Setting Aside All Authority: Giovanni Battista Riccioli and the Science against Copernicus in the Age of Galileo by Christopher M. Graney (review)

Christopher Graney’s recent monograph is best described by one word: scientific. It is a book about knowledge, process, and context. If only more history was like this.

Graney’s task is simple: to prove Galileo wrong. On the basis of the science/knowledge of the day, the weight of tradition, the arguments deployed, and the limits of the tools for observation at their disposal, Graney addresses in depth early modern arguments over the nature of the universe, and revises the popular image of Galileo as a saint of modern science facing down blind religion with demonstrable truth. Rather than perpetuating this memorialisation context, which generally presents geo-centricism as a largely theologically based relic of superstitious antiquity and helio-centricism as an objectively clear pointer to modernity’s clarity, Graney gets into the nitty-gritty of the science of the period. He produces a lucid refutation of the more facile narratives that dominate telling of this long-run scientific argument.

Graney reminds general readers, for instance, that there was in fact a two-sided argument, with scientific merit on both sides. He recognises and highlights how both sides cited Scripture, but points out this was merely secondary to their observations of the heavens and their mutual understandings of the physical nature of the universe learned from Aristotelian physics. Moreover, Graney allows the very human characteristics of the academic contestations to have their place, where personalities play a big role in much of the argumentative subtext, and where patronage plays its part in the forming of arguments and weighing of evidence. Graney’s observation about Cardinal Bellarmine’s doubt, for instance, is particularly astute.

At the core of Graney’s study is a detailed analysis of Riccioli’s New Almagest, and the science behind Riccioli’s assessment that, on the balance of contemporary evidence, the earth was at the centre of the universe. Drawing particularly on the observations of Tycho Brahe, and his modified geo-centric model, Riccioli weighed 126 arguments between the geo-centrists and the helio-centrists. So too does Graney, revisiting each of them in turn. Helping to rescue Riccioli from the prejudice of suspiciously hagiographical scientific writing – which dismissed him on the basis of his conclusion and his clerical garb – Graney treats Riccioli’s arguments with sensitivity to what was known then, as well as now. He comes to the surprising conclusion that Riccioli was on balance right and Galileo wrong, at least insofar as demonstrability and current science went.

In the end, there were arguments the geo-centrists offered which the helio-centrists could not answer without recourse to God. As Graney recognises, this was essentially because of wider scientific and technological limitations, but as limits they must nonetheless stand against Galileo’s reasoning. Being proven right in the end is not the same as being right at the time; and if the working was wrong, then the conclusion was flawed. Moreover, as Graney points out, the question was not properly, scientifically settled for several centuries, even after the hypothesis had come to be more generally accepted.

Yet there is more. This wonderful book is not just a one-line show. Putting the wider European scientific endeavour of the period into a broader perspective than just the leading figures, Graney recaptures a world of thinkers and experimenters who observed the stars, shared data, and tested hypotheses. His discussion of Jesuits dropping clay balls from towers, arguments about the motion of cannonballs fired at various directions from the equator, the clunky machines for measuring distances in the sky, and the problems with the optics of telescopy, all offer much-needed scientific rigor to the discussion of scientific phenomena and the history of science alike. This is scientific history at its best.