Zodiac signs

Well in first place we will have distinguish between zodiac signs according to Astrology and Astronomy, in this way, Astrology considered twelve shapes and the signs are geometric sections of equal size, each spanning thirty degrees and corresponds to a period of approximately one month, Astronomy, by another side, talk about fourteen figures and in contradiction to geometric sections of Astrology, the constellations of Astronomy have more irregular shapes, having no correspondence between the two.


As we were saying, there is a difference about the Zodiac signs between Astronomy and Astrology, but twelve of these shapes are the same in bought sciences. 


Is important to add, that the zodiac signs are classified by the elements and by qualities.

Classifications:

	Cardinals	Fixed	Mutable
Fire	ARIES	LEO	SAGITTARIUS
Earth	CAPRICORN	TAURUS	VIRGO
Air	LIBRA	AQUARIUS	GEMINI
Water	CANCER	SCORPIO	PISCES

The Elements:

An ancient Greek philosopher Empedocles, identified Fire, Earth, Air, and Water as elements. He explained the nature of the universe as an interaction of two opposing principles called love and strife manipulating the four elements. He stated that these four elements were all equal, of the same age, that each rules its own province, and each possesses its own individual character. Different mixtures of these elements produced the different natures of things.

Each sign is associated one of the classical elements (water, fire, earth and air.)  Fire and Air signs are considered positive or extrovert, masculine signs; while Water and Earth signs are considered negative, introvert, feminine signs.

The three qualities:

Cardinal signs: in astrology, a cardinal sign (also called by older astrologers a moveable sign) is a sign of the zodiac that initiates a change of temperate zone season when the Sun makes its annual passage into them. They were called moveable by traditional astrologers because, the "air" changes when the Sun enters each of these signs, bringing a change of season.

Fixed Signs: are associated with stabilization, determination, depth and persistence. They are powerful and willfull in all they do, often achieving much more than the other two qualities. On the other hand, they are also inflexible, rigid, stubborn, opinionated and single-minded. These traits are often paired with the need to be considered "right": they will ruthlessly fight on behalf of their beliefs, regardless of any contrary beliefs. Only during moments of importance or necessity would they consider changing an opinion.

Mutable Signs: Medieval Italian Guido Bonatti wrote his Liber Astronomiae, in the final years of the thirteenth century, the definition remained the same and his is more verbose:

"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."