Did Everyone in Pre-Modern Times Believe in Astrology?

There is a popular perception that people in ancient and medieval times all believed in astrology because they were all stupid and ignorant. This idea, recently promoted by the astrophysicist Neil deGrasse Tyson in a tweet, is inaccurate for two main reasons.

Firstly, believing in astrology only makes someone wrong; it doesn’t necessarily make them stupid. Secondly, there were some intellectuals in both ancient and medieval times who did reject astrology.

“A time of profound ignorance of nature”

On 4 April 2020, the renowned astrophysicist Neil deGrasse Tyson tweeted an image of a scene from the Bayeux Tapestry with a message claiming that the English word disaster is a “prescientific word meaning ‘Bad Star’ from a time of profound ignorance of nature, when misfortune was commonly blamed on cosmic events.”

Before I say anything more, let me just say that Neil deGrasse Tyson is a very smart man. He is extraordinarily charismatic and I admire him for the work he has done to promote knowledge of science. Unfortunately, when it comes to history, he has repeatedly demonstrated that he thinks he knows a lot more than he really knows. This is, unfortunately, a very common phenomenon among scientists.

I previously criticized Neil deGrasse Tyson for his historical errors in this article I published in February 2020 debunking an egregious historically inaccurate segment about the Library of Alexandria from Carl Sagan’s 1980 PBS miniseries Cosmos: A Personal Voyage, which is responsible for promoting all sorts of misconceptions about ancient history and the Library of Alexandria in particular.

Tyson’s errors often involve him relying on the old but deeply inaccurate trope that people in the Middle Ages were ignorant and stupid and they knew nothing about science. It is true that many people in the Middle Ages were uneducated and believed in superstitious nonsense, but this is not a quality that is unique to the Middle Ages; many people in classical Greece and Rome were uneducated as well and, unfortunately, so are many people today. (Indeed, superstition is still thriving as it always has.)

It is also true that educated people in the Middle Ages sometimes believed things that we find ridiculous today. Once again, though, this is not unique to the Middle Ages. Furthermore, there are a lot of things that medieval scholars did understand that they aren’t given credit for.

Even many of the ideas that medieval scholars believed that we find ridiculous today are not nearly as ridiculous as they superficially seem. Many of these beliefs only seem ridiculous to us now because we have been taught about discoveries that have only been made in more recent times that have shown them to be false.

For instance, one of the most commonly trotted out examples of medieval ignorance is the plague doctor costume, but, as I explain in this article I published at the beginning of March 2020, the standard bird-beaked plague doctor costume that we all know today was actually invented in the seventeenth century, meaning it isn’t really medieval. Furthermore, although plague doctor costumes were certainly flawed, they were actually a step in the right direction and they probably did provide doctors with some degree of protection from the plague.

ABOVE: Photograph from Wikimedia Commons of a surviving seventeenth-century plague doctor mask from Austria or Germany on display in the Deutsches Historisches Museum in Berlin

Etymology of the word disaster

Neil deGrasse Tyson is right about where the word disaster comes from, but he does not accurately represent about the historical context that the word originates from. The word disaster is first attested in English in the 1590s. It comes from the Middle French word désastre, which comes from the Italian word disastro, which is formed from the prefix dis-, meaning “ill” or “poorly,” and the masculine noun astro, meaning “star.” The word thus literally means “ill-starred.”

It you want to trace the etymology of the word back even further, the Italian prefix dis- is derived from the Latin prefix dis-, meaning “apart” or “reverse,” which is, in turn, derived from the Proto-Indo-European root *dwís, meaning “twice” or “doubly.” The Italian word astro, meanwhile, is derived from the Latin second-declension neuter noun astrum, which is derived from the Greek second-declension neuter noun ἄστρον (ástron).

The word disaster originates from belief in the pseudoscience of astrology, which originated in ancient Mesopotamia. Most people in the western world in classical antiquity, the Middle Ages, and the Early Modern Period believed in some form of astrology, although the forms of astrology that ordinary folk would have been exposed to would have been significantly more primitive than the more complex forms that the educated would have generally studied.

In its classical form, astrology holds that all events are determined by the motions and positions of celestial bodies, especially the stars and planets. Although there are many different forms that astrology can take, many astrologers throughout history have focused on predicting what will happen in people’s lives based on the positions of the stars and planets at the times of their births.

In ancient and medieval times, astrology was widely regarded as scientific. Indeed, for most of human history, the distinction between astrology and astronomy was often blurry and unclear. Many early astronomers, including Klaudios Ptolemaios (lived c. 100 – c. 170 AD) and Johannes Kepler (lived 1571 – 1630) also practiced astrology. It has only been over the course of the past three hundred years or so that a clear distinction has developed between astrology and astronomy and that belief in astrology has gradually diminished.

