This year, I'm in Japan, translating the poetic works of a woman whom I consider one of the greatest Japanese writers, the late nineteenth century wordsmith Higuchi Ichiyō. Ichiyō is primarily famous not for her poetry (though she left us more than five thousand waka), but for her short stories, the most famous of which is "Takekurabe".
There are several reasons for this. The first is that her short stories are, in fact, of a higher calibre than her poetry (but it is like comparing lamps to the sun: however wonderful the lamp, it will always come up short). The second is that of the over five thousand waka left behind, many of them were written as she studied how to write under the tutelage of a teacher. We thus have a nearly complete record of her progress as a poet, from neophyte to craftsman. Nevertheless, her early poems are clearly the poems of a neophyte, and to some degree they may lower the reputation of her other, more accomplished poems. And the final reason is that her poetry is viewed as being primarily derivative from the Kokinwakashū.
The Kokinwakashū, or Kokinshū for short, was one of the first of the great Japanese imperial anthologies of poetry, and was written roughly a thousand years before Ichiyō wrote. Its grip on Japanese poetic aesthetics held strong all that time. Only in the early twentieth century, with publications like Yosano Akiko's "Midaregami", did it begin to fade. "Midaregami" was wild and passionately individual, owing less to the proper traditions of waka than the poetry that had come before it, and if a style of poetry could be said to have defined an era, "Midaregami" defined its era.
But there is something one must understand about Japanese poetry: it is meant to be derivative. In the course of my studies at a Japanese university, I often take part in a graduate-level seminar on the Kokinshū composed of myself, a graduate student, and four very learned professors of literature. In a similar seminar of English poetry, one might expect to spend much of the time in discussion of the subtleties of meaning and overall consequences of theme, but I will tell you that in this seminar, a great amount of time is spent discussing issues of precedent.
The professors never cease to amaze me, with their incredible knowledge of poetic tradition and precedent.
Professor A: 'In this poem, the unknown author has written "on a bridge of autumn leaves" (紅葉の橋に), whereas the normally accepted term would be "on the boat of an autumn leaf" (紅葉の船に), wouldn't it?'
Professor B: 'Quite right. I believe it was from the Ise Monogatari, wasn't it?'
Professor C: 'Yes, but it seems that even before that, "the boat of an autumn leaf" was a term coined from Chinese poetry and brought over here at some uncertain point. So it's technically a Chinese term that was adopted by our people.'
Professor A: 'Ah, I see...so in that case this "bridge of autumn leaves" is an attempt to identify it as more uniquely Japanese, perhaps? Still, the precedent lies with "boat" rather than "bridge", so this is very strange.'
Professor C: 'Some later editions emend "bridge" to "boat", no doubt in light of that. And if in fact it were "boat", we might presume this unknown author to be Ki no Tsurayuki, because it is written that such things were talked about at "The Fortuitous Poetic Gathering at X River", where we know Tsurayuki to have attended.'
...and so forth. Nearly all of the great Japanese poems have derived in part from other poems or phrases in the past, and understanding which prior works they are linked to is a key to understanding the meaning of the poem at times. We might read one poem, and feel that the meaning is unclear, but then see that it derives from so-and-so poem a hundred years prior, in which such-and-such means this, and from that we can understand the meaning of the first.
Ichiyō's poetry is no exception to this. She had an encylcopædic knowledge of the ancient classics, and her short stories especially are replete with scattered references to them; but so are her poems. Like the poems in the Kokinshū, one can see where she derives her meaning, and the bonds of tradition that link her writings to the past. For example, in one poem, she refers to 'leaves from the moonlight' (月のかげより木の葉), and we determined this phrase to be a reference to a Chinese legend that a great tree grows on the moon.
This sense of derivation does not carry with it the negative connotations that might hold in English if we were to call a poem derivative. It is unfortunate that Ichiyō's poetry has been overshadowed by her other talents and by the Japanese equivalent of the great vers libre revolution, yet there is a proper and ancient value to be found in the derivative functions of her poetry, and that of the Kokinshū. It is not dissimilar to the common law principle of stare decisis. And it is at the very heart of traditional Japanese poetry.