Show Summary Details

Page of

Printed from Oxford Research Encyclopedias, Planetary Science. Under the terms of the licence agreement, an individual user may print out a single article for personal use (for details see Privacy Policy and Legal Notice).

Subscriber: Google Scholar Indexing; date: 02 October 2023

Astrology in Ancient Greek and Roman Cultureunlocked

Astrology in Ancient Greek and Roman Cultureunlocked

  • Nicholas CampionNicholas CampionUniversity of Wales Trinity Saint David, Sophia Centre for the Study of Cosmology in Culture


Astrology was a central feature of Greek and Roman culture. A knowledge of astrology’s claims, practices, and world view is essential for a full understanding of religion, politics, and science in the Greek and Roman worlds. Astrology is the name given to a series of diverse practices based in the idea that the stars, planets, and other celestial phenomena possess significance and meaning for events on Earth. It assumes a link between Earth and sky in which all existence, spiritual, psychological, and physical, is interconnected. Most premodern cultures practice a form of astrology. A particularly complex variety of it evolved in Mesopotamia in the first and second millennia bce from where it was imported into the Hellenistic world from the early 4th century bce onward. There it became attached to three philosophical schools, those pioneered by Plato, Aristotle and the Stoics, all of which shared the assumption that the cosmos is a single, living, integrated whole. Hellenistic astrology also drew on Egyptian temple culture, especially the belief that the soul could ascend to the stars. By the 1st century ce, the belief in the close link between humanity and the stars had become democratized and diversified into a series of practices and schools of thought which ranged across Greek and Roman culture. It was practiced at the imperial court and in the street. It could be used to predict individual destiny, avert undesirable events, and arrange auspicious moments to launch new enterprises. It could advise on financial fortunes or the condition of one’s soul. It was conceived of as natural science and justified by physical influences or considered to be divination, concerned with communication with the gods and goddesses. In some versions, the planets were neither influences nor causes of events on Earth, but timing devices, which indicated the ebb and flow of human affairs, like the hands on a modern clock. Astrology had a radical view of time in which the future already existed, at least in potential, and the astrologer’s task was to intercede in time, altering the future to human advantage. In this sense astrology was a form of “participation mystique” in which time and space were conceived of as a single entity and individual and social benefits were to be derived from engaging with it. There was no one single version of astrology and there were disputes about what it was and what it could do, for example, whether it could make precise predictions about individual affairs or merely general statements. From the early 4th century it went into a progressive decline, facing challenges from Christianity and the fragmentation of classical culture, especially in Western Europe. It survived in Persia, exerted a powerful influence on Indian astrology, and was transmitted to the Islamic world, from where it was reimported into the Latin West in the 12th century.


  • History of Ideas about Planets and Planetary Systems


Astrology was the main expression of planetary “science” in Greek and Roman culture, and mathematical astronomy largely developed in order to increase astrology’s predictive accuracy. Astrology is best understood as a series of diverse practices based in the idea that the stars, planets, and other celestial phenomena possess significance and meaning for events on Earth. It is a prime example of the interaction between astronomy and culture, and a knowledge of its theory and practice is essential for a full understanding of life in the Greek and Roman worlds. The central actors in classical astrology were the visible planets (Mercury, Venus, Mars, Jupiter, and Saturn) along with the Sun and Moon (sometimes referred to as planets in the literature). The planets exerted physical influences, possessed a range of meanings which held significance for terrestrial affairs, described individual destinies, indicated auspicious moments to launch new ventures, and represented divine intentions. Their relationship with each other as well as other celestial bodies (such as the fixed stars) and divisions of the sky (including constellations and zodiac signs) formed the interpretative centerpiece of astrology

To comprehend the role of the planets in the Greek and Roman worlds, it is necessary to consider the wider contexts of astrology: its theoretical background, technical basis, interpretative conventions, social functions, religious and political uses and theory of fate, as well as critiques of it. Astrology assumes a link between Earth and sky in which all existence, spiritual, psychological, and physical, is interconnected. Most premodern cultures practice a form of astrology. A particularly complex variety of it evolved in Mesopotamia in the second and first millennia bce from where it was imported into the Hellenistic world from the early 4th century bce onward. There it became associated with three philosophical schools, those pioneered by Plato, Aristotle, and the Stoics, all of which shared the assumption that the cosmos is a single, living, integrated whole. Hellenistic astrology also drew on Egyptian temple culture, especially the belief that the soul could ascend to the stars. By the 1st century ce, the belief in the close link between humanity and the stars had become democratized and diversified into a series of practices and schools of thought that ranged across Greek and Roman culture. Astrology was practiced at the imperial court and in the street. It could be used to predict individual destiny, avert undesirable events, and arrange auspicious moments to launch new enterprises. It could advise on financial fortunes or the condition of one’s soul. It was conceived of as natural science and justified by physical influences, or considered to be divination, concerned with communication with gods and goddesses. In some versions, the planets were influences or causes of events on Earth; in others, they were timing devices, which indicated the ebb and flow of human affairs, like the hands on a modern clock, but without exerting any causal influence. One reading of the classical texts leads to the conclusion that astrology had a radical view of time in which the future already existed, at least in potential, and so it was possible to predict the future. Others believed that the astrologer’s task was to intercede in time, altering the future to human advantage. In this sense, astrology may be seen as the modern world may see astrology: as a form of what Lucien Lévi-Bruhl (1926) called “participation mystique” in which time and space were conceived of as a single entity and individual and social benefits were to be derived from engaging with it. There was no one single version of astrology and there were disputes about what it was and what it could do; for example, whether it could make precise predictions about individual affairs or merely general statements. It may therefore be best to think about the issue in terms of diversity. That astrological authors wrote in Greek or Latin does not mean that they were Greek or Roman in any narrow sense. In the 5th century bce, there were Greek colonies around the Mediterranean and Alexander’s conquests extended Greek-speaking culture to the borders of India. The Roman Empire’s direct trading links also extended to India, and if it is known that there was a trade in artefacts, then the possibility of an exchange in ideas also exists.

From the early 4th century ce, astrology went into a progressive decline, facing challenges from the rise of Christianity and the fragmentation of classical culture, especially in Western Europe. It survived in Persia, exerted a powerful influence on Indian astrology, and was transmitted to the Islamic world, from where it was reimported into the Latin West in the 12th century. A knowledge of astrology’s place in Greek and Roman culture is essential for a full understanding of religion, politics, and science in the Greek and Roman worlds, as well as for the history of Western science in general.

Definition, Historiography, and Philosophy

The terms astrology and astronomy were used interchangeably until the 17th century. The idea that astronomy, defined as the study of the motion, nature, and physical composition of the stars, is separate to astrology, defined as the examination of their significance and meaning for terrestrial affairs, appears to have been largely unknown in non-Western and premodern cultures. That the words astronomia (loosely the law of the stars) and astrologia (the word of the stars) were used interchangeably in Greek literature suggests that there was no difference between what would be defined from the late 17th century onward as astronomy and astrology (although this may also be the result of a lack of standardization in the terms used). For example, the first complete extant work on what we would now call astrology, Marcus Manilius’ 1st-century text, was actually called the Astronomica (Manilius, 1977). Other titles for astrology books included the Apotelesmatiká, or “Outcomes” (of the stars), the original name for Claudius Ptolemy’s 2nd-century ce Tetrabiblos (1940), and the Anthologiae, compiled by Ptolemy’s rough contemporary, Vettius Valens (2010).

