Astrology and astronomy were archaically treated together ( la, astrologia), but gradually distinguished through the

Late Middle Ages The Late Middle Ages or Late Medieval Period was the period of European history lasting from AD 1300 to 1500. The Late Middle Ages followed the High Middle Ages and preceded the onset of the early modern period (and in much of Europe, the Ren ...

into the

Age of Reason The Age of reason, or the Enlightenment, was an intellectual and philosophical movement that dominated the world of ideas in Europe during the 17th to 19th centuries. Age of reason or Age of Reason may also refer to: * Age of reason (canon law), ...

. Developments in

17th century philosophy This is a timeline of philosophy in the 17th century (17th-century philosophy). Events * 1649 – Christina, Queen of Sweden (reigned 1633–1654) invited René Descartes to educate her in his philosophical views, particularly his insight in ...

resulted in

astrology Astrology is a range of divinatory practices, recognized as pseudoscientific since the 18th century, that claim to discern information about human affairs and terrestrial events by studying the apparent positions of celestial objects. Di ...

and

astronomy Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, g ...

operating as independent pursuits by the 18th century. Whereas the

academic discipline An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of secondary education, secondary or tertiary education, tertiary higher education, higher learning (and generally also research or honorary membershi ...

of astronomy studies observable

phenomena A phenomenon ( : phenomena) is an observable event. The term came into its modern philosophical usage through Immanuel Kant, who contrasted it with the noumenon, which ''cannot'' be directly observed. Kant was heavily influenced by Gottfried ...

beyond the Earth's atmosphere, the

pseudoscience Pseudoscience consists of statements, beliefs, or practices that claim to be both scientific and factual but are incompatible with the scientific method. Pseudoscience is often characterized by contradictory, exaggerated or unfalsifiable claim ...

of astrology uses the apparent positions of celestial objects as the basis for

divination Divination (from Latin ''divinare'', 'to foresee, to foretell, to predict, to prophesy') is the attempt to gain insight into a question or situation by way of an occultic, standardized process or ritual. Used in various forms throughout history ...

Overview

In pre-modern times, most cultures did not make a clear distinction between the two disciplines, putting them both together as one. In ancient

Babylonia Babylonia (; Akkadian: , ''māt Akkadī'') was an ancient Akkadian-speaking state and cultural area based in the city of Babylon in central-southern Mesopotamia (present-day Iraq and parts of Syria). It emerged as an Amorite-ruled state c ...

, famed for its astrology, there were not separate roles for the

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either ...

as predictor of celestial phenomena, and the

astrologer Astrology is a range of divinatory practices, recognized as pseudoscientific since the 18th century, that claim to discern information about human affairs and terrestrial events by studying the apparent positions of celestial objects. Di ...

as their interpreter; both functions were performed by the same person. This overlap does not mean that astrology and astronomy were always regarded as one and the same. In

ancient Greece Ancient Greece ( el, Ἑλλάς, Hellás) was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity ( AD 600), that comprised a loose collection of cu ...

, pre-Socratic thinkers such as

Anaximander Anaximander (; grc-gre, Ἀναξίμανδρος ''Anaximandros''; ) was a pre-Socratic Greek philosopher who lived in Miletus,"Anaximander" in ''Chambers's Encyclopædia''. London: George Newnes, 1961, Vol. 1, p. 403. a city of Ionia (in mo ...

Xenophanes Xenophanes of Colophon (; grc, Ξενοφάνης ὁ Κολοφώνιος ; c. 570 – c. 478 BC) was a Greek philosopher, theologian, poet, and critic of Homer from Ionia who travelled throughout the Greek-speaking world in early Classica ...

, Anaximenes, and Heraclides speculated about the nature and substance of the stars and planets. Astronomers such as Eudoxus (contemporary with

Plato Plato ( ; grc-gre, Πλάτων ; 428/427 or 424/423 – 348/347 BC) was a Greek philosopher born in Athens during the Classical period in Ancient Greece. He founded the Platonist school of thought and the Academy, the first institution ...

