Tetrabiblos
Encyclopedia
The Tetrabiblos also known under the Latin title Quadripartitum ('four parts'), is a text on the philosophy and practice of astrology
Astrology
Astrology consists of a number of belief systems which hold that there is a relationship between astronomical phenomena and events in the human world...

, written in the second century AD by the Alexandria
Alexandria
Alexandria is the second-largest city of Egypt, with a population of 4.1 million, extending about along the coast of the Mediterranean Sea in the north central part of the country; it is also the largest city lying directly on the Mediterranean coast. It is Egypt's largest seaport, serving...

n scholar Claudius Ptolemy
Ptolemy
Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...

 (AD 90–AD 168).

Ptolemy's Almagest
Almagest
The Almagest is a 2nd-century mathematical and astronomical treatise on the apparent motions of the stars and planetary paths. Written in Greek by Claudius Ptolemy, a Roman era scholar of Egypt,...

 was considered an authoritative text on astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

 until the general acceptance of the Copernican system, and the Tetrabiblos, its companion volume, was equally influential in astrology
Astrology
Astrology consists of a number of belief systems which hold that there is a relationship between astronomical phenomena and events in the human world...

, the study of the 'outcome' or 'effects' of the astronomical cycles upon earthly matters. But whilst the Almagest as an astronomical authority was largely superseded by acceptance of the heliocentric model of the solar system
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...

, the Tetrabiblos remains an important theoretical work for astrology, and is considered an indispensible source of reference for serious students of astrological philosophy.

As well as outlining the principles of astrological practice, Ptolemy's philosophical defence of the subject helped to secure the theological acceptance of astrology from the Medieval period through to the Age of Reason
Age of reason
Age of reason may refer to:* 17th-century philosophy, as a successor of the Renaissance and a predecessor to the Age of Enlightenment* Age of Enlightenment in its long form of 1600-1800* The Age of Reason, a book by Thomas Paine...

, when practitioners of intrinsically occult
Occult
The word occult comes from the Latin word occultus , referring to "knowledge of the hidden". In the medical sense it is used to refer to a structure or process that is hidden, e.g...

 studies were at risk of religious persecution. The historical importance of the text in antiquity, the Middle Ages and the Renaissance is indicated by the commentaries that have been published about it. The latest critical edition, by Professor Wolfgang Hübner, was published by Teubner in 1998.

Original title

The commonly known Greek and Latin titles (Tetrabiblos and Quadripartitum respectively), meaning 'four books', are traditional nicknames for a work which in some Greek manuscripts is entitled , 'Mathematical treatise in four books'. Frank Eggleston Robbins, editor of the Loeb
Loeb
Loeb may refer to:* Loeb , a Canadian chain of supermarket/grocery stores* Loeb's , a specialty department store...

 English translation published in 1940, considered it likely that this was the title used by Ptolemy himself, although he acknowledged that many other Greek manuscripts use the title , 'The prognostics addressed to Syrus'.
An ancient anonymous commentary on the work states that some considered the term Tetrabiblos to be a fictitious name.

Professor Wolfgang Hübner, editor of the most recent critical Greek edition published by Teubner in 1998, uses the title Apotelesmatiká (biblía) '(books on) effects', and this has been followed by recent scholars on the basis that the Hübner edition is now the authoritative one. Alexander Jones, editor of the Springer publication Ptolemy in Perspective (2010) considers that Ptolemy's own title remains unknown, but agrees that the term Apotelesmatika is "a credible guess". This term is variously translated to mean 'influences', 'effects' or 'prognostics'; reflecting the theme of work, which is concerned with gaining foreknowledge of the effects of predictable astronomical cycles.

General overview and influence

Ptolemy
Ptolemy
Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...

 has been referred to as “a pro-astrological authority of the highest magnitude” and as a source of reference his Tetrabiblos is an extensive and continually reprinted treatise on the principles of astrology. It is said to have "enjoyed almost the authority of a Bible among the astrological writers of a thousand years or more". It is still regarded as an important astrological text, which is considered to be an indispensible reference for serious students of western astrology.
The work's enduring popularity can be attributed to several factors: Ptolemy's reputation as one of the greatest philosophers and scientists of the ancient world, the fact that the Tetrabiblos presents one of the oldest almost complete manuals of astrological principles and techniques, and the unprecedented order and quality of Ptolemy's detailed astrological explanations. It has been said that "the outstanding mark of Ptolemy’s astrology [is] that it is informed by the philosophical and scientific spirit of his age". Ptolemy wrote at a time in which 'physics' was defined by philosophy, and his account of stellar effects was mainly expressed in terms of the four Aristotelian qualities (hot, cold, wet, and dry) and the notion of universal unity. Whilst concerned with explaining the rationale of astrology in these terms, Ptolemy's work is also notable for its dismissal of astrological practices which lacked a physical basis or an obviously plausible logic:

The Tetrabiblos begins with a detailed explanation of the philosophical framework of astrology, which answered the arguments of critics who questioned its validity in scientific terms. Of this, Lynn Thorndike
Lynn Thorndike
Lynn Thorndike was an American historian of medieval science and alchemy...

, in his History of Magic and Experimental Science, writes: "Only the opponents of astrology appear to have remained ignorant of the Tetrabiblos, continuing to make criticisms of the art which do not apply to Ptolemy's presentation of it or which had been specifically answered by him".

Ptolemy was not responsible for originating the astrological techniques he presented in the Tetrabiblos. His contribution was to order the material in a systematic way, in an effort to demonstrate that astrology is based upon logical principles. Astrological influences are frequently, for example, referred to the meteorological effects of humoural shifts, brought about by celestial cycles that bring correlated changes in the heating, cooling, moistening, and drying affects of the atmosphere.

The historical importance and influence of the Tetrabiblos can be witnessed by the considerable number of ancient, Medieval and Renaissance commentaries that have been published about it, as well as the many translations and paraphrased editions that aim to reproduce its content in an accessible manner. The Greek text has undergone transmission into Arabic, Latin and many modern languages. Although the first English translation did not appear until the 18th century, by the end of the 19th century the American astrologer Luke Broughton reported that he had at least half a dozen different English translations in his possession.

Introductory address and date of compilation

The text begins with Ptolemy's address to 'Syrus', an unidentified character to whom all of Ptolemy's works are addressed. In this Ptolemy differentiates between the two types of astronomical study: the first (astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

 proper) which discovers the astronomical cycles and movements; the second (astrology
Astrology
Astrology consists of a number of belief systems which hold that there is a relationship between astronomical phenomena and events in the human world...

) which investigates the changes that these movements bring about. Ptolemy reports that each has its own science and that the former is desirable in its own right “even though it does not attain the result given by its combination with the second”. He states that having dealt with the former in its own treatise, he “shall now give an account of the second and less self-sufficient method in a properly philosophical way, so that one whose aim is the truth might never compare its perceptions with the sureness of the first”.

These introductory comments reveal three significant facts: the first is that although the terms astronomia and astrologia were often used interchangeably in ancient texts, there was a clear sense of distinction between the subjects in the classical era, by which Ptolemy felt it necessary to keep his astronomical treatise, the Almagest
Almagest
The Almagest is a 2nd-century mathematical and astronomical treatise on the apparent motions of the stars and planetary paths. Written in Greek by Claudius Ptolemy, a Roman era scholar of Egypt,...

