Harry Potter and the Da Vinci code are not reducible to the MSS that J.K. Rowling and Dan Brown submitted to their publisher. This is true even if the published text was very close to those MSS and not, as sometimes happens, co-authored by their editors. At the very least, several hundred people were involved in drawing covers and typesetting and printing and physically manufacturing the object that you bought in Waterstone. And someone else created the marketing campaign; decided that it would be cool for bookshops to open in the middle of the night to sell the first editions; carefully honed the Rowling persona; spotted that a series of school based children's fantasy stories might be the sort of thing that kids would want to read. No-one but JK Rowling could have written Harry Potter but if JK Rowling hadn't written Harry Potter, some other publisher might have identified some very similar author to place at the center of a very similar maelstrom.
It is tempting for a writer to think "It is my words that the Public wants, and all the publisher does is put them in the hands of the reader."
It is equally tempting for a publisher to think "I make beautiful books, and one small part of the process is the artisan who I hire to write the words which go into them."
It is tempting for an actor to think: "I have a special talent: people come to see me act, and the director's job is simply to decide where I should stand so that the audience can hear me declaiming.
It is equally tempting for a director to think: "People have come to see my version of a play, based on my knowledge of literature and stage craft. An actor is simply a skilled individual whose job it is to read the words and perform the gestures that I am tell him to."
Would it therefore be unreasonable for the theatre architect to say "I am in the business of giving people an exquisite evening. You create a beautiful building, and then you hire anyone to sell ice cream, pour drinks, and strut about on the stage?"
You can sometimes get a very small child to eat his greens but arbitrarily declaring that these are special Tellytubby greens. It works better if the person performing the alchemy is Mr Sainsbury: the spinach that was wrapped in official Tellytubby packaging really does taste better than the kind which Mummy says came all the way from Tellytubbyland.
I am sometime told that Peter Jackson's parody of Lord of the Rings has to be judged on it's own terms: it doesn't matter whether or not it is an accurate translation of Prof. Tolkien's book.
It is certainly true that Lord of the Rings works very well as a Hollywood pop corn flick. I would place it almost precisely on a level with the Pirates of the Caribbean series, full of sound and fury but signifying less and less as it goes along.
This is not to deprecate Lord of the Rings. I like the Pirates of the Caribbean series very much indeed. They provide a huge dollop of cutlasses, cannons and eye patches, wrapped in the illusion of a narrative, and enough macguffins and plot coupons to propel the ships from exotic location to exotic location. They are, in short, exactly what you want from a pirate movie.
I feel much the same way about Lord of the Rings: it is the Goonies with dragons, ill matched semi competent protagonists dropped into the middle of a story in which far too many precipices collapse underneath them and far to many dragons drop rocks on them for anyone to have any chance to work out what is actually meant to be happening.
Saying that the Lord of the Rings is to be judged on its own merits is the same as saying that Jackson, having made his big budget cartoon, used the name Lord of the Rings to give it a quite spurious gravitas: that the Lord of the Rings movie is only a Lord of the Rings movie in a manner of speaking, just at the Tellytubby spinach is only Tellytubby spinach in a manner of speaking.
If I say this, I am accursed of snobbery by the meta geeks.