The Logical Fallacy Guide

Welcome to the 675 new members of the curiosity tribe who have joined us since Friday. Join the 98,027 others who are receiving high-signal, curiosity-inducing content every single week.Today’s newsletter is brought to you by Trends!Trends is my personal cheat code for generating new business and content ideas.It’s a premium newsletter from The Hustle that deconstructs the secret sauce of interesting businesses, side hustles, and emerging opportunities—and gives you the playbook to pounce on them. Even better, membership provides instant access to an exclusive community of 15,000+ entrepreneurs who are building the future.I learn something new from every single issue—it has become a core part of my content and learning engine. A true must-read. I can’t recommend it highly enough.Use the link below to join—no commitment, no catch, cancel anytime!Today at a Glance:Logical fallacies are errors in reasoning that undermine the quality of an argument.Combatting them relies first and foremost on establishing a level of awareness—both academically and practically.The Logical Fallacy Guide covers 20 common logical fallacies: Ad Hominem, Texas Sharpshooter, Sunk Cost Fallacy, Bandwagon Fallacy, Straw Man, Appeal to Authority, Post Hoc Ergo Propter Hoc, Personal Incredulity, False Dilemma, Burden of Proof, Red Herring, No True Scotsman, Hasty Generalization, Non-Sequitur, Tu Quoque, Slippery Slope, Begging the Question, Loaded Question, Equivocation, and Fallacy Fallacy.The Logical Fallacy GuideIf you’ve been reading this newsletter, you know that I like to say that humans are fascinating creatures.We possess the capacity to accomplish some complex feat of technology and engineering, and subsequently fall victim to the most obviously flawed base logic.Logical fallacies—errors in reasoning that undermine the quality of an argument—are classic examples of this fact.The Merriam-Webster Dictionary defines fallacy as a false or misleading idea. A logical fallacy, therefore, can simply be thought of as logic based on a false or misleading idea.Unfortunately, unless you went to law school—or took a robust philosophy course load in college—you’ve likely been minimally exposed to them in a formal context.Accordingly, we frequently fall victim to logical fallacies—our own emotional, psychological, and intellectual blindspots create the cracks and we fall right into them.There is no such thing as a perfect logician, but we can all strive to cover our blindspots and craft better arguments. Similar to the study of cognitive biases—which I’ve written about recently here and here—the first step in avoiding logical fallacies is developing an awareness of them.In that vein, today’s piece will cover 20 common logical fallacies to learn, identify, and avoid.Without further ado, let’s dive in…Ad HominemLatin phrase for "to the person”—an ad hominem attack is an attack of the individual rather than the argument.Instead of addressing the argument—its structure, logic, and merits—the offender attempts to refute the opposition on the basis of personal characteristics.It may be overt—openly attacking the person’s character or personality—or covert—subtly doing the same—but it always focuses on the person, not the argument.Often referred to as “mud-slinging” in political circles, if you’ve ever watched a political debate or political campaign ads, you’re already familiar with this one. It’s all-too-common on Twitter and other online discourse, as well.ExampleCandidate 1: “…and this is why I believe we need to implement a much more aggressive set of climate change regulations.”Candidate 2: “I’m sorry, but are we really expected to believe anything coming from a known liar who cheated on his college entrance exams to get to this position?”The offender (Candidate 2) has attacked Candidate 1 the individual, rather than the argument itself.The Texas SharpshooterThe name of this fallacy is based on a fable:A Texan fires a gun multiple times at a barn wall. He then walks over to the bullet-riddled wall and paints a target around the closest cluster of bullet holes to create the appearance of impressive marksmanship.Think of this as cherry-picking—selecting and highlighting evidence that supports the conclusion and systematically ignoring evidence that may refute it.Example“Tara is a really impressive and successful restauranteur. Her restaurant on Park Avenue is always full and gets really high ratings on Yelp.”This may be true, but it ignores the fact that Tara’s five other restaurant openings have failed. The cherry-picked data—the successful Park Avenue restaurant—is used to draw a broad conclusion about Tara’s quality as a restauranteur that may be inaccurate.Sunk Cost FallacyA favorite of behavioral economics.Sunk costs are the economic costs already invested in an activity that cannot be recovered. Money spent on non-refundable flights and hotels, time invested in a project, or energy put towards a relationship all qualify as sunk costs.The ...