This essay explores the environmental philosophy present in the works of the 20th-century poets Rainer Maria Rilke and William Butler Yeats. Based on a reading of central texts by Bruno Latour and Giorgio Agamben, I investigate the conception of the human self in poetry, pictured within processes of becoming, consummation and disappearance, never discreetly delineated over and against its environments, but in continuity with other species as well as ancestral traces and disincarnate presences. Modernist poetry performs a shift away from traditional enlightenment models of understanding the human self and its environments. In the case of Rilke and Yeats, a shift towards a deconstruction of the concretely delineated self goes hand in hand with explorations in occultism and environmental thought. What emerges in Rilke’s and Yeats’s poetry will be understood as environmental modernism—a term which this chapter attempts to define and make workable for the analysis of a wider scope of authors discussing the environmental constitution of the human self at the same time.