Editing Koan (section)

==== The breakthrough-{{transliteration|ja|kōan}} ====
In the Rinzai school, the Sanbo Kyodan, and the White Plum Asanga, {{transliteration|ja|kōan}} practice starts with the assignment of a {{transliteration|ja|hosshi}} or "break-through {{transliteration|ja|kōan}}", usually the {{transliteration|ja|[[Mu (negative)#The Mu-kōan|mu-kōan]]}} or "the sound of one hand".{{sfn|Hori|2000}} Students are instructed to concentrate on the "word-head", like the phrase {{transliteration|ja|mu}}. In the Wumenguan ({{transliteration|ja|Mumonkan}}), public case No. 1 ("Zhaozhou's Dog"), Wumen (Mumon) wrote:

{{Blockquote|[C]oncentrate yourself into this 'Wú'{{nbsp}}[...] making your whole body one great inquiry. Day and night work intently at it. Do not attempt nihilistic or dualistic interpretations.{{sfn|Shibayama|1974}}}}

Arousing this great inquiry or "Great Doubt" is an essential element of {{transliteration|ja|kōan}} practice. It builds up "strong internal pressure ({{transliteration|ja|gidan}}), never stopping knocking from within at the door of [the] mind, demanding to be resolved".{{sfn|Sekida|1985|pp=138–139}} To illustrate the enormous concentration required in {{transliteration|ja|kōan}} meditation, Zen Master Wumen commented:

{{Blockquote|It is like swallowing a red-hot iron ball. You try to vomit it out, but you can't.}}

Analysing the {{transliteration|ja|kōan}} for its literal meaning will not lead to insight, though understanding the context from which {{transliteration|ja|kōan}} emerged can make them more intelligible. For example, when a monk asked Zhaozhou (Joshu) "does a dog have Buddha-nature or not?", the monk was referring to the understanding of the teachings on [[Buddha-nature]], which were understood in the Chinese context of absolute and relative reality.{{sfn|Shibayama|1974|loc=Commentary on case No. 1}}{{sfn|Swanson|1997}}{{refn|group=note|The controversy over whether all beings have the potential for enlightenment is even older. Vigorous controversy still surrounds the matter of Buddha nature. See "Tao-sheng's Theory of Sudden Enlightenment", Whalen Lai, in ''Sudden and Gradual'' (subtitle) ''Approaches to Enlightenment in Chinese Thought'', p. 173 and 191. The latter page documents how in 429 or thereabouts (more than 400 years before Zhaozhou), Tao-sheng was expelled from the Buddhist monastic community for defending the idea that incorrigible persons ({{transliteration|ja|[[icchantika]]}}) do indeed have Buddha-nature ({{transliteration|zh|fo-hsing}}).}}