Logical Fallacies
Explore 6 expert techniques in logical fallacies.
Common reasoning errors to avoid and recognize in arguments.
A logical fallacy is a flaw in reasoning that makes an argument weaker than it looks. The premises might be true and the delivery might be confident, but the link between them breaks. Learning to name these errors does two jobs for a speaker. It keeps your own arguments honest, so a sharp listener cannot dismantle them, and it gives you a calm, specific way to respond when someone else leans on a shaky move in a debate, a meeting, or a Q&A.
The fallacies in this collection cluster into a few recognizable shapes. Some redirect the argument away from the actual claim: ad hominem swaps the idea for an attack on the person, and straw man swaps your real position for a weaker version that is easier to knock down. Others distort the available choices or the chain of events: a false dilemma shrinks a complex question into a forced either/or, while a slippery slope insists one modest step must trigger a cascade of disasters. A third group hijacks a decision with the wrong kind of reason, like the sunk cost fallacy, which treats money or effort already spent as a reason to keep going.
Reach for this category whenever you are building a persuasive case or evaluating one. Before you present, audit your own argument for these patterns and patch the weak joints. When you are on the receiving end, naming the move (without sneering) often resets the conversation around the real question. Work through the six concepts as a recognition kit: read each one, note how it feels persuasive in the moment, and practice the plain-language correction that exposes it.
Questions & answers
What is the difference between a logical fallacy and just a weak argument?
A weak argument can be valid in structure but thin on evidence, like a true claim backed by only one example. A logical fallacy is a specific defect in the reasoning itself: the conclusion does not follow from the premises, even if those premises are accurate. A straw man, for instance, fails not because it lacks data but because it argues against a position no one actually holds.
How do I point out a fallacy without sounding combative?
Name the move, not the motive. Instead of saying someone is being dishonest, restate the real question and ask to return to it. For a false dilemma, you might say, "Those are two options, but are they the only ones?" This keeps the exchange focused on the argument rather than the person, which is exactly the trap an ad hominem falls into.
Is appealing to tradition always a fallacy?
No. Tradition can be useful evidence when the practice has been tested over time and still works for good reasons. It becomes the appeal to tradition fallacy only when age alone is offered as the justification, with no account of why the practice is sound. The honest version explains the reasoning behind the custom; the fallacy substitutes "we have always done it this way" for that reasoning.
How can I check my own argument for fallacies before I present?
Pressure-test the joints, not just the claims. For each main point, ask what would have to be true for the conclusion to follow, then look for the usual shortcuts: are you arguing against a position no one actually holds (a straw man), forcing an either/or where more options exist (a false dilemma), or treating time and money already spent as a reason to keep going (the sunk cost fallacy)? Reading your draft aloud as the room's sharpest skeptic tends to surface the weak link faster than reading it as the author.