A poem is stored energy, a formal turbulence, a living thing, a swirl in the flow. Poems are part of the energy pathways which sustain life. Poems are a verbal equivalent of fossil fuel (stored energy), but they are a renewable source of energy, coming, as they do, from those ever generative twin matrices, language and imagination." William Rueckert, Literature and Ecology 1. Première définition de l'écologie donnée par Haeckel en 1866 (Haeckel, 1866).