Citation from COMMENTARY on DOGEN ZENJI'S
BENDOWA 辨道話, Discourse on the Practice of the Way
Eihei Dōgen: Mystical Realist, by HEE-JIN KIM
from Chapter Three: Activity, Expression, Understanding
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"What is the criterion of the rightly transmitted Buddha-dharma?"
Dogen stated [in the BENDOWA]:

The Buddha and Tathagatas have an excellent way — unequalled and natural — to transmit the wondrous Dharma through personal encounter and to realize supreme enlightenment. As it is imparted impeccably from Buddha to Buddha, its criterion is the samadhi (*) of self-fulfilling activity (jijuyu-sammai).
 For playing joyfully in such a samadhi (kono zammai ni yuki suruni), the upright sitting position in meditation is the right gate.

 [...] In the context of Dogen's thought, the Samadhi of self-fulfilling activity signified the Samadhi that at once negates and subsumes self and other.... It referred to a total freedom of self-realization without any dualism of antitheses. The critically important point to note is that in Dogen, opposites or dualities were not obliterated or even blurred; they were not so much transcended as they were realized. The total freedom in question here was that freedom which realized itself in duality, not apart from it.
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 (*) samadhi, sammai (三昧): "Concentration. Serene, settled, collected state of mind." (Moon in a Dewdroop). "It has been described as a non-dualistic state of consciousness in which the consciousness of the experiencing subject becomes one with the experienced object." (Wikipedia)

(Zen Master) DOGEN ZENJI'S (道元禅師)
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