, free of astrological themes.

The second is the demonstrated awareness that whilst astronomy is a reliable study, astrology is intrinsically speculative, and integrates many elements of subjective reasoning by which it can never achieve factual certainty. In this and further introductory remarks Ptolemy reveals his view that astrological prediction is extremely difficult and easily subject to error, but satisfactorily attainable to those who possess the necessary skill and experience, and of too much benefit to be dismissed simply because it can sometimes be mistaken.

Thirdly, although there is no firmly established date of publication for the Tetrabiblos, Ptolemy's disclosure that he wrote his astrological treatise after completing his astronomical one narrows its period of compilation. Evidence within the Almagest reveals that the astronomical work could not have been completed before about 145 AD, which demonstrates that Ptolemy wrote the Tetrabiblos towards the end of his life, sometime between completing the Almagest and his death, generally reported to be around 168 A.D.

Ptolemy's philosophical argument

The first three chapters of Book I have been particularly important historically because these give Ptolemy’s philosophical defence against the astrological criticisms made by skeptics
Philosophical skepticism
Philosophical skepticism is both a philosophical school of thought and a method that crosses disciplines and cultures. Many skeptics critically examine the meaning systems of their times, and this examination often results in a position of ambiguity or doubt...

. These chapters supported the traditional practice of astrology but have been highlighted by modern critics as the place where Ptolemy's "knowledge, intelligence and rhetorical skill" are deemed to have been "misused".

In chapter one Ptolemy asserts the legitimacy of the study and identifies the two main arguments set against it:
  1. the complexity of the subject makes its claim of providing reliable foreknowledge unattainable;
  2. reliable foreknowledge—if it can be attained—would imply such fatalism
    Fatalism
    Fatalism is a philosophical doctrine emphasizing the subjugation of all events or actions to fate.Fatalism generally refers to several of the following ideas:...

     as to make the subject's purpose useless (since if the future is predictable, anything which is destined to happen will happen whether predicted or not).

Ptolemy then answers each criticism in the following two chapters.

In chapter two Ptolemy maintains that knowledge gained by astronomical means is attainable and he attempts to define its limits. He points out how the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

 has the greatest influence upon the Earth’s seasonal and daily cycles, and that most things in nature are synchronized by the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

:
He extends this ability to stir the weather and steer the biological patterns of earthly creatures to the fixed stars
Stars in astrology
In astrology, certain stars are considered significant. Historically, all of the various heavenly bodies considered by astrologers were considered "stars", whether they were stars, planets, other stellar phenomena like novas and supernovas, or other solar system phenomena like comets and...

 and planets, so that everything which experiences cycles of growth, or patterns of behaviour, is in some way responsive to the celestial cycles. These bring about elemental changes (hot, windy, snowy or watery conditions, etc): led by the Sun, activated by the Moon and aided by the planetary configurations
Astrological aspect
In astrology, an aspect is an angle the planets make to each other in the horoscope, and also to the ascendant, midheaven, descendant, lower midheaven, and other points of astrological interest. Aspects are measured by the angular distance in degrees and minutes of ecliptic longitude between two...

 and the fixed stars' phenomena. The prevailing meteorological qualities are then considered to determine the temperament
Temperament
In psychology, temperament refers to those aspects of an individual's personality, such as introversion or extroversion, that are often regarded as innate rather than learned...

 – the quality of the moment of time at a specific place - which is presumed to be impressed, as a sort of temporal imprint, upon the seed of anything which comes into germination or manifestation at that moment in time. Ptolemy admits that successful analysis of this temperament is not easily attained but is capable of being determined by someone who is able to regard the data “both scientifically and by successful conjecture”. He questions why, if a person can reliably predict the general weather patterns and their effects upon agricultural seeds and animals from the knowledge of the celestial cycles:
Whilst suggesting that such arguments are enough to demonstrate the validity of astrology, Ptolemy accepts that many mistakes are made in its practice - partly because of “evident rascals” who profess to practice it without due knowledge and pretend to foretell things which cannot be naturally known (sometimes using the term 'astrology' for practices which are not true to the genuine study of astrology) and because legitimate practitioners must acquire a magnitude of knowledge and experience within a limited life-span. His summary is that the study is usually only able to give reliable knowledge in general terms; that astrological advice should be welcomed but not expected to be faultless; and that the astrologer should not be criticized but encouraged to integrate non-celestial information within the compilation of a judgement (such as what is known of an individual’s ethnic background, nationality and parental influences).
In chapter three Ptolemy argues that astrological prediction is both natural and beneficial. His reasons were to become pivotal in safeguarding the theological acceptance of astrology from the Medieval period through to the age of reason
Age of reason
Age of reason may refer to:* 17th-century philosophy, as a successor of the Renaissance and a predecessor to the Age of Enlightenment* Age of Enlightenment in its long form of 1600-1800* The Age of Reason, a book by Thomas Paine...

, when practitioners of intrinsically occult
Occult
The word occult comes from the Latin word occultus , referring to "knowledge of the hidden". In the medical sense it is used to refer to a structure or process that is hidden, e.g...

 studies were at risk of religious persecution.

Ptolemy first proposes that it is not “useless” to create predictions of what is likely to happen, even if the predictions do not provide the means to avoid impending disaster. This was one of the well known classical criticisms that had been brought to prominence in Cicero
Cicero
Marcus Tullius Cicero , was a Roman philosopher, statesman, lawyer, political theorist, and Roman constitutionalist. He came from a wealthy municipal family of the equestrian order, and is widely considered one of Rome's greatest orators and prose stylists.He introduced the Romans to the chief...

's text De Divinatione
De Divinatione
Cicero's De Divinatione is a philosophical treatise in two books written in 44 BC. It takes the form of a dialogue whose interlocutors are Cicero and his brother Quintus....

, in the argument that no good comes from warnings of imminent disasters when they offer no means of escape. Ptolemy gives a more positive view of divination in his assessment of astrology as a subject “by which we gain full view of things human and divine”, which, he argues, gives a better perception of “what is fitting and expedient for the capabilities of each temperament”. He views astrology as a subject which encourages enhanced self-knowledge, to be valued as a source of pleasure and well-being; since even if astrology cannot aid in the acquisition of riches or fame; the same can be said of all philosophy, which concerns itself with “greater advantages”. Hence, in the case of unfortunate events that will necessarily take place, Ptolemy asserts that astrological prediction still brings benefits, because “foreknowledge accustoms and calms the soul by experience of distant events as though they were present, and prepares it to greet with calm and steadiness whatever comes”.

Ptolemy's next argument was to avoid the criticisms that arise when the practice of prediction is seen to suggest fatal necessity
Fatalism
Fatalism is a philosophical doctrine emphasizing the subjugation of all events or actions to fate.Fatalism generally refers to several of the following ideas:...

. This point was crucial to later theological acceptance, since Medieval religious doctrine dictates that the individual soul
Soul
A soul in certain spiritual, philosophical, and psychological traditions is the incorporeal essence of a person or living thing or object. Many philosophical and spiritual systems teach that humans have souls, and others teach that all living things and even inanimate objects have souls. The...

 must possess free will
Free will
"To make my own decisions whether I am successful or not due to uncontrollable forces" -Troy MorrisonA pragmatic definition of free willFree will is the ability of agents to make choices free from certain kinds of constraints. The existence of free will and its exact nature and definition have long...

