The focus of this book is on the philosophy of breathing. It investigates breathing as its point of departure for the study of ontology (Being). It goes on to interrogate the connections between breathing and inert matter, breathing and emergence of life, and breathing and pneumatology. The book is a thinking of breathing as a theological question within the context of philosophy and its intersection with quantum physics. How does materialist (physical) breathing help us to rethink the emergence of biological life from inert matter and interrogate theological symbols associated with spiritual life, which is ultimately grounded in physical life? The most central theoretical tincture that binds philosophical theology to quantum physics in this book is the technical notion of yea-saying. Yea-saying is the set of materialist relations of vibrating particles to themselves, which constitute the power of being. Particles constitute the pulsating clearing for everything to exist or dissipate, appear or disappear. This book considers them the "openness" and connective tissue of being. Being is breathing; particles and human beings breathe together. From what scientists called "breath between atoms" to human beings breathing air, breath remains and it abides between life's end and its infinite returns.