This volume offers a contribution to Teilhardian scholarship with a particular focus in mind, namely his significance in current debates about the human relationship with the natural world. His cosmic mysticism and intense interest in both cosmological and evolutionary sciences are highly relevant to current debates about how best to construct a meaningful spirituality for the twenty first century. Not only does this book probe more deeply into his mystical insights in ways that challenge the reader's understanding of spirituality, it also offers a critical revision of aspects of his thought in the light of current debates in evolutionary science, ecotheology and the challenges posed by environmental ethics. By focusing on people, and the planetary context in which people are situated, Teilhard takes us beyond the current debates between anthropocentrism and biocentrism that have characterised contemporary discussion about environmental ethics. The volume highlights areas where scholars have different interpretations of Teilhard's thought, raising new and interesting areas of debate that have been ignored in the past. It also points to the significance of his thought for developing a creative and mutual exchange between Eastern and Western Christian traditions.