Beholding Signs

Those which have the same declination; i.e., at equal distances from the Tropics; as Aries and Virgo, Taurus and Leo, Gemini and Cancer, Libra and Pisces, Scorpio and 
Aquarius, Sagittarius and Capricorn. Because such pairs of Signs were either both Northern, or  both Southern, they were by Ptolemy deemed to be “of equal power.” This consideration,  however, applied only when two such Signs were joined by a body in each, mutually 
configurated.

DeVore, Nicholas. Encyclopedia of Astrology. New York: Philosophical Library, 1947.