, in order to be responsible for its own choices and the consequences that flow from them. Gerard of Feltre's 13th century text Summa on the Stars demonstrates the problem that astrological determinism creates for the theological argument: “If the stars make a man a murderer or a thief, then all the more it is the first cause, God, who does this, which it is shameful to suggest”. Ptolemy's comments counter the criticism by proposing that whilst the celestial cycles are entirely reliable and “eternally performed in accordance with divine, unchangeable destiny”, all earthly things are also subject to “a natural and mutable fate, and in drawing its first causes from above it is governed by chance and natural sequence”. He therefore declares that nothing is irrevocably ordained, and we are not to imagine that “events attend mankind as the result of the heavenly cause as if … destined to take place by necessity without the possibility of any other cause whatever interfering”.

In this discussion Ptolemy makes a point that was to be called upon by many later astrological writers, that “the lesser cause always yields to the stronger”. He sees an individual as unable to resist the greater cycles of change which happen to the wider community, so even a man whose horoscope indicates gain may perish at a time that his community is struck by natural disaster or pestilence. However, Ptolemy also maintains that disastrous events will only follow a natural course if no counter action is taken to avert the problem, as when “future happenings to men are not known, or if they are known and the remedies are not applied”. He takes a balanced position in the argument of fate versus free will in writing that certain things, because their effective causes are numerous, become inevitable, whilst others are able to be averted by the act of astrological prediction. The astrologer’s position is compared to that of the physician, who must be able to recognise beforehand which ailments are always fatal, and which admit of aid.

It is therefore reasonable, in Ptolemy’s estimation, to moderate actions with awareness of how the prevailing and future temperament prospers or injures the natal temperament, or to elect to act at a time that is astrologically suitable to the activity – just as it is deemed rational to use knowledge of the stars to ensure safety at sea; to use knowledge of the lunar cycle to ensure successful breeding and sowing, or to cool ourselves against the extremes of temperature in order that we suffer less.

Ptolemy's philosophical conclusion on the subject, which helped to secure its intellectual standing until the 18th century, is thus: "even if it be not entirely infallible, at least its possibilities have appeared worthy of the highest regard". Having justified his intellectual involvement in the study, according to the philosophical principles of his day, Ptolemy then turns his attention to the practical theory of astrology, and the rationale that lies behind the arrangement of its principles.

Introduction of principles

One of the unique features of the Tetrabiblos, amongst the astrological texts of its period, is the extent to which the first book not only introduces the basic astrological principles, but synthesises and explains the reasoning behind their reported associations in line with Aristotelian philosophy
Aristotelianism
Aristotelianism is a tradition of philosophy that takes its defining inspiration from the work of Aristotle. The works of Aristotle were initially defended by the members of the Peripatetic school, and, later on, by the Neoplatonists, who produced many commentaries on Aristotle's writings...

. Chapter four, for example, explains the “power of the planets” through their associations with the creative humoural qualities of warmth or moisture, or the reductive qualities of cold and dryness. Hence Mars is described as a destructive planet because its humoral association is excessive dryness, whilst Jupiter is defined as temperate and fertilising because its association is moderate warmth and humidity. These associations are based on the arrangements of the planets with regard to the Sun, as perceived from the geocentric perspective
Geocentric model
In astronomy, the geocentric model , is the superseded theory that the Earth is the center of the universe, and that all other objects orbit around it. This geocentric model served as the predominant cosmological system in many ancient civilizations such as ancient Greece...

, by which their orbits are measured is if they are centred upon the Earth.

In reference to these principles the next three chapters define the planets as benefic
Benefic planet
In astrology, a benefic planet, or simply benefic, is considered to be very positive influence. Traditionally, Jupiter is considered to be the greater benefic, while Venus has been assigned the position of the lesser benefic...

 (moderately warming or moistening) or malefic
Malefic planet
In astrology, a malefic planet, or simply malefic, is traditionally thought to bring bad luck and misfortune. Mars is considered the lesser malefic, while Saturn is the greater malefic. In modern astrology Uranus, Pluto and for some Ceres are also considered malefic.-See also:*Benefic...

 (excessively cooling or drying); either masculine (drying) or feminine (moistening); and either active and diurnal
Astrology of sect
Sect is an ancient astrological concept in which the seven traditional "planets" are assigned to two different categories: diurnal or nocturnal sect....

 (suited to the qualities of the day and aligned with the nature of the Sun) or passive and nocturnal
Astrology of sect
Sect is an ancient astrological concept in which the seven traditional "planets" are assigned to two different categories: diurnal or nocturnal sect....

  (suited to the qualities of the night and aligned with the nature of the Moon). Since these humoural associations derive from configurations with the Sun, chapter eight describes how they are subtly modified according to the phase of each planet’s synodic cycle with the Sun.

Chapter nine discusses the “power of the fixed stars”. Here, rather than give direct humoural associations, Ptolemy describes their “temperatures” as being like that of the planets he has already defined. Hence Aldebaran
Aldebaran
Aldebaran is a red giant star located about 65 light years away in the zodiac constellation of Taurus. With an average apparent magnitude of 0.87 it is the brightest star in the constellation and is one of the brightest stars in the nighttime sky...

 (“called the Torch”) is described as having “a temperature like that of Mars”, whilst other stars in the Hyades
Hyades
Hyades may refer to:*Hyades *Hyades , an open star cluster in the constellation Taurus...

 are “like that of Saturn and moderately like that of Mercury”. At the end of the chapter Ptolemy clarifies that these are not his proposals, but are drawn from historical sources, being “the observations of the effects of the stars themselves as made by our predecessors”.
Chapter ten returns to the humoural theme more explicitly, clarifying that the zodiac
Zodiac
In astronomy, the zodiac is a circle of twelve 30° divisions of celestial longitude which are centred upon the ecliptic: the apparent path of the Sun across the celestial sphere over the course of the year...

 is aligned to the season
Season
A season is a division of the year, marked by changes in weather, ecology, and hours of daylight.Seasons result from the yearly revolution of the Earth around the Sun and the tilt of the Earth's axis relative to the plane of revolution...

s and so expressive of the shifting emphasis through moisture, warmth, dryness and cold, (as brought about by spring
Spring (season)
Spring is one of the four temperate seasons, the transition period between winter and summer. Spring and "springtime" refer to the season, and broadly to ideas of rebirth, renewal and regrowth. The specific definition of the exact timing of "spring" varies according to local climate, cultures and...

, summer
Summer
Summer is the warmest of the four temperate seasons, between spring and autumn. At the summer solstice, the days are longest and the nights are shortest, with day-length decreasing as the season progresses after the solstice...

, autumn
Autumn
Autumn is one of the four temperate seasons. Autumn marks the transition from summer into winter usually in September or March when the arrival of night becomes noticeably earlier....

, and winter
Winter
Winter is the coldest season of the year in temperate climates, between autumn and spring. At the winter solstice, the days are shortest and the nights are longest, with days lengthening as the season progresses after the solstice.-Meteorology:...

