I learned the term L’appel du Vide—or Call of the Void—this week while having lunch with my friend and former colleague, Matt, after describing a recent drive along the north Maui coast, where I steadfastly fixed my eyes on the center line to my left to avoid reflexively veering over the edge of the steep cliff on my right. It never occurred to me this was a well-known psychological phenomenon. NeuroLaunch explains it:

Have you ever found yourself teetering on the edge of a cliff, heart racing, palms sweaty, when suddenly a tiny voice in your head suggests, “What if I just… jumped?” Don’t worry; you’re not alone in this peculiar experience. In fact, you’ve just encountered one of the most fascinating quirks of the human mind, one that has puzzled psychologists and philosophers for generations.

The “Call of the Void,” or “L’appel du Vide” in French, is a term that describes those fleeting, often disturbing thoughts that pop into our heads in potentially dangerous situations. It’s not just about heights, either. Maybe you’ve had the sudden urge to swerve your car into oncoming traffic or to stick your hand into a whirring blender. These thoughts can be jarring, but they’re a normal part of the human experience.

The term was new to me even if the phenomenon wasn’t: I’ve experienced the “call” innumerable times. I’ve often found myself at the edge of a mountaintop or skyscraper, and the sensation that I might slip and fall—or catapult myself—into the unknown was overwhelming. My rubbery, tingling legs and suddenly racing heart would impel me to move away with alacrity. It’s one reason I thoroughly dislike roller coasters, and will never go skydiving or bungee jumping. As I always tell people, I’m not afraid of heights, I’m afraid of falling from them.

Jessica Seigel, in a 2017 Nautilus article on the phenomenon, wrote:

The seemingly irrational, but common urge to leap—half of respondents felt it in one survey—can be so disturbing that ruminators from Jean-Paul Sartre (in Being and Nothingness) to anonymous contributors in lengthy Reddit sub-threads have agonized about it. While the French philosopher saw a moment of Existentialist truth about the human freedom to choose to live or die, ramp_tram called it “F***king stupid” when he had to plaster himself to the far wall of a 14th-floor hotel atrium away from the balcony railing because “I was deathly afraid of somehow jumping off by accident.”

“Accidentally jumping” is a remarkably apt—if contradictory—description of how it feels.

That urge to jump, to swerve off a cliff, or to stick our hand in a blender is basically our brain—the amygdala, or “fear center,” and the prefrontal cortex, or decision-making center—gaming out dangers, firing off warning signals, and conjuring these scenarios in an effort to keep us safe. If we envision sticking our hand in the blender, we also imagine the consequences of doing so, making it more likely we will take extra care to avoid liquefying our extremities.

NeuroLaunch, again:

From an evolutionary psychology perspective, this phenomenon might actually be a survival mechanism. By briefly considering the worst-case scenario, we become more aware of the danger and more likely to take precautions. It’s like our brain’s way of saying, “Hey, pay attention! This situation could be dangerous!”

Unsurprisingly, I may have succumbed to one form of L’appel du Vide. While in a New York subway station, I removed my backpack and in doing so, knocked my glasses off my face and onto the tracks. The train, I’d noticed moments earlier, was nine minutes away. I judged the distance to the tracks (four to five feet) and decided I could get back up easily enough, so without further thought—and in some small state of panic, as I am virtually blind without my glasses—I leapt down, grabbed my glasses, and… struggled to get back onto the platform. To complicate matters, transit police were on the platform and had to pull me up. I was certain I would be arrested, but managed to avoid that particular ignominy. Only after I was safely back on the platform did the utter stupidity of my actions hit me: What if the train had arrived early? What if there was no one to help me back onto the platform? What if I’d forgotten which was the third rail?

I still shudder when I recall it. Perhaps, though, this wasn’t L’appel du Vide but another relevant French phrase: J’suis un putain d’idiot.