The poetry of Japan has its seeds in the human heart and mind and grows into the myriad leaves of words. Because people experience many different phenomena in this world, they express that which they think and feel in their hearts in terms of all that they see and hear. A nightingale singing among the blossoms, the voice of a pond-dwelling frog–listening to these, what living being would not respond with his own poem? It is poetry which effortlessly moves the heavens and earth, awakens the world of invisible spirits to deep feeling, softens the relationship between men and women, and consoles the hearts of fierce warriors.
~Ki no Tsurayuki, (preface Kosinsbū, ca. 905)