Japanese poetry has the human heart as seed and myriads of words as leaves. It comes into being when men use the seen and the heard to give voice to feelings aroused by the innumerable events in their lives. The song of the warbler among the blossoms, the voice of the frog dwelling in the water -- these teach us that every living creature sings. It is song that moves heaven and earth without effort, stirs the emotions in the invisible spirits and gods, brings harmony to the relations between men and women, and calms the hearts of fierce warriors.
Preface to Kokin Wakasū, trans. Helen Craig McCullough.