THE STARS AND KNOWLEDGE

On this page

1. A manifesto against astrology (1975)
2. Science or pseudoscience? Popper and the Forer effect
3. What are horoscopes for? Adorno’s reading
4. Astronomy and astrology in the Middle Ages
5. The “science of the stars” in the Islamic world
6. The return to the West: translators and courts
7. Michael Scot at the court of Frederick II
8. Astrologers and power: from Baghdad to the White House
9. Between suspicion and condemnation
10. Women philosophers and scientists of the heavens
11. For classroom discussion
12. Bibliography and online sources

In 1975 hundreds of scientists signed a manifesto against astrology; eight centuries earlier Michael Scot, astrologer to Frederick II, had called it the “queen of the sciences”. This page traces the debate on astrology from twentieth-century criticism back to medieval discussions of free will, knowledge of nature and political power, showing that the status of the “science of the stars” has always been contested, for reasons that change from one age to the next.

This page continues the work begun with the Wiki “La corte del Puer Apuliae”, devoted to the intellectuals and the scientific and philosophical debates at the court of Frederick II.

In 1975 the American bimonthly The Humanist published the manifesto Objections to Astrology, signed by 186 scientists, including 18 Nobel laureates. It had been promoted and drafted by the astronomer Bart J. Bok (University of Arizona), the science writer Lawrence E. Jerome and the philosopher Paul Kurtz (University at Buffalo). In December of the same year the text appeared as a book, together with two essays by Bok and Jerome; by then the signatories had risen to 192, including 19 Nobel laureates.

Its declared aim was to counter “the growing acceptance of astrology in many parts of the world”, to reaffirm its lack of scientific validity and to warn readers against those whom the text bluntly called “charlatans”. The initiative attracted wide media attention and provoked mixed reactions within the scientific community itself.

Among the critical voices was that of the philosopher of science Paul Feyerabend. While stating that he was no supporter of astrology, Feyerabend objected to the way the manifesto had been written and circulated, judging it dogmatic and, ultimately, unscientific. In his view the document had a “religious tone”: it discredited the discipline not by a careful refutation of its premises but by relying on the number and authority of its signatories. In a deliberately provocative comparison, Feyerabend likened the manifesto to the Malleus Maleficarum, the treatise against witchcraft published in 1487 by the Dominicans Heinrich Kramer and Jacob Sprenger: at least the authors of the Malleus, he observed, knew the subject they were attacking thoroughly.

The 1975 controversy is only one episode in a much longer history. As early as 1953, in a famous lecture delivered in Cambridge, Karl Popper had used astrology as an example to illustrate the principle of falsifiability, his criterion for distinguishing science from non-science:

“Astrology did not pass the test. Astrologers were greatly impressed, and misled, by what they believed to be confirming evidence – so much so that they were quite unimpressed by any unfavourable evidence. […] It is a typical soothsayer’s trick to predict things so vaguely that the predictions can hardly fail: that they become irrefutable.”

K. Popper, Conjectures and Refutations

For Popper astrology, unlike the theory of relativity and not unlike psychoanalysis and Marxism, was a textbook case of pseudoscience, because it rested on statements so general that they could never be disproved.

In the late 1940s the American psychologist Bertram R. Forer had studied precisely this kind of generality. He gave his students one and the same personality description, made up of thirteen statements taken from an astrology magazine, and each of them declared that it described them well. This is the so-called Forer effect (also known as the Barnum effect, or personal validation effect): faced with vague formulations, which often contain both a trait and its opposite, everyone tends to find something of themselves in them, through a mechanism linked to confirmation bias.

In the twentieth century the debate was not confined to epistemology: people also asked what social function astrology performs. The 1975 manifesto offered an answer: “In these uncertain times many long for the comfort of having guidance in making decisions. They would like to believe in a destiny predetermined by astral forces beyond their control.”

A far more elaborate analysis had been carried out by Theodor W. Adorno, who studied the horoscopes published between November 1952 and February 1953 in Carroll Righter’s column “Astrological Forecasts” in the Los Angeles Times. The essay, which first appeared in 1957 in the Jahrbuch für Amerikastudien and was republished in Telos in 1974 and as a book in 1975, is known in English as The Stars Down to Earth. As Giulio Navarra has observed, Adorno, drawing on Marxist and psychoanalytic tools, is less interested in astrology’s lack of scientific foundation than in the role it plays in consumer society, now absorbed by the culture industry.

