If there’s an obvious problem or issue that no one is willing to acknowledge or discuss—especially although doing so would likely solve all other smaller or less serious issues—then there is a proverbial “elephant in the room.” But why do we call it that?

For such a quirky turn of phrase, perhaps it’s surprising that the original elephant in the room seems to have first emerged among some rather serious discussions of philosophy, metaphysics, and logical reasoning in the early 20th century—although back then, it wasn’t quite used in the same way as it is today.

The Philosophical Elephant

The Oxford English Dictionary has recently updated its earliest proverbially unacknowledged “elephant in the room” to 1935, when the American philosopher and psychologist Professor Harry Todd Costello (a one-time assistant of Bertrand Russell) published an essay entitled “A Philosopher Among the Metaphysicians.” In discussing the difference between how scientific and metaphysical minds deal with the observable and the unobservable (and therefore the knowable and the unknowable), Costello wrote that:

“If I say that there is something in my room which looks like a chair when I look at it, that is science; but if I assert it is still there when I look the other way, that is mere speculation. Let us remember, also, that it is going beyond observation to assert there is not an elephant in the room, for I cannot observe what is not.”

Tellingly, Costello’s phrasing here (“Let us remember…”) suggests that using a metaphysically invisible elephant in a room as an example of an unknowable truth must have already been an established metaphor in discussions like this in turn-of-the-last-century philosophy. Digging a little deeper, ultimately, we can take this rather peculiar expression even further back in time.

The Older Fables and Jokes

It’s certainly true, for instance, that elephants were being used as the punchline of jokes in the early 1900s that played on their obvious size and unavoidability. An 1882 short story by Mark Twain, entitled The Stolen White Elephant, might also be partly to blame for establishing an elephant as a metaphor for something so large that it should be impossible to ignore, lose, or go unseen.

Earliest of all, though, is a fable titled The Inquisitive Man, written by the Russian author and fabulist Ivan Krylov way back in 1814. In the story, a man is heard commenting on all the wonderful things he has seen at a local museum, including “flies, butterflies, cockroaches, little bits of beetles” and all kinds of incredible things “smaller than a pin’s head.” When asked what he thought of the museum’s display of a gargantuan elephant, however, the man replies that he didn’t see it.

Clearly, long before Costello popularized the visible/invisible elephant in the room among the philosophical discussions of the early 1900s, jokes and tales like Krylov’s had already long established it as a metaphor for something so comically immense and unavoidable that failing or being unable to see it—and therefore, in Costello’s writing, to refuse to acknowledge its existence—was utterly ridiculous.

The Modern Shift

Throughout the later 20th century, though, it seems the proverbial elephant in the room remained largely confined to philosophical discussions like Costello’s—defined by the OED as “something obvious and incongruous … which may or may not correspond to observable facts”—until the 1980s, by which time the phrase seems to have become established enough in the language to finally pick up the looser, more general use it still has today.

In this context, referring to something glaringly obvious that is being intentionally ignored, it was memorably used in the title of a best-selling 1984 book, An Elephant in the Living Room, about children living with alcoholic parents, and it was likely this that helped to further popularize the expression as it is in our language today.