history of science

Rochberg on Omens

Your humble correspondent in the Central European blizzard of January 2019

One of the books which I would like to find time to read is Francesca Rochberg’s Before Nature: Cuneiform Knowledge and the History of Science (University of Chicago Press, 2016) {available from the publisher}. About a decade ago, she was puzzled why Mesopotamian omen lists include situations which can never occur, such as the appearance of the sun at midnight or a lunar eclipse which moves from west to east across the moon. The Mesopotamian literati were intimately familiar with the movements of the heavens, and had thousands of years of records, so they probably had a firm conviction that this was not the sort of thing which could happen in the ordinary course of events. Were these absurd? The result of block-heads mechanically multiplying omens to cover different combinations of left/right, the three watches of the night, the four directions, and so on regardless of whether that combination was possible? Violations of the order of the heavens on special command of the gods?

Perhaps this is where we step into the realm of the conceivable, or the conceptually possible, as differentiated from the possible, or at least the metaphysically possible … To say certain phenomena in the omen lists are “impossible” or “absurd” because they do not occur and cannot be observed is our judgement and occurs nowhere in the ancient sources. That is to say, our definition of impossible (not in accordance with real properties) is not expressed in the texts. It seems more consistent with the overall makeup of the omen lists that recording a phenomenon as an entry in a codified omen list is evidence that it was regarded as epistemically possible [something which a reasonable person may chose to believe]. That is, the list of statements (P) constitute data, or knowledge, on the basis of which the diviner makes judgements and draws conclusions about what will happen. The use of the terms possible and impossible are, among other things, relative to one’s accepted knowledge of how and what things are.
Francesca Rochberg, “Conditionals, Inference, and Possibility in Ancient Mesopotamian Science,” Science in Context 22.1 (March 2009) pp. 5-25

The Classical Style of Argument

There is a style of argument which people trained in the classics often use. In this approach, one goes through the evidence piece by piece, artfully arranging it and discussing how to interpret the difficult points, then sums up by drawing it into a grand conclusion. This evidence is mostly widely available, great pains having been taken to publish Greek and Roman literature, the more important inscriptions and vases, and other remains of the ancient world in cheap editions and translations. Anyone with access to a library and the willingness to search should be able to find the main sources which lie behind a book on ancient history, and a growing number are available on the Internet. This style of argument can be great fun to read, with impressive learning and elegant transition from author to tombstone to vase. But eventually the lover of the ancient world discovers that learned and literate scholars can use this approach to write completely contradictory studies of the same topic. By selecting which passages to cite, by glossing the complicated ones, and by leaving out the inconvenient ones or sticking them in a dim corner of one’s scholarly edifice, its possible to present a case for whatever one wishes to argue. And the custom of going through the evidence piece by piece can make a lot of weak, hard to interpret pieces of evidence look solid (or many weak pieces of evidence which all lean in the same direction seem feeble). Just organizing a long list of pieces of evidence and commenting on them does not necessarily lead to the truth.

The promotion of Ada Lovelace Day and the publication of Sydney Padua’s steampunk graphic novel The Thrilling Adventures of Lovelace and Babbage has kindled the coals of the debate about whether Ada Lovelace was a capable mathematician or an enthusiast who needed her hand held. I do not care very much about 19th century mathematicians, but I do care about the truth, so I have been following this from a distance. And one thing which I notice is that people on both sides don’t really quote their sources at all.