Copernicus, Tycho, Galileo, and Kepler
[see Part One]
As recently as 300 years ago, many astronomers knew a good deal about astrology. Four hundred years ago many astronomers practiced astrology. Five hundred years ago every astronomer was, more or less, also an astrologer.
Further research from more “conventional” scholars affirms that this is indeed a pretty good generalization. Historian of science Thomas S. Kuhn writes in his book,The Copernican Revolution (New York: Random House / Vintage Books, 1957, 93-94):
[A]strology was inseparably linked to astronomy for 1800 years; together they constituted a single professional pursuit . . . those who gained fame in one branch were usually well known in the other as well . . . European astronomers like Brahe and Kepler . . . were supported financially and intellectually because they were thought to cast the best horoscopes.During most of the period with which the rest of this book is concerned, astrology exercised an immense influence upon the minds of the most educated and cultured men of Europe . . . during the late Middle Ages and the Renaissance, astrology was the guide of kings and of their people, and it is no accident that these are just the periods during which earth-centered astronomy made most rapid progress . . . astrology became a particularly important determinant of the astronomical imagination.
. . . It cannot be coincidence that astrology’s stranglehold upon the human mind finally relaxed during just the period in which the Copernican theory first gained acceptance. It may even be significant that Copernicus . . . belonged to the minority group of Renaissance astronomers who did not cast horoscopes.
Christianity strongly opposed astrology during the patristic period, but inroads into Christian culture took place again after the Renaissance (it had a strong correlation — one might ironically note — with humanism). For an in-depth treatment of this historical background, see Catholic Encyclopedia (“Astrology”).
The Catechism of the Catholic Church categorically rejects astrology:
2116 All forms of divination are to be rejected: recourse to Satan or demons, conjuring up the dead or other practices falsely supposed to “unveil” the future [Cf. Deut 18:10; Jer 29:8]. Consulting horoscopes, astrology, palm reading, interpretation of omens and lots, the phenomena of clairvoyance, and recourse to mediums all conceal a desire for power over time, history, and, in the last analysis, other human beings, as well as a wish to conciliate hidden powers. They contradict the honor, respect, and loving fear that we owe to God alone.
Copernicus too lived in an age when astronomy and astrology were inextricably connected. Astronomy was generally seen as a theoretical underpinning of astrology, problems and events in the one, having serious implications for the other. Both areas, however, seemed to be far from perfect. At Cracow, Copernicus learnt astrology as well as astronomy. He studied the Alfonsine Tables, read the works of Peurbach and Regiomontanus, who, inspired by ancient astronomy, sought to reform theoretical astronomy, fully aware that improvement in astronomy would lead to improvement in its practice, astrology. One of his teachers at Cracow, John of Gogów, wrote on the astrological consequences of a planetary conjunction. The University of Bologna, since 1404, required its professor of mathematics and astrology to issue annual prognostications. Thus Domenico Maria issued prognostications, which gave for the following year the date of Easter, phases of the moon, weather forecasts, times of eclipses (if any), various auspicious and ominous dates, and general predictions for the year. Copernicus thus lived in a time when astronomical events were impregnated with astrological meanings. He was equally aware of criticisms of astrology, such as the famous attack in Giovanni Pico della Mirandola’s Disputations against Divinatory Astrology (Disputationes adversus Astrologiam Divinatricem, 1496). (Copernicus and Astrology, Sachiko Kusukawa)
Copernicus left Bologna for Frombork in 1501 without having obtained his degree. The chapter then approved another leave of absence for Copernicus to study medicine at the University of Padua. The medical curriculum did not just include medicine, anatomy, and the like when Copernicus studied it. Siraisi (1990, 16) noted that “the reception in twelfth-century western Europe of Greek and Islamic technical astronomy and astrology fostered the development of medical astrology…the actual practice of medical astrology was greatest in the West between the fourteenth and the sixteenth centuries.” Astrology was taught in the medical schools of Italy. “The importance attached to the study of the stars in medieval medical education derived from a general and widely held belief that the heavenly bodies play an intermediary role in the creation of things here below and continue to influence them throughout their existence. The actual uses of astrology in medical diagnosis and treatment by learned physicians were many and various. ‘Astrological medicine’ is a vague and unsatisfactory term that can embrace any or all of the following: first, to pay attention to the supposed effect of astrological birth signs or signs at conception on the constitution and character of one’s patients; second, to vary treatment according to various celestial conditions…third, to connect the doctrine of critical days in illness with astrological features, usually phases of the moon; and fourth, to predict or explain epidemics with reference to planetary conjunctions, the appearance of comets, or weather conditions” (Siraisi, 1981, 141-42). It is true that astrology required that medical students acquire some grounding in astronomy; nevertheless, there is no doubt that Copernicus studied astrology while at the University of Padua. (Stanford Encyclopedia of Philosophy, “Nicolaus Copernicus”)
