Logical FallaciesHow to spot sloppy thinking, dirty tricks, and flamboyant lies

Pointy things go in the outlet, right?

Oh, look! It’s human nonsense generator, Donald Trump!

TRUMP! Everybody is excited about me! Big

crowds, big, big crowds… the polls…. TRUMP!!!!

Yeah… That really doesn’t make any sense… which reminds me that this is a good time to talk about logical fallacies!

A flawed argument is called a logical fallacy.They take several forms and usually involve some oversight, generalization, or purposeful attempt to mislead. Recognizing fallacious logic is the key to discerning good argumentation from bad. Right, Donald?

Ha ha ha! America! President from Sudan?

Losers are FIRED! TRUMP!!!

There are dozens of types of fallacies– some are rooted in erroneous analysis; some are

deliberately misleading efforts.

For our purposes, we’ll look at three different categories:• Fallacy of relevance• Fallacy of accuracy• Fallacy of insufficiency

Fallacies of Relevance• These fallacies confuse pertinent information with irrelevant details.

They can often be intentionally misleading.• Red Herring • ad hominem • Faulty Analogy• Appeal to False Authority• ad populum

Fallacies of Relevance: Red Herring

Definition: The speaker skips to a new and irrelevant topic in order to avoid the topic of discussion.

Examples

We can’t worry about the environment! We’re at war!!

What do you mean I get an F on this assignment? I worked sooooooo hard on it!

What do you mean I have to go to jail for repeatedly driving drunk? It’s soooooo difficult being famous!

Fallacies of Relevance: Red Herring

Trump vs. Broccoli

Now, look at this guy. He’s a little green guy. Bushy guy. I

was negotiating with this little bushy green guy. I beat him. I beat his rear end, I tell you.

You know what America thinks of you? You’re done.

Fallacies of Relevance: ad hominem

Definition: A type of red herring where the topic is switched from a particular topic to the character of the other speaker. Latin for “against the man.”

Examples

Of course Mr. Rossi would want to give a quiz on Thursday. He’s a communist!

That’s not an ad hominem attack, you idiot.

That was an ad

hominem attack!

YOUR MOM is an ad hominem

attack! HA! Am’I’rite?

Fallacies of Relevance: ad hominem

Trump vs. a forklift

I know all about forklifts. Very knowledgeable. They are

thieves and rapists and rapist thieves. I’m sorry, but there is no place in America for their

squishy liberalism. They cannot lift the truth.

Fallacies of Relevance: Faulty Analogy

Definition: A fallacy of irrelevance where two things are compared without an appropriate basis.

Examples

Because we allow terminally ill patients to use heroin, we should allow everyone to use heroin.

Because you allowed Lindsay—who was hit by an exploding truck and knocked off a cliff into a live volcano—to hand in her assignment late, you should allow the entire class to hand in their assignments late.

Fallacies of Relevance: Faulty Analogy

Trump vs. a lizard

“He’s a tiny guy and he’s super low-energy. Like a little sleeping dragon man. What I say about dragons? They’re extinct. You’re extinct. You

stink. Goodbye.”

Fallacies of Relevance: Appeal to False Authority

Definition: When someone with no expertise to speak on an issue is cited as an authority.

Examples

Dr. McBride diagnosed Brandon as having flesh eating bacteria.

Vikram says we shouldn’t have an ICE on Thursday, so we shouldn’t have an ICE.

Fallacies of Relevance: Appeal to False Authority

Trump vs. Existentialism

I’ll give you the straight dope. This is bum talk, this

stuff. Chumps. I’m America’s boss if I’m

anything, and I say it’s gotta go! 100%.

Fallacies of Relevance: ad populum (bandwagon appeal)

Definition: Evidence essentially boils down to “everyone is doing it, so it must be a good idea.”

Examples

"Increasingly, people are coming to believe that Eastern religions help us to get in touch with our true inner being. Eastern religions help us to get in touch with our true inner being.”

Everyone is selfish; everyone is doing what he believes will make himself happier. Why should you feel guilty for seeking your own happiness when that's what everyone else is doing, too?

