Universal Decimal Classification Apr 2026

Their quest to catalog every piece of human thought led to the creation of the , a system built on the bones of the Dewey Decimal Classification but designed for far more than just books. The Vision: The Mundaneum

Otlet and La Fontaine didn't just want a library; they wanted a "city of knowledge". In 1895, they founded the Mundaneum in Mons, Belgium—a pre-digital precursor to Google.

To make this work, they needed a classification system that was: universal decimal classification

Using numbers that any person, regardless of language, could understand.

In the late 19th century, two Belgian visionaries, and Henri La Fontaine , looked at the world’s exploding volume of information and saw a looming "Pit of Despair"—a future where human knowledge would be lost simply because it couldn't be found. Their quest to catalog every piece of human

Using symbols like colons (:) or pluses (+) to show how different subjects—like Physics and Medicine —linked together to form new ideas like Biophysics . The System: A Mathematical Map of Mind

The UDC divides all human knowledge into ten main "houses" (classes), numbered 0 to 9: To make this work, they needed a classification

Able to cover every field of knowledge, from Philosophy to Engineering.