Written on the Sky: How Ancient Scribes Invented Astrology
On the Mesopotamian origin of astrology — and its complex legacy
“That’s a topic my girlfriend and I argue about all the time,” a New York bartender once confessed after overhearing me chatting about astrology.
“What do you mean?” I asked.
“Well, I’m no scientist,” he said, “but I do value science and reason. There’s no evidence for zodiac signs or horoscopes — it’s all basically nonsense.” His girlfriend, however, was a keen enthusiast. To her, birth charts were legitimate maps of people’s destinies, and Mercury retrograde was very real.
“There’s just no scientific evidence,” the bartender went on, shaking his head as he rinsed beer glasses. “We know the stars are too far away to influence things on Earth. But she doesn’t care, and we fight whenever the subject comes up.”
My first thought when I heard his story was, they’re arguing about something invented thousands of years ago — now that’s what we call ‘unresolved baggage’!
Intrigued by the ongoing debate between skeptics and believers, I embarked on a deep dive into the history of astrology. My intent wasn’t to prove or disprove its validity, but rather to uncover its origin. How did the practice come to be? Did ancient astrologers observe real correlations between celestial and terrestrial events? How did it all begin?
Looking back at history, it’s clear that skeptics have long tried to slay the proverbial hydra. Cicero articulated many common arguments against astrology two thousand years ago. And yet, astrology flourished as a scholarly discipline for centuries until its decline during the Scientific Revolution, only to be revived in the 1900s with the rise of psychology and new-age spirituality. A 1975 manifesto signed by 186 prominent scientists denouncing astrology did little to diminish its popularity. Today, astrology thrives more than ever, easily accessible through popular apps like The Pattern, CHANI, and Co-Star. The bartender’s story resonated with me because it stood as a microcosm for this enduring debate.
To understand the roots of this controversy, I dove into the (vastly underrated) field of Assyriology. Assyriologists study the people and cultures of ancient Mesopotamia (present-day Iraq), the cradle of the world’s earliest civilizations. That’s where farming, writing, and the wheel were invented. That’s also the birthplace of astrology.
Our knowledge of astrology’s origins has been significantly enhanced by one of archeology’s greatest discoveries: the Library of Nineveh. This vast collection of clay tablets, amassed by the Neo-Assyrian king Ashurbanipal, lay buried for 2,500 years after Nineveh’s destruction in 612 BC — until it was unearthed by European explorers around 1850 AD.
Since then, assyriologists have painstakingly worked to decipher the library’s 30,000 tablet fragments (plus thousands more found at other sites like the ancient cities of Uruk and Babylon). Among these tablets emerged a crucial source for understanding astrology’s origin: a comprehensive book of omens, containing 7,000 lines of predictions inscribed on 70 tablets, dealing with all sorts of celestial phenomena. Known as Enuma Anu Enlil, this astrological handbook served as the ultimate guide for interpreting the heavens in ancient Mesopotamia. It was, in a way, humanity’s first “astrology app.”
Among the Nineveh tablets were also hundreds of letters penned by ancient astrologers and other court scholars, giving us a vivid glimpse into the lives and minds of ancient Mesopotamians. (For a truly immersive dive, I highly recommend reading Letters from Assyrian and Babylonian Scholars — State Archives of Assyria Volume X while listening to the “Game of Thrones” theme song.)
In essence, the Mesopotamian book of astrological omens was not grounded in empirical observations but was primarily a literary creation. The system of interpretation it employed, rooted in wordplay and analogy, was crafted by people who perceived the world through the advanced information technology of their era: cuneiform writing. Hence, to truly grasp the essence of astrology and its lasting impact, we must first look at things through the eyes of its creators: the Mesopotamian scribes.
The Writing in the Sky
The people who wrote the first astrological omens were, first and foremost, writers. As obvious as it sounds, this is one of our most important clues for understanding the origin of astrology.
The Assyriologist Jean Bottéro, in Mesopotamia: Writing, Reasoning, and the Gods, explains that the invention of writing completely changed how the Mesopotamians saw the world. “It is as if their spirit had been profoundly marked by the discovery itself,” he writes.
The Mesopotamians wrote by pressing a reed stylus into moist clay tablets. Their writing system, known as cuneiform (meaning “wedge-shaped”), was developed by the Sumerians in southern Mesopotamia around 3400 BC. When the Babylonians succeeded the Sumerians around 1800 BC, cuneiform had evolved into a highly complex and sophisticated technology.
Cuneiform began with pictograms, similar to Egyptian hieroglyphs, and then evolved to include ideograms and phonograms — symbols representing ideas and sounds. To master the script, a scribe had to become proficient in both Sumerian, the ancient language, and Akkadian, the spoken language of the Babylonians. Words could be represented in multiple ways, and signs could convey various meanings, decipherable only through context. That versatility of cuneiform formed the basis of what linguists call the “rebus principle” — a playful form of writing where symbols can be read as words or sounds (think of “Eye + Heart + Ewe” standing for “I love you”).
