Through the burgeoning fields of Posthumanities and Environmental Humanities, this edition examines the changing conception of human subjectivity, agency, and citizenship as shaped by the dynamic interplays between nature, technology, science, and culture. The proposed ‘symbiotic turn’, (the awareness of the multitude of interactions and mutual interdependencies among humans, non-humans and their environment) aspires to explore the complex recompositions of the “human” in the 21st century. By organizing and promoting interdisciplinary dialogue at multiple levels, both in theory and practice, Symbiotic Posthumanist Ecologies is suggested as a new narrative about the biosphere and technosphere, which is embodied literarily, philosophically, and artistically. The contributions to this volume emphasize interactive, symbiotic relationships between species, disrupting both anthropocentric and biocentric paradigms and positioning symbiosis as the planet’s vital ecological process. Offering a range of ecocritical and philosophical perspectives, this book provides a valuable introduction to major branches of the environmental humanities such as posthumanism and new materialism but also new directions in Gaia theory, neocybernetics and AI, Anthropocene studies, and other contested and cutting-edge topics. What emerges most prominently from these chapters, for me, is the case for decentering humanity in the discussion of ecological topics, while still recognizing powerful impact of human technologies. I find the combination of textual criticism and critical theory to be a graceful pairing in this book, and the essays are well written and accessible. (Scott Slovic, Oregon Research Institute, coeditor of Nature and Literary Studies)