English 104: College Composition

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Logical fallacies are flaws in reasoning that can throw your argument off track and confuse your reader. This video explains how to identify a few common logical fallacies and how to steer clear of them.

What Are Logical Fallacies?

Either you'll watch this video and decide it's the greatest thing you've ever seen, or you don't care about being a good writer.

That's an example of an either/or fallacy. It's something you want to avoid in your writing, and we'll talk about it a bit more in a minute.

When you write any essay, particularly an argumentative essay in which you're building a case for a particular position, it's important to be logical as you construct your points and as you move from one idea to the next. No reader is going to be convinced by an illogical or confusing argument.

So, when you're writing, you want to avoid logical fallacies. A logical fallacy is essentially a flawed argument or error in reasoning. Logical fallacies are problems in the way that a writer has constructed an argument.

It's not terribly important that you be able to name and identify the specific types of logical fallacies. What is important is that you're able to spot and fix a flawed argument when you've made one and, better yet, that you avoid faulty logic in the first place. We'll talk about a few common types of logical fallacies, how to identify them, and how to avoid them in your writing.

Avoid Broad Generalizations

When you're writing an argumentative essay, it's very important to establish credibility with your audience. Providing information that's not accurate and true is a surefire way to lose credibility with your reader, and once that's gone, you're unlikely to persuade your audience to your way of thinking.

It's obvious that you shouldn't put outright untruths in your essay. For example, if you're arguing that the music program, rather than the athletic program, should be cut at your school because of budget constraints, it wouldn't be a good idea to say that music education doesn't help students academically. Your reader might be familiar with research finding that teaching children music does help them learn other subjects like math.

So you may end up alienating your audience by stating an absolute that's just not true. Your reader will be less likely to believe other statements that you make even if they are backed up by facts.

OK - so we know that stuffing our essay full of convenient but inaccurate supporting statements isn't a good idea. But what about making overly broad generalizations? In other words, what if we present a kernel of truth but try to make it sound like that truth applies in a much larger context than it does?

Using our example from earlier again, let's say that you were to write an opinion piece for your school newspaper arguing that the school's music program budget, rather than the athletic program budget, should be slashed. Let's say that you've informally polled a group of student athletes at your school, and they showed a lot of support for your proposal. It could be very tempting to support your argument with the contention that:

Students overwhelmingly oppose cutting the school's sports budget and instead voice their support for denying funds to the music department.

Attributing this opinion to 'students' as opposed to a specific group of students - athletes who might be expected to oppose sports defunding - would be to make an overly broad generalization. It wouldn't be an outright untruth, but it would involve stretching the truth and wouldn't provide the basis for a solid, logical conclusion.

Try to avoid this type of broad generalization or mischaracterization so that you can maintain your integrity and credibility with respect to your audience. When you provide supporting statements in an argumentative essay, ask yourself whether those statements are accurate or whether they are so broadly cast as to mischaracterize the nature of the information you're discussing.

Avoid Non Sequiturs

No matter what career you want to pursue, you'll need to have strong writing skills, so be sure not to over-water your plants.

That's an example of a non sequitur, which is a Latin term meaning, 'it does not follow.' Essentially, a non sequitur is an error in reasoning that occurs when a conclusion doesn't follow logically from what precedes it. If you've laid the groundwork for a good argument, but then at the end you take a sharp turn and present a conclusion that doesn't match what you've just built toward and maybe doesn't even really make sense, you've produced a non sequitur.

My example a moment ago is not particularly subtle. It doesn't take a genius highly skilled in the art of detecting logical fallacies to notice that something is amiss with that sentence. Non sequiturs are usually a bit trickier to catch; if you've found moments in your writing - or in other people's writing - where the logic just doesn't seem quite right, and the conclusion didn't quite feel earned, you may have been catching non sequiturs. For example:

If newborn babies came with instructions, we would all be perfect parents. However, babies don't come with instructions. Therefore, my parenting skills can't be any better than they already are.

This non sequitur is a bit sneakier than our earlier example because all of the ideas presented are related, and I've used the basic structure of what might be a legitimate, logical argument. Notice that the final assertion - 'Therefore, my parenting skills can't be any better than they already are' - doesn't follow logically from the preceding reasoning. It may certainly be the case that I could have better parenting skills, but the fact that babies don't come with instructions doesn't mean that I can't brush up on my skills as a parent.

Subtle, sneaky non sequiturs can be quite problematic in persuasive writing because they might seem okay at first glance. But upon looking at the reasoning again, it may become clear that the writer just hasn't connected the dots to arrive at a sound conclusion.

Writers will sometimes squeeze these types of non sequiturs into their writing, either on purpose or accidentally, in order to race past the requirement of arriving at a point logically. If you want to reach a particular conclusion, you could just throw it out there without properly building to it, but it's not a good idea, as your reader will be able to see that you cut corners in your logic, and your conclusion just won't be convincing.

Whenever you present a series of logical steps to reach a conclusion in your persuasive writing, be sure to take a moment and read back through what you've written with a critical eye. Does it make sense how you've gotten from point A to point B? And from point B to point C? If not, go back and shore up your reasoning so that your reader can know that he or she is dealing with a trustworthy source.

Avoid The Either/Or Fallacy

I mentioned earlier that, Either you'll watch this video and decide it's the greatest thing you've ever seen, or you don't care about being a good writer.

You may be thinking that watching this video has made for the greatest, most exciting few minutes of your life, but it's certainly not the case that if you don't feel that way, that you don't care about your writing.

As you can see from this example of an either/or fallacy, writers who use this type of flawed reasoning tend to do so to try to force the reader into a corner - to make the reader feel that he or she has to adopt a certain way of thinking, or else there is a real problem.

As a reader, you'll probably be able to sense that there is a flawed argument when you come across an either/or fallacy because the writer simply hasn't provided enough options. The writer has communicated that things must be either this way or that way, with no in between.

This type of logical fallacy often comes into play around the time of elections, when advocates of certain candidates try to portray things in stark and extreme ways. For example: Either you support candidate X, or you don't believe in the Constitution.

The problem of course is that the either/or fallacy often produces a completely untrue statement, as things are rarely so black and white. Work on avoiding this type of logical problem in your writing, as it's one that's pretty easy for a reader to catch. Again, you don't want to lose credibility with your reader when you're trying to be persuasive.

Lesson Summary

When you write an argumentative essay, your goal should be to present reasoned, logical arguments that are geared to persuade the reader. In order to achieve this type of well-reasoned, logical argument, you'll need to avoid logical fallacies in your writing, including:

Overly broad generalizations, which imply that statements apply in much broader contexts than they actually do; non sequiturs, which occur when conclusions don't follow logically from the statements that precede them; and the either/or fallacy, which presents a false this or that choice to the reader that ignores other reasonable options.

By learning to spot these problems in your writing, and to avoid them altogether, you'll be on your way to crafting sound, convincing arguments.