Manilius’ Astronomica: a challenging primary source

There are few texts about astrology that survive intact from ancient Greece and Rome. Although there are fragments from early Greek writers, the oldest complete text is Astronomica, written in the early 1st century CE by a Roman, Marcus Manilius. Astronomica is a poem in five books totalling 4,258 lines. It purports to be an instructional text on the theory and practice of astrology, and it would be a very valuable record of astrological practice in the early Empire – if it were not for its fundamental defects.

What’s wrong with Astronomica, you wonder? Well, for one thing, Manilius wrote a lot about the constellations of the zodiac, but very little about the planets. In astrology, the positions of the planets in the sky at the time of the birth of the native (as astrologers call the person whose horoscope is being cast) are supremely important. Without making reference to the positions of the planets within the zodiac the only data you have are which sign was rising at the moment of the native’s birth (which is called the ascendant) and, perhaps, which sign the sun was in. Clearly this doesn’t allow for many variations on the native’s horoscope.

(Of course, the “horoscopes” printed in newspapers today are based solely on the sign the sun was in at the time of birth. Any astrologer, ancient or modern, who was worth his/her salt would scoff at such unsophisticated nonsense!)

Even within the information Manilius does provide, there are inconsistencies. At the end of Book 2 he describes the system of twelve temples or dodecatropos which govern different areas of a person’s life. Then, early in Book 3, he expounds a different and incompatible system of twelve lots or athla which perform a similar function to the dodecatropes. As Steven Green remarks:

The student is left in a quandary: either both systems are valid, in which case astrology is (for the first time) revealed as a dynamic craft resistant to static rules; or only one of the systems is ‘correct’ , in which case the student is forced to choose in the full knowledge that he may be wrong. (p. 30)

Manilius often seems to dwell on the details, with long passages on the various characteristics of personality each sign imposes on the native, without spending adequate time on the higher-level, unifying structure. Katharina Volk captures this neatly:

What we are presented with in the Astronomica is thus an astrological alphabet but not a text, a storehouse of building materials but not a structure. (p. 125)

It is no surprise that, part way through Book 4, the student can no longer contain himself and bursts forth with:

‘But’, you say ‘the task you bid me undertake is great and subtle, and you are plunging my mind back into deep darkness just when I thought a simple principle was enabling me to see light.’ (4.387–9)

The reader sympathises with the frustrated student and can only wonder what Manilius is up to. Why is Astronomica so confusing, incomplete and self-contradictory?

Given the inaccuracies in Astronomica and its incompleteness as a teaching text, some scholars have suggested that Manilius was more of a poet than an astrologer. He probably had access to older Greek manuals on astrology, but may not have understood them completely. Thus, he crafted a long, clever poem full of titbits gleaned from earlier texts. As Volk says:

It thus seems best to me to view didactic poems as a high-end ancient version of our coffee-table books . . . I suggest that didactic poems function in a similar manner: they are appreciated for evoking (not actually teaching) an interesting subject matter in an aesthetic way . . . We can thus conclude (and we may have suspected this all along) that Manilius’ poem—despite all its ‘sums in verse’ and discussions of astrological minutiae—is not really about how to do astrology, but about the idea of astrology itself. (p. 181)

Green takes a different view. He notes that Manilius was writing at a time when the rulers of Rome were quite concerned about the dangerous potential of astrology to foment popular unrest – or even to incite a noble who had an “imperial horoscope” to attempt a coup d’état. Green suggests that Manilius knew exactly what he was doing, and deliberately obscured important details of astrological knowledge in his poem.

It’s an interesting theory. It allows us to view Astronomica in a different light, a light that may illuminate aspects of the poem that have been overlooked before now. I’m sure we have not yet wrung every drop of available information from this elegant, frustrating work.

References

Green, Steven J. 2014. Disclosure and Discretion in Roman Astrology: Manilius and his Augustan Contemporaries. Oxford: Oxford University Press

Marcus Manilius (trans. G. P. Goold) 1992. Astronomica. Cambridge, Mass.: Harvard University Press

Volk, Katharina 2009. Manilius and his Intellectual Background. Oxford: Oxford University Press