Astrology

Hand-coloured version of the anonymous Flammarion woodcut (1888).

Astrology (from Greek: αστήρ, αστρός (astér, astrós), "star", and λόγος, λόγου (lógos, lógou), "word" or "speech") is a group of systems, traditions, and beliefs in which knowledge of the relative positions of celestial bodies and related details is held to be useful in understanding, interpreting, and organizing information about personality, human affairs, and other terrestrial matters. A practitioner of astrology is called an astrologer, or, less often, an astrologist. Numerous traditions and applications employing astrological concepts have arisen since its earliest recorded beginnings in the 2nd millennium BCE. It has played a role in the shaping of culture, early astronomy, and other disciplines throughout history.

Historically, astrology and astronomy were often indistinguishable, because the desire for predictive and divinatory knowledge were the primary motivating factors in both disciplines. Astronomy began to diverge from astrology after a long period of gradual separation in the 18th century, and has since distinguished itself as the scientific study of astronomical objects and phenomena without any concern for their supposed astrological correlation.

Astrology is variously considered by its proponents to be a symbolic language, a form of art, science, or divination. The scientific community generally considers astrology to be a pseudoscience or superstition as numerous Western astrologers have failed empirical tests in controlled studies. Despite the lack of scientific evidence, belief in astrology remains widespread.

Core beliefs

Astrological glyphs for some of the planets of astrology, including the Sun, the Earth, the Moon, and Pluto.

The core beliefs of astrology were prevalent in most of the ancient world and are epitomized in the Hermetic maxim "as above, so below". Tycho Brahe used a similar phrase to justify his studies in astrology: suspiciendo despicio, "by looking up I see downward". Although the principle that events in the heavens are mirrored by those on Earth was once generally held in most traditions of astrology around the world, in the West there has historically been a debate among astrologers over the nature of the mechanism behind astrology. The debate also covers whether or not celestial bodies are only signs or portents of events, or if they are actual causes of events through some sort of force or mechanism.

Although the connection between celestial mechanics and terrestrial dynamics was explored first by Isaac Newton with his development of a universal theory of gravitation, claims that the gravitational effects of the celestial bodies are what accounts for astrological generalizations are not substantiated by scientific research, nor are they advocated by most astrologers.

A common belief held by astrologers is that the positions of certain celestial bodies either influence or correlate with human affairs. A modern explanation is that the cosmos (and especially the solar system) acts as a single unit, so that any happening in any part of it inevitably is reflected in every other part, somewhat representing chaos theory. Skeptics dispute these claims, pointing to a lack of concrete evidence of significant influence of this sort.

Most astrological traditions are based on the relative positions and movements of various real or construed celestial bodies and on the construction of celestial patterns as seen at the time and place of the event being studied. These are chiefly the Sun, Moon, the planets, the stars and the lunar nodes. The frame of reference for such apparent positions is defined by the tropical or sidereal zodiacal signs on one hand, and by the local horizon (ascendant) and midheaven on the other. This latter (local) frame is typically further divided into the twelve astrological houses. Furthermore, the astrological aspects are used to determine the geometric/angular relationship(s) between the various celestial bodies and angles in the horoscope.

The claim of astrology to predict future trends and developments, or predictive astrology, is based on two main methods: astrological transits and astrological progressions. In astrological transits the ongoing movements of the planets are interpreted for their significance as they transit through space and the horoscope. In astrological progressions the horoscope is progressed forward in time according to set methods. Most modern astrologers no longer try to forecast actual events, but focus instead on general trends and developments. Skeptics respond that this allows astrologers to avoid making verifiable predictions, and gives them the ability to attach significance to arbitrary and unrelated events, in a way that suits their purpose.

In the past, astrologers often relied on close observation of celestial objects and the charting of their movements. Modern astrologers use data provided by astronomers which are transformed to a set of astrological tables called ephemerides, showing the changing zodiacal positions of the heavenly bodies through time.

