is Dogen's Japanese translation of the Chinese phrase zhǐguǎn dǎzuò (只管打坐 / 祇管打坐), "focus on meditative practice alone," although many modern Western practitioners have interpreted this very differently. The phrase was used by Dogen's teacher Rujing, a monk of the Caodong school of Chan Buddhism, to refer to the meditation-practice called "Silent Illumination", or "Serene Reflection," taught by the Caodong master Hongzhi Zhengjue (1091–1157). In Japan, it is associated with the Zen Soto school, Dogen's offshoot of Caodong. Some practitioners teach that shikantaza means that one should not focus attention on a specific object (such as the breath), instead "just sitting" in a state of conscious awareness; however, the 13th-century origin of the expression indicates a general emphasis on meditation in any form as sufficient for spiritual enlightenment. The original teaching was meant to criticize the complicated ceremony, abstruse study, endless tracing of spiritual lineage, and other aspects of Buddhism that even by the 12th century had been identified as excessive.
The term shikantaza is the Sino-Japanese reading of Zhǐguǎn dǎzuò (只管打坐 / 祇管打坐) "just sitting," "nothing but sitting," "meditation of just sitting," “just mind [yourself] sitting.” Zhǐguǎn dǎzuò (只管打坐 / 祇管打坐) translates as follows:
The inspiration for this teaching derives from a pivotal episode reportedly occurring sometime in the early 1220's (Song Dynasty), at Tiantong Mountain Monastery (天童寺, also known as Jingde Monastery 景德寺, east of modern-day Ningbo). An exchange took place between the eminent Chinese Caodong teacher Rujing and his disciples. In particular, it focuses on an inspiration by one of Rujing's Japanese disciples, Dōgen, who would later found the Sōtō Zen sect:
While T.G. Foulk's translation here reads only "sit," he and other interpreters clarify that the meaning of 打坐 is generally broad, meaning more than simply sitting. The original exchange between Rujing and his disciples indicates a clear meaning of the teaching: that high-flung ceremony and study are unnecessary and irrelevant, that zazen, dhyana, and similar meditation practice of whatever kind (whether sitting, resting, breathing, gazing at a scene, walking, or simply engaging in silence) should be sufficiently effective.
James Ishmael Ford states that "some trace the root of this word [''shikantaza''] to the Japanese pronunciation of Sanskrit vipassana, though this is far from certain." This etymological error about 只管 (shikan, "only," "just") is rooted in the fact that Japanese has many homophones pronounced shikan. It stems from a more commonly used Japanese word, namely 止観 (shikan, "concentration and observation") (as practiced by the Tendai sect) that translates the Sanskrit "śamatha and vipaśyanā," the two basic forms of Buddhist meditation.