Nature as Sacred Ground explores a metaphysics for religious naturalism. Donald A. Crosby discusses major aspects of reality implicit in his ongoing explication of Religion of Nature, a religious outlook that holds the natural world to be the only world, one with no supernatural domains, presences, or powers behind it. Nature as thus envisioned is far more than just a system of facts and factual relations. It also has profoundly important valuative dimensions, including what Crosby regards as nature's intrinsically sacred value. The search for comprehensive metaphysical clarity and understanding is a substantial part of this work's undertaking. Yet this endeavor also reminds us that, while it is good to think deeply and systematically about major features of reality and their relations to one another, we also need to reflect tirelessly about how to respond to metaphysical concepts that call for decision and action.