Traditions

Zodiac signs, 16th century European woodcut

There are many traditions of astrology, some of which share similar features due to the transmission of astrological doctrines between cultures. Other traditions developed in isolation and hold completely different doctrines, although they too share some similar features due to the fact that they are drawing on similar astronomical sources.

Current traditions

The main traditions used by modern astrologers are:

• Indian astrology
• Western astrology
• Chinese astrology

Indian and Western astrology share a common ancestry as horoscopic systems of astrology and are essentially similar in content. Both traditions focus on the casting of an astrological chart or horoscope, a representation of celestial entities, for an event based on the position of the Sun, Moon, and planets at the moment of the event. The main difference between the two traditions is that Indian astrology uses the sidereal zodiac, linking the signs of the zodiac to their original constellations, while Western astrology uses the tropical zodiac (see section below). Because of the phenomenon of the precession of the equinoxes, over the centuries the twelve zodiacal signs in Western astrology no longer correspond to the same part of the sky as their original constellations. In effect, in Western astrology the link between sign and constellation has been broken, whereas in Indian astrology it remains of paramount importance.

In Chinese astrology a quite different tradition has evolved. By contrast to Western and Indian astrology, the twelve signs of the zodiac do not divide the sky, but rather the celestial equator. The Chinese evolved a system where each sign corresponds to one of twelve 'double-hours' that govern the day, and to one of the twelve months. Also most notably and uniquely, each sign of the zodiac governs a different year, and combines with a system based on the five elements of Chinese cosmology to give a 60 (12 x 5) year cycle. The term Chinese astrology is used here for convenience, but it must be recognised that versions of the same tradition exist in Japan, Vietnam, Thailand and other Asian countries.

In modern times, these traditions have come into greater contact with each other, notably with Indian and Chinese astrology having spread to the West, while awareness of Western astrology is still fairly limited in Asia. Astrology in the Western world has diversified greatly in modern times. New movements have appeared, which have jettisoned much of traditional astrology to concentrate on different approaches, such as a greater emphasis on midpoints, or a more psychological approach. Some of its subsets include:

• Modern tropical and sidereal horoscopic astrology
• Cosmobiology
• Psychological astrology
• Sun sign astrology
• Hamburg School of Astrology
  • Uranian astrology, subset of the Hamburg School

Historical traditions

Main article: History of astrology

Throughout its long history, astrology has come to prominence in many regions and undergone developments and change. There are many astrological traditions that are historically important, but which have largely fallen out of use today. Astrologers still retain an interest in them and regard them as an important resource. Historically significant traditions of astrology include:

• Arab and Persian astrology (Medieval, near Eastern)
• Babylonian astrology (Ancient, near East)
• Egyptian astrology
• Hellenistic astrology (Classical antiquity)

The Mesoamerican traditions are included here because although they have not been widely used in their full form since pre-Columbian times, there is evidence that they have survived in some form as a living tradition up to the present day, particularly among the Maya. Aztec and Maya astrology recall the Chinese system, but use a more complex calendar scheme. These systems offer additional evidence concerning the original migration of native peoples from Asia to America. The history of Western, Chinese, and Indian astrology is discussed in the main article history of astrology.

Esoteric traditions

Extract and symbol key from 17th century alchemy text.

Further information: Renaissance magic

Many mystic or esoteric traditions have links to astrology. In some cases, like Kabbalah, this involves participants incorporating elements of astrology into their own traditions. In other cases, like divinatory tarot, many astrologers themselves have incorporated the tradition into their own practice of astrology. Esoteric traditions include, but are not limited to:

• Alchemy
• Chiromancy
• Kabbalah
• Medicine
• Numerology
• Rosicrucian or "Rose Cross"
• Tarot divination

Historically, alchemy in the Western World was particularly allied and intertwined with traditional Babylonian-Greek style astrology; in numerous ways they were built to complement each other in the search for occult or hidden knowledge. Astrology has used the concept of the four classical elements of alchemy from antiquity up until the present day. Traditionally, each of the seven planets in the solar system known to the ancients was associated with, held dominion over, and "ruled" a certain metal.

