History ) and First Point of Libra (). The
great circle containing the celestial poles and the ecliptic poles (P and P), intersect the ecliptic at 0° Cancer () and 0° Capricorn (). In this illustration, the Sun is schematically positioned at the start of Aquarius ().
Western astrology is a direct continuation of
Hellenistic astrology as recorded in Ptolemy's
Tetrabiblos in the 2nd century. Hellenistic astrology in turn was partly based on concepts from
Babylonian tradition. Specifically, the division of the ecliptic in twelve equal sectors is a Babylonian conceptual construction. This division of the ecliptic originated in the Babylonian "ideal calendar" found in the old compendium
MUL.APIN and its combination with the Babylonian
lunar calendar, represented as the "path of the moon" in MUL.APIN. In a way, the zodiac is the idealisation of an ideal lunar calendar. By the 4th century BC, Babylonian astronomy and its system of celestial omens influenced the culture of
ancient Greece, as did the astronomy of Egypt by late 2nd century BC. This resulted, unlike the Mesopotamian tradition, in a strong focus on the birth chart of the individual and the creation of
Horoscopic astrology, employing the use of the
Ascendant (the rising degree of the ecliptic, at the time of birth), and of the twelve
houses. Association of the astrological signs with
Empedocles' four classical
elements was another important development in the characterization of the twelve signs. The body of the Hellenistic astrological tradition as it stood by the 2nd century is described in
Ptolemy's
Tetrabiblos. This is the seminal work for later astronomical tradition not only in the West but also in India and the Islamic sphere and has remained a reference for almost seventeen centuries as later traditions made few substantial changes to its core teachings.
Western astrological correspondence chart The following table shows the approximate dates of the twelve astrological signs, along with the classical and modern rulerships of each sign. By definition,
Aries starts at the
First Point of Aries which is the location of the Sun at the
March equinox. The precise date of the Equinox varies from year to year but is always between 19 March and 21 March. The consequence is the start date of Aries and therefore the start date of all the other signs can change slightly from year to year. The following Western astrology table enumerates the twelve divisions of celestial longitude with the Latin names. The longitude
intervals, are treated as closed for the first endpoint (
a) and open for the second (
b) – for instance, 30° of longitude is the first point of Taurus, not part of Aries. The signs are occasionally numbered 0 through 11 in place of symbols in astronomical works. The twelve signs are positioned in a circular pattern, creating a pattern of oppositions related to different philosophically polarized attributes. Fire and air elements are generally 180 degrees opposed in Western astrology, as well as earth and water elements. Not all systems of astrology have four elements, notably the
Sepher Yetzirah describes only three elements emanating from a central divine source. Spring signs are opposite to autumn ones, winter signs are opposite to summer ones and vice versa. • Aries is opposite to Libra • Taurus is opposite to Scorpio • Gemini is opposite to Sagittarius • Cancer is opposite to Capricorn • Leo is opposite to Aquarius • Virgo is opposite to Pisces
Polarity In
Western astrology, the polarity divides the zodiac in half and refers to the alignment of a sign's
energy as either positive or negative, with various attributes associated to them as a result.
Positive polarity signs, also called active, yang, expressive, or masculine signs, are the six odd-numbered signs of the zodiac:
Aries,
Gemini,
Leo,
Libra,
Sagittarius, and
Aquarius. Positive signs make up the fire and air triplicities.
Negative polarity signs, also called passive, yin, receptive, or feminine signs, Each modality comprehends four signs, also known as Quadruplicities.
Triplicities of the four elements next to its longitude within the sign. Additional symbols may be added to represent
apparent retrograde motion (), or apparent stationary moment (shift from retrograde to direct, or vice versa: S). The Greek philosopher
Empedocles identified fire, earth, air, and water as
elements in the fifth-century BC. He explained the nature of the universe as an interaction of two opposing principles, love and strife, which manipulate the elements into different mixtures that produce the different natures of things. He stated all the elements are equal, the same age, rule their own provinces, and possess their own individual character. Empedocles said that those born with nearly equal proportions of the elements are more intelligent and have the most exact perceptions. The elemental categories are called triplicities because each
classical element is associated with three signs The four astrological elements are also considered as a direct equivalent to
Hippocrates' personality types (sanguine = air; choleric = fire; melancholic = earth; phlegmatic = water). A modern approach looks at elements as "the energy substance of experience" and the next table tries to summarize their description through keywords. The elements have grown in importance and some astrologers begin
natal chart interpretations by studying the balance of elements in the location of
planets (especially the Sun and Moon) and the position of
angles in the chart.
