As usual with Rémi Brague, writing is fluid and fun, humor present and impressive erudition! We learn a lot about the Middle Ages as caricatured and comparison between Christianity and the Islamic world is, too, exciting especially as regards the difference in status between philosophy in Christianity and philosophy land of Islam or in the Jewish communities. The author also reviews the thorny issue of transmission of ancient heritage (part of it) by making clear the role of each (Arab, Syrian, Jewish, Byzantine), he developed the idea Advanced in "Europe, the Roman road" the appropriation of ancient sources model (digestion / inclusion), explains some common issues to philosophy in the three medieval cultural areas and certainly the most confusing part of the book, questions the thesis that geocentrism was experienced as a tear, like an injury caused us to see qu'anthropocentrisme geocentric and was not related. Antiquity and the Middle Ages certainly thought that the Earth was at the center but it was not at all sth positive ... The book ends with a tasty little article on Averroes.