If you were a librarian, how would you organize the seemingly endless number of books under your care? One of the easiest ways to do so may be to arrange them alphabetically, but is that really helpful?
Using that system, a book titled Basic Human Biology may be next to Bob’s Big Adventure. The two books have nothing in common, and someone looking for books on human biology would have to know either the name of each book he’s looking for or blindly search each shelf to find other books on the same topic.
With that being said, a better system would be to organize books based on the topic, which is exactly what Melvil Dewey thought.