In Late Antiquity, Ptolemy’s treatise on cartography (2nd century AD) was yet to achieve the recognition that Ptolemy had hoped for, despite relatively wide distribution. However, in the early Middle Ages, knowledge of the Geographia did not disappear completely, owing mainly to treatises on astronomy translated from Arabic. The Latin version produced at the beginning of the 15th century did not, therefore, have the revolutionary character that is often attributed to it. The work that made it possible to understand the universe of Antiquity as it appeared in the classics was well received from the “literary” point of view. But the astrologists and scientists educated in universities were instrumental, in a way that has, until now, been little studied, in analysing the contradictions between the Ptolemy’s representation of the universe and other representations that were still current and accepted. The long process of the modernisation of Ptolemy’s vision entered a decisive phase at the beginning of the second half of the 15th century following the synthesis between humanism and natural philosophy. It continued until the beginning of the 16th century, considering the modes of representation (anachronistically called “projections”), retaining the concept of the influence of celestial bodies on the sublunar sphere, a feature of conceptions of the world held since Antiquity that the work of Ptolemy justified as best it could.

The reception of the Geographia, envisaged over a long period, does not therefore confirm the opinion that it played a fundamental role in the supposed move towards the “modern” concept of the universe that is distinct from a “mediaeval” model.

This book questions a certain number of common links with cultural history. It is based on the first hand analysis of Greek and Roman texts and maps from highly diverse intellectual sources.

Patrick Gautier Dalché is Director of Research at the Centre National de la Recherche Scientifique (IRHT) and Director of Studies at the Sorbonne Historic and Philological section of the École Pratique des Hautes Études.