). Similarly, the four angles of the chart
Angle (astrology)
The angles are the four Cardinal points of an astrological chart: the Ascendant, the Midheaven, the Descendant and the Imum Coeli.The astrological chart is a schematic representation of the sky at any given moment of time, projected upon the ecliptic--or the apparent path of the Sun as seen from...

 present an humoural emphasis through association with the effects of the four cardinal winds
WINDS
WINDS , is a Japanese communication satellite. Launch was originally scheduled for 2007. The launch date was eventually set for 15 February 2008, however a problem detected in a second stage manoeuvring thruster delayed it to 23 February...

 that blow from their aligned directions. The remainder of book one (up to the final two chapters which concern the planetary phases
Planetary phase
Planetary phase is the term used to describe the appearance of the illuminated section of a planet. Like lunar phases, the planetary phase depends on the relative position of the sun, the planet and the observer....

 and aspectual applications), presents the rulerships, divisions, and configurations of the zodiac signs, most of which are related to astronomical definitions, seasonal effects and geometrical relationships.

In Ptolemy’s era the boundaries of the zodiac signs were close to those of the visible constellations
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....

 whose names they bear, but Ptolemy demonstrates the theoretical distinction between the two frames of reference in describing the starting point of the zodiac as fixed, not to the stars, but to the mathematically calculated vernal equinox. This determines the seasonally-based tropical zodiac which takes its name from the Greek word τροπικός tropikos: ‘turning’, because it is set by the turn of the seasons and, being subject to precession, experiences a slow and gradual revolution through the visible constellations. For the same reason, the signs that mark the Sun’s summer and winter solstice
Solstice
A solstice is an astronomical event that happens twice each year when the Sun's apparent position in the sky, as viewed from Earth, reaches its northernmost or southernmost extremes...

 points (Cancer
Cancer (astrology)
Cancer is the fourth astrological sign in the Zodiac. It is considered a water sign and one of four cardinal signs. Cancer is ruled by the Moon. Individuals born when the Sun is in this sign are considered Cancerian individuals...

 and Capricorn) are described as the 'tropical signs', since these are the places where the Sun ‘turns’ its direction in celestial latitude, (thereby defining the terrestrial circles of latitude known as the Tropic of Cancer
Tropic of Cancer
The Tropic of Cancer, also referred to as the Northern tropic, is the circle of latitude on the Earth that marks the most northerly position at which the Sun may appear directly overhead at its zenith...

 and the Tropic of Capricorn
Tropic of Capricorn
The Tropic of Capricorn, or Southern tropic, marks the most southerly latitude on the Earth at which the Sun can be directly overhead. This event occurs at the December solstice, when the southern hemisphere is tilted towards the Sun to its maximum extent.Tropic of Capricorn is one of the five...

).

Whereas other ancient astrological writers gave their emphasis to the astrological interpretation of such definitions (for example, in describing how tropical signs are indicative of quickly changing situations), Ptolemy’s focus is notably different; given to the astronomical and philosophical factors that underlie the definitions rather than their astrological meaning in practice. Ptolemy explains that the definitions of the zodiac are not his own, but present “the natural characters of the zodiacal signs, as they have been handed down by tradition”. His approach finds elegant expression where he is demonstrating the logic of schematic arrangements (such as the philosophical principles behind the planetary rulership of signs)
Domicile (astrology)
In astrology, a planet's domicile is the zodiac sign over which it has rulership. This is a separate concept from the houses of the horoscope. A planetary ruler is given to each sign, over which the planet is said to have a more powerful influence when positioned therein...

, but has been noted to convey detachment in regard to the elements of astrology that are not so obviously plausible. This can be seen in the way that Ptolemy avoids going into detail on the facets of astrology that rely on mythological, or symbolic
Symbol
A symbol is something which represents an idea, a physical entity or a process but is distinct from it. The purpose of a symbol is to communicate meaning. For example, a red octagon may be a symbol for "STOP". On a map, a picture of a tent might represent a campsite. Numerals are symbols for...

 associations, and how he is willing to outline the reasoning behind conflicting astrological proposals without revealing any personal preference for one scheme over another.

Some commentators have viewed Ptolemy’s comparatively dispassionate approach towards points of astrological contention as reason to suppose he was more interested in the theoretical principles than the actual practice of astrology. On the other hand, the objective tone that marks his style; his assertion that the subject is natural (by which he makes no demand for oaths of secrecy from its students as some contemporaries do); and the way he shows respectful reference to alternative views without vilifying authors whose practices might differ from his own, all helped to secure the text’s historical reputation as an intellectually superior one. Classics
Classics
Classics is the branch of the Humanities comprising the languages, literature, philosophy, history, art, archaeology and other culture of the ancient Mediterranean world ; especially Ancient Greece and Ancient Rome during Classical Antiquity Classics (sometimes encompassing Classical Studies or...

 scholar Mark Riley raised these points in his assessment that Ptolemy approached the subject of astrology with exactly the same theoretical inclination that he applied to astronomy, geography and the other sciences on which he wrote. This distinctive style of approach led Riley to conclude: “The respect shown to Ptolemy’s work by all later astrologers was due, not to its usefulness to the practitioner, but to his magisterial synthesis of astrology and science”.

Book II: Mundane astrology

Book II presents Ptolemy's treatise on mundane astrology
Mundane astrology
Mundane astrology is the application of astrology to world affairs and world events, taking its name from the Latin word Mundus, meaning "the World". Mundane astrology is a branch of Judicial astrology and is widely believed by astrological historians to be the most ancient branch of astrology...

. This offers a comprehensive review of ethnic stereotypes, eclipses, significations of comets and seasonal lunations
Lunar phase
A lunar phase or phase of the moon is the appearance of the illuminated portion of the Moon as seen by an observer, usually on Earth. The lunar phases change cyclically as the Moon orbits the Earth, according to the changing relative positions of the Earth, Moon, and Sun...

, as used in the prediction of national economics, wars, epidemics, natural disasters and weather patterns. No other surviving ancient text offers a comparable account of this topic, in terms of the breadth and depth of detail offered by Ptolemy. Although no demonstrated examples are given, he writes with authority in this branch of his subject, which suggests it was of particular interest to him. Modern commentators have remarked that Ptolemy was “consciously taking a different approach” to contrast “with the ‘old’, infinitely complicated methods”.

Ptolemy begins by stating he has briefly reviewed the important principles and will now develop the details of astrology in the appropriate order. His point is that astrological assessment of any ‘particular’ individual must rest upon prior knowledge of the ‘general’ temperament of their ethnic type; and that the circumstances of individual lives are subsumed, to some extent, within the fate of their community.

The second chapter gives a broad generalization of how genetic differences develop between the inhabitants of the various climes (a demarcation based on latitude). Communities that live close to the equator, for example, are described as having black skins, small statures, and thick woolly hair, as a protective response to the burning heat of that location. By contrast, communities that have settled in high northern regions are defined by their colder environment and its greater share of moisture. Their bodily forms are paler, taller, with finer hair, and in their characteristics they are described as “somewhat cold in nature”. Both types are described as lacking civilization because of the extremes of their environment, whereas communities that live in temperate regions are medium in colouring, moderate in stature and enjoy a more equable lifestyle. The several regions are similarly defined according to the mix that arises within this kind of analysis. Ptolemy explains that such considerations are only dealt with summarily, as a background consideration for what follows. He also makes clear that such traits are to be found “generally present, but not in every individual”.

