Hakuin Ekaku's
...that Hakuin Ekaku's systematization of koan practice brought about a major revolution in Zen teaching?
...that <b id="mwArI"><a href="./Hakuin_Ekaku" id="mwArM" rel="mw:WikiLink" title="Hakuin Ekaku">Hakuin Ekaku</a>'s</b> systematization of <a href="./Koan" id="mwArQ" rel="mw:WikiLink" title="Koan">koan</a> practice brought about a major revolution in <a href="./Zen" id="mwArU" rel="mw:WikiLink" title="Zen">Zen</a> teaching?