At Home in the World
Rachel Mansfield-Howlett, Roshi
Modernly, in the Pacific Zen School, Mu is probably not the first koan you will encounter. We find that when folks are given a chance to work with other koans in the curriculum they get more a sense of the lay of the land and the whole thing doesn't seem quite so daunting. Introducing koans in this way, people find they can readily experience the insight koan practice offers.
But if you wind up getting serious about studying koans with an authorized teacher you will inevitably be given this one. James and Melissa put this book together to provide a little window into the different ways that people have approached the koan Mu.
A traveler of the Way once asked Chao-chou, “Does a dog have Buddha nature or not?” Chao-chou said, “Mu.”