Probably everyone has heard at some point the old story on how Columbus’ contemporaries refused to accept the possibility to cross the Altlantic due to fears of falling from the edge of the flat Earth. This false tale has been introduced in popular culture, general education, university teaching and to some extend to the academic world. In a landmark study, medievalist Jeffrey Russell (1991) called such modern distortion of the medieval cosmology as the ‘flat error’. He tracked down the origin of such error to the early 19^th century. In my Ph Thesis at the University of Bristol (2014-2022) I have defended that the origin of the flat error needs to be pushed backwards to at least c. 1600. To understand how the medieval knwoledge of the Earth could be distorted so much I engaged in a reception study of the key early Christian texts debated in the 16^th century, Lactantius’ Divine Institutes 3.24 and Augustine’s City of God 16.9, investigating the geographical context of their age and their influence up to the Renaissance. While the flat Earth soon disappeared from Western Europe, the medieval age agonised on the topic of the antipodes and their alleged antipodean inhabitants. The Iberian geographical discoveries in the 15^th and 16^th century gave a powerful shock to the European culture, not only changing their maps but also challenging the enormous authority of the ancient and medieval scholars (both, pagan and Christian). A new mentality grew during the 16^th century combining a disdain for the past with high hopes for the advance of knowledge in the future, showing very early signs of the 17^th century so-called Querelle des ancients et modernes and of the 18^th century ‘idea of progress’. To complicate the picture, the increasing suspicion from theological quarters towards the new Copernican heliocentrism led Copernicus himself, and later his followers such as Kepler, to deploy a defensive strategy which ended in an attack against theological interference in science. As part as this strategy, a few historical episodes were combined to create a successful narrative of science and Christianity conflict that helped to dismiss any criticism from theologians. This became the context where we can find the first elements of the flat error appearing c. 1600, and with that, the ‘conflict thesis’ of science and religion, which became widely popularised since the 19^th century until our days. A revised and reduced version of my PhD thesis is currently in press, Flattening the Medieval Earth (Routledge).

30 January 2025, FCUL