Given that there is no standard definition or usage of the word astrology in the Greek and Roman worlds, a modern definition must be used. Patrick Curry’s is becoming widely accepted in the 21st century: “Astrology is the practice of relating the heavenly bodies to lives and events on earth, and the tradition that has thus been generated” (Curry, 1999, p. 55). Curry emphasizes astrology as a practice that may include a range of activities and may include events not directly connected to human life. Enigmatically, Curry’s use of the nonspecific “lives” suggests that astrology may be concerned with any kind of material object that may be considered alive, such as magical talismans, religious icons, and statues. Curry’s definition can extend to almost any use of the planets and stars to inform, understand, or regulate human society. At its widest, astrology can then include calendars, particularly if they regulate the ritual and sacred year, together with the key moments at which worship, prayer, and divination are practiced in connection with planetary and stellar deities.

Astrology was divination in the sense that it required a conversation with divinity, but was also science in two senses: first, in the traditional meaning of the word, it was a rule-based system of inquiry; and, second, it was a form of Latin scientia (Greek epistēmē), meaning knowledge, its root being sciens, the present participle of scio (I know, understand). Classical astrology’s importance in the history of planetary science mainly arises from the need to make astrological diagnosis and prediction more precise by rendering the calculation of planetary motions more accurate. As a result, the development of scientific astronomy benefited from the widespread development of astrology.

A distinct feature of astrology in the Greek world was its democratized nature. The evidence suggests that until the 5th century bce, astrology in the Mesopotamian world (aside from any vernacular practices for which there is little or no evidence) had been practiced solely in the service of the king. By contrast, in the Greek world anyone could study or practice astrology.

There is a shortage of primary sources (i.e., astrological texts) between the 4th century bce, when astrology was imported from Mesopotamia, and the 1st century ce. However, the evidence suggests that during this time, Mesopotamian astrology encountered three of the major Greek philosophical schools (Platonic, Aristotelian, and Stoic) and the temple practices of Hellenistic Egypt. By the 1st century ce, the earliest extant primary sources describe an astrological scheme of great intricacy, which was capable of issuing detailed statements and precise advice on every aspect of human affairs.

The most important primary source is Ptolemy’s Tetrabiblos, which was to have huge significance for two reasons. The first was his reputation as an astronomer, established by the Almagest, his treatise on the measurement and motion of the celestial bodies, and the second was his use of a natural justification for astrology, which removed it from associations with planetary deities. The other key primary sources from the 1st and 2nd centuries are Manilius’ Astronomica, Vettius Valens’ Anthologiae, and Dorotheus of Sidon’s Carmen Astrologicum (also known as the Pentateuch). Julius Firmicius Maternus’ Mathesis, written in the 4th century, was a rare text composed in Latin, and the last of the classical Greek texts were composed by Olympiodorus (mid-6th century ce) and Rhetorius (early 6th or 7th century). All such sources include a series of problems: They survive from much later versions and may be subject to scribal errors, interpolations by copyists, and interpretations by modern translators. There are also a number of collections of horoscopes, notably by Neugebauer and van Hoesen (1959) and Heilen (2015). However, most surviving horoscopes consist of lists of planetary positions, with no surviving interpretation.

It appears that the rules of astrological interpretation were constructed either on the basis of theoretical models (e.g., military events coincide with significant movements of the planet Mars because it was associated with the warlike god Ares [the Greek equivalent of the Roman Mars]) or observation (e.g., if an event coincides with a particular planetary configuration on one occasion, it is assumed that the same configuration will coincide with a similar event on future occasions).

The modern historiography of classical astrology began with the publication of August Bouché-Leclercq’s L’astrologie Grecque in 1899, followed in 1912 by Franz Cumont’s Astrology Among the Greeks and Romans (1960). For Cumont, astrology was contextualized by the history of religion: He was also one of the chief editors of the first major collection of Greek astrological material, the 12-volume Catalogus Codicum Astrologorum Graecorum, known as the CCAG (1898–1953), and wrote on Mithraism and classical religion. Otto Neugebauer (1975), whose career spanned from the 1920s to the 1980s, then treated the history of astrology as a subset of the history of mathematics rather than religion. David Pingree (1997), whose prolific output of papers and translations spanned from the 1950s to the 2000s, continued Neugebauer’s concern with the accuracy of astrological computation and therefore what study of it could contribute to the history of mathematics. André-Jean Festugiere’s La Revelation d’Hermes Trismegiste, Vol. I: L’astrologie et les sciences occultes, published in 1946, was the first to explore the Hellenistic mystical astrological works attributed to Hermes, and Frederick Cramer’s work, published in 1954 (1996), developed the study of astrology’s broader cultural context, producing the authoritative study of astrology’s legal status and political uses in the Roman Empire.

Recent works include two general studies by Barton (1994) and Beck (2007) and material on the classical world in Campion’s (2009) history of ancient astrology. More detailed studies include Addey’s examination of divination in Neoplatonism (2014) and Greenbaum’s study of the daimon (2016). There are also a number of accounts of technical astrology, including Noonan (1984), Crane (2007), and Brennan (2017).

There are two central debates in the historiography of classical astrology, both now largely settled. The first centers on whether astrology was either (a) marginal or (b) a mainstream feature of classical culture. The second considers whether it was (a) an indigenous Greek invention, which had little relationship to Mesopotamian astrology, or (b) imported from Mesopotamia or had Egyptian input. The notion, however, that it was marginal is contradicted by the evidence that under the Roman Empire, it was practiced at all levels of society and could provide a huge range of functions, including predicting personal destiny, performing magical acts, aiding political action, and managing the soul’s ascent to the stars. However, while both debates pervade the older literature, recent work has established that the technical foundations of classical astrology had already begun to develop in 6th and 5th century Mesopotamia bce (Rochberg-Halton, 1988), including the 12-sign zodiac, the meanings of the planets, and the use of birth charts (the calculation of astrological configurations at birth in order to analyze personal destiny). It is also now known that there were also significant technical contributions from Egypt (Greenbaum & Ross, 2010).

The Structure of the Cosmos

Astrology’s rationale and interpretative structure is heavily influenced by Greek cosmological theory. The dominant model for the structure of the cosmos in the Greek world from the 5th century bce onward was geocentric, envisaging a spherical Earth at the center of a series of concentric spheres, each carrying a planet (Evans, 1998). The closest planet to the Earth was the Moon, followed by Mercury, Venus, the Sun, Mars, Jupiter, and Saturn, reflecting their observed speed and the resulting length of their orbit around the Earth, Mercury being the fastest and Saturn the slowest. The eighth and outermost sphere was that of the fixed stars, beyond which in Hermetic models (Copenhaver, 1992), which were common from the 2nd century bce, was God, usually imagined as Nous, or the universal supreme Mind. Following Pythagoras (ca. 570–495 bce), who argued that the basis of the cosmos is number, all celestial motions were understood as mathematical and the structure of the cosmos was conceived as geometrical. The consequence is that the Earth sits at the center of a completely unified, ordered system. The system is therefore known as kosmos, meaning beautiful or harmonious order. In principle, it is a necessary consequence of this model that all terrestrial events on Earth are synchronized with all celestial movements, and astrology is then an essential means of understanding these relationships.


