Montaigne and Jean-Jacques Rousseau form an astonishing, no doubt unique, couple in the history of literature as well as of philosophy. In their polemic against civilization and the Enlightenment, Montaigne and Rousseau reach ancient philosophy itself. The latter by positing the capacity of reason judiciously to organize the human world, constitutes the first, and most solid, foundation of the Enlightenment. In styles that are assuredly extremely different, the Apology of Raymond Sebond and the Discourse on the Origin of Inequality tend to bring together man and animal to the point of sometimes making them indistinguishable, the perfected reason of man appearing as a principle of degradation, rather than of amelioration, of the nature of man. In the ultimate discovery, reported by Rousseau in the Reveries of the Solitary Walker, the sentiment of existence is tasted without any active assistance from his soul.