Into the Woods

Ancient Astronomy and Celestial Divination, edited by N.M. Swerdlow. MIT Press, Cambridge, Massachusetts, 1999.

An Analysis of Celestial Omina in the Light of Mesopotamian Cosmology and Mythos (master’s thesis), by Robert Jonathan Taylor, 2006.

How did the ancients predict the future using the stars? Why do I care?

I care because, in Oratorio in Ursa Major (to be released April 1, 2016), Jake will meet characters in 48 B.C. who do celestial divination. As with all the science and history in my novels, I don’t want to just make stuff up. Research is required. A year or so ago in another post on another book, The History and Practice of Ancient Astronomy, I described how the ancients knew quite a lot about the science of astronomy. They were careful observers of celestial events, they developed pretty accurate theories, and they were much better at math than we might think today.

But divination — that is, prediction — obviously went much farther than astronomy. What were their methods?

As with astronomy, much of the work that went into celestial divination was done first by the Babylonians, and from there it spread throughout the ancient Mediterranean. Kings were particularly interested in predicting the future, and kings could afford astronomers. Will the crops be good? If a war begins, who will win? Is the king at risk of dying? Those were urgent questions, and the stars were believed to hold the answers.

Books such as Ancient Astronomy and Celestial Divination are more concerned about how the ancients did the observations than the kinds of predictions they made. The master’s thesis by Robert Jonathan Taylor was a lucky find, because Taylor is less concerned with the science and more concerned with the predictions.

Briefly put, the ancients composed catalogs of omina, also called omina series. The catalogs of omina lists celestial conditions determined from observations, then tell you what the observations mean. [If … then.] These predictions were based on experience, it seems. Though no doubt there was an intuitive element and some kind of reasoning.

Here are some examples of omina (taken from ancient clay tablets that have survived and that scholars have carefully catalogued and published):

If Venus is dimmed in month I: in that month the crop of the land will not succeed, the market will decrease.

If Venus enters Jupiter: the king of Akkad will die, the dynasty will change, either a soldier will go out or the enemy will send a message (asking for peace) to the land.

If the star of Marduk is dark when it becomes visible: in this year there will be the asakku-disease.

If an eclipse begins and clears in the north: Downfall of the army of Akkad.

Eclipses were very ominous. The observations listed in the omina had to do with the moon, the planets, certain stars, the sun, and even the weather. The planet Venus was of particular interest because (since Venus is close to the sun) it moves across the sky pretty speedily. Jupiter was thought to be especially predictive of dynasty changes.

As you can see, ancient celestial divination was not really the same as the kind of zodiacal astrology that many people believe in today.