In chapter 3 Ptolemy unites his interests in astrology and geography, to outline the astrological associations of “our inhabited world”. Maps based on Ptolemy’s Geographica show Ptolemy’s definition of the inhabited world as (roughly) extending from the equator to latitude 66°N, covering the land mass between the Atlantic Ocean and East China Sea. Ptolemy extends the logic given in ancient Babylonian texts where the four quarters of the known world are attributed to the four triplicity
Triplicity
In astrology, a triplicity is a group of three signs belonging to the same element.-Trines:Western astrology assumes that each sign of the same triplicity is 120 degrees apart, forming angles to one another called trines, which are each equivalent to the 360 degrees of the circle divided by three...

 arrangements of the zodiac. The attribution is based on association between the planets that govern the triplicities and the directions and winds those planets are affiliated with. For example, the ‘Aries triplicity’ (which includes Aries, Leo and Sagittarius) is chiefly dominated by Jupiter and assisted by Mars. Jupiter rules the north wind and Mars the west wind; therefore this triplicity governs the north-west quarter of Ptolemy’s ‘inhabited world’: the area known as Europe.

Again, these divisions are general, and specific rulership of each nation is modified by location and observed cultural distinctions. For example, in Europe, only those regions that lie to the north-west extremes are fully attributed to Jupiter and Mars, since those that lie towards the centre of the inhabited area incline towards the influence of opposing regions. In this way, the ‘inhabited region’ experiences a drift of astrological correspondence rather than sharp divisions within its quarters, and independent nations are variously affiliated with the signs of each triplicity and the planets that rule them. Ptolemy names Britain and Spain as two nations appropriately placed in the north-west quarter to accept the rulership of Jupiter and Mars. Such nations are described as “independent, liberty-loving, fond of arms, industrious”, based on characteristics attributed to those planets. Being predominantly governed by masculine planets they are also “without passion for women and look down upon the pleasures of love”. Observed characteristics influence his categorization of Britain as having a closer affinity with Aries and Mars (by which “for the most part its inhabitants are fiercer, more headstrong and bestial”), whilst Spain is reported to be more subject to Sagittarius and Jupiter, (from which is evidenced “their independence, simplicity and love of cleanliness”).

Though Ptolemy describes his analysis as a “brief exposition”, the chapter builds into an extensive association between planets, zodiac signs and the national characteristics of 73 nations. It concludes with three additional assertions which act as core principles of mundane astrology:
  1. Each of the fixed stars has familiarity with the countries attributed to the sign of its ecliptic rising.
  2. The time of the first founding of a city (or nation) can be used in a similar way to an individual horoscope
    Horoscope
    In astrology, a horoscope is a chart or diagram representing the positions of the Sun, Moon, planets, the astrological aspects, and sensitive angles at the time of an event, such as the moment of a person's birth. The word horoscope is derived from Greek words meaning "a look at the hours" In...

    , to astrologically establish the characteristics and experiences of that city. The most significant considerations are the regions of the zodiac which mark the place of the Sun and Moon, and the four angles of the chart
    Angle (astrology)
    The angles are the four Cardinal points of an astrological chart: the Ascendant, the Midheaven, the Descendant and the Imum Coeli.The astrological chart is a schematic representation of the sky at any given moment of time, projected upon the ecliptic--or the apparent path of the Sun as seen from...

     – in particular the ascendant
    Ascendant
    The ascendant , or rising sign, is the zodiacal sign and degree that was ascending on the eastern horizon at the specific time and location of an event. According to astrological theory, celestial phenomena reflect or determine human activity on the principle of 'as above so below'...

    .
  3. If the time of the foundation of the city or nation is not known, a similar use can be made of the horoscope of whoever holds office or is king at the time, with particular attention given to the midheaven
    Midheaven
    The midheaven is a point of definition in the ecliptic coordinate system. It aims to find the part of the ecliptic that corresponds to the highest point in a celestial object's apparent daily traverse of the visible sky, midway between its ascension on the eastern horizon and descension on the...

     of that chart.

Use of eclipses

The remainder of the book shows how this information is used in the prediction of mundane events. Focus is given to eclipses, as the “first and most potent” cause of change, supplemented by examination of the ‘stations’ of the superior planets: Saturn, Jupiter and Mars. Although eclipses are deemed relevant to any nation affiliated with the zodiac signs in which they occur, Ptolemy's scrutiny is reserved for regions where they are visible, which he argues will manifest the effects most noticeably. The period of obscuration determines the endurance of the effect, with each hour proportioning to years for a solar eclipse and months for a lunar eclipse. The location of the eclipse with relation to the horizon is then used to judge whether the effects are most prevalent at the beginning, middle or end of the period, with times of intensification identified by planetary contacts to the degree of the eclipse which occur within this period.

Chapter 7 begins the examination of what type of event will manifest. This is judged by the angle of the horizon
Angle (astrology)
The angles are the four Cardinal points of an astrological chart: the Ascendant, the Midheaven, the Descendant and the Imum Coeli.The astrological chart is a schematic representation of the sky at any given moment of time, projected upon the ecliptic--or the apparent path of the Sun as seen from...

 which precedes the eclipse in the chart set for the location under scrutiny and the planet(s) that dominate this angle by rulership and powerful aspectual connections. Whether the predicted effect is beneficial or destructive depends on the condition of these planets, whilst the type of manifestation is judged by the zodiac signs, fixed stars and constellations involved. The resulting prediction is of relevance to nations, but Ptolemy points out that certain individuals are more resonant to the effects than others; namely those have the Sun or Moon in their horoscopes in the same degree as the eclipse, or the degree that directly opposes it.

Within his Almagest Ptolemy explains that he had access to eclipse records kept for 900 years since the beginning of the reign of king Nabonassar
Nabonassar
Nabonassar founded a kingdom in Babylon in 747 BC. This is now considered as the start of the Neo-Babylonian Dynasty. At the time the Assyrian Empire was in disarray through civil war and the ascendancy of other kingdoms such as Urartu...

 (747 BC). In chapter 9 of the Tetrabiblos he shows knowledge of the Babylonian lore that accompanied these records in detailing the omens based on visual phenomena. The colours of eclipses and “the formations that occur near them, such as rods, halos, and the like” are considered along with the astrological significance of comets, in whether they take the form of “‘beams’, ‘trumpets’, ‘jars’, and the like”. Meaning is derived from their position relative to the Sun and assessment of “the parts of the zodiac in which their heads appear and through the directions in which the shapes of their tails point.” It has been noted that here Ptolemy uses principles that fall outside the neat theoretical logic he presents in book I, being explicable only in terms of the mythological and omen tradition inherited from his ancient sources. He also defends the subjective nature of the analysis involved, asserting that it would be impossible to mention the proper outcome of all this investigation, which calls for enterprise and ingenuity from the astrologer creating the judgement.