These are the linguistic roots from which ancient astrology sprang.
The Mesopotamians believed that the gods communicated with them through omens and signs, decipherable by skilled experts. “The job of the diviners was,” as the assyriologist David Brown puts it, “to interpret the signs much as would grammarians working on a text.” To them, the starry sky was like a divine book, with constellations and other celestial objects literally called “writing in the sky.”
But the night sky was just one of many mediums through which the gods communicated. Omens were also read in animal behaviors, human bodies, smoke and oil patterns, as well as the entrails of sacrificed animals, where the liver was the “clay tablet of the gods.”
Still, over time, astrology emerged as the most prestigious form of divination in Mesopotamia and eventually spread throughout the world.
Decoding the Heavens
That said, how did Mesopotamian astrologers determine the meaning of omens and signs? How, exactly, did they interpret the divine messages written in the sky?
Here’s what their clay tablets reveal. Mesopotamian astrologers were avid sky watchers; they meticulously tracked heavenly phenomena like moon phases, the rising and setting of stars, the movement of planets. But the connections they drew between celestial and earthly events, contrary to popular belief, were not rooted in empirical observations. As the Assyriologist David Brown explains in his seminal monograph, Mesopotamian Astrology-Astronomy, “cuneiform celestial divination was an invention, a deliberate encoding of the sky.”
The omens compiled in their astrological handbook, Enuma Anu Enlil, consisted of two parts: an observed sign and a predicted outcome (written in the form of “If X, then Y”). For example:
- If there is an eclipse in month III: the king of the universe will die.
- If Mars comes close to Scorpius: the ruler will die by a sting of a scorpion.
- If Venus is dimmed on her right side: women will struggle giving birth.
- If Saturn enters the Moon: universal peace.
As Brown demonstrates, Mesopotamian omens were essentially “literary creations” derived from wordplay, analogy, and other linguistic tricks in the scribe’s repertoire. Some involved basic analogies with polarities like left-right, up-down, bright-dim, fast-slow, which dictated whether an omen outcome was potentially good or bad.
What’s more, the planets were linked to specific gods, whose attributes were often embedded into their names through puns and word games. For instance, the chief Babylonian god Marduk, who was linked to the planet Jupiter, boasted fifty different names (i.e., “Giver of Farmland”), all derived from the three syllables of his cuneiform name. Similarly, the constellations often drew their meaning by analogy with the figures they symbolized.
The widespread use of astrology today, Brown argues, “owes a huge debt to the learned play of a few literate scholars” who began writing celestial omens around 1800 BC.
Their astrological handbook reached its standard form by 1100 BC, with 7,000 omens written on 70 tablets divided into four sections: omens dealing with the moon (including lunar eclipses), the sun (and solar eclipses), weather phenomena, the stars and planets. The title Enuma Anu Enlil comes from its opening line:
“When Anu, Enil and Ea, the great gods, laid down the design of heaven and earth…”
The handbook was then copied and passed down the generations, serving the needs of the king and the land — until around the 5th century BC, when it supported the emergence of a new genre of divination: personal astrology.
The Assyriologist Francesca Rochberg traces this development in The Heavenly Writing: Divination, Horoscopy, and Astronomy in Mesopotamian Culture. Although new tools were introduced — zodiac signs, birth charts, horoscopes — the new astrology still relied on the old Mesopotamian omen tradition, Rochberg explains. A key evolutionary step was the shift in focus to the moment of birth with so-called “nativity omens.”
- If a child is born when Venus comes forth and Jupiter set: his wife will be stronger than he.
- If a child is born in Taurus (…): that man will be distinguished; his sons and daughters will return and he will see gain.
Today’s astrologers clearly follow in the footsteps of Mesopotamian scribes, interpreting celestial phenomena through wordplay and metaphor. Not long after my conversation with the New York bartender, I visited a professional astrologer. My compulsion to explore the roots of astrology, he read in my chart, was due to three “intense planets” — Mars, Saturn, and Pluto — in Scorpio, a sign associated with caves and the underworld. This explains why I’m naturally drawn to exploring “deep, dark places,” he said. To each their own conclusions.
Meanwhile, let’s dig a little deeper.
Negotiating with the Gods
If Mesopotamian omens were essentially made up “literary creations,” how did the practice manage to thrive for so long? After all, the original guidebook, Enuma Anu Enlil, was copied and used for more than a thousand years. Did anyone ever question the accuracy of omen predictions?