The rationale for the sky-Earth link on which the discipline of astrology is founded may be understood in one of three distinct yet sometimes overlapping ways:


As a matter of causes or influences exerted by the celestial bodies on the Earth;


As a matter of coincidence in time so that, for example, an event on Earth is linked to a celestial pattern not through any cause of influence but because they happen at the same time; and


As a matter of signs and communication between celestial deities and humanity, or what may be called divination, and has been termed heavenly writing (Rochberg, 2004).

From the 4th century bce onward, three significant Greek philosophical movements added distinct cosmological rationales: those pioneered by Plato (ca. 427–347 bce), Aristotle (384–322 bce), and Zeno of Citium (ca. 334–262 bce)—the Stoic. All three shared one significant feature, which had a decisive effect on astrology, namely the concept of a soul, best understood as an animating force, which has both individual and collective forms. In what follows, the terms Platonic, Aristotelian, and Stoic astrology are used in order to clarify perspectives within classical astrology, although these were not categories identified at the time. No classical astrological author characterized their versions of astrology as belonging to any philosophical school, so Platonic, Aristotelian, and Stoic astrologies should be seen as ideal types which historians can identify in astrological texts. For example, F. E. Robbins (1940, p. ix) considers that Ptolemy generally took an Aristotelian position. By contrast, Long (1996, p. 220) describes Ptolemy as more Platonist than Stoic, but still influenced by Stoicism. Therefore Platonic, Aristotelian, and Stoic perspectives may be considered in astrology or how the essential assumptions of astrology may conform to Platonic, Aristotelian, or Stoic cosmologies. Following Robbins and Long, the author proposes to identify the key components of what Platonic, Aristotelian, and Stoic astrology may be. The three cosmologies and their impact on astrology can be summarized in the following (Campion, 2009, pp. 149–172; Campion, 2015).

Platonic Perspectives in Astrology

Plato referred to astrology only once, when he appeared to be critical of the visual astrology of Mesopomia and advocated instead a system based on logical and mathematical frameworks (Plato, 1931, p. 40C-D). However, his wider cosmology provided a foundation for later astrologers to build on. Platonic cosmology is set out primarily in the Timaeus (1931) and Book X of the Republic. The entire cosmos is a single living being in which the material cosmos is embedded in the World Soul, Latin Anima Mundi, understood as a universal consciousness or supreme Mind, Nous. This then manifests through Ideas (with a capital “I”) or Forms (known by later philosophers as Archetypes), which are the foundation of all material phenomena. For example, behind a tree lies a manifestation of an Idea, Form, or Archetype of “treeness.”

In the Republic, Book X, Plato sets out the proposition that the individual soul originates above the planets and in the stars. Guided by the daimon (a guardian spirit), the soul chooses a life and then descends via the planetary spheres to incarnate in the body at birth. The whole scheme takes place within a geometrical, mathematically ordered, Pythagorean cosmos in which the priority of social and political organization is therefore to harmonize terrestrial society with celestial spheres. Plato had little to say about astrology but what he did say was of immense importance. First, he stated that trying to assess the significance of planetary motions without models (i.e., without a theoretical and mathematical or geometrical framework) was a waste of time. He added that the planets came into being for “the determining and preserving of the numbers of Time” (Plato, 1931, p. 38C), the inference being that progress through time can be managed by paying attention to celestial motions. Second, the notion of the soul’s descent through the planetary spheres at birth was, over the following centuries, to lend support to the belief that individual destiny can be identified in the planetary positions at birth. However, because the soul originates from beyond the planets, it is not necessarily bound by them. Plato’s emphasis on correct education and lifestyle, set out primarily in the Republic and Laws, can therefore be applied either to the belief that one should better harmonize with one’s planetary destiny or justify the liberationist view that one can completely transcend it.

A Platonic astrology can therefore be identified, not articulated by Plato but rooted in his texts and which has the following characteristics:


It is acausal, assuming that astrology can be effective because of the synchronous movements of events on Earth and in the celestial spheres. Planetary movements have no causal function but correlate or coincide with terrestrial affairs, providing a clock which tracks both quantitative and qualitative changes in time.


It can be described as Idealistic or Archetypal in the sense that at significant moments in planetary cycles certain Ideas or Archetypes were more likely to manifest in the material world.


On the collective level, it is designed to regulate the state and maintain political stability.


On the personal level, because the soul can transcend the material universe, individuals are not bound to the planetary fate indicated at birth but can free themselves from it.

Aristotelian Perspectives in Astrology

There is no mention of interpretative astrology in any of Aristotle’s extant texts (only in pseudo-Aristotelian works), but his cosmology was to be vital in providing a series of mechanisms for how it may operate. An Aristotelian astrology can therefore be retrospectively talked about, which adapted Aristotle’s thought to its rationale and interpretative model. The question is not what Aristotle may have intended, but the appropriation of his ideas by astrologers. Like Plato, Aristotle adopted the notion of a single cosmos in which all things, whether tangible or intangible, were intimately related, being connected both by the matter of which they are made—the four elements: fire, earth, air, and water—and a series of influences and causes that are responsible for all change (Aristotle, 1930, pp. 194b–195a). All were to be of significance for astrology, though not to the same extent. Aristotle postulated the existence of four causes, of which three had a direct significance for astrology:


The material cause is the element from which an object is made and was to be particularly important in later diagnosis and treatment of disease as well as in the construction of magical talismans.


The formal cause is simply defined as an object’s shape but is easily confused with Ideal Forms in Plato’s cosmology.


The final cause is the state to which an object tends. For example, an acorn must become an oak tree, not a cabbage; therefore, the original acorn contains the final oak tree. It is clear that if final causes lie in the future and any present condition contains its future condition, then there is a clear rationale for astrological prediction.

The key agent of change was motion. The whole system is presided over by the Prime Mover, the being who initiates all motion and hence creation. Within this context the planets are then the secondary causes, and astrological causation could then be considered less a matter of planetary determinism than of the planets performing a task on behalf of the Prime Mover, and being subject to him.

Aristotle shared Plato’s geocentric cosmos and developed the concept that the slower a body moved, the more perfect it was on the grounds that speedier motion equals rapid change and therefore greater imperfection. Among the planets, Saturn, the slowest moving, is the most perfect, and the Moon, the fastest, the most imperfect. The sublunary realm, the area between the Moon and Earth, and including everything on the Earth, is therefore fundamentally imperfect, and the purpose of Aristotelian astrology is to track the changes that are caused as the planets move and the elements are disturbed, and the problems of terrestrial existence are stirred up.