The zodiac

Zodiac in a 6th century synagogue at Beit Alpha, Israel.

Main article: zodiac

The zodiac is the belt or band of constellations through which the Sun, Moon, and planets move on their journey across the sky. Astrologers noted these constellations and so attached a particular significance to them. Over time they developed the system of twelve signs of the zodiac, based on twelve of the constellations they considered to be particularly important. The Western and Indian zodiac signs have a common origin in the tradition of horoscopic astrology, and so are very similar in meaning. In China on the other hand, the development of the zodiac was different. Although the Chinese too have a system of twelve signs (named after animals), the Chinese zodiac refers to a pure calendrical cycle, as there are no equivalent constellations linked to it like the Western or Indian zodiacs. The common choice of twelve zodiac signs is understandable when it is considered that the interaction of the Sun and Moon was central to all forms of astrology. Thus, twelve cycles of the Moon — the months — coincided with one solar year, making twelve a natural choice.

The majority of Western astrologers base their work on the tropical zodiac which divides the sky into twelve equal segments of 30 degrees each, beginning with the first point of Aries, the point where the line of the earth's celestial equator and the ecliptic (the Sun's path through the sky) meet at the northern hemisphere spring equinox. Due to the precession of the equinoxes, the slow changing of the way Earth rotates in space, the zodiacal signs in this system bear no relation to the constellations of the same name but stay aligned to the months and seasons. Because of its connection to old locations of constellations, the tropical zodiac is used as a historical coordinate system in astronomy.

Practitioners of the Indian astrological tradition and a minority of Western astrologers use the sidereal zodiac. This zodiac uses the same evenly divided ecliptic but approximately stays aligned to the positions of the observable constellations with the same name as the zodiacal signs. The sidereal zodiac differs from from the tropical zodiac by an offset called the ayanamsa which steadily increases as the equinoxes drift further.

Horoscopic astrology

18th century Icelandic manuscript showing astrological houses and glyphs for planets and signs.

Horoscopic astrology is a very specific and complex system that was developed in the Mediterranean region and specifically Hellenistic Egypt around the late 2nd or early 1st century BCE. The tradition deals with two-dimensional diagrams of the heavens, or 'horoscopes', created for specific moments in time. The diagram is then used to interpret the inherent meaning underlying the alignment of celestial bodies at that moment based on a specific set of rules and guidelines. This is normally done for the moment of birth of an individual, or at the beginning of an enterprise or event, because the alignments of the heavens at that moment are thought to determine the nature of the subject in question. One of the defining characteristics of this form of astrology that makes it distinct from other traditions is the computation of the degree of the Eastern horizon rising against the backdrop of the ecliptic at the specific moment under examination, otherwise known as the ascendant. Horoscopic astrology has been the most influential and widespread form of astrology across the world, especially in Africa, India, Europe, and the Middle East, and there are several major traditions of horoscopic astrology including Indian, Hellenistic, Medieval, and most other modern Western traditions of astrology.

The horoscope

A computer-generated Western horoscope.

Central to horoscopic astrology and its branches is the calculation of the horoscope or astrological chart. This two-dimensional diagrammatic representation shows the celestial bodies' apparent positions in the heavens from the vantage of a location on Earth at a given time and place. The horoscope is also divided into twelve different celestial houses which govern different areas of life. Calculations performed in casting a horoscope involve arithmetic and simple geometry which serve to locate the apparent position of heavenly bodies on desired dates and times based on astronomical tables. In ancient Hellenistic astrology the ascendant demarcated the first celestial house of a horoscope. The word for the ascendant in Greek was horoskopos from which "horoscope" derives. In modern times, the word has come to refer to the astrological chart as a whole.

Branches of horoscopic astrology

Traditions of horoscopic astrology can be divided into four branches which are directed towards specific subjects or purposes. Often these branches use a unique set of techniques or a different application of the core principles of the system to a different area. Many other subsets and applications of astrology are derived from these four fundamental branches.

