← Encyclopedia of Astrology · lesson 200/235
Triplicity
What it is
A triplicity is a set of three signs that share an element. There are four:
- Fire — Aries, Leo, Sagittarius
- Earth — Taurus, Virgo, Capricorn
- Air — Gemini, Libra, Aquarius
- Water — Cancer, Scorpio, Pisces
The three signs of a triplicity stand 120° apart, a trine, so they make an equilateral triangle on the wheel; the older name is trigon, Greek for triangle, and Ptolemy's chapter on them is called "Of the Triangles". Each triplicity holds one sign of each mode — one cardinal, one fixed, one mutable — which is why the three modes and four elements together give each of the twelve signs a combination of its own (the modes are the quadruplicities). The fire and air triplicities are masculine or diurnal, the earth and water triplicities feminine or nocturnal.
So "triplicity" is, first, simply the element seen as a group: a fire sign, an earth sign, an air sign, a water sign. The entries on each element say what it is read as.
Triplicity as a dignity
In traditional astrology the word has a second, technical meaning. Each triplicity has its own planetary rulers, and a planet standing in a sign of a triplicity it rules is said to be in its own triplicity, one of the five essential dignities. It ranks below domicile and exaltation and above bounds and face; Lilly scores it three points, against five for domicile and four for exaltation. A planet in its own triplicity is read as comfortable and supported, like someone among their own people, though not in their own house.
The rulers are not the sign rulers. Which planets rule each triangle, and why, was explained in terms of the planets' natures and of sect: each triplicity has a ruler for a day chart and one for a night chart. The scheme most traditional astrologers use comes from Dorotheus of Sidon (first century), with a third, participating ruler who shares in both:
| Triplicity | Day · Night | Participating |
|---|---|---|
| Fire | Sun · Jupiter | Saturn |
| Earth | Venus · Moon | Mars |
| Air | Saturn · Mercury | Jupiter |
| Water | Venus · Mars | Moon |
Ptolemy gives a slightly different, two-ruler version. Fire, earth and air match the first two columns above; for water he makes Mars the ruler, with Venus by day and the Moon by night as co-rulers, and his wording leaves it unclear whether Mars rules alone at both times. Lilly, following the Ptolemaic line, gives Mars the water triplicity by day and by night. In the sixteenth and seventeenth centuries the Ptolemaic two-ruler version largely replaced the three-ruler one in European practice; the revival of Hellenistic and medieval texts since the 1990s has brought the Dorothean rulers back into common use. Both are in print and in software, so it is worth knowing which a given astrologer follows.
Other uses
- The life as a whole. Dorotheus, Valens and other Hellenistic astrologers judged the course of a life from the triplicity rulers of the sect light (the Sun by day, the Moon by night): the first ruler for the earlier part of life, the second for the later, the participating ruler helping throughout. Chris Brennan describes the technique in Hellenistic astrology.
- Reception. A planet in another's triplicity is "received" by that planet in a minor way, the courtesy that mutual reception builds on.
- Mundane astrology. Ptolemy tied each triangle to winds and regions of the known world. And the Jupiter–Saturn conjunction, every twenty years or so, stays in one triplicity for about two centuries before moving to the next, a shift mundane astrology has read as a turning of eras; the series moved from earth to air with the conjunction of December 2020.
In a reading here
The essential dignities in a chart here use the Dorothean table: a planet in its own triplicity scores three points, with the day ruler counting in a day chart and the night ruler in a night chart (and the night ruler when sect cannot be told). Reception between planets counts triplicity among its dignities. In horary, one of the tests of radicality asks whether the lord of the hour agrees with the lord of the Ascendant, and the lord of the hour being one of the triplicity rulers of the rising sign is one of the ways it can.