The remaining chapters of book II are dedicated to meteorological matters. Chapter 10 specifies that the new or full Moon preceding the Sun’s ingress into Aries can be used as a starting point for investigations concerning the weather patterns of the year. Lunations which precede the Sun’s ingress into any the other equinoctial and solstice signs (Cancer, Libra and Capricorn) can also be used for seasonal concerns, and within these “monthly investigations” bring more particular details based on lunations and the conjunctions of the planets. The recorded weather effects of the fixed stars in the zodiac constellations are systematically discussed, concluding with the relevance of generally observed sky phenomena such as shooting stars, cloud formations and rainbows. These final considerations are expected to add localized details to the original exploration of eclipse cycles. Ptolemy's theme throughout the book is that charts of this nature cannot be judged in isolation, but are to be understood within the pattern of cycles to which they belong, and where there are strong connections between the degree points involved; for:
With the astrologer expected to have knowledge and awareness of the mundane cycles that outline the background principles of the personal horoscope, Ptolemy closes this book with the promise that the next will supply “with due order” the procedure which allows predictions based on the horoscopes of individuals.

Book III: Individual horoscopes (genetic influences and predispositions)

Books III and IV explore what Ptolemy terms “the genethlialogical art”: the interpretation of a horoscope set for the moment of the birth of an individual. He explains that there are several cycles of life to consider but the starting point for all investigation is the time of conception or birth. The former “the genesis of the seed” allows knowledge of events that precede the birth; the latter “the genesis of the man” is “more perfect in potentiality” because when the child leaves the womb and comes “forth into the light under the appropriate conformation of the heavens” the temperament, disposition and physical form of the body is set. The two moments are described as being linked by a “very similar causative power”, so that the seed of the conception takes independent form at an astrologically suitable moment, whereby the impulse to give birth occurs under a “configuration of similar type to that which governed the child's formation in detail in the first place”. Chapter 2 continues this theme in discussing the importance of calculating the precise degree of the ascendant at birth, the difficulty of recording local time precisely enough to establish this, and the methods available for rectification (i.e., ensuring the chart is correct).

Chapter 3 describes how the analysis of the chart is divided into predictions of:
1) essential, genetic qualities established prior to birth (such family and parental influences),
2) those that become known at the birth (such as the sex of the child and birth defects), and
3) those that can only be known post-natally (such as length of life, the quality of the mind, illnesses, marriage, children, and material fortunes).


Ptolemy explains the order by which each theme becomes relevant, and follows this in his arrangement of topics presented in the remaining chapters of books III and IV.

First he deals with the prenatal matters, covering the astrological significators of the parents in chapter 4, and siblings in chapter 5. Then he deals with the matters “directly concerned with the birth”, explaining how to judge such issues as whether the child will be male or female (ch.6); whether the birth will produce twins or multiple children (ch.7); and whether it will involve physical defects or monstrous forms; if so, whether these are accompanied by mental deficiency, notability or honour (ch.8).

The exploration of post-natal concerns begins in chapter 9 with a review of astrological factors that occur when children are not reared. This considers the indications of still births and babies that seem "half-dead", or those that have been left exposed (including whether there is possibility they may be taken up and live). Chapter 10 then details the techniques for establishing the length of life under normal circumstances. This is an important and lengthy passage of text, the techniques of which require precise astronomical detail and advanced knowledge of complex progressive techniques. Jim Tester has commented on how Ptolemy goes into an unusual level of detail in a responsibility that Bouché-Leclercq
Auguste Bouché-Leclercq
- Life :Auguste Bouché-Leclercq was born in 1842 at Francières, Oise as son of Louis-Thomas Bouché and Marie-Joséphine Leclercq. His parents were farmers. He was educated at seminaries and took his school-leaving exam in 1861 in Paris. Later he travelled as private tutor several months through...

 described as “the chief task of astrology, the operation judged most difficult by practitioners, most dangerous and damnable by its enemies”. Such a prediction involves judicial skill as well as mathematical expertise since several 'destructive' periods may be identified but countered by other, protective astrological influences, resulting in periods of danger or illness that does not lead to death. This is followed, in chapter 11, by the astrological principles from which judgement is made of bodily appearance and temperament. Since these define, to some extent, predisposition towards bodily afflictions, there is a natural flow towards the content of chapter 12, which focuses on the astrological significators relating to injuries and diseases.

The third book concludes with chapters 13 and 14, which discuss the qualities and diseases of the soul. The concerns of the ‘soul’ (or 'psyche') include the faculty for conscious reasoning, which is attributed to the condition of Mercury, and the subconscious and unconscious elements of the mind (the “sensory and irrational part”) which is attributed to the condition of the Moon. These two chapters make analysis of instinctual impulses and moral inclinations, being concerned with psychological motives and behavioral expression rather than the physical temperament described in chapter 11. Diseases of the soul are defined as “affections which are utterly disproportionate and as it were pathological” including insanity, inability to exercise moderation or restraint, instability of the emotions, depraved sexuality, morbid pervasions, and violent afflictions of the intellectual and passive parts of the mind. The astrological explanations are mainly related to the exaggerated influence of destructive planets which are also in difficult configurations with Mercury and the Sun or Moon, or the planet associated with the psychological impulse (for example, Venus in matters of sexuality).

Within this book Ptolemy has surveyed all the topics that relate to inner qualities, genetic patterns, predispositions and the natural tendencies present from birth. His exploration of individual horoscopes continues smoothly into book IV, the only distinction being that subsequent topics relate to material matters and life experiences, or what Ptolemy refers to as “external accidentals”.

Book IV: Individual horoscopes ('external accidentals')

Book IV is presented with a brief introduction to reaffirm the arrangement of content as previously described. It starts with the topics of riches and honour. Ptolemy says: “as material fortune is associated with the properties of the body, so honour belongs to those of the soul”. Chapter 2, on material wealth, employs the “so-called ‘Lot of Fortune’” although Ptolemy’s instruction conflicts with that of many of his contemporaries in stating that for its calculation “we measure from the horoscope the distance from the sun to the moon, in both diurnal and nocturnal nativities”. Ptolemy’s reputation ensured this approach to calculation was adopted by many later Medieval and Renaissance astrologers, although it is now realized that most Hellenistic astrologers reversed the formula of calculation for nocturnal births
Astrology of sect
Sect is an ancient astrological concept in which the seven traditional "planets" are assigned to two different categories: diurnal or nocturnal sect....

. It is notable that in his discussion “Of the fortune of Dignity”, in chapter three, Ptolemy makes no reference to the Lot of Spirit (or Daimon), which would normally be used as the spiritual counterpart to the material wealth and happiness associated with the Lot of Fortune. This has been viewed as a demonstration of his general dislike (declared in bk. III.3) for "lots and numbers of which no reasonable explanation can be given".
The subsequent chapter, the title of which is translated by Robbins as ‘Of the Quality of Action’, concerns professional inclinations and the significators of career advance (or decline). This is followed by the treatment of marriage in chapter 5, which is primarily referred to the Moon in a man's chart, to describe his wife, and the Sun in a woman's chart to describe her husband. Here Ptolemy shows employment of the astrological technique known as synastry, in which the planetary positions of two separate horoscopes are compared with each other for indications of relationship harmony or enmity.

The next four chapters complete the survey of natal themes, dealing with the topics of children (ch.6); friends and enemies (ch.7); the dangers of foreign travel (ch.8) and the quality (or type) of death (ch.9 – as opposed to the time of death considered in III.10).

