It's March 27 669BC, and night has fallen over Nineveh, the Assyrian capital. On the temple roof, Balasi, chief astrologer to king Esarhaddon, is scanning the sky. An adviser has told the king that Venus is visible, which in Assyrian cosmology is a good thing, portending good rain, rich harvests and peace. Balasi knows it can't be true: Assyrian scholars have been recording the night sky and its predictable motions for a thousand years. But he's compelled to check. The king's informant has mistaken Mercury for Venus. Balasi doesn't hold back. "The man who wrote this to the king my lord is in complete ignorance," he wrote to Esarhaddon. Backstabbing, like stargazing, has a long history.

Long histories of all kinds are at the heart of Selena Wisnom's The Library of Ancient Wisdom, an absorbing exploration of the culture of Bronze Age Mesopotamia, via the abundant records its people left behind. Those records were written on clay tablets in cuneiform, the world's first writing script, formed through wedgeshaped marks made with a reed stylus. Cuneiform culture lasted for nearly three millennia -- half of recorded human history. These tablets were discovered by the British archaeologist Austen Henry Layard in 1850, and their decipherment seven years later shook the world.

One Victorian scholar was so excited to find a Flood narrative pre-dating the Bible -- complete with a ship on a mountaintop and a dove looking for dry land -- that he ran around the British Museum taking off his clothes.

Wisnom's approach is thematic: chapters by turn examine war, medicine, literature and so on. She is keen to stress the influence of Mesopotamian thought. We owe them the zodiac, the horoscope and the 60-minute hour. They developed irrigation and built aqueducts. They used algorithms to predict astronomical phenomena, and a form of calculus for planetary movement. Children in Nineveh were taught Pythagoras's theorem 1,000 years before Pythagoras.

Uruk, the first Mesopotamian city, emerged around 3,500BC, predating the earliest dynasties in Egypt by perhaps half a millennium; it was nearly 2,000 years ahead of Mycenaean Greece, and 3,000 ahead of the Roman Republic. Mesopotamia has thus been dubbed "the cradle of civilisation"; yet Wisnom finds the phrase -- and the simple mindedness it, by implication, imputes -- misleading. The intellectual sophistication of Mesopotamian culture, she argues, offers us "a mirror to our own attempts at rationalisation and certainty". The way they thought is entirely familiar; it's what they thought that seems strange.

Take extispicy, the science of divining the will of the gods in a sheep's entrails. A question was proposed, answerable only by "yes" or "no". Thus, in March 651BC, Ashurbanipal, at war with his brother, asked, "Will the Elamites join the war?" "The entrails were always checked by more than one diviner," Wisnom notes, "and in some cases they were inspected by as many as eleven." A second or even a third extispicy would test the validity of the initial conclusion. It's a model of process-driven decision making. (In the long run, the Elamites did rise against Assyria, even though the divination said they wouldn't; but divinations came with expiry dates -- typically a month -- so the decision held good.)

Just as the Assyrians wrote on clay, so their gods wrote on the world. Stars were "the heavenly writing"; a sheep's liver was "the tablet of the gods". You have a date palm with two tops? People here are hostile to you. Your gate creaks? You're at risk of attack. It was an exhausting body of knowledge to wield. Esarhaddon's chief exorcist complained about his workload: "The tablets are too numerous, God only knows when they will be written." Wisnom is stronger on reconstructing systems of thought than the routines and textures of ordinary Mesopotamian life. More of the latter would have been welcome. But the culture she reveals is always deeply, exhilaratingly human. Like us, the people of the 7th century BC looked to the past and to the world around them, alert for signs of comfort, consolation and hope.

Book: The Library Of Ancient Wisdom By Selena Wisnom.