That’s where the wealth of letters and other documents unearthed at Nineveh comes in handy, giving us front-row seats to the drama that unfolded in those times. (The State Archives of Assyria, spearheaded by the Assyriologist Simo Parpola in the 1980s, is a fascinating resource now available online.)
Here’s what we’ve learned: Mesopotamian astrology wasn’t about predicting the future as much as engaging with it. The scribes did not think of omen predictions as binding or deterministic “scientific laws.” Instead, celestial signs were like “judicial decisions” or “warnings from the gods” — which meant they could be appealed.
Indeed, some astrologers moonlighted as ‘lamentation priests,’ whose job was to sing, weep, and perform to appease the angry gods. Others also served as ‘magicians’ or ‘exorcists,’ prescribing prayers and rituals to “undo” bad omens. These rituals could include purifying baths, incense burning, and, in extreme cases, human sacrifices.
One of the most dramatic examples was the ritual of the substitute king. When an eclipse foretold the king’s death, a fake king (typically a prisoner or lower-class citizen) would be placed on the throne to absorb the evil omen. The substitute was given a queen, a royal entourage, and dined and wined for up to a hundred days, while the real king hid in a different palace — until the substitute and his queen were put to death, carrying the evil omen with them to their grave.
The implications here are profound. The scientific method relies on our ability to test and replicate our findings. But if you could change a god’s mind or undo an omen prediction, how would you know if your predictions were ever accurate? Well, you wouldn’t. But that wasn’t the point.
The point was that astrology, and divination in general, gave the Mesopotamians a sense of agency and control in their unpredictable world, as the Assyriologist Stefan Maul argues in The Art of Divination in the Ancient Near East: Reading the Signs of Heaven and Earth. Omen predictions put “a limit upon the almost infinite possibilities that an unknown future might hold,” encouraged people to “reflect prudently,” and “opened the door for goal-oriented planning.”
In the political realm especially, divination was a “powerful institution,” Maul writes, a mechanism that “directed their attention toward various spheres of a country’s internal and external security, prospects for harvest, and logistics.” Even if not a “science” in our modern sense, it would be unfair to dismiss it as a “useless superstition,” he argues, since it promoted “objective and cautious decision-making and allowed for the success and durability of Mesopotamian culture.”
The Library of Nineveh, with its tens of thousands of clay tablets, is a veritable time machine. The omen compendiums, astrological reports, and rich correspondence between kings and scholarly scribes all make one thing clear: the Mesopotamians did not question the value or validity of astrology.
Then came the Greeks.
Astrology Goes Global
This, I’d argue, is the plot twist at the root of our New York bartender’s “unresolved baggage.”
After Alexander the Great conquered Mesopotamia in 331 BC, astrology was absorbed into the Greco-Egyptian culture of the Hellenistic world — and transformed into the so-called “Western” astrology we’re familiar with today. New concepts were incorporated, such as the Greek theory of the four elements (fire, earth, air, water), or the Egyptian use of “rising signs” (aka the “ascendant”). But the modus operandi remained the same: celestial interpretations rooted in analogies and metaphors, and ultimately in the Mesopotamian scribe’s worldview.
This transplantation of astrology into foreign epistemological soil created a major snafu. For some time, the Greeks had been exploring the natural world through a new set of lenses: rational philosophy. They believed they could pierce the secrets of nature through intense inquiry, logic, and reason. This approach, of course, collided with the “literary mode” of celestial interpretations upon which Mesopotamians astrology was built. From then on, skeptics began questioning the validity of astrology, leading to the ongoing debate captured in Cicero’s famous treatise, On Divination.
(The spread of astrology from Mesopotamia to the rest of the world is actually a much more complicated story and an active area of research among modern scholars. The Assyriologist Mathieu Ossendrijver and his team at the Free University of Berlin are currently investigating the details of this important chapter through the ZODIAC project.)
To complicate things further, the astronomer Claudius Ptolemy in the 2nd century AD wrote a hugely influential treatise, Tetrabiblos, in which he spun astrology into a rational Greek science. In a feat of mental gymnastics, he reinterpreted the ancient practice in terms of cause-and-effects, assigning each planet a mix of the four qualities hot, cold, wet, dry. “Seldom, one could say from our own perspective,” writes the historian Anthony Long, “have knowledge, intelligence, and rhetorical skill been more misused than in the opening three chapters of Ptolemy’s Tetrabiblos.” It was Ptolemy’s work, which was then taught in Islamic and European Medieval universities, that would give astrology its long-standing status as a rational Greek science for the next 1,500 years.
Fast forward a few plot twists, and astrology eventually fell out of favor (along with Ptolemy’s geocentric view of the universe) in the aftermath of the Scientific Revolution — only to spring up again at the turn of the 20th century, this time repackaged as a psychological and spiritual tool (another complex but fascinating subplot). This revival would fuel our modern debate between skeptics and believers, and its fateful embodiment, thousands of years after the birth of astrology, as a story told in a New York City bar.
