This is the first book to apply philosophical thinking to trees. Through a series of sixteen diverse essays by leading scholars and writers, along with an in-depth introduction to the key issues and ideas, it examines the new and emerging understanding of trees in science and society. Contributors show how these developments encourage a revisioning of philosophical thought and a more sustainable relationship with trees and forests—a reconceptualization with important ecological and social implications for responding to deforestation, the loss of biodiversity, and the climate emergency. The interdisciplinary contributions in this collection investigate the many interconnected dimensions of arboreality, focusing on subjects related to time, mind, truth, memory, being, beauty, goodness, silence, wisdom, personhood, and death. The volume engages in a conversation about why trees matter, how they can best be protected, our obligations to them, and even what or who they are. Most of the chapters are informed by natural history or ecological science and many share a particular emphasis on continental philosophy and the environmental humanities.