ABSTRACT
This book that was lacking, and which will hopefully generate many others, teaches us that a book is a living being, alterity in its optimal guise. Not only because in this case the book is the inscription of two lives dedicated to research at the frontiers of thought, but also through the use Davoine and Gaudillière make of the writers who allowed them to progress on this path. Their adventure, like all adventures worthy of the name, makes fascinating reading.