“This reveals the most important idea of the column, namely that the readers are, or feel, fundamentally dependent, constantly finding themselves in situations they cannot handle on their own […]. By systematically following this procedure, the astrologer tends to spread the pattern of dependence and to turn a growing number of people into dependent individuals.”

T.W. Adorno, The Stars Down to Earth

What may look like a harmless pastime is, for Adorno, a genuine “ideology of dependence” containing “an implicit metaphysics of adjustment”. If the cosmos is already ordered and all the individual can do is wait for someone to say whether and when to act, the status quo appears natural, and therefore unchangeable. And since the horoscope addresses readers as if it were speaking to them in particular, promising that, despite effort and frustration, everything will turn out for the best, the existing order comes to seem good and just as well, and any urge to change it pointless or harmful. Astrology thus has, according to Adorno, a structurally authoritarian character: it keeps the individual in a state of perpetual childhood, able to act only with the approval of a higher authority.

The ideal addressee of this mechanism is, for Adorno, the “semi-educated” person: someone who has begun to ask questions and is dissatisfied with the surface of things, but lacks the critical tools needed to understand the social dynamics in which they are immersed. For such a person the horoscope becomes a daily ritual of apparent common sense, an outlet which, like dreams or soap operas, helps them adjust to reality rather than question it.

With all the caution such comparisons require, it is significant that in the United States the spread of astrology in the media coincided, in the case studied by Adorno, with the McCarthy years and, in the case of the 1975 manifesto, with a period of widespread disorientation marked by defeat in Vietnam, the Watergate scandal and the evolution of the youth movements of the 1960s towards New Age spirituality: periods of fear and social control, or of disillusionment and withdrawal, in which the need for reassurance was particularly widespread.

The twentieth-century controversies are no exception. As the historian Hilary M. Carey notes, there has been no period in which astrology did not find both supporters and detractors on rational, theological and moral grounds. Franco Ferrarotti, in his preface to the Italian edition of Adorno’s essay, stresses that astrology has always been hard to place within Plato’s distinction between epistēmē, demonstrable knowledge, and doxa, mere opinion.

What changes over time are above all the grounds of criticism. Today astrology is accused of being unscientific; in the Middle Ages, Carey observes, it was criticised rather for being too deterministic and too close to the natural sciences. To understand why, it helps to start from the definitions given by medieval authors themselves.

Isidore of Seville (6th–7th century), in his Etymologies, draws a clear distinction between the two disciplines:

“Astronomy concerns itself with the turning of the heavens, the rising, setting and motion of the stars […]. Astrology, however, is partly natural and partly superstitious. It is natural as long as it charts the courses of the sun and the moon, or the specific positions of the stars according to the seasons; but it is a superstitious belief that astrologers follow when they practise divination by the stars […] and when they attempt to predict the nativities and characters of people by the motion of the stars.”

Isidore of Seville, Etymologies

For Isidore, then, natural astrology, which studies the influence of the stars on physical phenomena, is legitimate, whereas what would later be called judicial astrology – the prediction of collective events and of individual destinies from the position of the stars at the moment of birth – is superstition.

At the end of the twelfth century the bishop and lexicographer Huguccio of Pisa, in his Magnae derivationes, presents astrology instead as an ars within astronomy: while the astronomer (from nomos, law) studies the laws governing the motion of the heavenly bodies, the astrologer (from logos, discourse) produces a “discourse on the stars”, an essentially interpretive kind of knowledge. Between Isidore and Huguccio the shifting identity of the medieval discipline emerges: an applied branch of astronomy, distinct from it or overlapping with it, and internally divided into morally acceptable and unacceptable practices.

An early distinction already went back to Claudius Ptolemy (2nd century), author both of the Almagest, the foundation of the geocentric model for over a thousand years, and of the Tetrabiblos, the great astrological handbook of antiquity.

