Calleva Seminar: Forecasting Epidemics, From Stars to Statistics

The Hilary 2025 Calleva Seminar will explore the history of predicting epidemics, from medieval to modern times, highlighting new work by Dr Michelle Aroney (https://www.history.ox.ac.uk/people/dr-michelle-pfeffer)

Forecasting is one of the world’s oldest professions, with governments across history relying on forecasters to predict crises from plagues and famines to wars and economic collapse. For most of recorded history, these forecasters were diviners—astrologers, oracles, and seers of various kinds—who helped those responsible for large populations to manage contingencies and plan ahead. Divination is often associated with individuals seeking guidance about their personal lives, but historically a large part of the practice of diviners was geared towards public, population-level concerns.

The reliance of these historical forecasters on divination rather than statistics has led many commentators to dismiss them as the dark, embarrassing side of the history of prediction. This lecture takes a different perspective. Showing that for most of recorded history the work of modern epidemiologists was done by diviners, the lecture argues that this fact deserves serious attention for two key reasons. First, in many historical cultures, divination was more akin to science than religion, involving pattern analysis, experimentation, and theory development. Secondly, these cultures of divination played a key role in the emergence of modern epidemiological forecasting. Indeed, before they were professionalised, different types of forecasting were often seen as no different from divination.

The lecture thus explores the fraught question of who we trust to produce knowledge about the future. While the forecasts of diviners did not always hit the mark, their efforts nevertheless were widely valued. After all, in practice the usefulness of forecasting is not only about accuracy. Forecasts are often less about the future and more about the present, telling us what we should do, and how we should feel, in the here and now. Regardless of the evidence-base of any form of forecasting, the authority of forecasters, and the perceived legitimacy of the knowledge they produce, has always been historically contingent.

Organised by the Calleva Centre (https://callevacentre.org/)

Host or Publisher Calleva Centre for Evolution and Human Science at Magdalen College