The zodiac signs
The twelve signs of the zodiac are the best known part of astrology — and the most misunderstood. A sign does not describe a person. It describes a section of the zodiac, and how a planet behaves within it.
The four elements
Each sign belongs to one of four elements, three signs to each. These groups of three are called triplicities:
- Fire — Aries, Leo, Sagittarius. Hot and dry: quick, directed outward.
- Earth — Taurus, Virgo, Capricorn. Cold and dry: persistent, attached to the tangible.
- Air — Gemini, Libra, Aquarius. Hot and moist: connecting, mobile.
- Water — Cancer, Scorpio, Pisces. Cold and moist: receptive, slow to change.
This allocation is not imagery. Hot, cold, dry and moist are the four primary qualities of ancient natural philosophy, and through them astrology is joined to the doctrine of temperaments — the ground a chart is read against first.
The three modes
A second ordering cuts across the first, according to position within a season:
- Cardinal — Aries, Cancer, Libra, Capricorn. They open a season: they set things going.
- Fixed — Taurus, Leo, Scorpio, Aquarius. They occupy the middle of a season: they hold.
- Mutable — Gemini, Virgo, Sagittarius, Pisces. They end a season: they hand over.
Element and mode together identify each sign uniquely — there is exactly one cardinal fire sign, and it is Aries.
The rulers
Every sign has a planet that rules it. In the classical arrangement the two lights rule one sign each, the remaining five planets two each:
| Planet | Signs |
|---|---|
| Sun | Leo |
| Moon | Cancer |
| Mercury | Gemini, Virgo |
| Venus | Taurus, Libra |
| Mars | Aries, Scorpio |
| Jupiter | Sagittarius, Pisces |
| Saturn | Capricorn, Aquarius |
The arrangement is symmetrical: from Leo and Cancer the assignments run outward in both directions in the order of the planetary periods. It is built, not assembled. In a particular chart these assignments do not stay a list: whatever sits in a sign answers to the planet that rules it. Which planet then outranks the rest — ruler of the ascendant, almuten, final dispositor — is the subject of a guide to rulerships and dignities.
What a sign actually is
A sign is a section of thirty degrees, and it describes not a person but the way a planet acts within it. Mars in Aries — in its own sign — can do what it is for. Mars in Taurus, the sign of its detriment, cannot do it properly.
From which follows the essential point about what people call "their sign": it is the position of a single planet, the Sun. The chart holds six others, plus the ascendant and the twelve houses. To read the sun sign alone is to look at an eighth of the picture.
See also: the planets, the twelve houses.