Tim Spalding of the Library Thing has announced an ambitious project to develop "the Open Shelves Classification (OSC), a free, "humble," modern, open-source, crowd-sourced replacement for the Dewey Decimal System." The comments on his posting show that this is a topic which can arouse an emotional response ..... bad temper, hurt feelings, wounded pride.
Tim is a shrewd and industrious character, but I wonder whether his project is not somewhat Quixotic. Dewey, with all its limitations, was meeting a challenge which no longer arises. Namely: a reasonable and extensible way of ordering any book, and any forthcoming stream of books on to a set of bookshelves, so that two libraries would agree on the order in which the books were placed. Dewey is linear (and arguably impoverished) through and through, to its decimal core. Libraries will not want such linear systems in the future. Books when they are digital will go on as many shelves as their users or librarians can countenance.
The best classification systems of the future library will embrace as many coherent classification systems as can be found. Everything from arbitrary user tagging, to the Dewey decimal system and back, via the Human Genome, the Appellation d’origine contrôlée, copyright status, Linnaeus, Wikipedia, Mozart's Koechel numbers and of course FIFA World Rankings.
Borges quoting his (fictional) Chinese Encyclopedia the 'Celestial Empire of benevolent Knowledge' should have the last and completely permissive word on this subject:
In its remote pages it is written that the animals are divided into: (a) belonging to the emperor, (b) embalmed, (c) tame, (d) sucking pigs, (e) sirens, (f) fabulous, (g) stray dogs, (h) included in the present classification, (i) frenzied, (j) innumerable, (k) drawn with a very fine camelhair brush, (l) et cetera, (m) having just broken the water pitcher, (n) that from a long way off look like flies.