. . . my view that Copernicus’s initial proposal to reorder the planets was part of an attempt to defend the theoretical foundations of both astronomy and astrology against the massive criticisms of Pico della Mirandola. (Kepler’s Early Physical-Astrological Problematic, Robert S. Westman)
In 1572, a new star appeared in the sky, one that set Brahe’s career in motion. The supernova of 1572 had only one known precedent in the West, and that had occurred in 125 B.C.E. Brahe meticulously observed and measured the star and published an astrological report on it. This report, called The New Star, contained 27 pages of precise measurements, followed by an analysis of its astrological effects. Brahe thought the star to be related to the preceding New Moon of November 5, 1572, which, he believed, was ruled by Mars. He also thought that, since the new star was related by its pole to the sign Aries, the Martian influence was reiterated. His astrological analysis suggested that the star was a forerunner of vast changes in politics and religion and that its influence would begin nine years after the 1583 Jupiter-Saturn conjunction in Pisces. This conjunction was the conclusion of a cycle of conjunctions of these two planets, which he interpreted as an indication of the impending birth of a new age . . . he published a number of astrological predictions and calendars, lectured on astrology at the University of Copenhagen, and regularly gave astrological readings to his patron, King Frederick II. (Bruce Scofield, Were They Astrologers? — Big League Scientists and Astrology)
Like the fifteenth-century astronomer Regiomontanus, Tycho Brahe appears to have accepted astrological prognostications on the principle that the heavenly bodies undoubtedly influenced (yet did not determine) terrestrial events, but expressed scepticism about the multiplicity of interpretative schemes, and increasingly preferred to work on establishing a sound mathematical astronomy. Two early tracts, one entitled Against Astrologers for Astrology, and one on a new method of dividing the heavens into astrological houses, were never published and are now lost. Tycho also worked in the area of weather prediction, produced astrological interpretations of the supernova of 1572 and the comet of 1577, and furnished his patrons Frederick II and Rudolph II with nativities and other predictions. The horoscope shown here is the nativity of King Christian IV of Denmark, composed by Tycho a few weeks after his birth in 1577.
An astrological world-view was fundamental to Tycho’s entire philosophy of nature. His interest in alchemy, particularly the medical alchemy associated with Paracelsus, was almost as long-standing as his study of astronomy, and Uraniborg was constructed as both observatory and laboratory. In an introductory oration to the course of lectures he gave in Copenhagen in 1574, Tycho defended astrology on the grounds of correspondences between the heavenly bodies, terrestrial substances (metals, stones etc.), and bodily organs. He was later to emphasise the importance of studying alchemy and astrology together with a pair of emblems bearing the mottoes Despiciendo suspicio – “By looking down I see upward” – and Suspiciendo despicio – “By looking up I see downward.” As several scholars have now argued, Tycho’s commitment to a relationship between macrocosm and microcosm even played a role in his rejection of Copernicanism and his construction of a third world-system. (Tycho Brahe and Astrology, Adam Mosley)
He was an imperious, hard-drinking aristocrat whose devotion to precise observation was motivated by his devotion to astrology. He was also an alchemist and lived for twenty years on a fantastic ‘sorcerer’s island’ near Hamlet’s castle of Elsinore, ending his days as Imperial Mathematicus at the court of the Holy Roman Emperor. In the history of astrology and astronomy, Tycho stands out as one of the most bizarre and colourful of all Urania’s children.
. . . Tycho also found time to provide an annual astrological almanac for King Frederick and to write detailed reports on the horoscopes of the king’s children. The royal horoscopes were presented as handsome bound volumes with up to 300 pages of natal delineations and directions. Tycho’s charts were not the square figures generally used by his contemporaries, but circular. He may have been the first astrologer to make regular use of a circular chart form.
