What Is a Logical Fallacy? (And How to Spot One)

A logical fallacy is a really fancy way of saying, "That's a bad argument." Nerds like to call them "errors in reasoning" but they're really just arguments that sound convincing. When you take a closer look, you find that the reasoning is either flawed, misleading, or just not the full picture.

A classic example is the Slippery Slope fallacy.

"If you eat one Tim Tam, you'll eat the whole tray and get sick."

The claim is that eating one chocolate biscuit will inevitably lead to eating the whole tray. It jumps from a small step to a huge, unlikely result - ignoring everything in between. That leap is what makes it a fallacy.

But how do we spot them?

Look at the argument being made and ask one simple question: Does the reason actually support the conclusion? If eating one biscuit doesn't actually prove you'll demolish all twelve in one sitting, the reasoning has a gap. That gap is the fallacy.

Let's look at the Ad Hominem Attack. You write on a social media post, "I think small dogs should be allowed to travel on planes." One of the commenters fires back, "You're just a crazy dog lover who thinks dogs are better than people!" The reason given - that you're a crazy dog lover - doesn't prove anything about whether dogs on planes is a good or bad idea. It's attacking you, not your argument. That's the Ad Hominem Attack.

Where do we find them?

You can find logical fallacies like these in everyday conversation, on television, on social media and all over the web. Anywhere and everywhere you find human beings, you'll find fallacies. They're a sneaky way of convincing others of our point of view - or getting them to do what we want - without actually proving anything.

Here's the thing though. Spotting a fallacy doesn't automatically mean the other person is wrong. It just means the argument hasn't proven their conclusion yet. The conclusion might still be true - it just needs better support. That's the difference between using fallacies as a debating weapon and using them as a genuine tool for finding the truth.

Want to go deeper?

Read our Why Should I Learn Fallacies? article to find out why understanding these critters is one of the most valuable thinking skills you can develop.