ABOVE: Photograph from Wikimedia Commons of the LH 95 star-forming region of the Large Magellanic Cloud, a satellite galaxy of the Milky Way, taken by the Hubble Space Telescope

How “stupid” is astrology really?

Astrology is now widely known among scientists to be wrong. There is no known physical mechanism by which the motions of the stars and planets could determine our behaviors, our personalities, or our destinies. Astrological predictions are usually non-falsifiable and only appear to come true due to confirmation bias. Furthermore, when astrology has made falsifiable predictions, these predictions have proven wrong the majority of the time.

Clearly, astrology is wrong. Nonetheless, we have to ask ourselves whether it is really “stupid” for someone to believe in it. When you think about it, it actually makes a lot of sense that people in ancient times came up with the idea that events are determined by the stars. People in ancient times didn’t know about most of the natural forces and laws of nature that we know about today because those laws had not been discovered yet. When they looked up at the night sky, though, they could see the stars shining above them.

People in ancient times made a number of empirical observations about the celestial bodies that seemed to support the basic premise of astrology. For instance, they noticed that, as the seasons changed, the stars changed as well. They also noticed that the changes in the tides corresponded to the phases of the moon. In line with these observations, it made sense to them for think that the objects that they could see every night in the sky were influencing the world around them. Even though this conclusion ultimately turned out to be wrong, for a very long time, it seemed to be supported by good evidence.

It is also worth noting that, even though the ancient arguments in favor of astrology were long ago debunked and there is no longer any good scientific evidence to support it, many people today still believe in it. A survey conducted by Chapman University in October 2014 found that roughly 13% of people in the United States agreed or strongly agreed with the statement “astrology is real.” That means over one eighth of the population still believes in astrology. For comparison, only around 21% of people in the same survey said they were confident that the universe began with a Big Bang.

Astrology isn’t so much a stupid idea as it is an outdated idea that has now been supplanted by better ones rooted in empirical observation. We should not see the fact that so many people in ancient and medieval times believed in astrology as evidence of their stupidity, but rather as evidence that they were trying to figure out how the world around them worked without access to the data and information that we have today.

Furthermore, it is worth pointing out that not everyone in ancient and medieval times believed in astrology; in fact, as we shall see in a moment, there were intellectuals who posed quite substantial arguments against the validity of astrology.

ABOVE: Photograph from Wikimedia Commons of an ancient Mesopotamian cylinder seal impression dating to the eighth or seventh century BC depicting the goddess Ishtar in her form as the goddess of the planet Venus. Astrology as it has historically been known in the west originated in ancient Mesopotamia.

Ancient Greek critics of astrology

Many people in the Greek world during the Hellenistic Period (lasted c. 323 – c. 31 BC) believed in astrology, but a number of Hellenistic Greek writers also argued against it. Unfortunately, most of the ancient Greek writings critical of astrology have been lost, but we know about some of them because the Roman orator Marcus Tullius Cicero (lived 106 – 43 BC) summarizes some of the arguments posed by these ancient Greek opponents of astrology in Book Two of his treatise De Divinatione (i.e. “On Divination”), which he wrote in Latin in 44 BC.

In the treatise, Cicero quotes the famous Greek mathematician and astronomer Eudoxos of Knidos (lived c. 390 – c. 337 BC), who was a student of the great philosopher Plato himself, as having utterly rejected the idea that the positions of the celestial bodies could be used to make any kind of useful predictions about the future.

Cicero also mentions that the Stoic philosopher Panaitios of Rhodes (lived c. 185 – c. 110 BC) utterly rejected astrology and so did the contemporary astronomers Anchialos, Kassandros, and Skylax of Halikarnassos. Unfortunately, no writings of any of these astronomers have survived to the present day, but, thanks to Cicero, we know that they all rejected astrology.

Specific ancient arguments against astrology given by Cicero

Cicero doesn’t just list authors who had been critical of astrology; he also summarizes some of the arguments they were using against it and he even poses some new arguments of his own. Cicero’s De Divinatione takes the form of a dialogue between Cicero and his brother Quintus Tullius Cicero. Quintus is presented as defending belief in divination from the perspective of a Stoic. Marcus, however, refutes Quintus’s arguments from the perspective of an Academic Skeptic, arguing that all forms of divination are not just unscientific but outright anti-scientific.

In De Divinatione 2.42–47, Cicero poses a number of arguments against the validity of astrology, many of them derived from earlier Greek sources. He first points out that the planets, stars, and constellations are so far away that it is silly to imagine that they exert any substantial influence on human beings. Meanwhile, he points out, weather conditions directly affect human beings every day, but yet astrologers don’t pay any attention to them.

Cicero further observes that children inherit their appearances, their personalities, and sometimes even their postures and mannerisms from their parents, which suggest that their personalities are at least partly the result of heredity, not celestial phenomena. He also observes that twins, who are born at almost exactly the same time, can grow up to have vastly different personalities, which indicates that the time of an individual’s birth is not a deciding factor in determining that individual’s personality.