Claudius Ptolemy’s rationale for astrology was to be the most famous expression of Aristotelian naturalism:

The sun, together with the ambient, is always in some way affecting everything on the earth, not only by the changes that accompany the seasons of the year to bring about the generation of animals, the productiveness of plants, the flowing of waters, and the changes of bodies, but also by its daily revolutions furnishing heat, moisture, dryness, and cold in regular order and in correspondence with its positions relative to the zenith. . .. The active power of the sun’s essential nature is found to be heating and, to a certain degree, drying.

(Ptolemy, 1940, p. I.2)

Aristotelian astrology, as rooted in Aristotle’s texts, although not developed by him, therefore has the following characteristics:


The entire cosmos is a single integrated organism in which all terrestrial and celestial phenomena are related.


The soul-psyche is an integral part of the natural world (even though in later classical and medieval Aristotelianism, part of the soul was considered to be transcendent, as in Platonism), so the entire human entity is embedded in the cosmos. Astrology can therefore make statements about individual destiny.


The entire cosmos operates according to natural mechanisms and influences that pervade all physical and psychological phenomena. Astrology is therefore removed from any connection with pagan deities, a point which was to be of crucial significance in medieval Christianity. All things in the cosmos aspire to find their natural place or their final condition. Astrology can therefore make statements both about what people should be and will do or experience.

To give a practical example, Aristotelian astrology envisages the planet Mars as responsible for hot influences which stir up heat in terrestrial affairs, provoking conflict, stimulating fevers, or causing droughts. The astrologer’s task is then to manage such problems through identifying auspicious times for appropriate actions and, in the case of disease, suggesting the best treatment.

Stoic Perspectives in Astrology

The third of the significant philosophical schools was the Stoic, founded by Zeno of Citium and usually said to be most closely associated with the development of the precise and detailed horoscopic astrology which was evident by the 1st century ce. The Stoics shared with Platonists and Aristotelians the concept of the cosmos as a single, living, ordered entity, the logical consequence being that people are connected to planets, plants, stars, and stones through their essential natures, known as sympathies. As this was to develop in practical astrology, the resulting series of complex correspondences is now termed the Great Chain of Being. As an example, the Sun is sympathetic to gold, kings, the zodiac sign Leo, the heart, heat, and Sunday. Change in one would therefore correspond throughout the corresponding chain of sympathies. The astrologer can then participate in, act on, or manipulate one part of the chain in order to cause change in another. A familiar stoic metaphor has the planets acting on material affairs like a signet ring in hot wax. Planets can therefore be discussed as having an impact on terrestrial affairs or (in that Stoic thought overlaps both with the mathematical Platonic cosmos and Aristotelian naturalism) correlating with or coinciding with or influencing Earthly matters.

Stoic psychology placed the psyche, or soul, entirely within the material realm (for the Stoics, everything is a body, and there is no distinction between the material and immaterial). The individual human is then completely embedded in a cosmos which, like the Platonic, was mathematically ordered. Fate is therefore generally seen as potentially unavoidable and, as a result, the future may therefore be predictable in precise detail: As the planets move, so events on Earth also move. However, in practice, Stoic compatibilism (in which free will and fate are compatible) looked for ways around an unalterable fate.

In summary, Stoic astrology has the following characteristics:


It assumed the complete interdependence of everything in the cosmos, linked by their underlying sympathies and their relationships.


It therefore suggests that everything could be predicted and, in some circumstances, managed and arranged using astrology.

Platonic, Aristotelian, and Stoic perspectives were distinct, yet they all shared a number of features: first, an assumption that the entire cosmos is a single entity in which human affairs are integrated with time and space, extending into the future as well as the past; second, a model of the soul with a higher, rational part contrasted with lower, irrational parts, related to the emotional and physical levels; third, the distinction between two concepts of time in all three philosophies is also significant. On the one hand, quantitative time is known as chronos; on the other, qualitative time, denoting the right moment for an appropriate action, is kairos. The fluctuation of kairos according to the passage of chronos may therefore be seen as astrology’s primary focus.


Two theoretical fault lines run through classical astrology. The first is between judicial and natural astrology, a distinction rooted in Isidore of Seville’s division between superstitious and natural astrology (Campion, 2015, p. 87). Interpretation in judicial astrology relied on the calculation and reading of what is known in modern times as the horoscope (hour watcher, or hour-marker). Strictly speaking, the horoscope is the ascending degree (ascendant), the degree of the ecliptic occupying the ideal horizon at the time for which the astrological calculations are set. However, the word was later used to describe the entire listing of significant astrological positions, including the planets, for a particular time and place, occasionally represented as a diagram, either square or circular, although surviving examples are rare (Neugebauer & van Hoeseen, 1959, pp. 18, 156, 163). Judicial astrology requires the astrologer to make a precise judgment, providing advice or making a prediction, whereas natural astrology requires only an assumption of general planetary influences, usually in relation to medicine or the weather.

The second theoretical fault line was between an astrology that was descriptive, predictive, and could be passive in that no action was necessary or possible, and one that required participation and engagement in order to amend the future. Launching a new enterprise was a kind of participation involving the selection of auspicious moments that could guarantee a successful outcome, but more overt was the manipulation of the future through astral magic. Religious uses of astrology similarly required action and were based around the notion that the soul could be prepared for its ascent to the stars after death (see the section “Religion”).

Within this framework, astrology possessed a number of different functions. First, its most high profile use was for political purposes (known in modern terms as mundane astrology); second, it was used to analyze and predict individual destinies (known in modern terms as natal astrology); third, it could be employed to identify the katarche, the beginning or inceptional moment at which to launch a new enterprise (known in modern terms as electional astrology); from the examination of the katarche, a fourth application of astrology developed: the use of the horoscope to answer precise questions (known in modern terms as horary astrology); fifth, it could be used to retrospectively analyze events; sixth, it was used as an aid to magic, the use of spells, and incantations in order to manipulate the future; seventh, it could engage with the gods and goddesses and assist the ascent of the soul through the planetary spheres to contact the divine, a process known from the mid-2nd century ce as theurgy.

By the 1st century ce, every feature of human life could be mapped onto an exact mathematical grid that could be used to identify physical weaknesses, psychological tendencies, career opportunities, financial prospects, and even one’s ability to contact the divine. It claimed to predict any eventuality, answer any question, and advise on every problem. It was not, however, universally regarded as infallible: Ptolemy described it as a stochastic (probabilistic) art.

Technical Foundations, Practice, and Criticism

The overarching technical framework within which astrological interpretation is conducted is the zodiac, a division of the ecliptic (the Sun’s apparent annual path around the Earth) into 12 30-degree sections, known as zōidia, singular zōidion, or zodiac signs in modern usage. The zodiac signs were derived from, although not equivalent to, the uneven-sized constellations which shared their names. However, the position of the signs astronomically was defined by the constellations and therefore, in the sidereal zodiac, fixed by the positions of the stars, they moved with the constellations in relation to the equinoxes (the so-called precession of the equinoxes). In the 2nd century ce, Ptolemy fixed the zodiac by the Sun’s position at the spring equinox, defined as 0 degrees Aries (the so-called tropical zodiac). Most classical astrologers continued to use a sidereal zodiac until the 4th century and it has been retained in Indian astrology.