) observed planetary motions and cycles, and created a geocentric cosmological model that would be accepted by

Aristotle Aristotle (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher and polymath during the Classical period in Ancient Greece. Taught by Plato, he was the founder of the Peripatetic school of ...

. This model generally lasted until

Ptolemy Claudius Ptolemy (; grc-gre, Πτολεμαῖος, ; la, Claudius Ptolemaeus; AD) was a mathematician, astronomer, astrologer, geographer, and music theorist, who wrote about a dozen scientific treatises, three of which were of importanc ...

, who added epicycles to explain the

retrograde motion Retrograde motion in astronomy is, in general, orbital or rotational motion of an object in the direction opposite the rotation of its primary, that is, the central object (right figure). It may also describe other motions such as precession ...

of Mars. (Around 250 BC,

Aristarchus of Samos Aristarchus of Samos (; grc-gre, Ἀρίσταρχος ὁ Σάμιος, ''Aristarkhos ho Samios''; ) was an ancient Greek astronomer and mathematician who presented the first known heliocentric model that placed the Sun at the center of the ...

postulated a proto-heliocentric theory, which would not be reconsidered for nearly two millennia (

Copernicus Nicolaus Copernicus (; pl, Mikołaj Kopernik; gml, Niklas Koppernigk, german: Nikolaus Kopernikus; 19 February 1473 – 24 May 1543) was a Renaissance polymath, active as a mathematician, astronomer, and Catholic canon, who formulat ...

), as Aristotle's geocentric model continued to be favored.) The Platonic school promoted the study of astronomy as a part of philosophy because the motions of the heavens demonstrate an orderly and harmonious cosmos. In the third century BC, Babylonian astrology began to make its presence felt in Greece. Astrology was criticized by Hellenistic philosophers such as the Academic Skeptic

Carneades Carneades (; el, Καρνεάδης, ''Karneadēs'', "of Carnea"; 214/3–129/8 BC) was a Greek philosopher and perhaps the most prominent head of the Skeptical Academy in ancient Greece. He was born in Cyrene. By the year 159 BC, he had be ...

and Middle Stoic

Panaetius Panaetius (; grc-gre, Παναίτιος, Panaítios; – ) of Rhodes was an ancient Greek Stoic philosopher. He was a pupil of Diogenes of Babylon and Antipater of Tarsus in Athens, before moving to Rome where he did much to introduce Stoic ...

. However, the notions of the Great Year (when all the planets complete a full cycle and return to their relative positions) and eternal recurrence were Stoic doctrines that made divination and fatalism possible. In the Hellenistic world, the Greek words 'astrologia' and 'astronomia' were often used interchangeably, but they were conceptually not the same. Plato taught about 'astronomia' and stipulated that planetary phenomena should be described by a geometrical model. The first solution was proposed by Eudoxus. Aristotle favored a physical approach and adopted the word 'astrologia'. Eccentrics and epicycles came to be thought of as useful fictions. For a more general public, the distinguishing principle was not evident and either word was acceptable. For the Babylonian horoscopic practice, the words specifically used were 'apotelesma' and '

katarche Katarche (''καταρχή'') is an ancient Greek word meaning a "beginning" or "inception." One of the older applications of the term was within the context of religious rituals to refer to the moment when the sacrifice was first offered, or wh ...

', but otherwise it was subsumed under the aristotelian term 'astrologia'. In his compilatory work

Etymologiae ''Etymologiae'' (Latin for "The Etymologies"), also known as the ''Origines'' ("Origins") and usually abbreviated ''Orig.'', is an etymological encyclopedia compiled by Isidore of Seville (c. 560–636) towards the end of his life. Isidore was ...

