Zen in the Art of Archery (Zen in der Kunst des Bogenschießens) is a book by German philosophy professor Eugen Herrigel, about his experiences studying Kyūdō, a form of Japanese archery, when he lived in Japan in the 1920s. It is credited with introducing Zen to Western audiences in the late 1940s and 1950s. The book sets forth theories about motor learning. Herrigel has an accepting spirit towards and about unconscious control of outer activity that Westerners heretofore considered to be wholly under conscious-waking control and direction. For example, a central idea in the book is how through years of practice, a physical activity becomes effortless both mentally and physically, as if our physical memory (today known as ""muscle memory"") executes complex and difficult movements without conscious control from the mind. Herrigel describes Zen in archery as follows: ""(...) The archer ceases to be conscious of himself as the one who is engaged in hitting the bull's-eye which confronts him. This state of unconscious is realized only when, completely empty and rid of the self, he becomes one with the perfecting of his technical skill, though there is in it something of a quite different order which cannot be attained by any progressive study of the art (...)""