The problem of free will

In the Latin West of the early Middle Ages, knowledge of Greek science, including astronomy and astrology, declined sharply. With the spread of Christianity astrology also became a matter of theological controversy. The study of the stars and their effects on the natural world continued to be regarded as useful; the problem was judicial astrology. To claim that the heavenly bodies determine events and destinies meant granting them independence from the will of the Creator and calling free will into question: if the stars decided people’s character and fate, what would become of individual responsibility? For this reason the Church Fathers, and Augustine of Hippo in particular, condemned astrology as superstition. Augustine, who in his Confessions recalls having consulted in his youth “those impostors called astrologers”, also disputed their alleged powers of prediction.

In the Byzantine and above all the Islamic world things were different. The “science of the stars” (ʿilm al-nujūm), which combined astronomy and astrology on the model of Ptolemy’s works, gained importance as early as the Umayyad caliphate and reached its peak under the Abbasid dynasty. According to tradition, in 762 the caliph al-Manṣūr founded the new capital, Baghdad, on the advice of his astrologers, among them the Jewish astrologer Māshāʾallāh: an episode showing how astrology could also serve to represent and legitimise political power.

During the so-called “Islamic Golden Age” Baghdad became a leading cultural centre, with an immense effort to recover and translate the Greek and Persian scientific heritage and with institutions such as the Bayt al-Ḥikma, the “House of Wisdom”. The patronage of the Abbasid court gave astrologers a far from marginal role in the balance of power at the palace. Here too, however, there was no lack of criticism: among the most important were those of Ibn Sīnā (Avicenna) and Ibn Rushd (Averroes), which should be read within their respective philosophies and are not equivalent to one another.

Between the twelfth and thirteenth centuries the Latin West saw a strong revival of astrological studies, fostered by the translation of Arabic scientific works, whose main centres were Toledo and the Norman Kingdom of Sicily. Among the protagonists of this transmission were Adelard of Bath, Gerard of Cremona and John of Seville, and, from the early thirteenth century, Michael Scot.

Astrology then made its way into the courts as well. Some scholars, including J.D. North, attribute to Adelard of Bath the horoscopes drawn up for Henry Plantagenet, whose tutor he probably was: in an age of bloody wars of succession, they may well have served to support Henry’s claim to the English throne, which he later obtained.

The figure who best embodies the relationship between astrology and politics in this period is Michael Scot. After working as a translator in Toledo, he joined the court of Frederick II of Swabia as an expert in astronomy, astrology and mathematics. The originality of the Scottish philosopher lies in his attempt to strengthen the scientific legitimacy of astrology by making it compatible with Christian orthodoxy. An entry of the Wiki “La corte del Puer Apuliae” is devoted to him.

The stars as signs

In his main work, the Liber introductorius, and especially in the fourth distinctio, devoted to the soul (De anima), Michael addresses the main objection raised by the Church Fathers: the danger of astral determinism. His answer is that God alone remains the cause and final end of all things; the stars are the means through which the divine will is made manifest, the signa of the divine plan, and cannot by themselves produce any effect on the sublunary world. In the Prohemium he explains this with a striking image:

“The stars are like the sign hanging outside a tavern: the sign shows that there is wine, but it is not the wine itself.”

Michael Scot, Liber introductorius

Through their presence and movements the stars point to the order willed by God, but they do not act on their own. Astrology, as the only science able to decipher these signs, thus becomes not only compatible with Christian doctrine but one of its highest expressions.

Inclination, not destiny

Michael meets the twins objection by reframing the question. The influence of the stars on character and fate is to be understood as a predisposition: not a fixed path towards a predetermined outcome, but an inclination, a possibility, open to different outcomes depending on other factors, such as the balance of the bodily humours, the place of conception and the differences between individual natures. In this way celestial influence remains compatible with a common experience: people with the same birth chart often lead very different lives.

Although it belongs to a conceptual world far removed from ours, Michael’s model shows a structural analogy with the epigenetic paradigm: like a genetic predisposition, the influence of the stars inclines towards certain traits or illnesses, but the final outcome depends on many environmental and contingent factors. Feyerabend himself noted that the maxim that the stars “incline but do not compel” is not so different from the way modern hereditary theory reasons in terms of inclinations.

The “queen of the sciences”

Michael does not merely answer the critics: he roots astrology in medicine and theology. In medicine, because the heavenly bodies, while not acting on the human will, affect the body and its functions; in theology, because interpreting the signs of the firmament makes it possible to contemplate the cosmic order willed by God. This is why astrology is for him the “queen of the sciences”: it serves both the health of the body and the salvation of the soul.

