The Zodiac is divided into three groups or modes of four Signs each, referred to as Quadruplicities.

Cardinal Mode: Aries, Cancer, Libra, Capricorn - leaders, determined, magnetic, manipulative, creative, selfish, demanding, charming

Fixed Mode: Taurus, Leo, Scorpio, Aquarius - stubborn, focused, uncompromising, tenacious, inflexible, slow and steady, controlled

Mutable Mode: Gemini, Virgo, Sagittarius, Pisces - flexible, volatile, complex, tolerant, open-minded, indecisive, social, impatient