Interest in Zen Buddhism has grown continually since this book was first published in German. Although it was then thought necessary to preface the work with some remarks for the benefit of Western readers about Zen and its living values, a general knowledge of Zen Buddhism can now be presupposed. To be sure, this knowledge is often and in many respects inadequate, distorted, or even altogether false. In the wake of the "Zen boom" in the United States, there originated "Beat Zen," "Square Zen," and other distorted forms which must be considered caricatures rather than true expressions of Zen Buddhism. A French scholar who had lived in Asia for many years once said to me: "One has to distinguish between Buddhism in Asia and Buddhism for Europeans." This very relevant remark applies to Zen Buddhism as well. Zen Buddhism in Asia can only be under- stood in terms of its Asian development-its origin in China, most likely in the sixth century, the meditation tradition of a thousand years' duration upon which it was based, and its thirteenth-century transplantation to Japan where it reached its : fullest and highest development. Hence, in order to obtain a reliable and correct knowledge of Zen Buddhism, our interest is directed towards a study of its history.