Each sign possessed a set of qualities that crossed the psychological and physical, which could be general or specific. Often the general suggests the specific. For example, in terms of professional or public role, a sign’s general qualities may point to a particular outcome. Aries, being bold and haughty, is related to kings (which does not mean that any individual born while Aries is strong will be a king, but that they will have kingly qualities), and Taurus, which is practical, rules farmers and builders. Men and women may fare differently depending on the gender balance of the signs at their birth: It is said that men born under Capricorn and Aquarius have a range of moral deficiencies and criminal tendencies which women lack. The range of possibilities extends from the intimate and personal to the general and public. There may, for example, also be meteorological and geological consequences: Cancer is linked to strong rains and earthquakes, Leo to scorching heat. Agricultural and seasonal connections then follow: Libra is linked to the production of fruit, wine, and olives. As set out by Vettius Valens (p. I.2) and Claudius Ptolemy (pp. I.11–16), the signs’ general qualities are as follows:

Aries: masculine, fiery, courageous, proud, and authoritative;

Taurus: feminine, earthy, stable, stubborn, hard-working, practical;

Gemini: masculine, airy, agreeable, communicative, good with language, connected to magic and the occult;

Cancer: feminine, watery, popular, changeable;

Leo: masculine, fiery, proud, just, consistent;

Virgo: feminine, earthy, organized, efficient;

Libra: masculine, airy, noble and just but can be malicious and envious;

Scorpio: feminine, watery, stubborn, destructive, scheming;

Sagittarius: masculine, fiery, changeable, noble, generous;

Capricorn: feminine, earthy, destructive, hard-working, fickle;

Aquarius: masculine, airy, moist, stable, stubborn, self-willed; and

Pisces: feminine, watery, changeable, restless, rough, sociable.

The planets have a range of associations as broad as those for the zodiac signs, physical qualities which exert a material influence. Saturn is cold and frozen, Jupiter warm, and Mars positively hot, while Venus is “the cause of the birth of all things upon earth” and “scatters a general dew” at its rising, which stimulates the sexual organs (Pliny, 1929, pp. II.iv.12, vi.32–40). The planets also possess a series of relationships with the zodiac signs. The Sun and Moon “rule” one sign each, the other five planets two signs each. Each planet was generally strong when within one of its own signs. Listed in order of the speed of their orbits, the planets’ general qualities and associations are as follows:

Moon: rules Cancer; feminine, queens, cities, crowds, homes;

Mercury: rules Gemini and Virgo; both masculine and feminine, intellectuals, teachers, communication

Venus: rules Taurus and Libra; feminine, benefic, love, peace, diplomacy, the arts;

Sun: rules Leo; masculine, kings, leaders, leadership;

Mars: rules Aries and Scorpio; malefic, masculine, generals, war, violence;

Jupiter: rules Sagittarius and Pisces; benefic, masculine, judges, justice, alliances, freedom, benefits; and

Saturn: rules Capricorn and Aquarius, malefic, masculine, administrators, austerity, restriction, delays, endings.

That the Sun and Moon ruled just one sign, the other five planets two signs each, created further overlaps. For example, Mercury’s link to esoteric and magical activity carries over into the two signs it rules, Gemini and Virgo. The planets’ genders lacked the balance that characterized the zodiac, and in the Ptolemaic system there were only two feminine planets compared to four masculine ones (Mercury combined both genders). Each planet was generally strong when placed in a sign it ruled and was favorably placed in signs spaced at one sixth or one third of the zodiac away. As an example, the Sun is strong in its own sign, Leo, and favorably placed in Gemini and Aquarius (from which it is separated by one sixth of the zodiac) and in Sagittarius and Aries (from which it is separated by one third of the zodiac). Planets are in a difficult relationship with the sign opposite their rulership (dividing the zodiac by two) and at right angles (dividing the zodiac by four) to the ones they rule. For example, the Sun, ruling Leo, is difficultly placed in Aquarius, opposite Leo, along with Taurus and Scorpio, the signs at right angles.

The whole system is an adaptation of Pythagorean numerology in which the number three is harmonious and the numbers two and four disharmonious, and is the basis of the aspects (angular distances between planets, which indicate astrological significance). The helpful aspects were the sextile (planets separated by one intervening sign) and trine (planets separated by three intervening signs). The difficult aspects were the square (planets separated by two intervening signs) and opposition (planets in opposite signs). The clear inference is that all the matters on which astrology comments, which include everything of concern to human beings, are geometrically and mathematically organized. Psychological inclinations, physical tendencies, patterns in life, the weather, and the harvest are all part of this numerically defined matrix.

The relationship between planets and zodiac signs then becomes more complex as each planet had a variety of ways of behaving in different signs (e.g., a planet was strong in a sign in which it was exalted, or functioned at its best), and the signs themselves were subdivided into further sections such as decans (thirds) and dodecatemoria (twelfths), each section carrying astrological significance. The third fundamental component of technical astrology was the system of places, later known as houses; each place or house representing a different area of life and activity, such as good and bad fortune, travel, money, marriage, and livelihood.

In terms of technology and instruments, the astrologer’s toolkit would have included ephemerides (tables setting out astronomical positions from which horoscopes could be calculated and astrological meaning could be derived) and horoscope boards on which the zodiac was already set out and on which stones representing planets could be moved around once calculations had been completed. Astrolabes and water clocks were available, although tables were used far more often than direct observation.


Such is the complexity of possible factors to be considered that no complete set of configurations would ever repeat: Every moment is potentially unique, every person a distinct individual. However, in practice the astrologer often had a particular question in mind and so only certain factors need to be considered in a unique interpretation. As an example of the variation of factors to be considered and the detailed nature of a possible prognostication, Ptolemy’s delineation of sexual problems is typical:

. . .when the sun is also in aspect, if the luminaries [the Sun and Moon] and Venus are made masculine, the moon is waning and the maleficent planets [Mars and Saturn] are approaching in the succeeding degrees, the males that are born will be deprived of their sexual organs or injured therein, particularly in Aries, Leo, Scorpio, Capricorn and Aquarius, and the females will be childless and sterile.

(Ptolemy, 1940, p. III.12)

There is no indication how such detailed diagnoses were constructed. It is likely that there was a combination of argument from theory (if Mars is a malefic planet, then its impact on any situation will be problematic) and empirical observation in which every time a baby was born with clear sexual difficulties, or a woman was found to be infertile, a record of the appropriate configurations was kept.

Psychological analysis was also dealt with, adapting the triple model of the soul common to Plato, Aristotle, and the Stoics. Again, according to Ptolemy:

Of the qualities of the soul, those which concern the reason and the mind are apprehended by means of the condition of Mercury observed on the particular occasion; and the qualities of the sensory and irrational part are discovered from the one of the luminaries which is the more corporeal, that is, the moon, and from the planets which are configured with her in her separations and applications.

