I am glad to have found Clay Shirky on the Internet.
I subscribed to his blog.
I think that the following is worth reading by Library students.
He makes a valid point that both the Dewey and LC systems were developed to enable people to locate books on shelves.
...if you've got enough links, you don't need the hierarchy anymore. There is no shelf. There is no file system. The links alone are enough.
One reason Google was adopted so quickly when it came along is that Google understood there is no shelf, and that there is no file system. Google can decide what goes with what after hearing from the user, rather than trying to predict in advance what it is you need to know.
A library catalog, for example, assumes that for any new book, its logical place already exists within the system, even before the book was published. That strategy of designing categories to cover possible cases in advance is what I'm primarily concerned with, because it is both widely used and badly overrated in terms of its value in the digital world.