan starts with the Leo ruler, the Sun, goes to the next fire sign Sagittarius for Jupiter and ends with Aries’ ruler, Mars.
Sometimes both systems mesh. For instance, the Sun rules the second decan of Aries via both the Chaldean rulers and the decans by triplicity.
Astrologers learn the decans by triplicity system, and often haven’t heard of the other system. On the other hand, tarot readers usually know only the Chaldean system. I’ve never heard of anyone using the decans by triplicity for tarot, but that’s not to say that there’s never been anyone who tried it!