One of the favorite techniques of mystery mongers when confronted by skeptics or good evidence—or just plain common sense—is to reply “But isn’t it possible?” This is a standard ploy on countless paranormal-themed television shows, including (and especially) those dealing with ancient aliens.
This is often said with some degree of smug satisfaction, as if some universal truth had been laid down and the critic should just concede defeat and move along. Sure, maybe there’s no evidence whatsoever for Claim X—but how arrogant it would be to confidently and omnisciently rule it out! When I’m confronted with this fallacy, as I often am, I explain that there’s some (often unintentional) confusion between possible, plausible, and probable. This is a point that hasn’t gotten a lot of attention in critical thinking and skeptical circles, and I thought it would be worth exploring.
To scientists, statisticians, and actuaries the distinctions between what is possible, plausible, and probable are important, especially in the context of threats and dangers. Because these distinctions are rarely made (and in fact are routinely conflated) by the media, understanding how risk is measured is an important part of critical thinking and media literacy.
• Possible is of course the lowest bar, and from a scientific view anything is possible. It’s possible that a huge asteroid might come out of nowhere next month and kill all life on the planet. It’s possible that as you’re reading these words a child is being born in Pakistan who can fly like Superman and breathe underwater. It’s possible that a close friend of yours will be mugged by a left-handed serial killer named Wilbur. Science does not operate on certainties, and strictly speaking, anything is possible. As such, it’s essentially meaningless. Defense attorneys and conspiracy theorists love to use this “retreat to the possible” logical fallacy despite significant evidence to the contrary: “Yes, my client was seen and videotaped robbing this store, and sure, his fingerprints were found at the scene—but isn’t it possible that he has an evil twin that no one knew about who did this crime, while my client was busy volunteering at the homeless shelter across town?”
• Plausible is a more subjective measure; what’s plausible, or believable, depends on who you ask, what their knowledge base is, the context, and other factors. Often a claim that is plausible to a layperson is implausible to an expert; for example, a religious group’s claim of reducing a city’s violent crime through prayer will likely seem implausible to a police chief, who would use other methods. Or a president’s claim that building a border wall will stop illegal immigration would be considered implausible by experts on national security. What’s plausible also depends on what sort of information a person has access to—which is why it’s vital to have accurate information about the world upon which to reach a conclusion.
• Probable is the most valid, important, and science-based criterion. Unlike the meaninglessness of stating what is possible, and the vagaries associated with plausibility, probability has recourse to hard data and statistics. Experts may have honest disagreements about data interpretation, but we have reasonably good data on baselines for countless metrics and demographics—from the causes of car accidents to cancer incidence to the numbers of homicides. Statisticians and actuaries can tell you what your overall likelihood is of anything from being a crime victim to getting cancer (based on your genetics, diet, and lifestyle choices). It’s not precise or guaranteed, and there are outliers—some hamburger-loving chain smokers live to be 100, and some diligent vegan exercisers drop dead at 30—but typically the data conforms to a normal, bell-curve distribution. This is the power of data over anecdotes.
Yet we do not see many accurate discussions on probability in news stories designed to gather clicks as they ride currents of fear or outrage. Getting into the habit of looking for data on probabilities—and noticing when it is conspicuously absent from an article or discussion—is a valuable way to cut through misleading narratives and claims. Doing so will not just raise your level of media literacy, it will likely also decrease your anxiety—if you, like many, find yourself overwhelmed at times by the flood of panic-inducing stories served up as news and social media commentary.
Fearmongers routinely inflate dangers in an attempt at social control. If you can exaggerate small, remote dangers into prominent and visceral ones, you can scare the public and create division. This is often done by activists or candidates with a social or political agenda in mind, but the media also regularly subjects the public to alarmist news and studies, some more fact-based than others. The same applies to mystery mongers forced to concede the paucity of evidence for their claims. As always, skepticism is an important tool in critical thinking, so the next time you hear the lame rhetorical ploy “Isn’t it possible?” just reply, “Of course; anything is possible. You’re asking the wrong question.”
A longer version of this piece appeared on my CFI blog; you can find it here.