The final chapter of the work has been described as “a curious one” for introducing a separate theme at the end of the book. This refers to the seven ‘ages of man’, which Ptolemy briefly mentioned in III.1 as a matter which varies the emphasis of astrological configurations according to the time in life they occur: "we predict events that will come about at specific times and vary in degree, following the so called ages of life.
His argument is that, just as an astrologer must consider cultural differences “lest he mistake the appropriate customs and manners by assigning, for example, marriage with a sister to one who is Italian by race, instead of to the Egyptian as he should”, it is necessary to consider the age in life that important astrological events occur. This is to ensure the prediction will “harmonize those details which are contemplated in temporal terms with that which is suitable and possible for persons in the various age-classes” and avoid out-of-context predictions such as imminent marriage for a young child, or “to an extremely old man the begetting of children or anything else that fits younger men”. This leads into a discussion of the planetary themes of the seven ages of life which:
The information in the passage can be summarized as follows:
EWLINE
Planet Period Years Age Planetary theme
Moon
Moon (astrology)
The Moon is the Earth's companion satellite. The Moon is large enough for its gravity to affect the Earth, stabilising its orbit and producing the regular ebb and flow of the tides. The Moon is also familiar to us for its different phases, waxing and waning in appearance in an unchanging cycle...

first 4 years 0–3 babyhood suppleness, growth, changeability, nourishment of the body
Mercury
next 10 years 4–14 childhood development of intelligence, articulation, physical and mental dexterity
Venus
next 8 years 15–22 youth impulse towards love and sexuality, burning passion, guile
Sun
Sun (astrology)
The sun is considered a very important part of astrology. It, as well as the Moon, are the most important of the astrological planets, and the two of them are often referred to as the luminaries. In Greek mythology the sun was represented by Apollo, the god of light, and Helios, the god of the sun...

next 19 years 23–41 early manhood responsibilities, ambition, substance, decorum, change from playfulness
Mars
next 15 years 42–56 later manhood severity, realisation of passing prime, labour to complete life-tasks
Jupiter
next 12 years 57–68 full maturity fulfilment, retirement, independence, dignity, deliberation, honour
Saturn
all remaining years 69–death old age coldness, weakness, decline, impediments, dispiritedness

The book ends with a brief discussion of astronomical and symbolic cycles used in the prediction of timed events, which includes mention of (primary) directions, annual profections, ingresses, lunations and transits.

The conclusion of the book is unreliable. The original ending is thought to have been lost so early that it is missing from all manuscripts. Of the variants that exist, one leaves the text unconcluded, one appears to have been supplied by reference to the Proclus Paraphrase, and another has Ptolemy declare that “since the topic of nativities has been summarily reviewed, it would be well to bring this procedure also to a fitting close”.

Centiloquium

A collection of 100 astrological aphorism
Aphorism
An aphorism is an original thought, spoken or written in a laconic and memorable form.The term was first used in the Aphorisms of Hippocrates...

s, known in Latin as the Centiloquium
Centiloquium
The Centiloquium , also called Ptolemy's Centiloquium, is a collection of one hundred aphorisms about astrology and astrological rules...

 and Arabic as Kitab al-Tamara ('Book of the Fruit'), was also attributed to Ptolemy and frequently associated with the Tetrabiblos. A commentary on the Centiloquium was written in the tenth century by Ahmad ibn Yusuf al-Misri, and at least four Latin translations were made of this in the 12th century. Editions of the Centiloquium were often appended to Ptolemy's Tetrabiblos as supposedly offering 'The Fruit of his Four Books'.

The Centiloquiums aphorisms mainly concern the principles of interrogational
Horary astrology
Horary astrology is an ancient branch of horoscopic astrology by which an astrologer attempts to answer a question by constructing a horoscope for the exact time at which the question was received and understood by the astrologer...

 and electional
Electional astrology
Electional astrology, also known as event astrology, is a branch found in most traditions of astrology in which a practitioner decides the most appropriate time for an event based on the astrological auspiciousness of that time...

 astrology, and touch upon points of astrological practice that are absent in the Tetrabiblos. Some scholars suggest that Ahmad ibn Yusuf was its true author, while others believe that the Centiloquium, though not Ptolemy's, may preserve some collation of authentic materials from Hellenistic astrology
Hellenistic astrology
Hellenistic astrology is a tradition of horoscopic astrology that was developed and practiced in Hellenistic Egypt and the Mediterranean, whose texts were written in Greek , mainly around the late 2nd or early 1st century B.C.E...

. Regardless of its true origin and authorship, the historical assumption that the Centiloquium was part of Ptolemy's astrological legacy allowed it to become an important, influential astrological treatise in its own right.

Editions and translations

No early manuscript copies of the text have survived; its contents are known from translations, fragments, paraphrased copies, commentaries and later Greek manuscripts.

The oldest extant manuscript is an Arabic translation of the 9th century by Ishaq ben Husein. This was translated into Latin, in Barcelona, by Plato de Tivoli
Plato Tiburtinus
Plato Tiburtinus was a 12th century Italian mathematician, astronomer and translator who lived in Barcelona from 1116 to 1138. He is best known for translating Hebrew and Arabic documents into Latin, and was apparently the first to translate information on the astrolabe from Arabic.Plato of...

 in 1138, and his version survives in at least nine manuscripts and five Renaissance printings.

An important 'anonymous' Greek paraphrase is speculatively attributed to the 5th century philosopher Proclus
Proclus
Proclus Lycaeus , called "The Successor" or "Diadochos" , was a Greek Neoplatonist philosopher, one of the last major Classical philosophers . He set forth one of the most elaborate and fully developed systems of Neoplatonism...

 (hence called the ‘Proclus’ Paraphrase although there is controversy concerning the authenticity of its origin). The text of the Paraphrase is close to that of manuscripts which purport to reproduce the Tetrabiblos directly, but it uses a simpler form of Greek to convey the gist of Ptolemy’s meaning without adhering to his highly complex and precisely structured language.

The oldest extant manuscript of the Paraphrase in Greek is a 10th century copy in the Vatican Library
Vatican Library
The Vatican Library is the library of the Holy See, currently located in Vatican City. It is one of the oldest libraries in the world and contains one of the most significant collections of historical texts. Formally established in 1475, though in fact much older, it has 75,000 codices from...

 (Codex Vaticanus Graecus 1453). This text was carefully reproduced in Greek with an accompanying Latin translation by the Vatican scholar Leo Allatius
Leo Allatius
Leo Allatius was a Greek scholar, theologian and keeper of the Vatican library....

 in 1635, and the Latin text of this work was used as the source for all the English translations of the Tetrabiblos prior to that made by Frank Eggleston Robbins in 1940. These include translations made by: John Whalley (1701), the Whalley ‘corrected edition’ made by the Ebenezer Sibly
Ebenezer Sibly
Ebenezer Sibly was an English physician, astrologer and writer on the occult.He had the M. D. degreeSibly is celebrated for the natal horoscope he cast of the United States of America, published in 1787 and still cited....

 and his brother (1786), J.M. Ashmand (1822), James Wilson (1828), and other privately circulated manuscripts of the 19th century such as that produced by John Worsdale.
The oldest Greek manuscript offering a text of the Tetrabiblos rather than the Paraphrase is dated to the 13th century. This forms the basis of a Greek and Latin translation by the German classical scholar Joachim Camerarius
Joachim Camerarius
Joachim Camerarius , the Elder was a German classical scholar.-Life:He was born at Bamberg, Bavaria...