. . . Within a few years of Tycho’s death, the telescope had revolutionised observational astronomy. Kepler, who succeeded him as Imperial Mathematicus, finally gained full access to his records. They became a key factor in the formulation of Kepler’s laws of planetary motion, which did away with the circles and epicycles of both the Ptolemaic and Copernican theories and gave the first glimpse of the solar system as it is perceived by astronomers today. The collapse of the old cosmology brought astrology down with it – at least so far as science and academia were concerned. Tycho Brahe is one of the last representatives of an age when astrology and astronomy were one, offering an integrated vision of humanity’s place in the Universe. Despite Kepler’s earnest attempts to clarify that vision in line with the new astronomy, it has yet to be recovered. (Tycho Brahe: A King Amongst Astronomers, David Plant)
Apparently Galileo was indeed knowledgeable of astrology. He cast many horoscopes, and he even worked at rectifying his own chart. This new information about Galileo comes via the research of Italian astrologer, Grazia Mirti, who presented her findings at the 1992 Astrological Association Conference and later published them in an Italian journal. Nick Kollerstrom used her research as the basis for his English language article on Galileo. It turns out that Galileo was later “sanitized” by biographers who, when forced to account for his horoscopes, either made comments about his “dark side” or found reasons to point out that he was a bad astrologer.The evidence suggests that Galileo was involved with astrology for a long time, probably most of his life. In 1604, he was accused of practicing “astral determinism” on his wealthy clients. In 1609, the Duchess of Tuscany asked Galileo to rectify the chart of her husband, the Grand Duke. Also in 1609, he published a short work that included an astrological delineation of Jupiter in the Midheaven of Cosimo de Medici’s horoscope. In 1613, he drew up charts for his daughters. . . . The last horoscope cast by Galileo is dated 1625, when he was 61. Finally, the contents of Galileo’s library reveal 14 books on astrology and many others on occult philosophy. His copy of Ptolemy’s Tetrabiblos was apparently annotated, but has unfortunately been lost. (Bruce Scofield, Were They Astrologers? — Big League Scientists and Astrology)
Galileo, like Kepler, was a mathematicus, a term which had a threefold meaning as referring to mathematics, astrology and astronomy. . . . The letters by Galileo to his astrological colleagues have been lost and we only have the replies, as likewise the most famous charts composed by him have been lost, however some twenty-five charts drawn up by him do remain, plus several instances of his chart analyses.
. . . In 1609 Galileo moved to Florence. His revolutionary bestseller,Sidereus Nuncius, ‘The Message of the Stars’ appearing in March, 1610, opened with an eloquent account of the traditional qualities assigned to Jupiter:
So who does not know that clemency, kindness of heart, gentleness of manners, splendour of royal blood, nobleness in public functions, wide extent of influence and power over others, all of which have fixed their common abode and seat in your highness – who, I say, does not know that these qualities, according to the providence of God, from whom all good things do come, emanate from the most benign star of Jupiter?
This indicates not merely that Galileo did not doubt the matter, but that he could hardly imagine anyone else doubting it. The text follows with an account of Jupiter’s position at the top of the chart of his young patron, Cosimo de Medici, the Duke of Tuscany:
Jupiter, Jupiter I say, at the instant of Your highness’s birth had already passed the slow, dull vapours of the horizon and was occupying the Midheaven, from which point it was illuminating the eastern angle, from that sublime throne saw the most happy delivery and all the splendour and magnificence of the newly-born diffused in the most pure air…
The Latin Orientalemque angulum sua Regia illustrans translates literally as “illuminating the Eastern angle of which he [Jupiter] is the ruler”: it alludes to Cosimo de Medici’s rising sign (‘orient’) Sagittarius, as traditionally belonging to Jupiter (sua Regia i.e. under his rulership). Galileo’s text continued:
…in order that your tender body and your mind might imbibe with their first breath that universal influence and power, …
– alluding to the condition of the horoscope at that instant, as dominated by the planet Jupiter. This is Galileo’s view of how astrology worked.Upon his publication of Sidereus Nuncius Galileo released knowledge of his discovery of four new planets, the Moons of Jupiter which he named the ‘Medici sidera’. A query was put to him by Piero Dini in Rome concerning how one could ascertain their influence upon mankind. Galileo replied on 21 May, 1611 with a letter occupying eleven pages of Favaro’s Opere. His arguments for the reality of the Medici sideraappear as indissolubly linked with the question of their influence. It would not seem right to assert that “these Medician Planets lack all influence, wherein the other stars abound”. He drew a comparison with different plant species which have their ‘qualities, virtues and effects’ to be explored. Galileo conjectured how the ‘little planets’ might affect us, contrasting ‘superior’ and ‘inferior’ causes:
If, therefore, of the inferior causes, those which arouse boldness of heart are diametrically contrary to those which inspire intellectual speculation, it is also most reasonable that the superior causes (if indeed they operate on us) be utterly different from those on which courage and the speculative faculty depend; and if the stars do operate and influence principally by their light, perchance it might be possible with some probable conjecture to deduce courage and boldness of heart from very large and vehement stars, and acuteness and perspicacity of wit from the thinnest and almost invisible lights.
