In his teaching, he refused to endorse the growing division between sūtra and kōan methods, believing the means are determined by the capacity of the student. He employed the term shōgyoku as a virtual equivalent to upāya.
Among many works, his Muchū-mondō shū (Dialogue in a Dream) explains Zen Buddhism in response to questions from the Shogun.
"Musō Soseki." The Concise Oxford Dictionary of World Religions. . Encyclopedia.com. (November 16, 2018). https://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/muso-soseki
"Musō Soseki." The Concise Oxford Dictionary of World Religions. . Retrieved November 16, 2018 from Encyclopedia.com: https://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/muso-soseki