Your logic is useless!

If you've just learned about logical fallacies, you're probably feeling pretty confident that you know how to deconstruct an argument and demonstrate when somebody's reasoning is faulty. Whether it's the post hoc ergo propter hoc, the no true Scotsman, the argument from ignorance, or any of the various other common fallacies that people make on a daily basis, you're ready to get to the truth of the matter.

There's a bit of a problem though.

You're assuming that everybody either knows about logical fallacies or, more importantly, cares about them.

When I first started getting really into skepticism, I would read various debates on usenet, and the skeptics would often point out the fallacies that were being committed by the paranormal advocates. I'm not some rube who's impressed by somebody simply naming off a fallacy, mind you. What convinced me was that they'd not only name them, but they'd explain them and show how the supposed reasoning that the other person was using didn't work by applying it to another example. In other words, my opinions started to change because I was already a pretty logical person, and even more significant, I valued logic.

Obviously, not everybody knows all the logical fallacies by heart, so simply saying to somebody: "You're making a strawman!" isn't going to get you anywhere if they don't know what that means. If the person is reasonable though, then you can correct this by explaining what that means and exactly how they're using it. This might get you somewhere, especially if you're clear that just because a person makes a fallacy, that doesn't mean that he or she is wrong. After all, you can have bad reasons for believing things that are true. If I said that the sun was going to rise tomorrow because it was the will of the monster who lives in my closet, I'd be right about the sun coming up, but I'd be wrong about the reason why.

Still, you might find yourself a bit annoyed, as even this isn't a sure-fire way to go about things. Some of the problems you might encounter include:

1. The other person thinks you're playing some kind of clever word game. I've been accused of  using "rhetoric" instead of making a point, and another person said that I was using words that are impressive in a debate class but don't mean anything in the "real world". Another person once referred to this as being my own personal method of analyzing things. That's very flattering, but I can't take credit for logic.

2. The other person will think that multiple examples of the same fallacy will eventually equal a truth. I get this a lot with "God of the Gaps" style arguments and anecdotes. You can point out that they're making a fallacy, but then they'll give you ten more of the same fallacy. When you take the time to point out that each one on the list is making the same bad bit of reasoning, they act like you're just being stubborn and "nothing will convince you".

3. They think that logic is subjective. I once had a guy tell me that he was using his own logic to reach his conclusions. I can't even...

4. Sometimes the most frustrating of all is a person who knows just enough to be dangerous. They'll throw out the terms without being able to explain how the argument fits the fallacy, or they'll just say, "No, I'm not doing that".

So, you know logic? Good for you. Before you go throwing it around, it's probably best to see if you and the person with an opposite point of view can agree to the rules before you start playing the game though.