What distinguishes human beings from other animals and creatures, and what does religion-in particular, Zen Buddhism-have to do with human nature ? In this book, Richard DeMartino (1922-2013), the pre-eminent Western Zen thinker of the 20th century presents the Zen understanding of man and his problematic nature ("human beings do not know who they are"); of awakening to his true nature (True Self); and of the Zen path leading to this Self-awakening. DeMartino's analysis in this book of the resolution to man's fundamental problem, and of the basic features of Zen methodology to achieve this goal, constitute his fullest discussion of these topics. Though teaching at Temple University in Philadelphia for some twenty years until his retirement in 1986, DeMartino was a reclusive thinker who shunned the limelight and was known to few outside the circle of his colleagues and students in Philadelphia. The present volume contains Richard DeMartino's hitherto unpublished Ph. D. dissertation of 1969. While other writings of his (published in 2021 and 2022) discuss some topics in greater detail, DeMartino's doctoral dissertation contains his unequalled comprehensive discussion of Zen. With this book, UniversityMedia's trilogy of Richard DeMartino's main writings is complete: Human Nature and Zen (2021). ISBN 978-3-906000-17-6 Zen Encounters (2022). ISBN 978-3-906000-22-0 The Zen Understanding of Man (2023). ISBN 978-3-906000-32-9