Zen is not a religion of God. Nor a religion of faith. It is a religion of emptiness, a religion of absolute nothingness. However it is not nihilistic but dynamically positive. For Zen is based on self-awakening, awakening to the self. In this book, a sequel to Zen and Western Thought, the author tries to clarify the true meaning of Buddhist emptiness in comparison with Aristotelian notion of substance and Whiteheadron notion of process. He also emphasises that Buddhism completely defies and overcomes dualism, but it is not monistic, but rather nondualistic. What is Nondualism? This is one of the important themes of this book.