(Ptolemy, 1940, p. III.13)

Individual tendencies could then be interpreted in terms of internal conflicts and struggles. For example, an influence of Mars and Saturn on the lower parts of the soul would indicate a sickly body and a violent temper, but a fortunately placed Mercury would indicate the wisdom and self-control necessary to overcome such disruptive tendencies. Fate may carve a trajectory, but it operates according to the totality of life in which human actions are agents of change alongside the planets.


Astrology was used for political purposes in the Roman world almost from its introduction, including to manipulate public opinion in order to reinforce imperial power. An early example was the claim by Octavian (the future Augustus) that a comet, which appeared at the time of Julius Caesar’s assassination, was the dead dictator’s soul on the way to join the stars and assume its divine status. Astrology could also be used to select auspicious moments to proclaim emperors. When Nero was proclaimed emperor in 54 ce, the astrologers had to move fast to ensure his ascension and chose noon, placing the Sun, symbol of kings, at the point of highest culmination. The last known examples are the proclamations of the rebel emperors Basiliscus and Leontius in 475 and 484, respectively.

Astrologers could choose fortunate times to found important cities, as was said to be the case with Seleucia, founded around 305 bce as the capital of one of Alexander the Great’s successors, Seleucus Nicator. There are also accounts of the astrological foundation of Constantinople by Constantine in 330 ce.

Countries and regions of the globe were also linked to the zodiac signs. Such cosmic geography enabled astrologers to identify the national characteristics of particular peoples and estimate where certain astrological configurations may be effective. For example, in Ptolemy’s system, Britain was ruled by Aries. Its people therefore had Arien (i.e., warlike) qualities, and significant Arien configurations would be more likely to have a correlation, manifestation, or influence in Britain than in, say, India, which was ruled by Capricorn.

Long-term political prediction relied on the analysis of planetary positions at the Sun’s entry into Aries, Cancer, Libra, and Capricorn, moments ideally coinciding with the equinoxes and solstices, which possessed particular significance for collective affairs. For example, if the benevolent planets Venus and Jupiter were prominent at the spring equinox (March 25 in the Julian calendar), a prosperous year could be forecast. If Mars and Saturn were strong, difficulties may be anticipated.


One may talk conventionally about religion in the classical world, but in most cases, religion was not conceived of as a separate sphere of activity from secular affairs. If, as the Stoics believed, the cosmos is God, then nothing is either religious or secular. That said, the term can be used as a convenience and identify two kinds of astrological religion. The first required the worship or veneration of celestial deities, the second the quest for personal salvation and the soul’s ascent to the stars.

The astrological planetary deities were imported into Greece from Mesopotamia, making their first appearance in the Platonic Epinomis.

The characters of the astrological planets are fundamentally derived from the personalities of their related deities, and their accompanying myths, as follows:

Moon: Greek Selene, Latin Luna

Mercury: Greek Hermes, Latin Mercury

Venus: Greek Aphrodite, Latin Venus

Sun: Greek Helios, Latin Apollo

Mars: Greek Ares, Latin Mars

Jupiter: Greek Zeus, Latin Jupiter or Jove

Saturn: Greek Kronos, Latin Saturn

Obvious examples of the transfer from myth to astrology include Ares, the militaristic deity whose planet Mars indicated war, and Aphrodite, whose planet Venus represented love. The planetary deities could feature in personal religion, occurring in household shrines along with images of other divinities and ancestors.

Astrology was also notable in the development of state religion in which the emperor could be linked to the Sun. A deliberate identification between the emperors and the Sun was evident from the reign of Nero (54–68 ce). Emperor worship and Sun worship were completely identified and religion was enrolled in the service of the state when the imperial solar cult was finally formalized in 274 as the cult of Sol Invictus, the Unconquered Sun. December 25th, the cult’s feast day, was later adopted as the celebration of Christ’s birthday, along with the incorporation of other solar iconography into Christianity. For example, typically, Christian churches were constructed on a roughly east–west axis, with the altar in the east, facing the direction of the rising Sun.

Such state-sponsored collective religion was contrasted with the individual quest for personal salvation. The concept of the soul’s ascent to the stars via the planetary spheres was elaborated in the Corpus Hermeticum (Copenhaver, 1992) a series of texts composed originally in Hellenistic Egypt from the 2nd century bce onward and attributed to Hermes. The texts describe the soul’s ascent as a purification. As it passes through each planetary sphere, the vices associated with that planet are shed. At the Moon, it sheds growth and decay, Mercury trickery, Venus deceit, the Sun arrogance and pride, Mars daring and recklessness, Jupiter greed, and Saturn falsehood (Libellus, p. I.25, in Scott, Hermetica, Vol. 1, p. 129.)

The celestial journey was most clearly codified in the Mysteries of Mithras, which adhered to the notion of an ascent through the planetary spheres rather than a sudden liberation via the Sun. Imported to Rome from the East, the Mysteries appear to have assumed their fixed form in the 1st century ce and became very popular throughout the Roman Empire, especially in the army, as membership was restricted to men. The initiate undertook a celestial ascent encouraged by ritual chanting, astrological magic, prayer to the planetary deities, a visionary encounter with the seven planets, and promises to worship the Sun and one true universal god. There appear to be different versions of the initiatory stages, however, and if these are linked to the planets, then the sequence, beginning with Mercury and rising to Saturn, appears to be (Beck, 1988, p. 1) as follows:

Pater (father)


Heliodromus (sun-runner)


Perseus (Persian)


Leo (Lion)


Miles (Soldier)






A rare text gives a description of what the initiate will experience if the appropriate path is followed:

Draw in breath from the rays, drawing up three times as much as you can, and you will see yourself being lifted up and ascending to the height, so that you seem to be in mid-air. You will hear nothing either of man or of any other living thing, nor in that hour will you see anything of mortal affairs on earth, but rather you will see all immortal things. For in that day and hour you will see the divine order of the skies: the presiding gods rising into heaven, and others setting.

(Betz, 1992, p. 51, lines 539–546)

In the astrological universe, everyone is an individual, having incarnated at a unique moment, and therefore not equal in terms of character and destiny. The third house in the horoscope represents the Goddess and the ninth house represents God and therefore the individual’s relationship with the divine. It therefore follows that whether one has a religious or devout disposition is dependent on the location of the planets at birth, and not everyone has the same chance of successfully making the ascent to the divine realms. For example, the person born with the benevolent planets Venus and Jupiter in the ninth house will be blessed, while the individual with Saturn and Mars may be unable to contact the divine. Although on a cosmic level religious truth may be absolute, as far as individuals are concerned it is relative: The truth of the gods and goddesses may make more sense to one person than another.


The conceptual frameworks that underpinned astrology (whether of an underlying order in the cosmos, planetary causes or influences, or divine intervention) all have consequences for issues of fate and free will. A key problem in astrological practice was the extent to which fate could be managed, and the central question is to what extent there is an autonomous self that can moderate fate.

