Enlightenment, the cosmic experience of universal unity, is a notoriously elusive concept in Zen. Here, the renowned scholar Heinrich Dumoulin traces the development of Zen and the concept of enlightenment from its origins in India through its development in China to its fruition in Japan. Delineating the Buddhist origins, as well as the Taoist and yogic influences, he traces the historical path Zen has followed, with special emphasis given to the development of koan practice and the writings of the great Japanese Zen master Dogen (1200–1253). He then brings the experience to life by presenting, in his own words, the enlightenment experiences of a number of contemporary practitioners of Zen.