By the third millennium BC, the Babylonians had become obsessed with celestial omens, eclipses in particular. As a result these heavenly phenomena had assumed a central position in their religious beliefs. Unlike the Egyptians, who had little interest in the dozens of solar eclipses whose paths crossed the Nile during this same period, the Babylonians were so concerned about eclipses of the Sun and the Moon that they developed elaborate schemes to record these events over very long periods of time. This kind of record-keeping is very similar to our own. In fact, many have said that the Babylonians were the fathers of astronomy. However, while their methods of observing and record-keeping were similar to our modern applied mathematical astronomy, their motivations were very different. As J. J. Finkelstein has explained:
To the Mesopotamian, the entire objective universe was the crucial and urgent study, without any interposition of the self between the observer and the observed … There probably has never been another civilization so single-mindedly bent on the accumulation of information, and on eschewing any generalization or enunciation of principles.
The Babylonian quasi-religious belief in divination is an unexpected place to start a search through history for the origins of astronomy. Divination was an attempt to determine the will of the gods. To the Babylonians this was the same as an attempt to predict a future event. They believed themselves to be constantly surrounded by a host of evil spirits who caused insanity, sickness, accidents and death. To protect themselves against these spirits, they wore charms, put the image of a god at their doors and had magicians recite incantations. In addition, they depended on an elaborate hierarchy of priests who offered supplication to the gods. This was not idle superstition, but an important part of Babylonian philosophy: they believed that their very destiny was in the hands of the gods. They also believed, surprisingly, that their destiny was negotiable.
Divination rites were a way to communicate with the gods, to determine their will and perhaps change it. The discovery of signs from the gods, usually found in nature, was the first step in this process. As early as the third millennium BC they practised extispicy, the reading of the entrails of animals for clues from the gods to the nature of disasters to come. A sheep’s liver was commonly used for this practice. Extispicy was studied for centuries in the temple schools of Babylonia.
Considered as an act of religion, extispicy was an attempt to consult with the gods, to placate them, obtaining their cooperation and learning of their future intentions. The Babylonian gods were ‘sympathetic’, and might choose to change the divine decree, as a human king might. In addition to the entrails of sheep, the priests looked for clues to their fate in the behaviour of birds and other animals, the path of smoke from incense and the patterns of oil on water. We can look upon these divinations as the forerunners of readings of tea leaves settled in the bottom of a cup.
At some point in their history the Babylonians began to look to the heavens, thought to be the home of the gods. They sought their destiny in unusual celestial happenings – and there is none more unusual than an eclipse. Strange omens in the heavens, like strange patterns in the entrails of sheep, were not the cause of impending disaster but a warning intended to elicit the appropriate ritual of supplication. But this transition from extispicy to the birth of archaic astrology did not take place overnight. For example, a letter from a diviner from the time of Hammurabi in about 1780 BC reported on an eclipse of the Moon which he suspected was a bad omen. However, the letter shows that he was not yet confident in the new celestial form of divination. So in addition to celestial observation, the diviner also checks out the omen by means of extispicy.
Nevertheless, the practice of divination-astrology was growing. For example, a short manual of celestial omens that appeared during Hammurabi’s dynasty contained the following instruction, ‘If, on the day of its disappearance, the god Sin [the Moon] slows down in the sky [instead of disappearing suddenly], there will be drought and famine.’ Although celestial omens were beginning to be studied during the Old Babylonian period, the real development in the observation of the heavens came later, in the first millennium BC, in the time of the Assyrian empire.
Figure 2.2. Nineveh, capital of Assyria, the walled city on the Tigris.
The Assyrians were an extremely warlike people who lived around Assur in the Tigris Valley. They had discovered the secret of smelting iron to make weapons, iron being a tougher metal than the bronze used by the Babylonians. With this advance they initiated a series of great and often cruel wars in the early part of the first millennium BC, destroying the first Babylonian state and extending their boundaries towards Asia Minor and Armenia. The new capital of the Assyrian empire was Nineveh. The political centre of a large military empire, the city was adorned with magnificent buildings, all made of the ubiquitous clay. As a great and rich commercial centre only a few hundred kilometres from Nineveh, Babylon initially retained its rank as a venerable seat of ancient culture. However, in 689 BC the Assyrians turned against the great city and had it destroyed. Even the mudbanks controlling the Euphrates were broken, flooding much of the city and turning the area into a swamp.
The Assyrians had adopted from the Babylonians the ancient and quasi-religious practice of ‘divination’, and absorbed the methods of observation and recording the movements of the Sun and Moon carried over from the Old Babylonian period. Their rulers also began to employ specialists in divination to continue the tradition of recording and interpreting eclipses, conjunctions of the Moon with planets, planetary movements, meteors and comets.
Having taken up the Babylonian philosophy of divination and developed their own astrology, the Assyrians applied their skills of organisation and discipline to the systematic observation of the heavens. They began to build astronomical observatories with temple towers all over the region. Thus began a programme of heavenly omen collection previously unknown in the ancient world. Reports that have come down to us from the period 709–649 BC indicate not just detailed observations, but, in the case of unfavourable eclipses, attempts at prediction. As the divination cult decreed, a successful prediction might provide the opportunity to make supplication to the gods against the expected danger.
While Assyria spread its kingdom by death and destruction as far as Asia Minor, parts of Persia and Egypt, the priests and scribes at Nineveh advanced the astronomical cult inspired by the sacred rites of divination. Over the hundred and fifty years of the empire’s predominance, a wealth of observations and predictions were recorded and collected in the great library at Nineveh. The library had been built by the Assyrian king Assurbanipal to store over twenty-two thousand clay tablets. Hundreds of reports were sent from the observation stations to the king’s palace. A cuneiform tablet of this period records that, ‘The King has given me the order: watch and tell whatever occurs, so I am reporting to the King whatever seems to me to be propitious and well portending and beneficial for the King, my Lord can know.’
Eventually, the harshness and cruelty of the Assyrians drove their subjects to revolt. They were attacked by the Medes from the north and the Chaldeans from the south. After a terrible siege the great capital of Nineveh was taken by storm (612 BC) and the great library was destroyed. The Assyrian empire, which had dominated the Fertile Crescent between the Tigris and the Euphrates for a century and a half, was gone. Nevertheless, it is one of the ironies of ancient history that only because the great library was completely destroyed were the clay tablets preserved. They were buried under the collapsed walls of the library.
After the defeat of the Assyrians, power passed into the hands of the Chaldeans. They revived the old capital of Babylon as the centre of their empire. To historians of science, the Chaldeans are known in particular for their obsession with celestial observation and prediction which they inherited from the Babylonians. There are conservative estimates that these people observed