After "One day I will go / without being told everything," Jean d'Ormesson, Alexandrian returns with "Where danger grows ... / grows also what saves" Hubert Reeves (our two poets were the co-guests "The great library" of 17 October). The work of HR (176 pages, wide typography) is a "defense and illustration" of Humanity & Biodiversity Association, which he chairs. Quasi-Hegelian demonstration, conducted as it should be in three stages. 1-Thesis: the work of Nature is a "nice-history," which led the Big Bang to man. 2-Antithesis: Promethean but the intelligence of man has resulted in a "less-in-history," to the endangerment of the planet (including its biodiversity). 3-Synthesis: But even the intelligence of man can lead him to react, and, thanks to a "Rayon Vert" whose beginnings appear to be "aware of the interdependence of all living beings" (p. 153) and to work towards biodiversity. HR shows clear and convincing thanks to a talented popularizer proven by decades of publications (pp. 171-174). He at least, as he went, "said everything will be in."