Thanks to Sun-sign horoscope columns, Zodiac signs are the first thing most people think of when they hear the word “astrology.”
And, if you’ve studied astrology for yourself, you’ll know that Zodiac signs modify the expressions of a planet located in the sign, much like a colored filter modifies the color of light that shines through it. Signs intensify – or muddle – a planet’s vibe.
But, what exactly are Zodiac signs? Where did they come from, and why do astrologers care about them?
Coordinates in the Sky: The Ecliptic
If you read our article on astrology charts, you know that charts aren’t magic. A chart’s just a map of the sky from the point of view of a particular time and place on Earth.
More specifically, it’s a map of where the planets appear in the sky from that place.
As you remember from elementary school, the solar system is like a giant spinning disk. All of the planets circle around the Sun like the grooves on an old-fashioned record.
Of course, Earth is a planet, too. And so, from our vantage point, we look out at this disk edge-on. To us, the Sun and all of the planets appear to travel within a narrow band, like a belt stretching across the sky. We call this belt the Ecliptic.
To make it easier to describe where planets are, the Babylonians divided the Ecliptic into 12 equal sections, each named for a corresponding constellation. These sections became as the 12 signs of the Zodiac.
Zodiac is a Greek word which loosely translates as “the Way of Life.” It’s both the place where the living planets reside, as well as a spiritual path for living.
As the name implies, there’s deep esoteric wisdom about how life happens — how creation occurs — encoded in the Zodiac signs.
Let’s sneak a peek behind the veil at some of this secret wisdom…
Yang and Yin: Zodiac Sign Polarities
If you’re studying the sky, the first thing you’ll notice is the obvious: the unending rhythm of Day. Night. Day. Night.
Most people are active in the bright daylight hours of the Sun-filled sky; it’s when we work and move about the world. Whereas at night, we rest, dream and focus on our interior, subjective experiences under a gentle glow of moonlight.
Life itself requires this cosmic dance of polarities. Too much of one or the other and things fall apart.
And so astrologers divided Zodiac Signs into these same two polarities: day signs (sometimes called diurnal, masculine or yang) and night signs (sometimes called nocturnal, feminine or yin).
What’s the difference between them? Well, just what you’d expect!
Day signs are more outgoing, extroverted, or interested in what is going on in external, objective, light-filled world. In other words, day signs have a Sun-like quality.
On the other hand, night signs are more receptive or introverted. Again, as you’d imagine, night signs have a Moon-like quality.
Counting around the Zodiac, every other sign is diurnal or nocturnal. Like a swinging pendulum, planets shift from one polarity to the other and back as they move around the celestial circle. Or in other words, they follow the same day-to-night-to-day rhythm as we do on Earth.
Most astrology charts have planets in a mix of both day and night signs. But, to have many planets in one of the polarities and few of the other would indicate a definite outward or inward turn of energy, with visible effects on your life.
The Staff of Hermes: Zodiac Sign Rulerships
Beyond the rhythm of day and night, we also experience a seasonal pulse – the shift from summer to winter and back again. In the summer, days are hot and light-filled; winter months are colder and darker.
As the seasons shift over the year, following the Sun’s travels through the 12 Zodiac signs is one of the oldest versions of the archetypal “Hero’s Journey,” in which the Sun King voyages from light, into darkness, and back to light again.
This seasonal progression is the prototype for the “stairway to heaven.” Together, the Zodiac signs – and specifically the planets which rule them — form a kind of “planetary ladder.”
Here’s how it worked…
Naturally, the main light-givers of the sky, the Sun and Moon, claim the light-filled summer signs, Leo and Cancer. These two planets serve as polarities for one another.
The remainder of the planets are assigned along this seasonal axis according to how quickly they move through the heavens, from fastest to slowest. Each planet claims one day sign and one night sign, representing the two polarities of a planet’s expression.
Climbing down beneath the Summer signs:
- Speedy Mercury claims Virgo and Gemini
- Lusty Venus claims Libra and Taurus
- Heroic Mars claims Scorpio and Aries
- Stately Jupiter claims Sagittarius and Pisces
- Slow-moving Saturn claims Capricorn and Aquarius, the two signs of winter furthest from the Sun.
Now, these “ruling” planets are essential to astrology.
Until a hundred years or so ago, no one would have asked you your Sun sign. You would have been described by the planetary energy which dominated your personality.
In fact, English still has lots of planet-words: sunny or beaming (Sun), lunatic or (Moon), mercurial (Mercury), venial or venereal (Venus), martial (Mars), jovial (Jupiter), saturnine (Saturn).