This new dignity of the discipline goes hand in hand, in the work, with a genuine praise of the astrologer, perhaps also intended to legitimise Michael’s own position. Because the astrologer can decipher the will of heaven, his soul is closer to God than that of a carpenter or a farmer, engaged in purely practical activities. In the third distinctio this superiority translates into a privileged social role: the astrologer’s expertise can make up for the short-sightedness of rulers, too absorbed in daily affairs to foresee what might happen and to intervene in time. The astrologer thus becomes a key figure in the work of government.

The link between the science of the stars and politics, already visible in the founding of Baghdad and at the court of Frederick II, would extend to the Renaissance courts and, in some contexts, last well beyond the early modern period. Carey notes, for example, that the post of court astrologer survived at the Ottoman court until 1924, when it was abolished as part of the secularisation of Turkey promoted by Atatürk.

The twentieth century also offers well-known examples. Ronald Reagan, elected governor of California in November 1966, was sworn in on 2 January 1967 at 00:10. The night-time hour had a precise political reason, namely to prevent the outgoing governor Pat Brown from using his last hours in office to appoint judges close to him; some sources nevertheless claimed that 00:10 had been recommended as a propitious moment by Carroll Righter, the astrologer whose column Adorno had studied and whom the Reagans knew from their Hollywood years.

After the 1981 assassination attempt on President Reagan, his wife Nancy turned to the San Francisco astrologer Joan Quigley to identify the safest times for her husband’s public appearances. According to the former White House Chief of Staff Donald T. Regan, from then on important political decisions were also submitted to her judgement. The Reagans rejected the charge: for Nancy, they maintained, astrology had been only a way of coping with the trauma of the attack, with no influence on the President’s policy. Whatever the exact facts, the uproar the case caused shows how far the subject touches not only on the relationship with power but also on the human need to find ways of tolerating uncertainty.

The synthesis between Arabic-Islamic science and Christian orthodoxy attempted by Michael Scot does not mean that astrology was accepted without reservation. Dante places Michael among the soothsayers in Hell, as one who “truly knew the game of magic frauds” (Inferno XX, 116-117): a sign of the strong association, in the imagination of the time, between astrology and deception.

In the late Middle Ages astrology was part of the university curriculum, especially in connection with medicine, but those who practised it had to express themselves cautiously, always exposed to the charge of heresy. Such was the case of Peter of Abano, physician, astrologer and professor of medicine at Padua between the thirteenth and fourteenth centuries, tried several times for necromancy and astral determinism and condemned to the stake by the Inquisition after his death. Others, such as the theologian Pierre d’Ailly between the late fourteenth and the early fifteenth century, attempted new reconciliations with the faith.

The following centuries would deepen this ambivalence. The early modern period marked the high point of astrology at the European courts; the Scientific Revolution, whose protagonists, such as Tycho Brahe, Kepler and Galileo, had often studied and practised it, would instead help to expel it from the canon of the sciences, separating it for good from astronomy. This would not prevent it from keeping, to this day, a place and a function in society, however controversial.

The history of astronomy and astrology has long been told as a history of men alone. Yet, between Antiquity and the Middle Ages, a number of women studied the heavens, built instruments to observe them and reflected on the relationship between the cosmos and the human body. Some examples:

• Hypatia of Alexandria (4th–5th century), Neoplatonic philosopher, mathematician and astronomer, worked with her father Theon on the commentaries on Ptolemy’s Almagest – the same author from whom the distinction between astronomy and astrology takes its start.
• Maryam al-Asṭurlābī (10th century), active in Aleppo at the court of Sayf al-Dawla, was known as a maker of astrolabes, the instrument Huguccio of Pisa considered proper to the astronomical art.
• Hildegard of Bingen (1098–1179), Benedictine abbess, developed in her works a vision of the cosmos in which macrocosm and microcosm, universe and human body, correspond to one another, and wrote on medicine and natural science.

CETEFIL devotes a dedicated pathway to these and other figures, designed also for schools and built around the figure of Hypatia.

The questions below can be used for a debate: the class splits into two groups, each defending one of the proposed theses.

Text by Chiara Valentini. Web page funded by OPEN APULIA: Territorial Pact of the Apulian University System for Advanced Business Training.