The Isaac Asimov Dewey Decimal Myth: Almost Complete

You've probably heard this one before: Isaac Asimov is the only author to have a book in every single Dewey Decimal category. It appeared in The New York Public Library Desk Reference, showed up on Jeopardy!, and circulates endlessly on "amazing facts" lists across the internet.

There's just one problem: it's not true.

The Missing Category

Asimov was spectacularly prolific—he published over 500 books during his lifetime—but not one of them was classified in the 100s, the Dewey Decimal category for Philosophy and Psychology. He conquered nine out of ten major categories, which is still an extraordinary achievement, but that tenth category remained forever out of reach.

Yes, he wrote essays about psychology. Yes, he penned forewords for philosophy books like The Humanist Way (1988) and In Pursuit of Truth (1982), which were themselves classified in the 100s. But none of his own books earned a spot in that category.

Why Does Everyone Believe It?

The myth spread because it's the kind of fact that should be true. Asimov wrote about biochemistry, astronomy, history, Shakespeare, the Bible, humor, limericks, and of course his legendary science fiction. His intellectual range was staggering. When you look at the breadth of his work, covering all ten categories seems inevitable.

Even Asimov himself repeated the claim—but always with a careful disclaimer: "I have been told by a librarian that..." He knew it was hearsay, not fact.

What Are the Dewey Decimal Categories?

For context, here are the ten major categories Asimov almost conquered:

• 000 – Generalities (encyclopedias, computers, knowledge)
• 100 – Philosophy & Psychology (the missing one)
• 200 – Religion
• 300 – Social Sciences
• 400 – Language
• 500 – Pure Sciences
• 600 – Technology & Applied Sciences
• 700 – Arts & Recreation
• 800 – Literature
• 900 – History & Geography

Philosophy was the sole holdout. Whether Asimov never found the time, never felt qualified, or simply never got around to it remains a mystery. But the result is clear: he was a near-polymath, not a complete one—at least by Dewey Decimal standards.

Still Impressive

Let's be honest: nine out of ten is still phenomenal. Most authors never escape a single category. Asimov wrote authoritative works on everything from black holes to the Bible, from ancient Rome to the future of robotics. Missing one category doesn't diminish his legacy—it just makes the myth a little less tidy.

So the next time someone tells you Asimov conquered every Dewey Decimal category, you can smile knowingly and say: "Actually, he missed philosophy." Then watch them frantically Google it.