How to Argue without Cheating Exploring Syllogisms and Avoiding Fallacious Reasoning

Today Goals Focus Questions What is an argument? What is a fallacy? To investigate how to “delineate” an argument To begin evaluating arguments To look for valid reasoning Determine if arguments use fallacious reasoning What is an argument? What is a fallacy? How can we argue effectively?

How to Argue without Cheating Arguing is fun Whether it’s a persuasive essay, a formal debate, or unenthusiastic discussion with a parent over the precise moment at which the garbage should be removed, we humans like to argue.

Using Logic Generally, these arguments don’t seem to have much method. You say this, they say that, and you go back and forth until somebody storms away. Little do you suspect that underneath this chaos, there is (or should be) a structure. There are whole sciences devoted to making a good argument, and one of them, logic, gets down to the nitty-gritty of proving even a single point.

First Look: In the world of logic, you can make a point (called the conclusion) by using two sentences called premises. Like so: premise: All dogs have a liver. premise: Froofi is a dog. conclusion: Therefore, Froofi has a liver. You may not be thrilled by this perky factoid, but in the world of logic, this syllogism is a slam dunk.

Syllogism All dogs have wings. Froofi is a dog. Therefore, Froofi has wings. Let’s consider: If all dogs had wings, Froofi would have wings. The syllogism is valid. But dogs don’t have wings. So although the syllogism is valid, the conclusion is false. When the error is in the facts, not the logic, the argument is unsound. When the facts are right, but the logic isn’t, the syllogism has a fallacy.

What’s a Logical Fallacy?

What is a Fallacy? According to Webster’s Dictionary, a fallacy is an error in reasoning or a flawed argument. It’s an argument that does not conform to the rules of logic, but appears to be sound.

Fallacy Example: Cheryl jumped inside the house. Then the house collapsed. Therefore, Cheryl made the house collapse. Let’s say that happened. The premises are true, but is the syllogism valid? No. Even if Cheryl is a bit overweight, it’s unlikely she caused the house to collapse. The syllogism is invalid. It’s fallacious (it has a fallacy). Your teacher won’t be happy. Nor will Cheryl.

Where Fallacies come in: Fallacies become important within the premises, or the claims. They also are important when reviewing the conclusion- can you come to this conclusion from these premises? We will be going over common fallacies and their problems in logic. You will be expected to know what the fallacy means, and apply it to a syllogism for your quiz (Friday, May 11th)

Fallacies we’ll cover Post Hoc Ergo Proctor Hoc Non Sequitur Ad Hominem Either/Or Slippery Slope Hasty Generalization Red Herring Ad Verecundiam Bandwagon Card Stacking Circular reasoning

1. Post hoc ergo propter hoc (aka Post Hoc) After this, therefore, because of this Just because Thing 1 happened before Thing 2, it doesn’t mean Thing 1 caused Thing 2

Post hoc ergo propter hoc Ms. Bugica sneezed. Then her students laughed. Therefore Ms. Bugica’s sneezing makes her students laugh.

2. Non Sequitor “it does not follow” The writer’s conclusion is not necessarily a logical result of the facts.

Non Sequitor

Attacks the person and the person’s character, not the issue 3. Argument Ad Hominem “to the man” Attacks the person and the person’s character, not the issue

Example:Ad Hominem

4. Either/or “False Dilemma” The writer tries to convince the reader that there are only two sides to an issue. Most reasonable people understand that there is often a middle ground, especially when dealing with complex issues.

The assumption that one thing lead to another after another Slippery Slope Chain reaction The assumption that one thing lead to another after another

Jumping to conclusions about a population based on a small sample. Hasty Generalization Jumping to conclusions about a population based on a small sample. Bases argument on insufficient data

Red Herring Presenting an irrelevant topic to divert attention away from the original issue (A red herring is a fish that smells really bad that people would use to distract bloodhounds)

Example: Red Herring

Ad Verecundiam argument from inappropriate authority an appeal to the testimony of an authority outside the authority's special field of expertise. From a logical point of view, anyone is free to express opinions or advice about what is thought true; however, the fallacy occurs when the reason for assenting to a statement is based on following the recommendation or advice of an improper authority.

Ad Verecundiam These can come from: (1) experts in a particular field of knowledge (cognitive or epistemic authority); (2) prestigious or powerful individuals or institutions; (3) governmental, legal or administrative officials; (4) social, family, religious, or ancestral heads; and so forth. Oprah is reading this book, so you should too! Wait, what makes her an “expert” at anything?

Bandwagon Appeal Creates an impression that everybody is doing it, and so should you In other words, if you suggest that someone’s claim is correct simply because it’s what most everyone is coming to believe, then you’re committing the bandwagon fallacy.

Card Stacking The writer selects only data that supports his own viewpoint and ignores contradictory data

Card Stacking They’re still fries!!!! !!!!!!!!! !!

Circular Reasoning A claim which contains it’s own evidence Can often be said both ways, and proves nothing. You can trust me because I would never lie to you. I would never lie to you because you can trust me.

Let’s try some! #1 Trees have roots fact/error This maple is a tree. Fact/error Therefore, this maple has roots. Valid/invalid ___________________________sound/unsound X has Y Z is X =Z has y

Let’s try some! #2 Birds can fly fact/error Airplanes can fly. Fact/error Therefore, airplanes are birds. Valid/invalid ___________________________sound/unsound X can Y Z can y =Z are X

Let’s try some! #5 X has Y All Y is Z =X’s Y are Z Kangaroos have pouches. fact/error All pouches are made of denim. Fact/error Therefore, kangaroos pouches are denim. Valid/invalid ___________________________sound/unsound X has Y All Y is Z =X’s Y are Z

https://www. youtube. com/watch https://www.youtube.com/watch?v=fXLTQi7vVsI&ytsession=YraRLeDiE2ziD3Z9 wld7jjJz2do3VFc5brwt52wo9gMWSBsoXgpQmPscNs50KYZ7nWUADTfvs80o1yUK kl1Zk1VFbaQhrjFRZaaFbS7ibBgLqYihVxEMF875- PxZK7ildcYqMifhRcfhs2YLj_z6ftLAELcQ6zWEfB1wUJbQgCEbQBp- TTNXSTPG1ZbRRm_R37s8ILpdp8L https://www.youtube.com/watch?v=vRJUvFG8gbE&feature=related

http://psms29.com/cgi/example-of-bandwagon