Celestial body rulerships '' table illustration Rulership is the connection between
planet and correlated sign and
house. The conventional rulerships are as follows: •
Aries:
Mars •
Taurus:
Venus •
Gemini:
Mercury •
Cancer:
Moon •
Leo:
Sun •
Virgo: classically
Mercury,
Ceres in the late 20th century •
Libra: classically
Venus,
Eris starting in the 21st century •
Scorpio: classically
Mars,
Pluto starting in the 20th century •
Sagittarius:
Jupiter •
Capricorn:
Saturn •
Aquarius: classically
Saturn,
Uranus starting in the 20th century •
Pisces: classically
Jupiter,
Neptune starting in the 20th century
Dignity, detriment, exaltation and fall traditional A traditional belief of astrology, known as
essential dignity, is the idea that the Sun, Moon, and planets are more powerful and effective in some signs than others because the basic nature of both is held to be in harmony. By contrast, they are held to find some signs to be weak or difficult to operate in because their natures are thought to be in conflict. These categories are Dignity, Detriment, Exaltation, and Fall. •
Dignity and
Detriment: A
planet is strengthened or
dignified if it falls within the sign that it rules. In other words, it is said to exercise
Rulership of the sign. For example, the Moon in Cancer is considered "strong" (well-dignified). If a planet is in the sign opposite which it rules (or is dignified in), it is said to be weakened or in
Detriment (for example, the Moon in Capricorn). This may also be termed a "debility". In traditional astrology, other levels of Dignity are recognised in addition to Rulership. These are known as Exaltation,
Triplicity,
Terms or bounds, and Face or
Decan, which together are known as describing a planet's
Essential dignity, the quality or ability of one's true nature. In addition to essential dignity, the traditional astrologer considers
Accidental dignity of planets. This is placement by
house in the chart under examination. Accidental dignity is the planet's "ability to act". So we might have, for example, Moon in Cancer, dignified by rulership, is placed in the 12th house it would have little scope to express its good nature. The twelfth is a cadent house as are the third, sixth and ninth and planets in these houses are considered weak or afflicted. On the other hand, Moon in the first, fourth, seventh, or 10th would be more able to act as these are Angular houses. Planets in Succedent houses of the chart (second, fifth, eighth, eleventh) are generally considered to be of medium ability to act. Besides Accidental Dignity, there are a range of
Accidental Debilities, such as retrogradation, Under the Sun's Beams, Combust, and so forth.
Additional classifications Each sign can be divided into three 10° sectors known as decans or decanates, though these have fallen into disuse. The first decanate is said to be most emphatically of its own nature and is ruled by the sign ruler. The next decanate is sub-ruled by the planet ruling the next sign in the same triplicity. The last decanate is sub-ruled by the next in order in the same triplicity. While the element and modality of a sign are together sufficient to define it, they can be grouped to indicate their symbolism. The first four signs, Aries, Taurus, Gemini, and Cancer, form the group of personal signs. The next four signs, Leo, Virgo, Libra, and Scorpio form the group of interpersonal signs. The last four signs of the zodiac, Sagittarius, Capricorn, Aquarius, and Pisces, form the group of transpersonal signs. Dane Rudhyar presented the tropical zodiac primary factors, used in the curriculum of the RASA School of Astrology. The tropical zodiac is the zodiac of seasonal factors as opposed to the sidereal zodiac (constellation factors). The primary seasonal factors are based on the changing ratio of sunlight and darkness across the year. The first factor is whether the chosen time falls in the half of the year when daylight is increasing, or the half of the year when darkness is increasing. The second factor is whether the chosen time falls in the half of the year when there is more daylight than darkness, or the half when there is more darkness than daylight. The third factor is which of the four seasons the chosen time falls in, defined by the first two factors. Thus • The
spring season is when daylight is increasing and there is more daylight than darkness. • The
summer season is when darkness is increasing and there is more daylight than darkness. • The
autumn season is when darkness is increasing and there is more darkness than daylight. • The
winter season is when daylight is increasing and there is more darkness than daylight.
Western sign gallery File:Aries Astrological Sign at the Wisconsin State Capitol.jpg|Aries at the Wisconsin State Capitol File:Taurus Astrological Sign at the Wisconsin State Capitol.jpg|Taurus at the Wisconsin State Capitol File:Gemini Astrological Sign at the Wisconsin State Capitol.jpg|Gemini at the Wisconsin State Capitol File:Cancer Astrological Sign at the Wisconsin State Capitol.jpg|Cancer at the Wisconsin State Capitol File:Leo Astrological Sign at the Wisconsin State Capitol.jpg|Leo at the Wisconsin State Capitol File:Virgo Astrological Sign at the Wisconsin State Capitol.jpg|Virgo at the Wisconsin State Capitol File:Libra Astrological Sign at the Wisconsin State Capitol.jpg|Libra at the Wisconsin State Capitol File:Scorpio Astrological Sign at the Wisconsin State Capitol.jpg|Scorpio at the Wisconsin State Capitol File:Sagittarius Astrological Sign at the Wisconsin State Capitol.jpg|Sagittarius at the Wisconsin State Capitol File:Capricornus Astrological Sign at the Wisconsin State Capitol.jpg|Capricornus at the Wisconsin State Capitol File:Aquarius Astrological Sign at the Wisconsin State Capitol.jpg|Aquarius at the Wisconsin State Capitol File:Pisces Astrological Sign at the Wisconsin State Capitol.jpg|Pisces at the Wisconsin State Capitol == Indian astrology ==