Chaldean Decans (Faces)

Definition

The Chaldean-order convention hands out the 36 decans to the seven traditional planets in what is called Chaldean, or heptazone, order — Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon — lined up by how fast each appears to move, slowest to fastest. Following Liber Hermetis Chapter I, the cycle starts not from Saturn but from Mars at the first face of Aries (0-10°). So the rulers run Mars-Sun-Venus across Aries, Mercury-Moon-Saturn across Taurus, and on around the zodiac.

In Tradition

In the medieval traditional astrology organised by Lilly, Bonatti, and the Picatrix, Chaldean-order decan rulership — the same thing as the medieval Latin facies, or "face" — counts as the weakest of the five essential dignities. Lilly's Christian Astrology I gives it +1 point in his +5/+4/+3/+2/+1 dignity grading. The same Chaldean order also governs the rulers of the planetary hours, tying decan-rulership and hour-rulership together in classical practice.

In Practice

To find a planet's decan-face, you read its sign-degree. Starting from 0° Aries, count Mars (1st face, Aries 0-10°), Sun (2nd face, Aries 10-20°), Venus (3rd face, Aries 20-30°), Mercury (1st Taurus 0-10°), Moon (2nd Taurus 10-20°), Saturn (3rd Taurus 20-30°), Jupiter (1st Gemini 0-10°), then keep cycling through the heptazone for all 36 decans. A planet in its own face earns +1 essential-dignity point in Lilly's 5-point system; the decan-ruler also serves as a third-string ruler for chart-points — the Ascendant, the Midheaven, the Lots — when the sign-ruler and bound-ruler are both weak. Renaissance image-magic practice, in the Picatrix and Agrippa, uses the Chaldean-order decan as the planetary sequence anchoring decanic talismans.

Historical Origin

The Chaldean planetary order is attested in Babylonian astronomical-omen cuneiform of the 1st millennium BCE, and applied to decan-rulership in Liber Hermetis Trismegisti Chapter I — a Hellenistic-era Latin redaction of a lost Greek original; Gundel 1936. It was set down in the medieval Latin tradition by the Picatrix (Arabic Ghāyat al-Ḥakīm, 11th century; Latin translation, 13th century) and by Bonatti's Liber Astronomiae. Lilly's Christian Astrology I (1647) treats Chaldean-order faces as the +1-point essential-dignity tier.

Definition

In Tradition

In Practice

Historical Origin

Further Reading