Who Should You Actually Trust? A Practical Guide to Evaluating Sources
“Harvard study says” isn’t good enough Good Morning! Let’s continue talking about critical thinking! This is part of my Critical Thinking series of essays - you can find the link to 1-15 in the comments! We just finished talking about 30 logical fallacies - and it took what seemed like forever! So, what’s…
False Dilemma: When the Menu Only Shows Two Items
Most debates have more than two options “Either we let AI run completely unregulated, or we ban it entirely.” That isn’t a choice between two options. It’s a choice between two extremes with an enormous middle ground being quietly erased. The person presenting it as a two-way decision is counting on the listener to accept…
Ad Hominem: When the Attack Is Personal
Attacking the person doesn’t address the argument Let’s say you make an argument about something - could be anything, healthcare policy, a restaurant recommendation, whatever. And the response you get back isn’t really about the argument at all. It’s about you. Your motives, your background, your credentials, what you look like. The argument you made…
Post Hoc: When ‘After This’ Becomes ‘Because of This’
Sequence is not the same as causation The rooster crows, then the sun rises. Therefore the rooster’s crowing causes the sunrise. Obviously absurd. People make this exact mistake constantly with less obvious examples. The rooster version is easy to laugh at. The real-world versions slip past most people’s filters because the two events feel plausibly…
Burden of Proof: Who Has to Show Their Work
You made the claim - now prove it Somebody on the internet says vaccines cause autism. Somebody else asks for evidence. The response - “prove they don’t.” No. That’s not how this works. You made the claim. You prove it. This is the burden of proof. The principle is that whoever makes a claim is…
Composition and Division: When Scale Changes Everything
What’s true of the parts isn’t automatically true of the whole These are two mirror-image fallacies, which is why they make sense to cover together. Fallacy of Composition - assuming that what’s true of the parts must be true of the whole. Fallacy of Division - assuming that what’s true of the whole must be…
Special Pleading: Carving Out Exceptions for Yourself
Why the rules that apply to everyone else apparently don’t apply here There’s a speed limit on somebody’s street. Everyone follows it. Except the one neighbor who drives 45 in a 25 because he “knows this road” and “has excellent reflexes” and “has never had an accident.” He isn’t arguing the speed limit is wrong.…
Slippery Slope: The Fallacy of the Inevitable Cascade
One step doesn’t inevitably lead to catastrophe - show the mechanism “If we allow same-sex marriage, next people will want to marry animals.” “If we legalize marijuana, everyone will be on heroin within a decade.” “If we allow any gun regulation at all, the government will confiscate every firearm in America.” These are slippery slope…
Moving the Goalposts: The Argument That Can Never Be Won
Changing the evidence standard so nothing ever qualifies Climate scientists show temperature records. “That’s just weather patterns.” They show decades of data. “Could be natural cycles.” They demonstrate the mechanism linking CO2 to warming. “Correlation isn’t causation.” They explain why the mechanism proves causation. “But climate models have been wrong before.” They show the models…
False Compromise: When Splitting the Difference Gets It Wrong
The truth is not always in the middle Two people are arguing. One says the earth is round. One says the earth is flat. A mediator steps in. “Let’s be fair to both sides and say the earth is slightly curved.” That’s not fairness. That’s false compromise. The assumption that the truth must lie somewhere…
Equivocation: The Bait-and-Switch of Language
When a word quietly changes meaning in the middle of an argument “Nothing is better than happiness.” “A sandwich is better than nothing.” “Therefore, a sandwich is better than happiness.” Both premises are true. The conclusion is absurd. What went wrong? The word “nothing” is doing different work in each premise. In the first sentence,…
Single Cause Fallacy: When One Explanation Isn’t Enough
Complex problems have multiple causes - pretending otherwise leads to failed solutions Homelessness is caused by drug addiction. Homelessness is caused by lack of affordable housing. Homelessness is caused by mental illness. All three of those claims contain real information. All three, taken alone, are wrong. Because homelessness is caused by all of those things…