Isidore of Seville Isidore of Seville ( la, Isidorus Hispalensis; c. 560 – 4 April 636) was a Spanish scholar, theologian, and archbishop of Seville. He is widely regarded, in the words of 19th-century historian Montalembert, as "the last scholar of ...

noted explicitly the difference between the terms astronomy and astrology (Etymologiae, III, xxvii) and the same distinction appeared later in the texts of Arabian writers. Isidore identified the two strands entangled in the astrological discipline and called them ''astrologia naturalis'' and ''astrologia superstitiosa''. Astrology was widely accepted in

medieval Europe In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire a ...

as astrological texts from Hellenistic and Arabic astrologers were translated into Latin. In the

late Middle Ages The Late Middle Ages or Late Medieval Period was the period of European history lasting from AD 1300 to 1500. The Late Middle Ages followed the High Middle Ages and preceded the onset of the early modern period (and in much of Europe, the Ren ...

, its acceptance or rejection often depended on its reception in the royal courts of Europe. Not until the time of

Francis Bacon Francis Bacon, 1st Viscount St Alban (; 22 January 1561 – 9 April 1626), also known as Lord Verulam, was an English philosopher and statesman who served as Attorney General and Lord Chancellor of England. Bacon led the advancement of both ...

was astrology rejected as a part of scholastic metaphysics rather than empirical observation. A more definitive split between astrology and astronomy in the West took place gradually in the seventeenth and eighteenth centuries, when astrology was increasingly thought of as an occult science or superstition by the intellectual elite. Because of their lengthy shared history, it sometimes happens that the two are confused with one another even today. Many contemporary astrologers, however, do not claim that astrology is a science, but think of it as a form of divination like the I-Ching, an art, or a part of a spiritual belief structure (influenced by trends such as

Neoplatonism Neoplatonism is a strand of Platonic philosophy that emerged in the 3rd century AD against the background of Hellenistic philosophy and religion. The term does not encapsulate a set of ideas as much as a chain of thinkers. But there are some ...

Neopaganism Modern paganism, also known as contemporary paganism and neopaganism, is a term for a religion or family of religions influenced by the various historical pre-Christian beliefs of pre-modern peoples in Europe and adjacent areas of North Afric ...

Theosophy Theosophy is a religion established in the United States during the late 19th century. It was founded primarily by the Russian Helena Blavatsky and draws its teachings predominantly from Blavatsky's writings. Categorized by scholars of religion a ...

, and

Hinduism Hinduism () is an Indian religion or '' dharma'', a religious and universal order or way of life by which followers abide. As a religion, it is the world's third-largest, with over 1.2–1.35 billion followers, or 15–16% of the global p ...

Distinguishing characteristics

The primary goal of astronomy is to understand the

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which ...

of the

universe The universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy. The Big Bang theory is the prevailing cosmological description of the development of the univers ...

. Astrologers use astronomical calculations for the positions of celestial bodies along the

ecliptic The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic agains ...

and attempt to correlate celestial events (

astrological aspects In astrology, an aspect is an angle that planets make to each other in the Horoscope; as well as to the Ascendant, Midheaven, Descendant, Lower Midheaven, and other points of astrological interest. As viewed from Earth, aspects are measured by ...

, sign positions) with earthly events and human affairs. Astronomers consistently use the

scientific method The scientific method is an empirical method for acquiring knowledge that has characterized the development of science since at least the 17th century (with notable practitioners in previous centuries; see the article history of scientifi ...

, naturalistic

presupposition In the branch of linguistics known as pragmatics, a presupposition (or PSP) is an implicit assumption about the world or background belief relating to an utterance whose truth is taken for granted in discourse. Examples of presuppositions include ...

s and abstract

mathematical Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented in modern mathematics ...

reasoning to investigate or explain phenomena in the universe. Astrologers use

mystical Mysticism is popularly known as becoming one with God or the Absolute, but may refer to any kind of ecstasy or altered state of consciousness which is given a religious or spiritual meaning. It may also refer to the attainment of insight in u ...

or religious reasoning as well as traditional

folklore Folklore is shared by a particular group of people; it encompasses the traditions common to that culture, subculture or group. This includes oral traditions such as tales, legends, proverbs and jokes. They include material culture, rangin ...

symbol A symbol is a mark, sign, or word that indicates, signifies, or is understood as representing an idea, object, or relationship. Symbols allow people to go beyond what is known or seen by creating linkages between otherwise very different conc ...