. . . Galileo not only drew up charts for his two illegitimate daughters, but composed character-judgements based upon them. For Virginia the elder daughter he noted that the Moon (traditionally of feminine significance for motherhood, etc) was ‘debilitated’, and wrote grimly:
The Moon is very debilitated and in a sign which obeys. She is dominated by family relationships. Saturn signifies submission and severe customs which gives her a sad demeanour, but Jupiter is very well with Mercury, and well-aspected corrects this. She is patient and happy to work very hard. She likes to be alone, does not talk too much, eats little with a strong will but she is not always in condition and may not fulfil her promise.
In the younger daughter Livia he discerned (quite wrongly, according to Sobell ) a more extrovert character. Her De Ingenio affirmed:
Mercury rising is very strong for all things, and Jupiter which is conjunct gives knowledge and bounty, simplicity, humanity, erudition and prudence.
Sobell’s six-hundred page opus Galileo’s Daughter makes no allusion to these texts, though published by Favaro, indicating how censored the topic remains.. . . For centuries the image of Galileo has functioned as an icon of the new science he did so much to found. This has meant ignoring the real person. His biography becomes more interesting if we see him in the context of a Renaissance mathematicus without imposing our preconceptions upon him. French philosophers such as Descartes and Gassendi were sceptical towards astrology, whereas this had not become an issue in Renaissance Italy: there was no social context as could have supported astronomers sceptical towards astrology during Galileo’s life. Only later on, in the latter half of the seventeenth century, was astrology expelled from the universities, whereby astronomy became established as a separate and independent discipline. (Galileo’s Astrology, Nick Kollerstrom)
Johannes Kepler [Lutheran] (1571-1630)
There is no denying that this great scientist – the man who gave Newton the clues he needed – not only practiced astrology, he liked it. In fact, Kepler’s motivations were so cosmologically astrological that historians paint him as having one foot in the Middle Ages and one foot in the modern world. Science textbooks sanitize this image and focus almost entirely on his scientific achievements. There’s a famous quote from Kepler that we’ve all heard in one form or another. In his 1610 publication, Third Party Intervening, in which he discussed the conflicts between astrology and astronomy, he advised readers critical of astrology “not to throw the baby out with the bath water.”. . . In 1600, Kepler began to work with Tycho Brahe. When Brahe died the following year, he inherited his position as imperial mathematicus (read “royal astrologer”) to Rudolph II in Prague . . . Between 1612 and 1626, Kepler worked as provincial mathematicus (“personal astrologer”) in Linz, the capital of upper Austria. During this time, he published the best ephemerides of the century and also his third book,The Harmony of the World. This work was the climax of his lifelong obsession with astrology, astronomy, numbers, and music.
. . . Kepler’s astrological writings have been suppressed. The Mysterious Cosmos has never been translated into English. The Harmony of the World was only recently translated from the German, but The New Astronomy, his math and physics book, has long been available. Kepler wrote about 80 other essays and treatises on astrology and astronomy, only a few of which are available to English readers. In spite of what skeptical debunkers would have us believe, Kepler was a metaphysically-oriented astrologer who was a whiz at geometry and did good science. He introduced a number of minor aspects, which included the sesquiquadrate, the quintile, and the biquintile. He attempted to reform astrology by emphasizing the symmetry of the planets and dispensing with the zodiac. He also worked with harmonics. Uranian astrology of the 20th century has built a system based on many of his ideas. Other so-called pioneers of astrology in this century have been deeply influenced by him. Kepler is, without a doubt, one of astrology’s greats. (Bruce Scofield, Were They Astrologers? — Big League Scientists and Astrology)
Kepler disdained astrologers who pandered to the tastes of the common man without knowledge of the abstract and general rules, but he saw compiling prognostications as a justified means of supplementing his meagre income. Yet, it would be a mistake to take Kepler’s astrological interests as merely pecuniary. As one historian, John North, put it, ‘had he not been an astrologer he would very probably have failed to produced his planetary astronomy in the form we have it.’