Fallacies of Relevance: ad populum (bandwagon appeal)

Trump vs. a humpback whale

“This guy, he’s got no chance against me. No chance. I’m up in

every poll. Women. Veterans. They love me. America has heard your whale song and it’s a bum song,

I’m afraid to say it, it’s a bum song and I’m going to change America.”

Fallacies of Accuracy

• These fallacies occur when the wrong conclusion is drawn or the wrong assumptions are made.

• Straw Man• False Dilemma• post hoc ergo propter hoc

Fallacies of Accuracy: Straw Man Fallacy

Definition: A speaker chooses a deliberately poor or oversimplified example in order to ridicule and refute the opponent’s point.

Examples

"Senator Jones says that we should not fund the attack submarine program. I disagree entirely. I can't understand why he wants to leave us defenseless like that.“

We should have nap class. People don't want to have nap class because they think it’s lazy. But they should realize that there are more important things than work.

Follow the yellow brick road? What is this, a thinly-veiled

allegory for the American gold

standard?

Fallacies of Accuracy: Straw Man Fallacy

Trump vs. a couch

“This guy, he’s squishy, can’t pin him down. I know what he’s all about. I give

him $4000; he spends it on garbage! Makes bad decisions, not like I would do

if I were in his shoes. He doesn’t even own shoes. I say, “where are your shoes,

buddy?” What does he say? Nothing. Scumbag.”

Fallacies of Accuracy: False Dilemma

Definition: The speaker presents two extreme positions as the only possible options when others, in fact, exist.

Examples

"Either you’re with us or you’re ag’in’ us!”

America: Love it or leave it!

Fallacies of Accuracy: False Dilemma

Trump vs. a toothbrush

The red flags are up, my friends. Red flags. Guy says, “brush your teeth, or you’re finished.” I say,

“Who are you, this bristle face?” Look, I’m sorry, but that’s the way

it is. Your breath stinks, and I would not give you gold or

money. Bristleface is a loser.”

Fallacies of Accuracy: post hoc ergo propter hoc

Definition: Latin for “after which, therefore because of which.” Makes a fallacious connection between effects and antecedents. In other words, suggests correlation implies causation.

Examples

"Joan is scratched by a cat while visiting her friend. Two days later she comes down with a fever. Joan concludes that the cat's scratch must be the cause of her illness.”

Every time my mother attends a game, it rains. Therefore, my mother is a Pagan weather goddess and I must sacrifice a lowing calf as tribute.

Fallacies of Accuracy: post hoc ergo propter hoc

Trump vs. a balloon

“The first thing that happens with floaties is that they want free stuff. I give ‘em free stuff,

a million dollars, 500,000 dollars. Then what? They got the iPhone, the big screen,

the Ferrari, and they’re eating out of the trash store. If he wasn’t a bozo, making

things float, maybe he could cut it. He would be a star. But he’s a yellow gross baby.”

Fallacies of Insufficiency

• Conclusions are drawn without sufficient evidence.• Hasty Generalization• Circular Reasoning

Fallacies of Insufficiency: Hasty Generalization

Definition: A claim is made without sufficient evidence to prove it.

Examples

"I asked six of my friends what they thought of the Patriot Act and they liked it. Therefore, the Patriot Act is popular.”

All of my friends think that a fourth high school needs to be built. Therefore, the taxpayers will vote for a fourth high school.

Fallacies of Insufficiency: Hasty Generalization

Trump vs. a Vespa

Scooter

I saw one of these on the street. Not from around here,

probably an illegal. I know how to help him. He needs four wheels! They come to

America to take our wheels! Sorry, game over.

Fallacies of Insufficiency: Circular Reasoning

Definition: A claim is repeated as a way to provide evidence.

Examples

"You can’t give me a C! I’m an A student!”

The New England Patriots are the best football team because they’re better than the other teams.

Fallacies of Insufficiency: Circular Reasoning

Trump vs. The Horsehead

Nebula

I’ll tell you right now that he’s scared to debate me. He’s scared to debate me because I’m frightening. What is

he? A cluster of stars? No class. What can he say to me? It will come back to him. I know what a boomerang feels like in my hand, friend. No. It’s over.

The End

I’m calling it right now: this PowerPoint is over.

Done-so. Kaput. TRUMP!