The purpose of this work is to critically assess Errol E. Harris's process philosophy in the face of contemporary research in the special sciences. Harris devoted his life to grappling with the big questions concerning the relationships between nature, mind, and knowledge. His 70-plus year career was distinguished, his texts on the history of philosophy, philosophy of science, political philosophy, philosophy of religion, and consciousness were widely published, and yet his metaphysics has until now remained excluded from mainstream discussions. This book's contention is that Harris's work reveals as yet unnoticed connections between theories in numerous scientific disciplines ranging from psychology to cosmology and that an examination of certain theories within these disciplines may serve to strengthen his original arguments. This work maintains that the resulting metaphysics frames a transdisciplinary paradigm shift and provides a viable solution to the hard problem of consciousness.