As always with Rémi Brague, we escape the idle discussions of dubious philosophism and what a boon to the single thought. This scholar who is fluent in Arabic and Hebrew, and with the subjects it addresses it is not a detail, draws its knowledge to the only acceptable sources, texts, and develops a rigorous and impressive argument, not without humor elsewhere. When the book is closed, we put a new perspective on the subject and Rémi Brague, not content to enlighten us, we proposed to sharpen our critical spirit by inviting us to understand before judging. Arguably the works of Rémi Brague make work of public health: is that why he is ostracized by the proponents of the single thought that hold the media keys? It is true that demonstrate, among other things, that the Middle Ages was anything but obscurantist or the thought of medieval Europe - that Christian - did not wait Avicenna or Averroes to exist bluntly contradicts the words of counter "thinkers" fashionable. Books like those of Rémi Brague are absolutely necessary and more exciting to read.