When Pigs Fly Ben Jonson The Devil Is An Ass

When Pigs Fly: How Ben Jonson Invented a Phrase That Outlived the Devil

Here's the thing about idioms — most of them have a story behind them, and most of us have no idea what that story is. Think about it: we toss around phrases like "when pigs fly" like they've always existed, like they grew naturally out of common speech. But sometimes, they have a very specific origin point. Sometimes, they come from a play.

Ben Jonson didn't just write plays. They're living, breathing works that still shape how we talk today. He wrote the kind of plays that stuck around. Day to day, volpone*, The Alchemist*, Bartholomew Fair* — these aren't just Restoration curiosities gathering dust in university libraries. And one of them — The Devil Is an Ass* — gave us a phrase that's been annoying people for four centuries.

What Is "When Pigs Fly" Doing in a 17th Century Play?

Let's get this straight: "when pigs fly" as a standalone expression didn't start with Jonson. The concept of impossible things happening was already floating around in various forms. But Jonson was the first to put it on paper in a way that stuck. In The Devil Is an Ass* (1607), the character Poinsfoot uses the phrase in a moment of exasperation, essentially saying something along the lines of "that will happen when pigs fly" — a sarcastic dismissal of an unlikely scenario.

The play itself is a comedy about good and evil, specifically about the devil Asmodeus being sent to Earth to report on human corruption. He's supposed to be this fearsome, worldly-wise demon, but what he finds among humans is so absurd and petty that he's constantly bewildered. It's the kind of play where the devil is more innocent than the people he's observing, which is exactly the kind of irony Jonson loved.

Poinsfoot isn't a major character. He's a lawyer's clerk, one of those secondary figures who exists mostly to deliver exposition or comic relief. But in this one moment, he says something that resonates beyond the play's immediate context. He's talking about another character's chances of reforming, and his response is essentially: "Sure, that'll happen when pigs fly.

Why This Phrase Endured

Most phrases from Jacobean drama died with the playgoers. You just need to look at a pig and imagine it flying. But "when pigs fly" had something special — it was visual, ridiculous, and instantly understandable. You don't need to know Latin or Greek mythology to get it. The absurdity makes it memorable.

What's interesting is how the phrase evolved after Jonson. In the original context, it was more about moral reform — the idea that certain people would never change their ways. But as it moved into common usage, it became more general. Any unlikely event, any promise that sounds too good to be true, any situation that's clearly never going to happen — that's when you say "when pigs fly.

The phrase also works because it's self-aware. That's rare in language. And nobody actually believes pigs can fly. Worth adding: most idioms require some cultural knowledge or historical context. Even so, it's a joke that's obvious the moment you hear it. It's not a metaphor that requires interpretation. "When pigs fly" requires none of that.

How the Phrase Works in Practice

Language purists sometimes complain about idioms, saying they're illogical or confusing for non-native speakers. But "when pigs fly" actually breaks this rule. It's perfectly logical in its own way. The structure is simple: "This impossible thing will happen when [equally impossible thing] happens.

In practice, you'll hear it used in conversations like this:

Someone says: "I'm going to start exercising every day and eat nothing but kale." Another person responds: "Yeah, right. That'll happen when pigs fly.

Or in writing, it shows up in everything from children's books to political commentary. It's remarkably versatile because the underlying concept — something that will never happen — is universal.

The phrase also has a built-in humor that makes it hard to take seriously. Even so, even when you're frustrated, saying "when pigs fit" forces a slight smile. It's difficult to be truly angry while invoking flying pigs. This makes it a useful tool for defusing tension or lightening a conversation.

What Most People Get Wrong About the Phrase

Here's what most people don't know: the modern version of "when pigs fly" is actually a simplification. Jonson's original line was longer and more specific to the play's themes. The phrase as we know it today is more of a distillation — someone heard it, liked the concept, and ran with it.

Another common misconception is that the phrase originated in folk tales or children's stories. Some people think it's ancient, passed down through generations of storytellers. But no, it has a clear literary origin in Jonson's play. This doesn't make it any less valid, but it does mean the phrase is younger than most people assume.

People also tend to forget that Jonson wasn't just coining a handy expression — he was making a point about human nature. In practice, in the context of The Devil Is an Ass*, the phrase is about the gap between what people say they'll do and what they actually do. Still, it's cynical, but also realistic. Most of us have met someone who promised to change and never did.

Practical Ways to Use the Phrase (Without Sounding Like a Textbook)

The key to using "when pigs fly" effectively is timing. Drop it into a conversation at the right moment, and it lands perfectly. Use it too obviously, and it feels forced.