Kepler believed in astrology in the sense that he was convinced that planetary configurations physically and really affected humans as well as the weather on earth. He strove to unravel how and why that was the case and tried to put astrology on a surer footing, which resulted in the On the more certain foundations of astrology (1601). In The Intervening Third Man, or a warning to theologians, physicians and philosophers (1610), posing as a third man between the two extreme positions for and against astrology, Kepler advocated that a definite relationship between heavenly phenomena and earthly events could be established.
At least 800 horoscopes drawn up by Kepler are still extant, several of himself and his family, accompanied by some unflattering remarks. As part of his duties as district mathematician to Graz, Kepler issued a prognostication for 1595 in which he forecast a peasant uprising, Turkish invasion and bitter cold, all of which happened and brought him renown. Kepler is known to have compiled prognostications for 1595 to 1606, and from 1617 to 1624. As court mathematician, he explained to Rudolf II the horoscopes of the Emperor Augustus and Mohammed, and gave astrological prognosis for the outcome of a war between the Republic of Venice and Paul V. In the On the new star (1606) Kepler explicated the meaning of the new star of 1604 as the conversion of America, downfall of Islam and return of Christ. The De cometis libelli tres (1619) is also replete with astrological predictions. (Kepler and Astrology, Sachiko Kusukawa)
Kepler’s new aspects were based upon harmonic theory and grounded in empirical observation of astrological effects. From his long-term study of weather conditions correlated with planetary angles and from detailed analysis of his collection of 800 birth charts, Kepler concluded that when planets formed angles equivalent to particular harmonic ratios a resonance was set up, both in the archetypal ‘Earth-soul’ and in the souls of individuals born under those configurations. He considered this ‘celestial imprint’ more important than the traditional emphasis on signs and houses: “in the vital power of the human being that is ignited at birth there glows that remembered image…” The geometric-harmonic imprint constitutes “the music that impels the listener to dance” as the movements of the planets, by transit and direction, echo and re-echo the natal theme.
. . . Kepler later qualified his criticism of the zodiac signs by remarking that, “…the human race has envisioned this partition from the time of the Chaldeans down to our own time”. This being so, he wondered whether “God himself does not conform to it… and whether He does not wish to speak to human beings therewith in a language or method of communication that they understand”. (Kepler’s Astrology, David Plant)
Although he first became famous for the accuracy of his predictions and scored an impressive number of ‘hits’ during his career, Kepler’s attitude to conventional astrology was ambivalent and complex. In attempting to disentangle it, we can at least begin by dismissing the notion that he rejected astrology out-of-hand. In the official history of scientific progress, the values of the Age of Reason and Industrial Revolution were projected onto the brilliant mathematician who had unravelled the laws of planetary motion. It seemed inconceivable that he could be tainted with the medieval superstition of astrology. Like Isaac Newton’s passion for alchemy and theology, this aberration was best glossed over or, as actually happened in Kepler’s case, twisted into a distortion of the truth.
Kepler’s famous metaphor comparing astrology to the ‘foolish daughter’ of the ‘wise mother’ (astronomy) has often been cited as evidence of his disbelief. Seen in context, however, the foolish daughter represents a particular style of astrology — popular astrology — which was not to Kepler’s taste. He was always careful to distinguish his reverential vision of the celestial harmonies from the practices of the backstreet astrologers and almanac-makers “who prefer to engage in mad ravings with the uneducated masses”. Kepler’s astrology was on another plane altogether. Before condemning him for his blatant intellectual snobbery, however, consider how many ‘serious’ astrologers today feel exactly the same way about Sun-sign columns. Kepler was neither the first nor the last astrologer to pour scorn on those who practise apparently inferior forms of the art. His disapproval stems from his conviction that astrology is nothing less than a divine revelation, “…a testimony of God’s works and… by no means a frivolous thing”. Unfortunately, Kepler’s salary as Imperial Mathematicus was rarely paid (the Imperial treasury owed him 20,000 florins by the end of his career) so he was obliged to scratch out a living by giving astrological advice to wealthy clients and composing astrological almanacs for the ‘uneducated masses’ he so despised. Reluctantly, Kepler conceded that “the mother would starve if the daughter did not earn anything”. In another famous turn of phrase, he warned those learned professors who had grown sceptical of astrology that they were likely to “throw the baby out together with the bathwater” if they rejected it entirely.