Fate takes a number of forms in Greek mythology and philosophy. The three Fates, or Moirae, described in Hesiod’s Theogony in the 8th century bce, constantly spin a web of fate, including at a baby’s birth, suggesting a dynamic quality and intent: As they continue to spin, so fate may change. Other central concepts include ananke, or necessity (the unavoidable laws of physical existence), heimarmene (usually translated as “fate”), and tyche (chance). However, astrology does not fit easily into a single concept of fate. For example, while an infant who is born into particular circumstances and a probable future, which are represented by the disposition of stars and planets at his or her birth, is clearly subject to a fate, forms of astrology aiming to alter the future clearly assume that individuals are not subject to fate but can actively engage with it. In modern terms, astrology as a whole is best understood as compatabilist in that a kind of fate or determinism in which the future already exists, coexists with an assertion of free will in which the future can be changed.

The most extreme attitude to fate was represented by the Stoics, for whom fate was defined, in Cicero’s words, as an “orderly succession of causes” (Cicero, 1929, p. Stoicism is commonly seen as subjecting humanity to an inevitable future in which human freedom resides only in adapting to it. This is indeed the view held by some Stoic thinkers. However, Bobzien (1998) argues that as all things in the cosmos participate in the orderly succession of causes, freedom of action is indeed constrained by character and circumstances, but is possible for those human beings who are able to acquire an understanding of their fate through education and the development of virtue and wisdom. The Stoic cosmos is relational, and all bodies, including people and planets, are constantly interacting with each other. Therefore, fate emerges as the product of the sum total of all actions in the universe, a process in which people are active participants. People are subject to fate but can become equal partners in creating it. At the same time, one can never be sure when an act is free and when it is not, or how free it is.

Astrological texts which contain a Stoic perspective are composed in a style that suggests an unalterable future, yet the question as to whether the Stoic has to accept fate or can change it is an open one. For example, in the 2nd century ce, Claudius Ptolemy, who exhibits both Stoic and Aristotelian influences, stated both that the foreknowledge of the future brought by astrology calms one’s soul, and that astrology (his example was taken from the healing practices of the Egyptian temples) would not exist unless it could be used to change the future (i.e., heal the sick). Speaking of the Egyptian temple priests, he wrote “they would never have devised certain means of averting or warding off . . . the universal and particular conditions that come or are present by reason of the ambient, if they had any idea that the future cannot be moved and changed” (Ptolemy, 1940, p. I.3).

The selection of auspicious moments for any event, from administering a remedy to proclaiming an emperor, was the obvious means of arranging the future to personal or collective advantage within the constraints of an ordered cosmos. Magic offered another means of altering the future, in this case for medical purposes:

Another amulet for the foot of the gouty man: You should write these names on a strip / of silver or tin. You should put in on a deerskin and bind it to the foot of the man named, on his two feet: ‘THEMBARATHEM OUREMBRENOUTIPE / AIOXTHOU SEMMARATHEMMOU NAIOOU, let NN, whom NN bore, recover from every pain which in his knees and two feet’. You do it when the moon is [in the constellation] Leo.

(Betz, 1992, pp. PDM xiv.1003–1014)

One important solution to the problem of astrological fate was to pose the existence of an autonomous psyche-self which transcended the influence of the stars and planets. The origin of this autonomous psyche lies in Plato’s theory of the soul: As the soul descends to its life on Earth, it commences its journey beyond the planets and then passes through the seven planetary spheres. Astrology is then left with a permanent ambiguity which can be phrased as a question: In this life, is the soul contained entirely within the astrological universe or is a part of it still able to contact the realm beyond the stars? Plato’s solution is that contact with the realm beyond that stars is possible, but only for those who lead a correct and virtuous lifestyle. A tradition then begins in which self-understanding and self-development, prompted by education and ritual action, becomes a path to freedom. Fate can then be negotiated by the individual as an equal participant in the cosmos.

The autonomous psyche of Platonic cosmology and Hermeticism posed a model of astrological causation which is dependent on the rational soul’s ability to remain free from planetary influence in the Corpus Hermeticum. It was claimed that, as the planets move, the daimons are able to enter and influence the irrational levels of the soul (Libellus, pp. XVI.15–16 in Scott, 1982, p. 271). Individual freedom is guaranteed because the rational soul can make choices that overrule the daimon’s disruptive influence on the irrational levels of the soul. It was also claimed that contact with the divine light of the Sun, or God, could result in an instant release from planetary fate, a belief that was taken up by Gnostic Christians. Astrology could therefore involve not just (a) subjection to fate or (b) an attempt to change it, but (c) the possibility that it could be entirely escaped.

Skepticism and Critiques of Astrology

Platonic philosophy sustained astrology on account of its emphasis on the planets’ role as keepers of time and the soul’s descent through the planetary spheres. However, Platonism was also skeptical of any attempt to gain knowledge from the material world, and the stars and planets had a material existence. Platonism was therefore both supportive of astrology and critical of it. It was Carneades, head of the Platonic Academy until his death in 129 bce, who launched the first major philosophical attack on astrology. His arguments, though lost, have survived thanks to Cicero (106–43 bce) and form the basis of all rational critiques of astrology down to the present day. Among the key questions was the twins problem: If two babies are born at the same time, how can they have different destinies and, if so, how can astrology still be valid? The complexities of the Platonic position were revealed in the world of Plotinus (204–270 ce) who was in no doubt as to humanity’s deep spiritual connections to the stars and planets, but was highly critical of astrologers’ claims to be able to make precise predictions. Only one surviving text completely rejects any meaningful connection between humanity and the stars: Against the Professors, composed by Sextus Empiricus (160–210 ce), rejected the possibility of almost any knowledge and argued that astrological forecasts are equally useless if the future is predetermined, in which case living beings can do nothing about it, or not, in which case they can alter the future themselves, rendering astrology and prediction of the future futile.

From the 2nd century onward, rational criticisms of astrology were taken up by Christian evangelists and subordinated to the larger argument that astrology was demonic and anti-Christian. The last major classical critique of astrology was composed by St. Augustine in his Confessions, composed around 400 ce, and City of God, written in 426 ce. Augustine combined Christian and philosophical arguments, claiming that astrology could work, but for one of two reasons: either chance has decreed that the astrologers’ words would be accidentally correct, or the devil, rather than the planets, had revealed the truth in order to seduce the faithful away from God into false beliefs. Augustine did concede, however, the reality of celestial influences, a concession that would be used to justify astrology in the Middle Ages.

Demise and Legacy

Astrology suffered from two main pressures from the early 4th century onward. The first was the rise of Christianity, which attacked astrology as inextricably tainted by its pagan associations. The second was the decline of literacy, as the Western empire gradually succumbed to the Germanic migrations of the 5th century. An important symbolic date is 529, when Justinian closed the Platonic Academy in Athens. However, classical astrology had already spread to Persia and India, was to be patronized by the Islamic caliphs from the late 8th century onward, was encouraged across the Islamic world through to al-Andalus in the West, and was reimported into the Latin West in the 12th century. It then remained a central feature of European culture until a sharp decline in the mid-17th century. The horoscopic astrology of modern-day India is still heavily influenced by the technical framework developed in the classical world, although with many preexisting Indian interpretative and philosophical adaptations, as is the horoscopic astrology which was revised in the 20th century in the West, associated with the New Age movement.