ABOVE: Photograph from Wikimedia Commons of a Roman marble bust believed to depict the famous orator Cicero, who argued in his treatise De Divinatione that astrology was complete claptrap

Cicero also observes that some people who have been born with certain congenital defects have been cured of these defects, which suggests that a person’s condition at birth does not necessarily determine how they will be for the rest of their life. Meanwhile, he notes that people born at the same time in different parts of the world look and act differently, indicating that the positions of the stars, planets, and other celestial bodies do not determine a person’s appearance, personality, or fate.

Cicero also points out that Hannibal killed 70,000 Romans in the Battle of Cannae in 216 BC; all these men died at the same place on the same day in the same manner, but yet it is ridiculous to think that they all had the same horoscopes. Furthermore, he notes that the great men of history have been born on all different days of the year; whereas, if astrology were true, one would expect to find that all the great men were born on the same few days.

Also, he says that, since there are countless people born each day, if astrology were really true, then we would expect to find thousands upon thousands of people all over the world with the same personality. Obviously, since we don’t see this, astrology cannot be true.

Finally, Cicero points out that astrologers’ predictions are often demonstrably wrong; for instance, he points out that he had personally witnessed astrologers telling Crassus, Pompey, and Caesar that they would live to be extremely old and die peacefully of old age at home after having won tremendous glory—but yet every single one of these men suffered a horrible and violent death.

ABOVE: The Death of Aemilius Paullus at the Battle of Cannae, painted in 1773 by the American painter John Trumbull. Cicero used the example of the Romans who died in the Battle of Cannae to argue against the validity of astrology.

Criticism of astrology in antiquity after Cicero

Several other ancient writers after Cicero also wrote critiques of astrology. Notably, the Roman commonplace author Aulus Gellius (lived c. 125 – after c. 180 AD) records in his book Attic Nights that the rhetorician Favorinus of Arelate (lived c. 80 – c. 160 AD), who was of Gallic ancestry but wrote in Latin, had given a speech arguing against astrology.

Aulus Gellius records that Favorinus posed the twin argument, asking how it was that two people born at almost exactly the same time could have completely different fates. Favorinus further contended that, if the few minutes that pass between the birth of one twin and the birth of the other are enough time for their fates to be completely different, then clearly astrology is completely useless for all predictive purposes, since it is impossible to know the time of anyone’s birth or the positions of the stars at that time with such a level of exactitude.

Aulus Gellius reports Favorinus also argued that it is absurd to think that the motions of the planets would affect the human body in the same way that the moon affects the tides and that it is equally absurd to think that the slightest motions of distant celestial bodies could exert significant effects on people’s lives.

Aulus Gellius says that he wasn’t sure if Favorinus really meant any of his criticisms of astrology seriously, saying that he may have just given the speech in order to show his own brilliance. Aulus Gellius was not unjustified in this belief, since Favorinus is known to have frequently written speeches arguing things that no sane person would agree with just to show that he could argue for them convincingly. For instance, he once wrote a speech praising Thersites, who is presented in Book Two of the Iliad as an ugly, despicable, cowardly character.

The Greek Pyrrhonist philosopher Sextos Empeirikos (lived c. 160 – c. 210 AD) also criticized astrology in his writings, declaring that astrology was useless because it was impossible to know the exact time of a person’s birth or the exact positions of the celestial bodies at the particular moment, especially considering the fact that the stars appear in different positions depending on which part of the world someone is observing them from.

We have no reason to doubt that Sextos Empeirikos meant everything he wrote about astrology seriously, but his criticism of astrology is hardly surprising given that he was a proponent of radical skepticism and he basically rejected all forms of knowledge. In addition to attacking astrology, he also attacked grammar, rhetoric, arithmetic, geometry, music, logic, ethics, and natural science. Astrology, then, in his mind, was no more ridiculous than any other area of knowledge.

ABOVE: Fictional modern illustration intended to represent what the artist imagined Sextos Empeirikos might have looked like

Early Christian critics of astrology

The revered Christian Church Father Augustine of Hippo (lived 354 – 430 AD), who lived in North Africa, was of Berber ancestry, and wrote in Latin, consulted astrologers frequently when he was a young man, but, in his mature years, became convinced that astrology was nonsense. In both his memoir Confessions and his apologetic work The City of God, he repeatedly denounces astrologers as hoaxsters and charlatans. In The City of God 5.1, Augustine invokes the famous twin argument that had been previously invoked by Cicero and Favorinus, writing, as translated by J. F. Shaw:

“…how comes it that they [i.e. astrologers] have never been able to assign any cause why, in the life of twins, in their actions, in the events which befall them, in their professions, arts, honors, and other things pertaining to human life, also in their very death, there is often so great a difference, that, as far as these things are concerned, many entire strangers are more like them than they are like each other, though separated at birth by the smallest interval of time, but at conception generated by the same act of copulation, and at the same moment?”