So Kepler was undoubtedly an astrologer — but he was no respecter of astrological tradition. His ideas seem radical even by the standards of mainstream astrology today. For a start, he dismissed the use of the 12 houses as ‘Arabic sorcery’. While accepting that the angles were important, he could see no justification for conventional house division. “Demonstrate the old houses to me,” he wrote to one of his correspondents, “Explain their number; prove that there can be neither fewer nor more… show me undoubted and striking examples of their influence.” He even went so far as to question the validity of the signs of the zodiac, arguing that they were derived from human reasoning and arithmetical convenience rather than any natural division of the heavens. He had no time for elaborate schemes of planetary sign rulership and saw no reason why some planets should be classed as benefic and others as malefic.
Kepler left no astrological convention unchallenged. His rigorous questioning hints at a massive reformation of astrology, on a scale which Ken Negus has compared to the reformation that Martin Luther brought about in the Church. Kepler’s great attempt to purge astrology seems to echo the Pythagorean katharsis — a frenzied purification of the soul undertaken in order to restore divine harmony. More prosaically, it should be seen in the context of the monumental changes taking place in theoretical astronomy during the 16th and 17th centuries. The ancient Aristotelian doctrines that had given astrology some measure of scientific credibility were crumbling fast. Copernicus had displaced the Earth from the centre of the universe; Tycho had proved that the ‘immutable’ heavens were subject to change as new stars blazed in the sky; Galileo’s telescope had opened up dimensions undreamt of by Ptolemy; Kepler himself had shattered the serene, circular motions of the planetary orbits forever. He sensed that astrology would have to adjust to the new astronomy if it were to keep pace with the march of science.
The New Aspects
The key to Kepler’s proposed reform is his approach to the aspects. Traditional astrology recognises five significant relationships, based upon the twelvefold division of the zodiac signs. Ptolemy taught that their significance was derived by analogy with the ratios of the musical scale. The conjunction is equivalent to the same two notes played in unison. The opposition divides the circle in the ratio 1:2, which corresponds to the octave. The sextile (5:6) corresponds to a minor third, the square (3:4) to a perfect fourth and the trine (2:3) to a perfect fifth. By placing less emphasis upon the zodiac signs, however, Kepler was free to explore additional aspect relationships in his pursuit of the Pythagorean synthesis of music, geometry and astronomy.
Kepler’s geometric scheme of the solar system which led to the formulation of his Laws of Planetary Motion Kepler’s new aspects were based upon harmonic theory and grounded in empirical observation of astrological effects. From his long-term study of weather conditions correlated with planetary angles and from detailed analysis of his collection of 800 birth charts, Kepler concluded that when planets formed angles equivalent to particular harmonic ratios a resonance was set up, both in the archetypal ‘Earth-soul’ and in the souls of individuals born under those configurations.  He considered this ‘celestial imprint’ more important than the traditional emphasis on signs and houses: “in the vital power of the human being that is ignited at birth there glows that remembered image…” The geometric-harmonic imprint constitutes “the music that impels the listener to dance” as the movements of the planets, by transit and direction, echo and re-echo the natal theme. In addition to the Ptolemaic aspects, Kepler proposed the quintile (72°), bi-quintile (144°) and sesqui-quadrate (135°). Extending the analogy of the musical scale, the quintile is equivalent to an interval of a major third (4:5), the sesqui-quadrate to a minor sixth (5:8) and the bi-quintile to a major sixth (3:5). (Kepler and the Music of the Spheres, David Plant)
Kepler attempted to devise a new method of computing astrological influences in the heliocentric (Sun-centred) universe . . . (Encyclopaedia Britannica, 1985, “Occultism: Astrology after the Hellenistic period,” Vol. 25, 83)
Photo credit: An Astrologer Casting a Horoscope from Robert Fludd’s Utriusque Cosmi Historia, Oppenheim, 1617 [public domain / Wikimedia Commons]