, published at Nuremberg
Nuremberg
Nuremberg[p] is a city in the German state of Bavaria, in the administrative region of Middle Franconia. Situated on the Pegnitz river and the Rhine–Main–Danube Canal, it is located about north of Munich and is Franconia's largest city. The population is 505,664...

 in 1535. Robbins used the second edition of the Camerarius text as his primary source and noted the page numbers of the Greek text from Camerarius in his own Greek text (which faces the English translation). In the same year (1940) a Greek critical edition was published by Teubner, Germany, the result of the unpublished work of Professor Franz Boll
Franz Boll
Franz Boll was a German scholar. He became Professor of Classical Philology at the University of Heidelberg.He is known for his editorial and biographical work on Claudius Ptolemy. He also wrote on astrology. He is quoted as saying "Astrology wants to be religion and science at the same time; that...

 (died: 1924) being completed by his student Emilie Boer. Robbins confessed regret at having published slightly beforehand, and so not being able to integrate the benefit of this new critical Greek edition. In 1994 the 'Boll-Boer' edition became the basis of the English translation serialised by Robert Schmidt for Project Hindsight
Project Hindsight
Project Hindsight is a translation project founded in 1993 to translate and interpret the surviving texts of the Western astrological tradition. The project is mainly supported by the astrological community through donations and through sales of translations and related material.- History :The...

.

The most recent critical edition of the Greek text was published by Wolfgang Hübner in 1998. Based on 33 complete and 14 partial manuscripts, Hübner also incorporated the unpublished notes of Boer and the reasoning given in the Robbins and Boll-Boer editions. A reviewer’s comment in The Classical Review declares of it “Progress over previous editions is evident on virtually every page”.

Scholars and historical astrologers have also given significant attention to an ‘anonymous’ Commentary on the Tetrabiblos, which has obscure origins but is also speculatively attributed to Proclus, as the presumed author of the Paraphrase. This was published in Greek with a Latin translation by Hieronymus Wolf
Hieronymus Wolf
Hieronymus Wolf was a sixteenth-century German historian and humanist, most famous for introducing a system of Byzantine historiography that eventually became the standard in works of medieval Greek history.- His life :...

 in 1559 and subsequently incorporated into various Latin commentaries on the Tetrabiblos, which explained its principles alongside elaborate collections of example horoscopes. Two notable examples are Jerome Cardan's Ptolemaei De Astrorvm Ivdiciis (Basel, 1578) and Francisco Junctinus's Speculum Astrologiae (Lugduni, 1583). Modern translators also continue to make reference to the Hieronymous Wolf Commentary in their explanatory annotations.

See also

  • Babylonian astronomy - the ancient sources transmitted to Ptolemy.
  • Greek astronomy
    Greek astronomy
    Greek astronomy is astronomy written in the Greek language in classical antiquity. Greek astronomy is understood to include the ancient Greek, Hellenistic, Greco-Roman, and Late Antiquity eras. It is not limited geographically to Greece or to ethnic Greeks, as the Greek language had become the...

     - the astronomy of Ptolemy's era.
  • Ptolemy's world map
    Ptolemy's world map
    The Ptolemy world map is a map of the known world to Western society in the 2nd century AD. It was based on the description contained in Ptolemy's book Geographia, written c. 150...

     – map of the ancient world as described by Ptolemy.

Works cited

.

Further reading

  • Theoretical and Practical Astrology: Ptolemy and his Colleagues by Mark Riley, 1974; Transactions of the American Philological Association, 117, (Baltimore; London: John Hopkins University Press). Explores the difference of approach taken by Ptolemy to that of other contemporary astrologers.
  • Science and Tradition in the Tetrabiblos by Mark Riley, 1988; Proceedings of the American Philosophical Society, 132.1, (Philadelphia: American Philosophical Society). Considers the question of what Ptolemy contributed to astrology and why his work was so significant.

External links

English language reproductions of the Tetrabiblos and associated texts:

Greek and Latin reproductions of the Tetrabiblos and associated texts:
  • Erhard Ratdolt, Venice, 1484. First printed Latin edition of Tetrabiblos based on Plato de Tivoli
    Plato Tiburtinus
    Plato Tiburtinus was a 12th century Italian mathematician, astronomer and translator who lived in Barcelona from 1116 to 1138. He is best known for translating Hebrew and Arabic documents into Latin, and was apparently the first to translate information on the astrolabe from Arabic.Plato of...

    's 12th century Latin translation. Also includes the Centiloquium and Commentary by Haly Abenragel
    Haly Abenragel
    Abû l-Hasan 'Alî ibn Abî l-Rijâl was an Arab astrologer of the late 10th and early 11th century, best known for his Kitāb al-bāri' fi ahkām an-nujūm. He was a court astrologer to the Tunisian prince al-Mu'izz ibn Bâdis in the first half of the 11th century...

     (Albohazen). Biblioteca Virtual del Patrimonio Bibliografico; retrieved 10 November 2011.
  • Bonetum Locatellum, Venice, 1493. Compemdium of Latin texts including the Tetrabiblos, Centiloquium, and Ali ibn Ridwan
    Ali ibn Ridwan
    Abu'l Hasan Ali ibn Ridwan Al-Misri was an Egyptian Muslim physician, astrologer and astronomer, born in Giza.He was a commentator on ancient Greek medicine, and in particular on Galen; his commentary on Galen's Ars Parva was translated by Gerardo Cremonese...

    's Commentary. Gallica Biblioteque nationale de France; retrieved 20 November 2011.
  • Heirs of Octavius Scoti, Venice, 1519. Compendium of Latin texts including the Tetrabiblos and Centiloquium. Universidad de Sevilla; retrieved 20 November 2011.
  • Johannes Hervagius, Basel, 1533. Latin edition based on Plato de Tivoli
    Plato Tiburtinus
    Plato Tiburtinus was a 12th century Italian mathematician, astronomer and translator who lived in Barcelona from 1116 to 1138. He is best known for translating Hebrew and Arabic documents into Latin, and was apparently the first to translate information on the astrolabe from Arabic.Plato of...

    's translation. Warburg Institute; retrieved 19 November 2011.
  • Heinrich Petri, Basel, 1541. Latin edition containing Ptolemy's Almagest, Tetrabiblos, and the Centiloquium. Biblioteca Virtual del Patrimonio Bibliografico; retrieved 19 November 2011.
  • Heinrich Petri, Basel, 1591. Latin reproduction of Hieronymous Wolf's translation the 'anonymous' Commentary attributed to Proclus. Biblioteca Virtual del Patrimonio Bibliografico; retrieved 19 November 2011.
  • Leo Allatius, Lugd. Batavorum, 1635. Greek and Latin translation of the 'anonymous' Proclus Paraphrase (Procli Diadochi Paraphrasis) based on manuscripts housed in the Vatican Library (oldest dates to 10th century: Codex Vaticanus Graecus 1453). Warburg Institute; retrieved 19 November 2011.
  • Emily Boer, Leipzig, 1961. Greek language edition of the Centiloquium published by Teubner. Open Library; retrieved 26 November 2011.


Greek and Latin astrological works with substantial reference to the Tetrabiblos and the Commentary:
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