Astrology in Greek and Roman culture provided a framework for analyzing and managing terrestrial affairs, relying on cosmic mechanisms and sources of authority which transcended any human power. Also, in modern terms it advocated what is known as a deep green ecology (Naess, 1973, p. 95) in which the entire cosmos is a single integrated system, and in some versions (particularly the Stoic) human interests are subservient to the wider environment.

The geometrically determined cosmos of classical astrology, however, is not blind. It is designed in the mind of the Platonic demiurge and that the mathematically defined motions of the planets can be projected into the future suggests that future states exist. The cosmos therefore has purpose and intention.

Scholars struggle to find a definition of astrology in Greek and Roman culture. Was it a form of science, divination, or religion? The problem with such attempts to characterize a premodern practice of such breadth is that they all present a limited picture. Astrology was indeed a science in the traditional sense that it was a discipline with its own rules, but not in the modern sense of an investigative discipline driven by experiment. It could be a form of divination if divinities were consulted but not if it was used for weather prediction. It could be religious in a conventional sense if it was linked to worship of celestial deities or a path to salvation, but not if it offered advice on how to deal with one’s slaves.

Astrology’s central claim is that human beings possess a significant relationship with the stars and planets. One useful theoretical framework for understanding astrology is therefore Lucien Lévy-Bruhl’s theory of participation-mystique (1926) in which a blurring of boundaries between people and objects leads to a heightened sense of a meaningful relationship: As applied to astrology, the participatory relationship is between people and planets, Earth, and sky.

Further Reading

  • Barton, T. (1994). Ancient astrology. London, U.K.: Routledge.
  • Beck, R. (1988). Planetary gods and planetary orders in the mysteries of Mithras. Leiden, The Netherlands: E. J. Brill.
  • Beck, R. (2007). A brief history of ancient astrology. Oxford, U.K.: Blackwell.


  • Addey, C. (2014). Divination and theory in neoplatonism: Oracles of the gods. Farnham, U.K.: Ashgate.
  • Aristotle. (1930). Physics (2 Vols.). Translated by F. M. Cornford & P. H. Wickstead. Cambridge, MA: Harvard University Press.
  • Barton, T. (1994). Ancient astrology. London, U.K.: Routledge.
  • Beck, R. (1988). Planetary gods and planetary orders in the mysteries of Mithras. Leiden, The Netherlands: E. J. Brill.
  • Beck, R. (2007). A brief history of ancient astrology. Oxford, U.K.: Blackwell.
  • Betz, H. D. (1992). The Greek magical papyri in translation, including the Demotic spells. Chicago, IL: Chicago University Press.
  • Bobzien, S. (1998). Determinism and freedom in stoic philosophy. Oxford, U.K.: Clarendon Press.
  • Brennan, C. (2017). Hellenistic astrology: The study of fate and fortune. Denver, CO: Amor Fati.
  • Campion, N. (2009). A history of western astrology: Vol. 1. The ancient world. London, U.K.: Bloomsbury.
  • Campion, N. (2015). Definitions of astrology in the classical world. In F. Pimenta, N. Ribeiro, F. Silva, A. Joaquinito, & L. Tirapicos (Eds.), Stars and stones: Voyages in archaeoastronomy and cultural astronomy—a meeting of different worlds (pp. 84–89). Oxford, U.K.: British Archaeology Reports.
  • Cicero. (1929). De Divinatione. Trans. W. A. Falconer. Cambridge, MA: Harvard University Press.
  • Copenhaver, B. P. (1992). Hermetica. Cambridge, U.K.: Cambridge University Press.
  • Crane, J. (2007). Astrological roots: The Hellenistic legacy. Bournemouth, U.K.: Wessex Astrologer.
  • Curry, P. (1999). Astrology. In K. Boyd (Ed.), The encyclopedia of historians and historical writing (Vol. 1, pp. 55–57). London, U.K.: Fitzroy Dearborn.
  • Cramer, F. (1996). Astrology in Roman law and politics. Chicago, IL: Ares.
  • Cumont, Franz (Ed.). (1898–1953). Catalogus codicum astrologorum Graecorum (Vols. 1–12). Brussels, Belgium: Lamertin.
  • Cumont, F. (1960). Astrology among the Greeks and Romans. New York, NY: Dover.
  • Evans, J. (1998). The history and practice of ancient astronomy. Oxford, U.K.: Oxford University Press.
  • Greenbaum, D. G., & Ross, M. (2010). The role of Egypt in the development of the horoscope. In L. Barres, F. Coppens, & K. Smolarikova (Eds.), Egypt in transition: Social and religious development of Egypt in the first millennium BCE (pp. 146–182). Prague, Czech Republic: Czech Institute of Egyptology.
  • Greenbaum, D. G. (2016). The daimon in Hellenistic astrology: Origins and influence. Leiden, The Netherlands: E. J. Brill.
  • Heilen, S. (2015). Hadriani geniture: Die astrologischen Fragmente des Antigonos von Nikaia (2 Vols.). Berlin, Germany: De Gruyter.
  • Lévi-Bruhl, L. (1926). How natives think. Translated by L. A. Clare. London, U.K.: Allen & Unwin.
  • Long, A. A. (1996). Stoic studies. Cambridge, U.K.: Cambridge University Press.
  • Manilius, M. (1977). Astronomica. Trans. G. P. Goold. Cambridge, MA: Harvard University Press.
  • Naess, A. (1973). The shallow and the deep, long-range ecology movement. Inquiry, 16, 95–100.
  • Neugebauer, O. (1975). A history of ancient mathematical astronomy. Berlin, Germany: Springer Verlag.
  • Neugebauer, O., & Van Hoesen, H. B. (1959). Greek horoscopes. Philadelphia, PA: The American Philosophical Society.
  • Noonan, G. C. (1984). Classical scientific astrology. Tempe, AZ: American Federation of Astrologers.
  • Pingree, D. (1997). From astral omens to astrology from Babylon to Bikaner. Rome, Italy: Istituto Italiano Per L’Africa E L’Oriente.
  • Plato. (1931). Timaeus. Trans. R. G. Bury. Cambridge, MA: Harvard University Press.
  • Pliny. (1929). Natural history (Vol. 1, Book II). Translated by H. Rackham. Cambridge MA: Harvard University Press.
  • Ptolemy, C. (1940). Tetrabiblos. Translated by F. E. Robbins. Cambridge, MA: Harvard University Press.
  • Robbins, F. E. (1940). Introduction. In C. Ptolemy, Tetrabiblos (pp. vii–xxiv). Translated by F. E. Robbins. Cambridge, MA: Harvard University Press.
  • Rochberg, F. (2004). The heavenly writing: Divination and horoscopy, and astronomy in Mesopotamian culture. Cambridge, U.K.: Cambridge University Press.
  • Rochberg-Halton, F. (1988). Elements of the Babylonian contribution to Hellenistic astrology. Journal of the American Oriental Society, 108(1), 51–62.
  • Scott, W. (Trans.). (1982). Hermetica: The ancient Greek and Latin writings which contain religious or philosophic teachings ascribed to Hermes Trismegistus (Vol. 1). Boulder, CO: Shambala.
  • Valens, V. (2010). Anthologies (Book I). Translated by Mark Riley. Sacramento: California State University.