A physicist and a philosopher of science, Etienne Klein directs the Research Laboratory on Material Sciences (Larsim) of the French Atomic Energy Commission (CEA). He is an essayist and a radio producer, and he publishes at a steady pace many popular works and books of scientific reflection including, recently, “Le Goût du vrai” (lit. The Taste of Truth) (2020), which deals with the relationship to science in our democracies, “Psychisme ascentionnel” (lit. Ascending Psyche) (2020), on his passion for mountaineering, and “L’Esprit du corps” (lit. The Spirit of the Body) (2021) on our modern relationship to the body.