Dogen's revaluation of commonplace Buddhist metaphors in particular leaves us no doubt about his understanding of language .... Concepts, metaphors, parables, and so forth are not just instrumental, convenient means to communicate truth, for they themselves manifest the truth-or rather, since that is still too dualistic, they themselves are the truth that we need to realize. "Metaphor in Dogen's sense is not that which points to something other than itself, but that in which something realizes itself," summarizes Kim. "In short, the symbol is not a means to edification but an end in itself-the workings of ultimate truth." As Dogen himself puts it in the Muchu-setsumu ... : "The Buddha-dharma, even if it is a metaphor, is ultimate reality." If I do not try to get some graspable truth from the metaphor, it can be a way my mind consummates itself: although symbols can be redeemed only by mind, the mind does not function in a vacuum but is activated by-or as-symbols.
In the Sansuikyo fascicle, Dogen criticizes those who have only an instrumentalist view of language and who think that koans are simply nonsensical ways to cut off thought: "How pitiable are they who are unaware that discriminating thought is words and phrases, and that words and phrases liberate discriminating thought." What a challenge to the traditional Buddhist dualism between language and reality: the goal is not to eliminate concepts but to liberate them! Despite their problematical aspects, "words are not essentially different from things, events, or beings-all 'alive' in Dogen's thought."
... [Dogen] shows us that words and metaphors can be understood not just as instrumentally trying to grasp and convey truth (and therefore dualistically interfering with our realization of some truth that transcends words), but as being the truth-that is, as being one of the many ways that Buddha-nature is. To the many dualisms that Nagarjuna deconstructs, then, Dogen explicitly adds one more: he denies the dualism between language and the world. If we are the ones who dualize, why blame the victims? A birdsong, a temple bell ringing, a flower blooming, and Dogen's transpositions, too, blossoming for us as we read them: if we do not dualize between world and word, then we can experience the Buddha-dharma-our own "empty" nature-presencing and playing in each.
http://www.thezensite.com/ZenEssays/Dog ... gainst.htm