• Natal astrology, the study of a person's natal chart to gain information about the individual and his/her life experience.
• Katarchic astrology, which includes both electional and event astrology. The former uses astrology to determine the most auspicious moment to begin an enterprise or undertaking, and the latter to understand everything about an event from the time at which it took place.
• Horary astrology, used to answer a specific question by studying the chart of the moment the question is posed to an astrologer.
• Mundane or world astrology, the application of astrology to world events, including weather, earthquakes, and the rise and fall of empires or religions.

History of astrology

Main article: History of astrology

15th century image from the Très Riches Heures du Duc de Berry showing believed correlations between areas of the body and the zodiacal signs.

Origins

The origins of much of the astrological doctrine and method that would later develop in Asia, Europe, and the Middle East are found among the ancient Babylonians and their system of celestial omens that began to be compiled around the middle of the 2nd millennium BCE. This system of celestial omens later spread either directly or indirectly through the Babylonians to other areas such as India, China, and Greece where it merged with pre-existing indigenous forms of astrology.. This Babylonian astrology came to Greece initially as early as the middle of the 4th century BCE, and then around the late 2nd or early 1st century BCE after the Alexandrian conquests, this Babylonian astrology was mixed with the Egyptian tradition of decanic astrology to create horoscopic astrology. This new form of astrology, which appears to have originated in Alexandrian Egypt, quickly spread across the ancient world into Europe, the Middle East and India.

Before the scientific revolution

From the classical period through the scientific revolution, astrological training played a critical role in advancing astronomical, mathematical, medical and psychological knowledge. Astrological influences included the observation and long-term tracking of celestial objects. It was astrologers who provided the first systematic documentation of the movements of the Sun, the Moon, the planets, and the stars. The differentiation between astronomy and astrology varied from place to place; they were indistinguishable in ancient Babylonia and for most of the Middle Ages, but separated to a greater degree in ancient Greece (see astrology and astronomy). Astrology was not always uncritically accepted before the modern era; it was often challenged by Hellenistic skeptics, church authorities, and medieval thinkers.

The pattern of astronomical knowledge gained from astrological endeavours has been historically repeated across numerous cultures, from ancient India through the classical Maya civilization to medieval Europe. Given this historical contribution, astrology has been called a protoscience along with pseudosciences such as alchemy (see "Western astrology and alchemy" below).

Many prominent scientists, such as Nicholas Copernicus, Galileo Galilei, Tycho Brahe, Johannes Kepler, Carl Jung and others, practiced or significantly contributed to astrology.

Effects on world culture

Main article: Cultural influence of astrology

Astrology has had a profound influence over the past few thousand years on Western and Eastern cultures. In the middle ages, when even the educated of the time believed in astrology, the system of heavenly spheres and bodies was believed to reflect on the system of knowledge and the world itself below.

Astrology has had an influence on both language and literature. For example, influenza, from medieval Latin influentia meaning influence, was so named because doctors once believed epidemics to be caused by unfavorable planetary and stellar influences. The word "disaster" comes from the Latin dis-aster meaning "bad star". Adjectives "lunatic" (Luna/Moon), "mercurial" (Mercury), "venereal" (Venus), "martial" (Mars), "jovial" (Jupiter/Jove), and "saturnine" (Saturn) are all old words used to describe personal qualities said to resemble or be highly influenced by the astrological characteristics of the planet, some of which are derived from the attributes of the ancient Roman gods they are named after. In literature, many writers, notably Geoffrey Chaucer and William Shakespeare, used astrological symbolism to add subtlety and nuance to the description of their characters' motivation(s). Often, an understanding of astrological symbolism is needed to fully appreciate such literature.

Some modern thinkers, notably Carl Jung, believe in astrology's descriptive powers regarding the mind without necessarily subscribing to its predictive claims. In education astrology is reflected in the university education of medieval Europe, which was divided into seven distinct areas, each represented by a particular planet and known as the seven liberal arts. Dante Alighieri speculated that these arts, which grew into the sciences we know today, fitted the same structure as the planets. In music the best known example of astrology's influence is in the orchestral suite called "The Planets" by the British composer Gustav Holst, the framework of which is based upon the astrological symbolism of the planets.

