"Discuss the difference between astrology and astronomy.
To what extent did the ancients differentiate them "
To some extent these two disciplines are not directly comparable. Astronomy seeks empirical evidence from which cosmological hypotheses may be formulated. Astrology is but one cosmological system. In this sense astronomy is a tool of astrology. Modern definitions, and therefore, their differences are more clear cut than in the past. Astronomy is an empirical science whereas astrology has been dubbed pseudo-science. The development of these discourses have been guided and informed by varying cultural preconceptions. Astronomy by ancient ideas of physics such as perfect Pythagorean circles and astrology by religious and mythological beliefs. They have both been motivated by the need to navigate, keep time and divine meaning from the depth of space.
To define astrology I shall allow those versed in its knowledge and practiced in its application to speak for themselves. Charles Carter, in his book The Principals of Astrology claims to offer a "concise presentation of the essential facts of modern astrology"(Carter, 1973, V). He has no compunction in applying the word science to describe his discipline; "astrology", he says, "is the science of certain cryptic relations between the celestial bodies and terrestrial life". He avoids language of cause and effect and relies upon a personal familiarisation with the topic to prove its usefulness, convinced that practical application will "soon convince any practitioner" (ibid. p14). Mayo (1979, p2) is no less optimistic and sees astrology as "a system of interpreting symbols correlated to human behaviour and activity". He talks of the symbols deriving from the "cosmic space-time energy-system". Although he does not state exactly what this might be. Astrology is a study of correspondences, predispositions and tendencies of human life which are in some way mirrored in the positions and movements of planets and stars. Astronomy has been concerned with gathering evidence of apparent juxtapositions between events of human individuals and societies with heavenly bodies within arbitrarily defined segments of space.
Modern astrology uses the same collection of symbols that, deriving from Babylonian originals, has been in common usage since its adoption during the Hellenistic period. The night sky is divided into twelve segments, through which the planets traverse. This is the known as the Zodiac, the 12 divisions are arbitrary and bear no relation to any fundamental structure of the stars. Each star that makes up a single constellation may be very remote in terms of its depth to other stars in the constellation, although this was not know to the Ancients. The earth is thought to project 12 divisions known as houses onto the sphere of the heavens and represent departments of everyday life. The interpretation comes as the practitioner decides what the interactions of planet, sign and house may mean for forthcoming events, on the scale of society or the individual. In the case of the individual these conjunctions are of paramount importance at the time of birth.
Astronomy literally means "star arranging". This is something of an etymological misnomer and in strict terms, as Bio-logy is the science of life, astro-logy would be a better term to describe the practice of astronomy. However the terminological division is historically justified. Astronomy is concerned with the appearances of positions and movements of celestial bodies and using this empirical evidence to suggest hypotheses for understanding future positions. The observable motions of the heavens are bewildering as Lloyd so concisely summarises (Lloyd, 1970, 85). The heavens rotate east to west in 24 hours. Constellations differ with seasons, but reappear in like positions in successive years. The position of the sun in relation to the stars changes regularly in a west to east direction through the zodiacal constellations during the year. The moon and planets move east to west, also through the zodiac, although each body takes a different length of time (Saturn takes 30 years, the moon 1 month). Planetary motion is erratic (planet = lit. wanderer) and the motion is sometimes retrograde. It is the chief concern of astronomy to correlate mechanical relations and to provide a cosmological hypothesis to explain these motions. This is achieved by application of a strict hypothetical/deductive method which makes clear its a priori assumptions upon which the system's epistemology stands and any a posterioi assumptions which result from such a system. To exemplify, Aristarchos's heliocentric system had to give account of the absence of stellar parallax, which depended on the a priori assumption that the earth circled the sun. Rational process, relying on an understanding of parallax suggests ( a posteriori) that stars must be at a considerable distance from earth. It has always been the goal of astronomy to find the best hypothesis to explain the phenomena or "save the appearances".
Astrology still accommodates the new discoveries from astronomical science such as planets of Pluto, Neptune and Uranus and has adopted the heliocentric system despite this "shattering blow" (Enc. Brit.) dealt by Copernicus. Modern astronomy on the other hand still applies traditional mythological nomenclature to its new discoveries such as the planetary satellites (Io, Miranda etc.). The modern division between these sciences is quite clear. Astrology applies assumptions of a metaphysical nature and as such are quite unacceptable to modern science which, as closely as possible relies on assumptions of an observable and mechanical kind. The metaphysical assumptions of astrology are that there is a grand design or final cause to the universe, that nothing happens by chance and that this teleological scheme can be divined by celestial observation.
