Modern astrologers are fascinated by astrological methods which allow us to sort out our similarities and differences by sign and house. We consider planets, aspects and sign divisions in myriad combinations, always searching for some new clue to our individuality. The ancient astrologers were no different and some of them have passed down patterns which are as new as this article and as old as time.
Marcus Manilius was a Roman astrologer, born about the time of Christ. He based his poetic astrological work on foundations of Greek thought, for the most part, producing ASTRONOMICA. Manilius considers all aspects of chart erection and delineation. He demonstrates his thorough knowledge of astronomy and astrology throughout his discussion. He states that the earth is a sphere and he uses two arguments to support this idea: the behavior of the constellations and the path and progress of the Moon's shadow on the earth during solar eclipses.
Manilius allots the decanates (or decans - ten degree divisions of the zodiac) to the signs of the zodiac. He assigns the first decanate of the zodiac to Aries. The next ten degrees go to Taurus then to Gemini. The sign of Taurus gets decanate rulership from the signs Cancer, Leo and Virgo. This pattern continues until the last decanate of Pisces finds Pisces for its ruler.
Manilius' system of decanates depends on a simple elegance in approach. Using this method of assigning decanate rulership, we discover that every fire sign begins with Aries as the ruler of the first decan. The appropriateness of this rulership is evident. Mars, ruler of Aries, is a planet of energy and this fits well with the fiery creativity we find in any fire sign.
The earth signs all begin with Cancer as the ruler of the first decanate. At first this connection may puzzle the reader, but when the need for water and nurturing is considered, Cancer rulership of earth decanates makes a lot of sense. Air signs follow the pattern of having Libra as common ruler of the first decanate and the intellectual thrust is maintained. Capricorn is found to begin each water sign, adding a crystalline quality to these first degrees of water signs. Water flows through the earth and thus earth can provide a structure for water.
Further examination of the pattern reveals that the cardinal and mutable signs all contain a ruler which is conjunct or opposite to the sign itself, while the fixed signs contain a decanate ruler which is square aspect to the sign ruler. The fixed signs of the zodiac are those which provide the most rigid structure and most stable condition. The square aspect is one which provides the most rigid tests and obstacles for us to overcome. Here again, the sense of the pattern is borne out.
In Manilius' decanate system each sign has a cardinal sign ruling the first decanate, then one which is fixed, and then mutable. Each sign has one decanate ruler which is of its own element. The first ten degrees of each sign are ruled by a compatible sign, offering opportunity for the best in that sign to be expressed
The reader is invited to do some personal experimentation with this system of decanate rulership. The system offers a fresh view of an already proven astrological tool.