“The Tao of Zen is a nonfiction book by Ray Grigg. The work argues that what we recognize as traditional Chinese Ch’an/Japanese Zen Buddhism is in fact almost entirely grounded in Chinese Taoist philosophy, though this fact is well shrouded by the persistence of Mahayana Buddhist institutional trappings. Utilizing an array of scholarly commentary on the two traditions and historical deduction from what can be considered to be the best primary source material available, the author traces the development of Taoism and Buddhism in China and Japan for two millennia.” (Wikipedia)

I’ve read this book twice and expect to read it again but I wouldn’t know where to begin to describe it. The Wikipedia link above is a good start. As is my habit with nonfiction, I highlighted as I read: The Tao of Zen (Ray Grigg)