Astrology and science

The Ptolemaic system depicted by Andreas Cellarius, 1660/61

By the time of Francis Bacon and the scientific revolution, newly emerging scientific disciplines acquired a method of systematic empirical induction validated by experimental observations, which led to the scientific revolution. At this point, astrology and astronomy began to diverge; astronomy became one of the central sciences while astrology was increasingly viewed as an occult science or superstition by natural scientists. This separation accelerated through the eighteenth and nineteenth centuries.

Astrology has been criticized as being unscientific both by scientific bodies and by individual scientists. and has been labeled as a pseudoscience. In 1975, the American Humanist Association published one of the most widely known modern criticisms of astrology, characterizing those who continue to have faith in the subject as doing so "in spite of the fact that there is no verified scientific basis for their beliefs, and indeed that there is strong evidence to the contrary". Astronomer Carl Sagan did not sign the statement, noting that, while he felt astrology lacked validity, he found the statement's tone authoritarian. He suggested that the lack of a causal mechanism for astrology was relevant but not in itself convincing.

Although astrology has had no accepted scientific standing for some time, it has been the subject of much research among astrologers since the beginning of the twentieth century. In his landmark study of twentieth-century research into natal astrology, vocal astrology critic Geoffrey Dean noted and documented the burgeoning research activity, primarily within the astrological community.

Claims about obstacles to research

Astrologers have argued that there are significant obstacles in carrying out scientific research into astrology today, including funding, lack of background in science and statistics by astrologers, and insufficient expertise in astrology by research scientists. There are only a handful of journals dealing with scientific research into astrology (i.e. astrological journals directed towards scientific research or scientific journals publishing astrological research). Some astrologers have argued that few practitioners today pursue scientific testing of astrology because they feel that working with clients on a daily basis provides a personal validation for them.

Another argument made by astrologers is that most studies of astrology do not reflect the nature of astrological practice and that existing experimental methods and research tools are not adequate for studying this complex discipline. Some astrology proponents claim that the prevailing attitudes and motives of many opponents of astrology introduce conscious or unconscious bias in the formulation of hypotheses to be tested, the conduct of the tests, and the reporting of results.

Early science, particularly geometry and astronomy/astrology, was connected to the divine for most medieval scholars. The compass in this 13th century manuscript is a symbol of God's act of Creation, as many believed that there was something intrinsically divine or perfect that could be found in circles

Mechanism

An editorial published by the Astronomical Society of the Pacific reports that they can find no evidence for a scientifically defined mechanism by which celestial objects can supposedly influence terrestrial affairs. Though physical mechanisms are still among the proposed theories of astrology, few modern astrologers believe in a direct causal relationship between heavenly bodies and earthly events. Some have posited acausal, purely correlative, relationships between astrological observations and events, such as the theory of synchronicity proposed by Jung. Others have posited a basis in divination. Still others have argued that empirical correlations can stand on their own epistemologically, and do not need the support of any theory or mechanism. To some observers, these non-mechanistic concepts raise serious questions about the feasibility of validating astrology through scientific testing, and some have gone so far as to reject the applicability of the scientific method to astrology almost entirely. Some astrologers, on the other hand, believe that astrology is amenable to the scientific method, given sufficiently sophisticated analytical methods, and they cite pilot studies they claim support this view. Consequently, several astrologers have called for or advocated continuing studies of astrology based on statistical validation.

Research claims and counter-claims

The Mars effect: relative frequency of the diurnal position of Mars in the birth chart of eminent athletes.

Several individuals, most notably French psychologist and statistician Michel Gauquelin, claimed to have found correlations between some planetary positions and certain human traits such as vocations. Gauquelin's most widely known claim is known as the Mars effect, which is said to demonstrate a correlation between the planet Mars occupying certain positions in the sky more often at the birth of eminent sports champions than at the birth of ordinary people. Since its original publication in 1955, the Mars effect has been the subject of studies claiming to refute it, and studies claiming to support and/or expand the original claims, but neither the claims nor the counterclaims have received mainstream scientific notice.

