To begin with this has absolutely nothing to do with the differences, either in quality or manner, between the poem/lyric/words on the page and the same in a song e.g. it has nothing to do with the quality of a Dylan lyric compared with a page poem. Secondly it is not at base to do with how good or bad we think Dylan is as a wordsmith because it is possible to agree with what I am going to say below while still thinking that Dylan doesn't deserve the prize because he is not good enough.

Literature appears to be that area of human activity concerned with the purposeful use of words above and beyond utilitarian communication, recording and information giving. It is part of the larger concept of art. It involves itself both with the seemingly true and the seemingly unreal and is closely associated both with story telling, personal expression/exploration of feelings and opinions and imaginative invention. (I'm sure any of us would be able to provide their own general definition such as this one). 

In order to work, to be presented, literature needs form, but there is no predetermined form for literature in general. Different uses of literature seem to require different forms and these forms developed and changed over time. Literature's most common forms today, particularly in what we call the 'west', are poetry, fiction, song lyrics and scripts (feel free to add to this list). Poetry and fiction as they appear on the page are unaccompanied language (I say 'appear' because there is no such thing as unaccompanied language, it is just that in these instances there is no immediate accompaniment, such as music or pictures or voice). However, they developed INTO those forms. Literature did not develop OUT of those forms. They are a part of literature, but they are not the only part. The novel for example is a particular type/form of fiction/story telling which has been very successful, but at heart it is an artificial form of language use. Poetry is a far broader and far more problematic form of literature than the novel because of the huge variety of purposes and contexts in which it has been written. Form-wise, very broadly speaking, fiction developed out of oral story telling while poetry developed out of singing and chanting, but the details of these developments, though very interesting, have no bearing on the main issue. Any higher status and priority given the 'unaccompanied word' forms of literature does not disqualify the other forms from adhering to the general definition of literature I gave above. If so then this points to a much narrower and much more recent and westernised idea of literature, one which would in fact require a different definition. As an aside I don't think it would be a definition which would go down very well in the wider culture. It would be seen, quite rightly, as retrogressive and elitist.

As a writer of the stuff they call poetry, and as that poetry is written first and for-most on the page and for the page, of course I recognise its differences and possibilities compared with lyrics written to be sung. But this has got absolutely nothing to do with the above argument.

Despite the above statement re writing poetry, there is in fact no way of knowing or judging the actual strength of a particular art form as it operates/impinges (whatever word you want) on an individual sensability. While it is not important to my argument above I still think it has relevance when trying to understand the reasons behind the counter arguments - which is what draws me in this case towards a type of reception theory. I don't go along with the post-modern cultural levelling theories, but I can see where they come from and why they are so appealing. I have always found the patronising judgements on another's individual capacity for experience which are made by those artists, writers, critics and cultural philosophers with a hierarchical notion of art not just unpleasant but, more importantly, entirely unprovable.

Apologies for the length but it was unavoidable. 

Cheers

Tim