Here’s another astrological secret hidden in plain sight…
If you position the planetary ladder with the Sun and Moon at the top, then draw a line connecting all of the Sun planets, and another connecting all of the Moon planets, you’ll see one of the oldest symbols for astrology emerge: the caduceus, otherwise known as the staff of Hermes.
To the Romans, Hermes was known as Mercury, or the patron god of astrology.
Beginnings, Middles and Ends: Zodiac Sign Modes
All time-bound things have beginnings, middles and ends, and the seasons are no different.
Cardinal signs mark the beginning of seasons in the Tropical Zodiac. Their starting points are the two solstices and two equinoxes, points astrologers sometimes collectively refer to as the World Axis. Cardinal signs feel active, dynamic, enterprising or crisis-oriented.
Fixed signs sit at the midpoint of seasons. When the Sun is located in these signs, we’re at the height of the season – like how when the Sun is in the fixed sign Leo, it’s typically the hottest part of the summer. The energy of these signs feels stabilizing, caretaking, sustaining, and value-oriented.
And, last but not least, mutable signs fall at the end of seasons. We’re wrapping things up and getting ready to move to the next phase. Mutable signs feel adaptable, transformative, negotiating or fickle.
Fire, Earth, Air, Water: Zodiac Sign Triplicities
The architects of astrology also felt certain Zodiac signs had special affinity for one another. They called these harmonious signs triplicities, and were named for the cardinal signs Aries, Cancer, Libra and Capricorn.
After a few centuries passed, astrologers began to associate the four classical elements fire, air, water and earth, with the triplicities, adding new dimension to the Zodiac signs.
The classical element’s qualities emerge from our human experience of them…
Fire and air move up and outward, and belonged to the Zodiac’s day tribe. Fire signs cast their exuberant, fiery nature onto planets. Air sign planets yearn to be more social, intellectual and communicative.
Conversely, as water and earth both fall downward, these made up the Zodiac’s night tribe. Water signs encourage planets to emphasize their instinctual, emotional, feeling natures. The Earth signs planets seek to express themselves in physical, practical ways.
The 12 Zodiacal Signs
By combining the meanings of the triplicity and mode of expression, with the ruling planet, we create the signatures of the 12 Zodiac Signs.
Modern Influences on Traditional Zodiac Signs
The astrological model endured for nearly 2,000 years until the scientific revolution – and the discovery of Uranus – challenged the system.
Astrology was already faced an identity crisis. The “enlightenment” ages obsession with measuring the physical world left little room for holistic sciences like astrology (or alchemy for that matter). The number of books published on the topics dropped to near nothing.
But, astrologers had their own innovation to contend with – the discovery of Uranus in 1781. After several decades of debate, self-styled modern astrologers linked Uranus to the sign Aquarius, the first sign of “shared” rulership.
Once Neptune was discovered in 1846, astrologers more quickly linked to Pisces, the next sign in line after Aquarius. It seemed a fortuitous fit, the lord of the sea naturally aligned with the sign of the Fish.
Theosophical astrologers felt they were onto something. Believing in elegant design, they reasoned the solar system must have undiscovered planets. Once 12 planets were found, each Zodiac sign would have its very own ruling planet.
And so, when Pluto was discovered in 1930, he was crowned ruler of the sign Aries. (And, I kid you not, the hypothetical planet Vulcan was earmarked for Taurus.)
However, debate on Pluto’s proper rulership continued until the 1970s, when the consensus among astrologers shifted Pluto to Scorpio, the other Mars-ruled sign, as a “better” fit. (And by this time, we realized that Vulcan only existed in the Star Trek universe.)
To make room for these new planets in the system of sign rulerships, modern astrologers shifted the meanings of the signs Aquarius, Pisces and Scorpio to include more of the qualities associated with these new planets.
In other words, Aquarius sign descriptions became more original, Pisces more mystical, and Scorpio more obsessive-compulsive.
But the debate on modern rulerships heated up once again in the 1990s.
Thanks to computer-guided telescope technology, astronomers began discovering more planets like Pluto in the outer solar system. So far we’ve found more than 20 of these “Plutinos” other trans-Neptunian objects (not to mention the tens of thousands of asteroids and other minor bodies.) Clearly, there are more planets and minor planets than we ever imagined.
Meanwhile, a group of astrologer-historians had been working to recover the “lost” history of astrology. They found and translated texts exploring the history and logic of astrology as practiced over the millennia.
From this combination of new and old ideas a revitalized 21st century astrology is slowly emerging – one with a more robust sense of itself, more capable of integrating with a tech-savvy world.