The scientific community, where it has commented, claims that astrology has repeatedly failed to demonstrate its effectiveness in numerous controlled studies. Effect size studies in astrology conclude that the mean accuracy of astrological predictions is no greater than what is expected by chance, and astrology's perceived performance has disappeared on critical inspection. When tested against personality tests, astrologers have shown a consistent lack of agreement with these tests. One such double-blind study in which astrologers attempted to match birth charts with results of a personality test, which was published in the reputable peer-reviewed scientific journal Nature, concluded that astrologers' could not solve clients' personal problems by reading individuals' natal charts and that astrologers had no special ability to interpret personality from astrological readings. Another study that used a personality test and a questionnaire contended that some astrologers failed to predict objective facts about people or agree with each other's interpretations. When testing for cognitive, behavioral, physical and other variables, one study of astrological "time twins" showed that human characteristics are not molded by the influence of the Sun, Moon and planets at the time of birth. Skeptics of astrology also suggest that the perceived accuracy of astrological interpretations and descriptions of one's personality can be accounted for by the fact that people tend to exaggerate positive 'hits' and overlook whatever does not fit, especially when vague language is used. They also argue that statistical research is often wrongly seen as evidence for astrology due to uncontrolled artifacts.

See also

• Astrologers (list of)
• List of astrological traditions
• List of astrological types

• Astrology and astronomy
• Astrology and computers
• Astrological aspects
• Astrological houses
• Astrological sign
  • Zodiac
• Astrological symbols
• Proposed theories of astrology

Further reading

• Tamsyn Barton, Ancient Astrology. Routledge (USA, 1994) ISBN 0415110297.

• David Berlinski, The Secrets of the Vaulted Sky: Astrology and the Art of Prediction. Harcourt (USA, October 2003) ISBN 0-15-100527-3.

• Benson Bobrick, The Fated Sky: Astrology in History. Simon & Schuster (New York, 2006) ISBN 0743268954.

• Jean-Louis Brau, et al. Larousse Encyclopedia of Astrology. McGraw-Hill Pub. (USA, 1983) ISBN 0070072442.

• Nicholas Campion, The Great Year: Astrology, Millenarianism, and History in the Western Tradition. Penguin (USA, 1995) ISBN 0140192964.

• Geoffrey Cornelius, Moment of Astrology. Wessex Astrologer Ltd. (UK, August 2005) ISBN 1-902405-11-0.

• V.K. Choudhry, Systems´ Approach for Interpreting Horoscopes, Third Revised Edition, 2002, Sagar Publications, New Delhi, India. ISBN 81-7082-017-0.

• Ibid, How to Identify Significant Events (Through Transits), Revised Edition, 2003, Sagar Publications, New Delhi, India. ISBN 81-7082-030-8.

• V.K. Choudhry and K. Rajesh Chaudhary, How to Analyse Married Life, Revised Edition, 2002, Sagar Publications, New Delhi, India. ISBN 81-7082-022-7.

• Ibid, How to Avert Professional Setbacks, Revised Edition, 2002, Sagar Publications, New Delhi, India. ISBN 81-7082-018-9.
• Nicholas De Vore, Encyclopedia of Astrology. Astrology Classics (New York, 2005) ISBN 1-933303-09-3.

• J. C. Eade, The Forgotten Sky: A Guide to Astrology in English Literature. Oxford University Press (USA, 1984) ISBN 0-19-812813-4.

• Reinhold Ebertin, The Combination of Stellar Influences. American Federation of Astrologers (USA, 1972) ISBN 086690087X.

• Abraham Ibn Ezra, The Beginning of Wisdom. ARHAT Publications (USA, 1998) ISBN 0-9662266-4-X.

• Michel Gauquelin, Cosmic Influences on Human Behavior. Aurora Press (Santa Fe, NM; June 1985) ISBN 0-943358-23-X.

• Michel Gauquelin, The Scientific Basis of Astrology. Stein and Day Publishers (New York, 1970) ISBN 0-8128-1350-2.