The roots of astrology/astronomy can be traced to the third millennium BCE in ancient Mesopotamia. The ancient Chaldeans were accomplished star gazers and had achieved remarkable results. The length of the year was computed to an error of less than 0.001 % and the motions of the moon and sun had only three time the error when compared to 19th century CE astronomers (Koestler, 1959, 20). They were able to predict astronomical events because of a coherent arithmetic method aided by application of a place value numerical system of base 60: sexigesimal. This study was chiefly motivated by the belief in the ability to divine human events. "Shortly after a sign people assumed a connection (with events)... Whenever a sign occurred again, it was thought to produce the same event once more " (Hunger, 1992, XIII). Astronomy was applied in the hope of predicting forthcoming natural disasters. An industry grew up in the creation of stone tablets which recorded events and simultaneous celestial conjunctions in the search for patterns.
e.g." TABLET 538
The sighting of Venus(ishtar) in Pisces
[If Venus} becomes visible [in Sheba]t
the harvest of the land will prosper
If the worm star is very massive
there will be peace in the land." (Hunger 1992, 295)
The perceived correlations were fully systematised by the seventh century BCE in the Enuma Anu Enlil. Significant celestial events were solar and lunar eclipses, new or full moons on particular days, planetary motion (whether retrograde or not) and planetary position with respect to constellation.
According to Sachs (1974) monthly tablets from the 1st dynasty of Babylon record not only the astronomical event but also commodity values: the respective amounts of barley, dates, sesame seeds and wool that could be purchased with a single shekel of silver. Not only was astrology linked to astronomy but also to agriculture, economy, religion and politics. Modern astronomy owes its origins to ancient Babylon so too does our 12 monthly calendar, days of the week ( in Latin countries) and also the 60 minutes per hour are from sexigesimal time. The middle east is often referred to as the cradle of Western civilisation. For it was here that agricultural practice was first organised and capitalised. This required a detailed knowledge of the changing seasons and an ability to organise labour. Astrology provided a religious framework, a control system, under which workers were bound by the astral destiny to plant crops in spring and harvest in autumn. On a lighter note it was believed that Persian Kings were so concerned with astronomy that Aristophanes jokes that the Great King waited for a full moon before he "buttoned up his arse".(The Archarnians, p 52).
Astrology came west in the second century BCE following the conquest of Chaldea by Alexander in 331 BCE. In 280 Berossus priest of the Marduk Temple of Babylon introduced astronomical ideology to the Hippocratic school on Cos. (e.g. Hippocratic Writings: Aphorisms IV, 5, p216). It came into a culture with long standing traditions of divination and astronomy and its differentiation from astrology was an inevitable consequence of astrology moving out of its original cultural context. There had been many attempts by Greek philosophers to devise mechanistic models to explain the observed celestial phenomena. Anaximander (610-547 BCE) suggested the world was a cylinder and the sun an axle hole. The Pythagorean school developed the hearth (counter earth) theory which held that the sun merely reflected the light from a great central hearth. Eudoxus developed the Crystal sphere hypothesis, improved upon by Callipus and Aristotle which introduced the notion that the universe was made from a nest of concentric spheres. This hypothesis went some way to explain the retrogradations as only some spheres had planets and the various planets were attached to transparent spheres which were pivoted and various points. What was important is that astronomy searched for a mechanical explanation. The cultural milieu was philosophically eclectic: Greeks who consciously or unconsciously accepted the precepts embodied in Stoicism had no need to differentiate. But those accepting the emerging Epicurean scepticism the division was more clear.
The historical tension between astronomy and astrology is paralleled in the philosophical differences between Epicureanism and Stoicism. Although this tension can still be seen today it was not to be resolved until Newton provided a sound mathematical methodology (calculus) to assert the existence of the void in Principia Mathematica. Astrology became a fact of Mediterranean life and was enthusiastically received by the Stoics (Koestler, Gauquelin) who held that nature, reason, fate and god were one agency, a material agency. This intelligent agency fused the heavens with pnuema, a life force, which totally penetrated all living things. Astronomy provided the mechanics and astrology provided the intelligible structure to support Stoicism. The rejection of astrology would find a home in the growing Epicurean philosophy which held that existence was made up of atoms and void, that the senses were of primary significance, laying the ground for empiricism and therefore the differentiation of astrology and astronomy.
