As a child visiting American public libraries, I had a vague idea of how it all worked. Each book had a bunch of numbers typed on the edge, and you've got to search rows of books until you come across a sudden area with books on Greek mythology, as opposed to the group on the American pioneers or the Ancient Sumerians. Religion is towards the beginning, books about penguins are in the middle, and e.e. cummings's poetry is at the end.
I never questioned it. But now that I work in a library, I've gotten a much closer look at how one American social reformer tried to classify all of human knowledge. In 1876, Melville Dewey created a decimal system for ordering books in his library. Although the list was designed over 120 years ago by one man trying to make sense of the main categories of knowledge in his society, this system is now used worldwide as the "Universal Decimal Classification" for library books.
Melville Dewey's reforms
According to his 1931 obituary, Melville Dewey was born in rural New York state, where he "split wood, pastured cows and did other chores for the pennies and nickels offered by farmers. The meagre earnings he saved, until he had enough for an unabridged dictionary, and he walked ten miles to Watertown, N.Y. to buy it."
When he graduated from university, Melville argued for the metric system of 100s and 1000s over the English measurements (twelve inches to a foot, 5280 feet to a mile). He lost this battle, though, and America remains one of the few countries in the world that still operates on the English system.
According to his obituary, Mr. Dewey also advocated reform of English spelling, to make the language simpler for native and foreign learners alike. Because of this, he changed his name from the visually-pleasing Melville to the simpler Melvil. And when he promoted tourism in New York's beautiful Lake Placid region, he also advertised a 1927 dinner menu which:
"is headed 'Simpler spelin' and features dishes like Hadok, Poted beef with noodls, Parsli or Masht potato, Butr, Steamd rys, Letis, and Ys cream. It also advises guests that 'All shud see the butiful after-glo on mountains to the east just befor sunset. Fyn vu from Golfhous porch.'"
Again, he was not successful, and so students of English continue to grapple with words such as "parsley," "lettuce," and "fine view" today.
Knowledge changes more quickly than any of us realize
The Dewey Decimal System
But what did catch on was Melvil's library system. Scholars and clerks have long sorted books (and mental categories of knowledge) in many ways, but Melvil wanted to design an all-encompassing "modern" system. So in 1876, he drew up his own list of all the categories and subcategories of knowledge in his world at the time. Basically, he had ten major classes, each of which had ten subclasses, including:
000 Computer science
020 Library and information sciences (etc)
And each of those had ten categories, such as:
012 Bibiographies of individuals…
014 Bibliographies of anonymous and pseudonymous works
And from there, decimals mark even more finely grained subjects of knowledge, à la 312.565…
Knowledge: Unassigned, changed, no longer used
But if you read modern versions of Dewey's list, you'd soon wonder why so many numbers are marked "unassigned." Maybe Dewey wanted to leave spots open for the future. But it's more likely that it is because what passed for the major categories of knowledge in America 120 years ago no longer makes sense in any part of the world. Knowledge changes more quickly than any of us realize. And for me, this is the most interesting point of comparison: look at Dewey's list, look at the modern 22nd edition, and let's see what's changed over time.
Knowledge of humans
So, at first the study of Anthropology involved:
131 Mental physiology and hygiene.
132 Mental derangements.
133 Delusions, witchcraft, magic.
135 Sleep, dreams, somnambulism.
138 Physiognomy. [racial characteristics]
139 Phrenology. [telling personality through head bumps]
Hmm. There's a lot of metaphysical stuff here, as well as ideas on how to sort humans that have long been discarded. So modern librarians have changed the label to highlight, well, crazy theories:
130 Parapsychology and occultism
• 130 Parapsychology and occultism
• 131 Parapsychological and occult methods
• 132 No longer used—formerly Mental derangements
• 133 Specific topics in parapsychology and occultism
• 134 No longer used—formerly Mesmerism and Clairvoyance
• 135 Dreams and mysteries
• 136 No longer used—formerly Mental characteristics
• 137 Divinatory graphology
• 138 Physiognomy
• 139 Phrenology
Anthropology, sadly, is relegated to a footnote within 301 Sociology & anthropology.
Knowledge of God
Theology, or the study of God, has also had some major changes. One big critique of the modern system is that it still devotes 90% of its space to Christianity, and for this reason, some Jewish and Islamic libraries chop the system apart or flip it to focus on their religions. And even in the standard American system, there are big changes in the categories of knowledge about God:
§ =210 Natural Theology.=
§ 211 Theism and Atheism.
§ 212 Pantheism.
§ 213 Creation.
§ 214 Providence.
§ 215 Religion and science.
§ 216 Evil.
§ 217 Prayer.
§ 218 Future Life.
§ 219 Analogies.
To the rather more dull:
** 210 Philosophy & theory of religion
211 Concepts of God
212 Existence, knowability & attributes of God
215 Science & religion
Again, many of the early categories are no longer considered important parts of our mental map of the world.
Knowledge of the political world
And in political science, Dewey's system has moved from:
=320 Political Science.=
321 Patriarchal Institutions.
322 Feudal Institutions.
323 Monarchic Institutions.
324 Republican Institutions.
325 Colonies and Emigration.
327 Foreign and Domestic relations.
328 Legislative annals.
329 Political essays and speeches.
To this modern classification:
320 Political science
321 Systems of governments & states
322 Relation of state to organized groups
323 Civil & political rights
324 The political process
325 International migration & colonization
326 Slavery & emancipation
327 International relations
328 The legislative process
You can see the problem, though. Even as categories are changed, they're really just modifications of Dewey's original system of knowledge, which put categories like the Christian God, western Science (and occultism), and the study of Western languages far above all the other ways people might think through what we know and value in the world.
And libraries around the world still rely on "fixed" versions of Dewey's classification of knowledge, even though it's outdated by a hundred years and vast swaths of social change. How we organize knowledge says a lot about what we value in the world, and so it's important for the world's languages, religions, and cultures not to just be a footnote in the American system of knowledge.
Dewey's system is also difficult because it has to be learned; it doesn't come naturally. This is why many librarians advocate dropping the system completely. One suggests we switch to Netflix categories for American movies; another suggests user-generated tags in an electronic database.
But what could we actually replace Dewey's system with? Can we find ways of sorting books on a shelf and in a database that are more intuitive for readers, and more representative of all readers? How could we let readers and writers from all groups of people develop the categories that they find important, and what role would a librarian play in that categorization of knowledge and stories?