We have 12 signs because it is such an easily divisible number. The number 12 can be evenly divided by 1, 2, 3, 4, 6, and 12. It is a beautifully symmetrical number, as it has 4 factors below it and 4 factors above it. Centered between 1 and infinity, 12 is perfect equilibrium.
It began in Mesopotamia, when the Sumerians developed a numerical system using 12 as a base. This early duodecimal system influenced later timekeeping and measurement. Why we have 12 months, 12 numbers on the clock, 12 inches in a foot, 12 for a dozen eggs. China ‘s Shang dynasty, the 12 Earthly Branches were used to record 12 key divisions of day and night. The ancient solar calendar had 12 months matching the Sun‘s journey, and lunar phases divided a year into 12. The Babylonians associated 12 demigods with each of the zodiac signs, assigning each with 12 divine qualities.
We see the 12 tribes of Israel descended from the 12 sons of Jacob in Judaism. In Christianity, we have the 12 apostles chosen by Jesus to teach the gospels. In Islam, the Quran describes Allah’s 12-month reckoning of time. The Buddha gave 12 discourses after his enlightenment. The number 12 has been considered sacred and sublime throughout history.
Jupiter in astrology is considered the great benefic planet, it has a 12-year orbit. When you consider this gas giant planet protects the Earth from asteroids, such as a recent one that was 90-miles wide! It has a protective relationship to Earth, protecting us from things flying through space. Also, in astrology Jupiter represents God, religion, our beliefs. The number 12 signifies governance, divine authority and completeness.
So, as you can see, 12 is a very sacred and important number for humanity. We have 12 signs because there are 12 months. Originally, a month was one new moon to the next new moon. One-twelfth part of a year; one of the twelve parts into which the calendar year is divided. The word ‘month’ comes from Old English monað, which is related to menon, meaning moon. In a 365-day interval (one Earth year) we have 12 lunar cycles – 12 months.
The entire tropical system is based upon the connection between the Sun, the Moon and the Earth, this is how we get our eclipses. We have 12 lunar cycles and one solar year, from the reference point of the Earth.
Signs are not constellations they are cycles. They are archetypes that we carry in our psyche, our microcosm within, not the external macrocosm, universe that is external. They are the mythology of our humanistic experiences. The signs are not the constellations, this is where people get confused. Two people can have the same name it doesn’t mean they’re the same person, right? Because the signs and the constellations are called the same names it doesn’t mean they are the same. Constellations are sectors in the sky, we can observe with an app on our phone. Signs are cycles not something we can observe.
It’s like time, we cannot ‘see’ time, you cannot localize it physical space. It isn’t tangible, it is an abstract concept, that we change and manipulate, with daylight savings time, and time zones. The signs are also like this, they are an abstract concept, not observable in the night sky.
The Babylonians originally, named 20 something constellations along the ecliptic, but some configurations were resized or dropped to bring it into harmony with the sacred number 12, so it would fit into the 12-cycle tropical system.
The signs inherited the constellation names because ancient astrologers needed a method to position the Sun, the Moon and the planets along the ecliptic. They started with the first sign Aries because that was the start of the year, the Spring Equinox, 30 degrees over Taurus, 60 degrees Gemini and so on. This is how they could observe where Mercury or Venus was located. This is how they were named, because the Babylonians had already named the constellations. They could’ve been named anything, like the Greek alphabet, Aries Alpha, Taurus Beta, but they weren’t because something was already in place, the named constellations.
We have an anomaly in the procession of the equinoxes, and that is the constellations move approximately 1 degree every 72 years, as we see the night sky from Earth. The sky looks different that it did 2000 years ago when Ptolemy wrote Tetrabiblos, the book on astrology. However, this does not affect our seasonal 12-sign system because again, the signs are not based on the constellations. The tropical signs are solar system centered. The constellations and the stars are NOT in our solar system. The equinoxes and the solstices will still happen at the same time they have every year. The signs cannot shift because they are based on the seasonal equinoxes and solstices.
In Western tropical astrology, Aries, Cancer, Libra and Capricorn correlate with the start of each season, we call these the Cardinal signs. Aries is the Spring Equinox, Cancer is the Summer Solstice, Libra is the Autumn Equinox and Capricorn is the Winter Solstice. These are important points in a chart because they initiate.
The signs in the middle of the seasons are Taurus, Leo, Scorpio, and Aquarius, they are the fixed signs, because this is the part of the season that is most stable. Then the end of the season is more transitionary, Gemini, Virgo, Sagittarius and Pisces. We call these mutable signs because this is when the season becomes changeable. These are called modalities.
We combine modalities with the elements fire, Aries, Leo and Sagittarius; earth Taurus, Virgo and Capricorn; air Gemini, Libra and Aquarius and water Cancer, Scorpio and Pisces. Cardinal, fire is Aries, fixed earth is Taurus, mutable air is Gemini and so on. [refer to my resources for a handout]. This helps astrology to describe personality and interpret transits.
These elements are necessary for life, think about a tree it is planted in the earth to draw the nutrients from the soil. It uses carbon dioxide from the air to convert it to oxygen. It requires water and sunlight (fire) to convert light energy into chemical energy. This in turn sustains us, the oxygen we breathe, the fruit from the tree that we eat. This is another cycle. Nature is cycles and the signs in astrology mirror these cycles.
Even though this tropical system was created from a Northern hemisphere perspective it still works in the Southern hemispheres because the cardinal points are still cardinal points, they still initiate a season. There isn’t a winter in Hawaii, the weather is different all over the world, it doesn’t change the fact we are still on planet Earth, and all the planets are cycling through sectors in the sky.
There you have it, we have 12 signs, because 12 is a number of divine balance and elegance that has been recognized in cultures and faiths all over the world. It aligns perfectly with how we measure time and seasons here on planet Earth.