ism and

superstition A superstition is any belief or practice considered by non-practitioners to be irrational or supernatural, attributed to fate or magic, perceived supernatural influence, or fear of that which is unknown. It is commonly applied to beliefs ...

blended with mathematical predictions to explain phenomena in the universe. The scientific method is not consistently used by astrologers. Astrologers practice their discipline

geocentric In astronomy, the geocentric model (also known as geocentrism, often exemplified specifically by the Ptolemaic system) is a superseded description of the Universe with Earth at the center. Under most geocentric models, the Sun, Moon, stars, an ...

ally and they consider the universe to be harmonious, changeless and static, while astronomers have employed the scientific method to infer that the universe is without a center and is dynamic, expanding outward per the

Big Bang theory The Big Bang event is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models of the Big Bang explain the evolution of the observable universe from the ...

. Astrologers believe that the position of the stars and planets determine an individual's personality and future. Astronomers study the actual stars and planets, but have found no evidence supporting astrological theories. Psychologists study personality, and while there are many theories of personality, no mainstream theories in that field are based on astrology. (The Myers-Briggs personality typology, based on the works of

Carl Jung Carl Gustav Jung ( ; ; 26 July 1875 – 6 June 1961) was a Swiss psychiatrist and psychoanalyst who founded analytical psychology. Jung's work has been influential in the fields of psychiatry, anthropology, archaeology, literature, ph ...

, has four major categories that correspond to the astrological elements of fire, air, earth, and water. This theory of personality is used by career counselors and life coaches but not by psychologists.) Both astrologers and astronomers see Earth as being an integral part of the universe, that Earth and the universe are interconnected as one ''cosmos'' (not as being separate and distinct from each other). However, astrologers philosophically and mystically portray the cosmos as having a

supernatural Supernatural refers to phenomena or entities that are beyond the laws of nature. The term is derived from Medieval Latin , from Latin (above, beyond, or outside of) + (nature) Though the corollary term "nature", has had multiple meanings si ...

metaphysical Metaphysics is the branch of philosophy that studies the fundamental nature of reality, the first principles of being, identity and change, space and time, causality, necessity, and possibility. It includes questions about the nature of conscio ...

and

divine Divinity or the divine are things that are either related to, devoted to, or proceeding from a deity.divine< ...

essence Essence ( la, essentia) is a polysemic term, used in philosophy and theology as a designation for the property or set of properties that make an entity or substance what it fundamentally is, and which it has by necessity, and without which it ...

that actively influences world events and the personal lives of people. Astronomers, as members of the scientific community, cannot use in their scientific articles explanations that are not derived from empirically

reproducible Reproducibility, also known as replicability and repeatability, is a major principle underpinning the scientific method. For the findings of a study to be reproducible means that results obtained by an experiment or an observational study or in a ...

conditions, irrespective of their personal convictions.

Historical divergence

For a long time the funding from astrology supported some

astronomical Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxi ...

research, which was in turn used to make more accurate

ephemerides In astronomy and celestial navigation, an ephemeris (pl. ephemerides; ) is a book with tables that gives the trajectory of naturally occurring astronomical objects as well as artificial satellites in the sky, i.e., the position (and possibly ...

for use in astrology. In

Medieval Europe In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire a ...

the word ''Astronomia'' was often used to encompass both disciplines as this included the study of astronomy and astrology jointly and without a real distinction; this was one of the original

Seven Liberal Arts Liberal arts education (from Latin "free" and "art or principled practice") is the traditional academic course in Western higher education. ''Liberal arts'' takes the term '' art'' in the sense of a learned skill rather than specifically th ...

. Kings and other rulers generally employed court astrologers to aid them in the decision making in their kingdoms, thereby funding astronomical research. University medical students were taught astrology as it was generally used in

medical practice Medicine is the science and practice of caring for a patient, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care practic ...

