"Mushotoku mind" means an attitude of no profit, no gain. It is the core of master Taisen Deshimaru's Zen. This respected teacher of Japanese Soto Zen moved from Japan in 1967 and brought this work to Paris, from where it was disseminated throughout the West. This book presents his commentary on the most renowned of Buddhist texts, the Heart Sutra, known in Japanese as Hannya Shingyo -- a philosophical investigation on the futility of philosophical investigation. Deshimaru's work fills a great gap in the interpretations of this seminal text in that he emphasises "mind-emptiness" (ku) as the foundation of Zen practice, in contrast to the usual "mindfulness" focus of many other Zen approaches. This "emptiness" and "purpose of no purpose" is one of the most difficult ideas for Westerners to understand. Yet we know that our most cherished values are based on mushotoku mind when it comes, for example, to love. We value the unselfish love of family or country that is based not on what we can get from the relationship but on what we can give. We know, too, that these virtues are not accomplished directly through our will but indirectly through dropping our expectations. His lectures on this subject have been translated by Ilsa Fatt and edited by Reiryu Philippe Coupey of Deshimaru's British and French groups; and here completely revised and reedited for an American audience by Reishin Richard Collins. This edition emphasises Deshimaru's chorus: Mushotoku mind is the key attitude characterising the way of the Buddha, the way of the bodhisattva, the way of Zen and zazen, and the way of all sutras (teachings).