A Linguistic Rorschach
I’ve come to view astrology as a sort of “linguistic Rorschach,” a projective storytelling tool akin to inkblot images but painted with words. Astrological statements are neutral on their own; they come to life when we project our personal experiences onto them.
When the professional astrologer I visited in New York City described my Sun Sign, Aries, as “fiery, impulsive, impatient, action-oriented, bold, courageous,” I conjured anecdotes that fit the description and dismissed those that didn’t. When he brought up my Rising Sign, Cancer, I projected the parts of me that were “sensitive, full of feelings, introspective.” And so on with my Moon in Taurus, which gave me both a “practical side” and a “sweet disposition,” my Venus in Pisces, which indicated that “my career loves me,” and Saturn entering my eighth house, which foretold major life changes.
The idea that astrology — and divination in general — works as a projective tool was further reinforced when the astrologer took out a pack of tarot cards. “The cards won’t contradict the way I read the chart,” he said. “They’ll simply add details.” When I pulled The Lovers and The Devil cards, we again projected stories from my life that fit the cards’ symbolic imagery. The Lovers cautioned me to think twice before making an impulsive decision, like a “young man in love thinking with his crotch” (I was considering changing jobs), while The Devil dealt with overcoming doubts and fears of insecurity.
The experience reminded me of a poem I’d seen many times before in the New York City subway. Titled The Lovers (by Timothy Liu), it read:
I was always afraid
of the next cardthe psychic would turn
over for us —Forgive me
for not knowing
how we wereevery card in the deck.
Our minds are both cameras and projectors. We take in impressions of the outside world through our senses, but we also project our inner world onto everything around us. This is how we create meaning. This is why we don’t all experience a movie, book, or art piece the same way; our interpretations depend on what we project onto the experience. That’s how art works, and that’s likely why astrology resonates for so many people today.
The bartender’s dilemma can be resolved once we view astrology as two inventions entangled into one: a scientific (predictive) tool and a psychological (projective) tool. The problem is that astrology doesn’t work as a scientific tool; it can’t be used to make accurate predictions about the influence of the stars, moon, and planets. Many researchers have tested the tenets of astrology, and they simply don’t hold up under scientific scrutiny. However, astrology must have deep value as a psychological tool, or it wouldn’t have endured for so long.
A legitimate issue, of course, is that the language of astrology is detached from the physical reality of the stars and planets. As a result, astrological claims can seem inherently deceptive when viewed through the lens of scientific knowledge, particularly when marketed for financial gain.
That said, astrology can also be approached as a historical literary genre, offering a snapshot of people’s concerns in different times and cultures. In L’Egypte des Astrologues, Archeologist Franz Cumont mines the astrological literature to recreate a vivid portrait of Hellenistic Egypt. In Manilius and his Intellectual Background, Classics Professor Katarina Volk draws from the astrological poem of Marcus Manilius to bring the early Roman Empire to life. Today, the most popular astrologers, like Chani Nicholas, engage with culturally relevant topics such as social justice, trauma healing, and self-exploration.
What I find even more fascinating is that the story of astrology itself often acts as a mirror for people’s biases and beliefs. Books about the history of astrology tend to reflect their authors’ personal biases. Those written by astrology enthusiasts often romanticize the practice as “ancient wisdom,” while those written by skeptics usually dismiss it as “outdated superstition.”
A significant challenge for modern scholars has been to move beyond the biases of predecessors like George Sarton, the founder of the history of science as an academic discipline, who admonished his colleagues against studying “wretched subjects” like astrology. Today, we owe much to the efforts of Assyriologists who strive to uncover our ancient past while staying mindful of modern prejudices.
Studying the heavens was both a scientific and a literary enterprise in ancient world. The Mesopotamian scribes were acute observers of the night sky. They developed ingenious ways to track the movement of heavenly bodies, marking the birth of scientific astronomy. But they were also literary innovators who experimented with wordplay, metaphor, and analogy. They turned the night sky into a versatile language, a book of cosmic projection, its power residing in its ability to reflect what’s meaningful in our lives back to us: this was the origin of astrology.
Their relationship with the night sky was a launchpad for the development of science, but also for the arts, literature, and religion. This relationship was the catalyst that led us to explore the universe above our heads — and the one within ourselves.
Along the way, however, the direction of our relationship with the heavens became muddled. Do the stars and planets influence our lives on Earth? As above, so below? Or are we projecting our inner worlds onto the sky? As below, so above?
In the end, whether we side with the bartender or his girlfriend in their debate, we must acknowledge that our views on astrology often reflect our deeper beliefs and biases. Perhaps the real question is, are we aware of our own projections? As within, so without.
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