. Astronomy and astrology diverged over the course of the 17th through 19th centuries.

did not practice astrology (nor empirical astronomy; his work was theoretical), but the most important astronomers before

Isaac Newton Sir Isaac Newton (25 December 1642 – 20 March 1726/27) was an English mathematician, physicist, astronomer, alchemist, Theology, theologian, and author (described in his time as a "natural philosophy, natural philosopher"), widely ...

were astrologers by profession—

Tycho Brahe Tycho Brahe ( ; born Tyge Ottesen Brahe; generally called Tycho (14 December 154624 October 1601) was a Danish astronomer, known for his comprehensive astronomical observations, generally considered to be the most accurate of his time. He was ...

Johannes Kepler Johannes Kepler (; ; 27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his laws ...

, and

Galileo Galilei Galileo di Vincenzo Bonaiuti de' Galilei (15 February 1564 – 8 January 1642) was an Italian astronomer, physicist and engineer, sometimes described as a polymath. Commonly referred to as Galileo, his name was pronounced (, ). He ...

. Also relevant here was the development of better

timekeeping Time is the continued sequence of existence and events that occurs in an apparently irreversible succession from the past, through the present, into the future. It is a component quantity of various measurements used to sequence events, to co ...

instruments, initially for aid in

navigation Navigation is a field of study that focuses on the process of monitoring and controlling the movement of a craft or vehicle from one place to another.Bowditch, 2003:799. The field of navigation includes four general categories: land navigation ...

; improved timekeeping made it possible to make more exact astrological predictions—predictions which could be tested, and which consistently proved to be false. By the end of the 18th century, astronomy was one of the major sciences of the Enlightenment model, using the recently codified

, and was altogether distinct from astrology.

Astrology and Zodiac Signs in the Modern Age

Astrology is considered by many philosophers and astronomers to be a false representation of the universe that individuals may use to associate the movement of the celestial bodies to their own ideas of human life and spirituality. Although many scholars consider astrology to be a pseudoscience, those that believe in zodiac signs and their meanings will argue the opposite, and these followers will support their claims with explanations for how and why the universe is connected to the human condition. The most popular and well-known form of astrology is seen in horoscopes that people are exposed to through social media, popular news outlets, and digital media. The horoscopes allow people interested in astrology and zodiac signs to associate planets like Mars to human emotions such as drive and courage, and further increase the notion that these planets and their motions have an effect on their daily lives. Although astrology was considered factual predictions in ancient science, in modern times it is used as a spiritual belief system for many people. Ancient forms of astrology often combined with astronomy, but eventually split into separate paths during the time of Copernicus, Kepler, and Galileo. Zodiac signs in modern times are constructed from constellations seen across the earth, and they are used to associate human emotions and tendencies with the stars and heavenly bodies. In some ways, astrology has become somewhat of a pseudo-religion, due to the emphasis put on the meanings of constellations and how they relate to each individual. One may “judge” another person based on their zodiac sign, simply because there are unique listed traits carried by each sign, which reflect on the person who it refers to. The signs that are attributed to individuals are based on the time of year that each individual was born in. For example, people born between the dates of April 19 - May 4th will carry the zodiac sign of Aries, and those born between the dates of July 21 - August 10th carry the Cancer sign. Despite the many individuals that consider zodiac astrology to be factual, many consider the horoscope meanings to be false and simply participate in this modern astrology for enjoyment. Lastly, zodiac signs and astrology in the modern era are very different from the astrology of the ancient world. The minimal technology, knowledge, and expertise of the ancient world allowed for the combination of astrology and astronomy to become the generally accepted explanation for the universe and its impact on human lives. Whereas in current times, astrology and astronomy are extremely different. Zodiac signs and horoscopes are a product of cultural developments (such as the internet) that allow for easy access to information on the horoscopes through social media, tabloids and news outlets that benefit from promoting these aspects of astrology. Many individuals that are interested in horoscopes are not aware that the signs and their respective dates are inaccurate, and do not have any basis in science. Due to the “trendy” nature of zodiac signs and their popularity, it is widely recognized as part of global culture.

References

External links

The Geoffrey Chaucer Page: Astrology & Astronomy

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of highe ...

An Astronomer Looks at Astrology
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