Augustine remained one of the most revered Church Fathers in western Europe throughout the Middle Ages and, even today, The City of God remains one of the most influential works of Christian apologetics. His argument against the validity of astrology therefore carried great weight for medieval scholars who had access to his works.

Some prominent Christian intellectuals in western Europe during the Early Middle Ages were skeptical of astrology as well. Most notably, the Christian scholar and archbishop Isidore of Seville (lived c. 560 – 636 AD) put forth an argument in his encyclopedic work Etymologiae from a Christian theological standpoint that astrology could not accurately predict the future. Much like Augustine’s City of God, Isidore’s Etymologiae remained widely read throughout the Middle Ages.

ABOVE: Sixth-century AD fresco from the city of Rome, believed to be the earliest surviving representation of Augustine of Hippo

Late Medieval and Renaissance critics of astrology

Despite the rejection of astrology by prominent Church Fathers, astrology remained commonly practiced throughout Europe during the Middle Ages. Nonetheless, there were some intellectuals who spoke out against it. The French friar Laurens Pignon (lived c. 1368 – 1449) was so frustrated by the chicaneries of the astrologers at the court of King Charles VI that, in 1411, he published a treatise titled Contre les Devineurs in which he argued that all forms of divination are fraudulant and that astrology is useless for predicting the future.

In 1495, the Italian Renaissance philosopher Giovanni Pico della Mirandola (lived 1463 – 1494) published the book Disputationes contra Astrologos, in which he totally denounced astrology in all forms, declaring that the heavens do not cause events in the terrestrial realm to happen and that they are not useful for predicting future events in the terrestrial realm either.

In this book, Pico della Mirandola notably describes an experiment he conducted in which he kept track of both astrological predictions that were made and the actual events that ended up happening. He declares that he found that, out of 130 days over the course of which he was running the experiment, the astrological predictions were only correct for seven days.

Pico della Mirandola concludes that the only reason why anyone believes in astrology is because the celestial bodies bear the names of the ancient deities, which people once thought had a tremendous influence on their everyday lives. Despite the valiant efforts of Pico della Mirandola and the few others like him, most people in Europe—including even most educated people—continued to believe in astrology.

ABOVE: Portrait from the Uffizi Gallery in Florence of Giovanni Pico della Mirandola, the author of the Disputationes contra Astrologos

Criticism of astrology in Shakespeare’s plays

The English playwright William Shakespeare (lived 1564 – 1616) includes characters who make some rather memorable criticisms of astrology in his plays. In Shakespeare’s tragedy Julius Caesar, Act I, Scene II, the character Cassius famously tells Brutus:

“Men at some time are masters of their fates:
the fault, dear Brutus, is not in our stars,
but in ourselves…”

This passage is closely paraphrased by Neil deGrasse Tyson in his tweet, indicating that he has knowledge of it.

An even more explicit (albeit less famous) criticism of astrology can actually be found in Shakespeare’s history play Henry IV, Part 1. In Act III, Scene I, the following exchange occurs between Owen Glendower and Sir Henry Percy (a.k.a. “Hotspur”). In the exchange, Glendower resorts to an astrological explanation for their troubles only to be sharply rebuked by Hotspur:

Glendower: “I cannot blame him: at my nativity
the front of heaven was full of fiery shapes,
of burning cressets; and at my birth
the frame and huge foundation of the earth
shaked like a coward.”

Hotspur: “Why, so it would have done at the same season, if
your mother’s cat had been but kittened, though yourself
had never been born.”

It is hard to say whether these passages represent Shakespeare himself voicing his own skepticism of astrology or Shakespeare merely trying to portray certain characters as skeptics of astrology. I am personally rather inclined to think that the former of these options is more likely. In any case, these passages do illustrate the fact that some people in Shakespeare’s time were seriously questioning the validity of astrology.

ABOVE: Photograph of John Wilkes Booth, Edwin Booth, and Junius Brutus Booth Jr. in a production of William Shakespeare’s tragedy Julius Caesar from 1864

Conclusion

It is certainly true that many people in Europe during late antiquity, the Middle Ages, and the Early Modern Period believed in some form of astrology, but not everyone believed in it and there were some educated people who posed very sensible arguments against the validity of astrology—both in ancient times and in medieval times. It is partly for this reason that framing the Middle Ages as “a time of profound ignorance of nature” because people believed in astrology is a mischaracterization.

One thing we always have to remember is that ignorance is natural; whereas knowledge is exceptional. Rather than framing the Middle Ages as a period of ignorance because people back then didn’t know everything we know today, we should be impressed by how much they did know.