Continue exploring with our guides on which expression is equal to 72 and things fall apart the center cannot hold.

Real talk: the phrase works best when it's not the main point of your sentence. " The difference is subtle but important. Worth adding: " So instead of saying "That's impossible — when pigs fly," try something like "Sure, that might happen when pigs fly. The first version sounds dismissive. On top of that, it's a qualifier, an aside, a way of saying "I don't buy that. The second sounds more conversational.

In writing, the phrase can add character to dialogue or provide comic relief in tense scenes. It's particularly effective in fiction because it grounds characters in a shared cultural understanding. When a character says "when pigs fly," readers immediately know both the meaning and the tone.

The phrase also works well in titles and headlines because it's instantly recognizable. Editors know that readers will click on something called "When Pigs Fly: Why That Project Will Never Happen" because it promises both humor and insight.

FAQ

Is "when pigs fly" from Shakespeare? No, it's from Ben Jonson's play The Devil Is an Ass*. Shakespeare and Jonson were contemporaries, but this particular phrase belongs to Jonson.

What does "when pigs fly" mean in slang? It means something will never happen. It's used to express skepticism about a promise or prediction.

Where did the flying pig symbol come from? The image of a flying pig predates Jonson's play, but the specific phrase "when pigs fly" as we use it today comes from the 1607 play.

Can you use "when pigs fly" in formal writing? It's generally too informal for academic or business writing, but it works well in casual contexts, fiction, and opinion pieces.

Are there other phrases from The Devil Is an Ass?* The play contributed several expressions to English, though "when pigs fly" is by far the most enduring.

The Phrase That Refuses to Die

Four hundred years later, "when pigs fly" is still going strong. It's appeared in movies, TV shows, songs, and countless conversations. It's been translated into dozens of languages, though not always successfully — the humor doesn't always translate.

What's remarkable is how the phrase has maintained its original spirit of gentle mockery. In an age of increasingly harsh language, "when pigs fly" remains relatively harmless. In real terms, it's dismissive without being cruel, skeptical without being mean. Maybe that's why it's lasted so long.

Ben Jonson probably didn't think he was creating a timeless idiom when he wrote The Devil Is an Ass*. He was just trying to make people laugh. But sometimes, the best comedy sneaks up on you and becomes part of how we talk to each other centuries later.

The next time you find yourself saying "when pigs fly," remember that you're quoting a

The next time you find yourself saying “when pigs fly,” remember that you’re quoting a line that has survived wars, revolutions, and the rise of the internet. Its longevity isn’t just a linguistic curiosity; it’s a testament to how humor can fossilize in everyday speech.

In contemporary culture, the phrase has taken on new layers. Social‑media memes frequently pair a cartoon of a pig soaring over a city skyline with captions like “Me trying to finish my thesis before the deadline” or “When my cat finally stops knocking over my coffee.” The visual absurdity amplifies the idiom’s punch, making it instantly relatable to a generation that thrives on rapid, visual communication.

Even in scientific discourse, the expression finds a home—though usually with a tongue‑in‑cheek disclaimer. Researchers studying aerodynamics might write, “Our model predicts lift for a pig in flight only when pigs fly,” acknowledging the impossibility while still engaging with the playful spirit of the phrase.

The idiom also serves as a cultural touchstone in negotiations and politics. When a policy maker promises a sweeping reform that would require unprecedented cooperation, opponents may retort, “Sure, that’ll happen when pigs fly,” signaling both skepticism and a refusal to accept unrealistic expectations. In this way, the phrase remains a concise shorthand for “that’s never going to happen,” preserving its original function while adapting to new contexts.

Beyond English, the concept of a flying pig appears in folklore from China to Brazil, each version reflecting local humor and societal anxieties. Also, in some traditions, the flying pig is a symbol of unexpected prosperity; in others, it represents the absurdity of over‑ambitious dreams. These cross‑cultural echoes reinforce the universality of the idiom: no matter the language, people understand that a pig in the sky signals the impossible.

So the next time you hear someone say “when pigs fly,” you’re not just hearing a witty retort—you’re hearing a piece of linguistic history that has been polished, repurposed, and passed down through centuries. It reminds us that language is alive, constantly reshaped by the stories we tell and the jokes we share.

To wrap this up, “when pigs fly” endures because it captures a perfect blend of skepticism, humor, and cultural resonance. It started as a clever jab in a 17th‑century play and has since become a versatile tool for everyday conversation, creative writing, and even academic discourse. Its survival illustrates how a simple, vivid image can transcend time, continuing to make us smile whenever we’re reminded that the impossible is, quite literally, on the horizon.