Besides the ruler and the element, “orientation” is the third factor granting unique character to each zodiac sign. Orientation is about the way the sign inspires movement and progress. There are three: cardinal, fixed, and dual.
Signs with cardinal orientation inspire us to move in new directions. Those with fixed orientation inspire us to remain dedicated to our current path. Those with dual orientation try to maintain our current directions without missing out on new possibilities. So, cardinal signs have an element of adventure, while fixed signs indicate loyalty and dual signs have a balanced or non-committal approach to things.
The sun’s movement determines the orientation of a sign.
Aries, Cancer, Libra, and Capricorn are the four cardinal signs because each one begins from a crucial waypoint on the sun’s yearly journey, a point at which the sun begins moving in a new direction. Aries begins from the vernal equinox, at which point the Sun begins moving into the northern hemisphere. Cancer begins from the summer solstice, when the sun reaches its most northern point and begins a new journey southward. Libra begins from the autumnal equinox, where the sun begins moving into the southern hemisphere. Capricorn begins from the winter solstice, where the sun has reached its most southern point and begins a new journey northward.
This is why the cardinal signs represent ambition – moving in new directions, towards new goals.
Taurus, Leo, Scorpio, and Aquarius are the four fixed signs because in each one the sun remains fixed and loyal to its current direction. Taurus comes after Aries. In it the sun remains steady on its movement into the northern hemisphere. Leo comes after Cancer. In Leo the sun remains steady on its southward journey. Scorpio comes after Libra. In it the sun remains fixed in its progress through the southern hemisphere. Aquarius comes after Capricorn. In Aquarius the sun stays loyal to its northern course.
This is why the fixed signs represent loyalty to the path one has committed to.
Gemini, Virgo, Sagittarius, and Pisces are the four dual signs. Gemini comes before Cancer. While in this zone, the sun continues its progress into the northern hemisphere, but slows down greatly, preparing to make a new journey southward. Virgo comes before Libra. Here the sun continues its southward progress, yet also makes ready to cross into a new hemisphere. Sagittarius comes before Capricorn; in it the sun continues its progress into the southern hemisphere, but slows down markedly, preparing to make a new journey northward. Pisces comes before Aries; here the sun continues its northward movement, but makes ready to cross into a new hemisphere.
This is why the dual signs indicate balance, and equal commitment to both sides of any story.
Vic DiCara's Astrology 