Astrology came to Rome via slaves of Greek origin during the Republic and both Pompey and Caesar had personal horoscopes read (Gauquelin, 32). Cicero, a student of the new Academy had studied both philosophical traditions had the opportunity to reject both of their absolutism (Ross, 1972, 9), the synthesis that followed provided Cicero's pragmatism. Cicero was convinced that divination was a superstition (Falconer, 192, 216), he refers to astrology as "inconceivable madness!" (De Divinatione, II, 90). Despite his objections the comet that appeared during the games given at the death of Caesar was to render rational objections to astrology academic during a time when astrology was growing daily (Rose, 1948 112ff). The survival of belief systems is not to be judged by rational philosophical methods or the rational arguments of the wise but merely by popularity of its application. Cicero died in the year following the publication of De Divinatione at the hands of the man who was to elevate astrology to new heights, Augustus. His own propaganda applied the astrological notion of the saeculum or Golden Age, the minting of silver coinage stamped with the sign of Capricorn (his conception sign, a Royal sign) and the reading of his personal horoscopes raised it's respectability. Astrology was readily adopted into the eclectic religious milieu. It embrace by Roman thought is evidenced in Georgics I,1 ;" What makes the cornfields happy, under what constellation / It's best to turn the soil...".also I,32; " Or whether you make a new sign in the Zodiac, where amid the / Slow months gap is revealed between Virgo and Scorpio..."
Following this period astronomy also enjoyed a flowering. For Neugebaur (p4) it becomes a "real science" when the phenomena can be observed as numerical data which are made the criteria for supporting theories. For this he sites the application of sexigesimal mathematics by Hipparkhos in 150 BCE, without which Almagest could not have been written (Ibid., 541). Such is the priority that a mathematical historian gives to mathematics. Despite the inadequacy of Greek maths to deal with celestial phenomena, Aristarkhos c. 230 developed a fully heliocentric system without the benefit of the sexigesimal system. Aristarkhos did not fudge the issue as he made it quite clear what the implications of such a system were. This is the mark of "real science": when all possible assumptions are made clear and consequent contingent assumptions realised. However, for a theory to become established it must satisfy the twin conditions set by current scientific knowledge and social acceptability.
Aristotelian physics and religious preconceptions prevented the uptake of this system. The distinction of Astronomy and Astrology can be demonstrated, paradoxically in the works of a single man: Ptolemy. His Almagest is a work of science. He sets out to " increase the love of the discipline of things ... astronomical "( p6). He carefully sets out his assumptions which precede a set of proofs and hypotheses. He also raises objections to other possibilities such as the objections of physics to a mobile earth. The rest of the work is concerned with a mathematical description, applying Euclidean geometry, of his hypotheses concerning the motions of the planets. He considers all known phenomena and saves the same with models, which introduce the notion of eccentric orbits and epicycles. It is easy for us to ridicule his assumption of perfect circles or geocentricism but his system worked sufficiently for over 1200 years. In sharp contrast Ptolemy's Tetrabiblos is a work of pure astrology. Here we see the sharp division in the two subject exemplified in the works of a single individual.
The strength of science is that, as a body of knowledge it may be challenged and accommodate change. No scientific "fact" is immune from such a challenge. All theories stand and fall upon the strength and weakness of their assumptions. Euclid in his Elements carefully sets out his definitions and postulates and it is within those parameters alone that his propositions apply. In more recent years it has been possible to overturn his mathematical method by challenging those postulates, especially the fifth which induces that parallel lines in extension never meet. This has been abandoned by the analytical methods of Newton (Sklar, 16). Scientific theories may be challenged in the revelation of their inadequacy or in the light of new discoveries. What finally sets astrology apart is that its assumptions are metaphysical and therefore cannot be challenged as its claims simply transcend the limits of empirical evidence and are therefore purely a matter of belief and taste. This is why it is still practised today.
Bibliography
Astrology, J. Mayo, Hodder and Stoughton, 1979.
The Principles of Astrology, Charles Carter, Theosophical Publishing House, 1963.
The Cosmic Clock, Michel Gauquelin, Peter Owen, 1967.
Early Greek Science, G. E. R. Lloyd, Norton, 1970.
Aristophanes, Lysistrata and other Plays, trans., Sommerstein, Penguin, 1973.
Greek Science after Aristotle, G. E. R. Lloyd, Norton, 1973.
Almagest, Ptolemy, Great Books of the World, Enc. Brit, 1952.
The Place of Astronomy in the Ancient World, eds., Oxford, 1974.
A History of Ancient Mathematical Astronomy Part One, Neugebaur.
Astrological Reports to the Assyrian Kings, Herman Hunger, Helsinki Univ., 1992.
The Sleepwalkers, Arthur Koestler, Hutchinson, 1959.
The Nature of the Gods, Cicero, trans. J.M. Ross, Penguin, 1972.
De Divinatione, Cicero, trans. W.A. Falconer, Loeb,1923.
Ptolemy’s Tetrabiblos, J. M. Ashmand, Fowler, 1917.
Space, Time and Space/Time, Lawrence Sklar, Univ. C.A., 1974.
Virgil, The Eclogues/The Georgics, trans. C. Day Lewis, Oxford, 1983.
Hippocratic Writings, trans. J. Chadwick, Penguin, 1950.
