Shelves, not piles: how Dewey taught us to find things

Imagine a library with no system. Books are arranged by when they arrived, or by size, or by whoever happened to shelve them. You would need a guide just to find a single title.

For a long time, many libraries worked something like that. Collections were small enough that a librarian could simply remember where things were.

Then collections grew, and memory stopped being enough.

The idea#

In 1876, an American librarian named Melvil Dewey published a scheme for organising books by subject. The first edition came out anonymously. What it offered was simple: divide all knowledge into ten broad classes, give each a number, and then keep subdividing.

The decimal part is what made it clever. A number could always be extended with another digit to describe something more specific, so the system could grow without being rebuilt. A book could sit exactly where its subject sat, between its neighbours.

Why it spread#

The strength of the system was not that it was perfect. It was that it was predictable. Once you understood the scheme, you could walk into a library you had never visited and find the right shelf. Knowledge became something you could navigate, not just something you stumbled on.

The flaws#

It is also worth saying that the system has been criticised, and fairly. It was designed in a particular time and place, and its categories reflect the assumptions of that world. Some subjects are given far more room than others, and many libraries have adapted or moved away from it as a result.

That is a useful reminder of something true about any category: how you divide things up reflects what you think matters.

What it teaches#

Dewey's idea outlived its details because the underlying lesson is sound.

• Few, broad categories beat many narrow ones. Ten classes were enough to start with.
• Let the system grow from the inside. Subdivide when you need to, not before.
• Put things where people will look. A good category is one you can guess without being told.

This is exactly what we have tried to do on this site. A handful of shelves, each with room to grow, and a place for everything you publish.