In astrology, mutable signs are associated with adaptability, extroversion, an analytical but sympathetic mindset and versatility. These signs mediate change and change their modes of expression frequently in order to meet this end, and they are often described as being diplomatic and assisting others through transitions; however, mutable signs may demonstrate duplicity, inconsistency, hypocrisy and the inability to take sides in controversies as required.
Mutable signs often signify the ends of seasons.
The four mutable signs of the Zodiac are:
- Gemini () marks the end of spring in the northern hemisphere, and of autumn in the southern hemisphere.
- Virgo () marks the end of summer in the northern hemisphere, and of winter in the southern hemisphere.
- Sagittarius (), which marks the end of autumn in the northern hemisphere, and of spring in the southern hemisphere.
- Pisces (), which marks the end of winter in the northern hemisphere, and of summer in the southern hemisphere.
In a Byzantine scholium to an introductory text on Ancient Roman astrology, Paulus Alexandrinus wrote that "A double-bodied zoidion [sign] is said to be between two seasons, such as Gemini between spring and summer, ending the spring and beginning the summer [...] That is to say, double-bodied as being between the two bodies of spring and summer."
Guido Bonatti gave a similar definition in his Liber Astronomiae:
"The moveable (cardinal) signs are so-called [...] because at the time when the Sun enters them the disposition of the air is changed [...] The common signs are so-called because when the Sun enters any of these signs it makes the time common, neither truly fixed nor truly movable, but it partakes of both, fixed and moveable. Whence part of that time it is of one [nature] and part of the other [...] when [the Sun] leaves Leo and enters Virgo, then the season is changed, and is made partly summer and partly autumnal."
- Paulus Alexandrinus. "Introductory Matters."" Text as translated by Dorian Gieseler Greenbaum in Late Classical Astrology: Paulus Alexandrinus and Olympiodorus. ARHAT Publications (Archive for Retrieval of Historical Astrological Texts) (Reston, VA; 2001.) P. 5.
- Guido Bonatti. Liber Astronomiae. [translated by Robert Zoller] Project Hindsight. The Golden Hind Press. (Berkeley Springs, WV, 1994.) Second tractate, Chapter XI. (Vol. 2, p. 2.)