• Ann Geneva, Astrology and The Seventeenth Century Mind: William Lilly and the Language of the Stars. Manchester University Press (Manchester, UK; 1995) ISBN 0-7190-4154-6.

• Robert Hand, Horoscope Symbols. Schiffer Publications (Altgen, PA; March 1987) ISBN 0-914918-16-8.

• Michael Hoskin, The Cambridge Concise History of Astronomy. Cambridge University Press (UK, 2003) ISBN 0521576008.

• Johannes Kepler, The Harmony of the World (Latin: Harmonice Mundi, [1619]) American Philosophical Society (USA, April 1997) ISBN 0-87169-209-0.

• Johannes Kepler, On The More Certain Fundamentals of Astrology (1601) (Latin: De Fundamentis Astrologiae Certioribus). Kessinger Publishing (USA, January 2003) ISBN 0-7661-3375-3.

• James R. Lewis, The Astrology Book: The Encyclopedia of Heavenly Influences. Visible Ink Press (USA, 2003) ISBN 1578591449.

• William Lilly, An Introduction to Astrology, [Zadkiel, ed., 1852]. First published in 1647 as Christian Astrology.

• Louis MacNeice, Astrology. Doubleday & Co., Inc. (USA, 1964) ISBN 0385052456.

• William R. Newman & Anthony Grafton (Editors), Secrets of Nature: Astrology and Alchemy in Early Modern Europe. MIT Press (Cambridge, MA; March 2006) ISBN 0-262-64062-7.

• Gunther Oestmann, et al. Horoscopes and Public Spheres: Essays on the History of Astrology. Walter de Gruyter Pub. (DE, 2005) ISBN 3110185458.

• Garry Phillipson, Astrology in the Year Zero. Flare Publications (London, 2000) ISBN 0-9530261-9-1.

• Ptolemy, Tetrabiblos. Harvard University Press (Cambridge, MA; October 1980) ISBN 0-674-99479-5.

• Francesca Rochberg, The Heavenly Writing: Divination, Horoscopy, and Astronomy in Mesopotamian Culture. Cambridge University Press (Cambridge, UK; 2004) ISBN 0-521-83010-9.

• Gunter Sachs, The Astrology File: Scientific Proof of the Link Between Star Signs and Human Behaviour. Orion Books (December 1999). ISBN 0-7528-1789-2

• Laura A. Smoller, History, Prophecy, and the Stars: The Christian Astrology of Pierre D'Ailly, 1350-1420. Princeton University Press (Princeton, NJ; 1994) ISBN 0-691-08788-1.

• Richard Tarnas, Cosmos and Psyche: Intimations of a New World View. Viking (New York, 2006) ISBN 0-670-03292-1.

• Jim Tester, A History of Western Astrology. Ballantine Books (New York, 1989) ISBN 0345358708.

• Harry Ezekiel Wedeck, Dictionary of Astrology: Astrological Concepts, Techniques, and Theories. Carol Pub. Corp. (USA, 1995) ISBN 0806517123.

• Theodore Otto Wedel, Astrology in the Middle Ages. Dover Publications (Mineola, NY; 2005) ISBN 0-486-43642-X.

• Peter Whitfield, Astrology: A History. British Library (UK, 2004) ISBN 0712348395.

• James Wilson, Dictionary of Astrology. Astrology Classics (USA, 2006) ISBN 1933303182.

External links

• Template:Dmoz
• Database with links to 1000+ astrology articles

Astrology and science

• Astrology and Science, a critical look at astrology and science.
• The Astrotest, an account of a test of the predictive power of astrology, with references to other experiments.
• The Real Romance in the Stars, a critical view of astrology by Richard Dawkins.

Astrology and religion

• Astrology in the Old and New Testament by J. J. Dewey.
• Astrology: Between Religion and the Empirical, a treatise on astrology by Dr. Gustav-Adolf Schoener, translated by Shane Denson.
• Medieval Astrology - a learning resource from the British Library