Stop!….Grammar Time: Logic Will Break Your Heart

But, style-god, how is your logic?

It’s unfortunate that most writing courses, both at the high school and college level, don’t spend much time on making good arguments. Sure, we talk about evidence and thesis statements and body paragraphs, but that’s structure, not logic. Too often, students are told something along the lines of “Give us an argument in the first paragraph, state three related points in the middle, and then remind us of what you said in the introduction at the end.” This model is not only boring, it also doesn’t help us become more rigorous thinkers.

So today, let’s run through some common logical mistakes. Your online commenting and tweets are about to get turned up to 11.

 

1. Hasty Generalization

Basically, this means drawing a conclusion about the whole based on a sample-size that is either too small or non-representative.

Example: Everyone I know who likes Ayn Rand is a real jerk. I sure would hate to go to an Ayn Rand fan convention.

Explanation: The number of people you know who like Ayn Rand is too small to make a reasonable claim about all people who like Ayn Rand. Frankly, I would be more concerned that you know too many jerks in general.

 

2. Post Hoc Ergo Propter Hoc

This is Latin for “Hey dumbass, just because something happened before something else, it doesn’t mean it caused it.”

Example: Ever since Amazon released the Kindle, e-reading has exploded. Man, I wish they had never made that thing.

Explanation: Surely, e-reading’s rise has been accelerated by the Kindle. But there are a boatload of other factors at play here, and the Kindle might not be the primary cause.

 

3. Composition Error

A personal favorite, just because the examples are fun to write. This one is about grouping together things with a shared quality and assuming the resulting group would maintain that quality.

Example: Man, stories about wizards, zombies, black maids, vampires, and dystopias are all really popular. My novel about a wand-wielding, undead minority housekeeper set after the apocalypse is going to make me a jillion dollars!

Explanation: Just because a the individual items in a group share a quality, the resulting group doesn’t necessarily have that quality.

 

4. Division Error

This is the inverse of the compostion error–thinking that the quality of a category must apply to each individual member of that category.

Example. The average American read 1.7 books last year. Hey, you are an American, which 1.7 books did you read?

Explanation: This is a silly example, but sub “democrat” or “republican” or “pro-life” or “romance reader” in and it’s depressingly common.

 

5. Gambler’s Fallacy

Assuming that what has occurred must continue or that an event that hasn’t happened must occur to fulfill the “average” occurrence for that event.

Example: Paper books have been around for hundreds of years, so they aren’t going anywhere.

Explanation: Remember, an event is produced by its causes, not itself. So if the underlying causes change, the statistical or historical likelihood will also change. (As sad as that might be in this particular example).

 

6. Appeal to Belief.

Basing an argument for the truth of a claim based on the fact that many people believe it.

Example: Millions of people love YA and very few people love literary fiction, so YA is clearly better than literary fiction.

Explanation: The majority can be wrong. Hell, 70% of Americans don’t know what The Constitution is, but you wouldn’t then argue that it is unknowable.

 

7. Straw Man

Ignoring (or replacing) an actual argument in place of an exaggeration version of it.

Example: I can’t believe they teach graphic novels as literature now. Just goes to show that academics have totally abandoned rigor. 

Explanation. This one usually happens when the claim-maker doesn’t have sufficient knowledge of the real reasons for a decision or positions and so inserts the worst, most easily defeatable reason in its stead.