Decan

Meaning

Each sign of 30° divides into three decans of 10°, thirty-six in the whole zodiac. The word comes from the Greek dekanos, “of ten”. Each decan has a ruling planet of its own, which tints the sign without changing it: the decan says which side of the sign a planet in it tends to show.

There are two main ways of giving the decans their rulers, and they do not agree.

• By element: the first decan belongs to the sign itself, the second to the next sign of the same element, the third to the one after. Aries has an Aries, a Leo and a Sagittarius decan, ruled by Mars, the Sun and Jupiter. The first decan is read as the sign in its clearest form; the other two add a touch of their own sign.
• By the Chaldean order: the rulers follow the order of the seven classical planets by speed, from Saturn, the slowest, down to the Moon, starting with Mars at 0° Aries and running round the zodiac. Aries has Mars, the Sun and Venus. Traditional astrology calls these decans the faces, the smallest of the five essential dignities.

In practice

• A planet’s decan refines its sign. A planet at 25° Taurus is in the third decan, the Capricorn decan ruled by Saturn, which adds patience and seriousness to the Taurus style. At 5° Taurus it would be in Taurus’s own decan, ruled by Venus.
• Sun-sign readings often use the decans to tell apart people of the same sign born in different weeks: about ten days per decan.
• In traditional technique, a planet in its own face holds the smallest of the dignities, though it is no longer peregrine. Lilly likens it to “a man ready to be turned out of doors”, still just keeping his standing.

Across traditions

• Indian astrology uses the element scheme for its drekkana, the third of a sign. Varahamihira gives the three thirds to the lords of the sign itself, the fifth sign and the ninth sign from it, the signs of the same element. The drekkana is one of the divisional charts read beside the birth chart.
• Ancient Egypt gave the name to thirty-six star groups that rose one after another through the year, each for about ten days.

Origin and history

The decans began as stars, not as slices of the zodiac. Egyptian star clocks painted on coffin lids from about 2100 BC list thirty-six star groups whose risings marked the hours of the night, and the year of 360 days plus five fitted thirty-six decades of ten days, as Otto Neugebauer and Richard Parker showed. In the Hellenistic era the decans were set into the zodiac as its thirty-six 10° divisions, each with its ruler and often an image of its own. The Chaldean faces came down through medieval astrology to William Lilly, whose table of essential dignities of 1647 still lists them. Varahamihira, in sixth-century India, recorded the element scheme, which many modern Western astrologers prefer.

How Ulune calculates it

Ulune uses both schemes, each in its own place, and names them apart.

• The readings use the decans by element, with modern rulers: Pluto for the Scorpio decans, Uranus for the Aquarius decans and Neptune for the Pisces decans. Each planet’s reading names its decan and that decan’s ruler, and each sign’s three decans have a reading of their own. The wheel draws them as a ring.
• The dignities table uses the Chaldean faces, from Mars at 0° Aries, and calls them faces. A planet in its own face scores +1 in Lilly’s points.
• A planet at 0° of a sign is in its first decan, at 10° in its second and at 20° in its third.

Correspondences