Logical Fallacies: Why We Don’t Always Think So Good

I’m not going to lie. Logic can be hard! When I dived into this subject headfirst, it felt like I’d barely gotten started and I was already in the deep end, drowning in some of these big, heavy concepts.

What is truth really? How do you know when you have it? How do you prove it? What makes up actual proof? If you are going to have a nice or maybe not so nice discussion with someone else, how do you know who’s right?

After seeing how murky this all looks, it seemed way easier to me just chuck it all overboard and stick with what “feels” good. Right?

Well, not so much.

While logic and analysis may be deep and heavy subjects, I think that most any subject can be broken down into simple, easy-to-chew pieces, and critical thinking is no different.

I’m going to do my level best here to make it practical, easy and, hopefully, interesting too. So let’s get into the real meat and potatoes of this subject, which is helping you determine whether what you are hearing or reading is actually true or not. I’ve certainly made more than my share of mistakes in this and I know I’m going to make plenty more, but maybe some of this information can help you and me in guiding us to do better.

What is a Logical Fallacy?

A logical fallacy is an error in reasoning. It’s a flaw, a kink, a loose gear that keeps the engine of rational thinking from running smoothly. An engine has lots of moving parts and can look pretty complicated, but if you break it down into each part, it’s really not too hard to figure out.

First you have to understand what an argument is. I don’t mean two people fighting, I mean in logic. An argument is a series of sentences, two or more, which assert that something is true and offer information which support why it is true. For example:

Cartoons are not real. Bugs Bunny is a cartoon. Therefore, Bugs Bunny is not real.

The first two statements are called the premises and since they are both true, they support the statement that Bugs Bunny is not real, which we call the conclusion. In order for any conclusion to be true, the premises which support it must also be true. This is a valid or good argument because not only are the premises true, but the conclusion automatically follows as a consequence from those premises. In other words, it all goes together and makes sense.

A fallacy is a type of bad argument. There are lots of these different kinds of bad arguments, so they have been given different names to identify the different types. You can have an infinite number of bad arguments, but by breaking them down into different types of bad arguments, we can classify them easier.

So what is a bad argument? Well, there are lots of them. One would be where the premises don’t necessarily add up to or support the conclusion that is being asserted. For example:

Many people get refunds after they file their taxes. I filed my taxes. Therefore, I’m sure to get a refund.

This is a bad argument. The premises are true statements but they don’t inevitably lead to the conclusion because there could be many reasons I would not get a refund on my taxes this year, such as if I didn’t pay more in taxes than I owed. Or maybe I forgot that I owed unpaid taxes from earlier years and the IRS is going to keep my refund to pay for those. Either way, I’m not sure to get a refund simply because of the first two statements.

Here’s another example of a bad argument:

Scientology is a destructive cult. People who get involved with destructive cults almost invariably come to regret it. Therefore, if we don’t get rid of Scientology, the world is going to come to a bloody and horrible end.

This conclusion is not justified even though the premises are true. This type of bad argument is called a slippery slope fallacy, because this argument is not just a bad argument, but it’s a type of bad argument where too many steps have been skipped in between points A and Z. A relatively small case is made to start with and then suddenly we are jumping to a disastrous consequence that is not at all justified. This is one of the top fallacies used by conspiracy theorists, fear mongers and politicians and unfortunately, many people don’t pay enough attention to this and they fall for it.

Sometimes, logical fallacies can be very subtle and other times they can be as big as the Titanic. It takes a lot of practice to spot them consistently. Sometimes you will run into something that “just doesn’t make sense.” Odds are, it doesn’t make sense because one or more of these logical fallacies is going on.

Here’s the bottom line: when someone is trying to convince you of something or change your mind about a given issue, they are going to use arguments to do so. If those arguments are actually fallacies, which they often are, and you don’t recognize them, then you’ll end up making bad decisions. You can run into fallacies in things you read or hear, sales pitches, media shows, speeches from politicians, from people you know or countless other ways.

I’ve put together three public service announcements, and there will be many more, which each define and discuss a particular logical fallacy. Here they are.

Fallacy PSA #1: Strawman

Fallacies are errors in reasoning. Sometimes we hear or make bad arguments and these can be broken down into different types. One of these is called a strawman, which means refuting an opponent’s argument by arguing against something that opponent didn’t say in the first place or purposefully exaggerting or distorting their argument. For example:

John claims that the government should spend more money on AIDS research because it’s killing too many people. Sally says that she guesses John wants to bankrupt the country with his reckless spending proposals. Sally is changing the premise of John’s argument and attacking something he never said and which may not even be true. If John starts fighting against what Sally said, he has fallen for her strawman and gone off his argument entirely.

Using a strawman is an active effort to undermine honest debate and is very common in politics and in PR. Don’t fall for them!

And now you know.

Fallacy PSA #2: Slippery Slope

Fallacies are errors in reasoning. Sometimes we hear or make bad arguments and these can be broken down into different types. One of these is called a slippery slope, which is stating that if A happens, that Z will happen as a consequence, skipping all the logical steps in between. This type of fallacy is a way of sidestepping the actual issue at hand by shifting attention to some baseless extreme hypothetical. For example:

John claims that if the US Treasury is allowed to upgrade the currency, the next thing we know we’ll be under the control of a one-world government. What’s missing in this statement are all the logical steps in between which justify this extreme conclusion, so the conclusion doesn’t really make sense.

The slippery slope fallacy is one of the favorite kinds of bad arguments that conspiracy theorists use, but they aren’t the only ones. When someone is giving you some extreme consequence that doesn’t seem to follow from a relatively mild situation, they are probably using a slippery slope fallacy.

And now you know.

Fallacy PSA #3: Anecdotal Evidence

Fallacies are errors in reasoning. Sometimes we hear or make bad arguments and these can be broken down into different types. One of these is called anecdotal, which means using a personal experience or an isolated instance to prove something instead of a sound argument or actual evidence. For example:

John claims that because he prayed for his Grandmother, she responded to chemotherapy and her cancer went into remission. While it’s great that she got better, his anecdote doesn’t prove anything about the power of prayer. In fact, the actual cause of her recovery can easily be proven to be the chemotherapy, but John wants to believe in prayer so he will discount that medical evidence and claim it was prayer alone that worked.

This kind of bad argument is used all the time by people who generally don’t understand how evidence and science work or want to believe something different for personal reasons. We call this confirmation bias.

And now you know.

Conclusion

There are many many different kinds of logical fallacies and no one expects us to memorize all of them. If you understand what makes a good or valid argument, that alone will help you spot bad ones. By learning the various fallacies, just a few at a time, you will be able to spot bad arguments even easier in the same way that a car mechanic can spot what is wrong with an engine just by looking at it or hearing it run. It’s an acquired skill. No one is born knowing all this stuff but I think anyone can learn it.

I hope this helps. Thank you for watching.