Logical Fallacies

[Teallaura]

Okay, what you do is identify the logical fallacy in a given statement, then give a fallacious statement of your own.

I'll start:



Two out of three* Americans agree that vegemite is too salty; therefore, vegemite is bad for you.










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*Based on testimonials in Pal-Talk

[jordanriver]

Okay, what you do is identify the logical fallacy in a given statement, then give a fallacious statement of your own.

I'll start:



Two out of three* Americans agree that vegemite is too salty; therefore, vegemite is bad for you.

-----------------------------------------
*Based on testimonials in Pal-Talk

bandwagon fallacy

over 90 percent of Americans eat at mcdonalds therefore mcdonalds is good for you

JR

[ApologiaPhoenix]

bandwagon fallacy

over 90 percent of Americans eat at mcdonalds therefore mcdonalds is good for you

JR

Argument ad populum

"What I do is justified since you do the same thing after all."

[Cyrus Johnson]

Argument ad populum

"What I do is justified since you do the same thing after all."

"Appeal to common practice", something is right because everyone does it.

Jones is always late when his alarm clock doesn't go off. Since he's late, his alarm clock must not have gone off.

[jordanriver]

"Appeal to common practice", something is right because everyone does it.

Jones is always late when his alarm clock doesn't go off. Since he's late, his alarm clock must not have gone off.

affirmation of the consequent


Jones is always late when his alarm clock doesn't go off. He is early therefore his alarm clock went off.

[{Tim}]

What's wrong with that? If he's early, he's not late. Therefore,

~ alarm --> late
~ late
(therefore) ~ ~ alarm
(therefore) alarm

[John Powell]

TELLAURA:
Okay, what you do is identify the logical fallacy in a given statement, then give a fallacious statement of your own.

POWELL:
A non sequitur. That you tell us what to do is no guarantee that we do it.

TELLAURA:
I'll start:

Two out of three* Americans agree that vegemite is too salty; therefore, vegemite is bad for you.

POWELL:
A non sequitur. That vegemite is too salty is no guarantee that vegemite is bad for you.

TEALLAURA:
Okay, what you do is identify the logical fallacy in a given statement, then give a fallacious statement of your own.

I'll start:

Two out of three* Americans agree that vegemite is too salty; therefore, vegemite is bad for you.

JORDAN RIVER:
bandwagon fallacy

over 90 percent of Americans eat at mcdonalds therefore mcdonalds is good for you

JR

POWELL:
Non sequitur. That 90% of Americans eat at McDonalds is no guarantee that McDonald's is good for you. If the argument is inductive then it's strong.

JORDANRIVER:
bandwagon fallacy

over 90 percent of Americans eat at mcdonalds therefore mcdonalds is good for you

JR

APOLOGIANICK:
Argument ad populum

"What I do is justified since you do the same thing after all."

POWELL:
Non sequitur. That I do the same thing as you is no guarantee that it's justified.

APOLOGIANICK:
Argument ad populum

"What I do is justified since you do the same thing after all."

CYRUS JOHNSON:
"Appeal to common practice", something is right because everyone does it.

Jones is always late when his alarm clock doesn't go off. Since he's late, his alarm clock must not have gone off.

POWELL:
Likely false claim. Likely it's not the case that Jones is always late when his alarm clock doesn't go off.

CYRUS JOHNSON:
"Appeal to common practice", something is right because everyone does it.

Jones is always late when his alarm clock doesn't go off. Since he's late, his alarm clock must not have gone off.

JORDAN RIVER:
affirmation of the consequent

Jones is always late when his alarm clock doesn't go off. He is early therefore his alarm clock went off.

POWELL:
Likely false claim. Likely it's not the case that Jones is always late when his alarm clock doesn't go off.

{TIM}:
What's wrong with that? If he's early, he's not late. Therefore,

~ alarm --> late
~ late
(therefore) ~ ~ alarm
(therefore) alarm

POWELL:
What's fallacious with your argument is that the first premise is a non sequitur. ~alarm is no guarantee that late.

Here are two of mine to consider:

1. I exist therefore I exist.

2. According to expert authorities of logic, the circular argument is a logical fallacy, therefore the circular argument is a logical fallacy.

John Powell

[themuzicman]

1) Tautology
2) Appeal to unknown experts.


Frozen water is ice.
Ice is hard.
Water that is not frozen isn't hard.

Therefore frozen water is ice.

[{Tim}]

POWELL:
What's fallacious with your argument is that the first premise is a non sequitur. ~alarm is no guarantee that late.

I was assuming that "~ alarm --> late" was a premise. But, yes, it's probably a false premise. But that's not a logical error per se, is it?

[John Powell]

I was assuming that "~ alarm --> late" was a premise. But, yes, it's probably a false premise. But that's not a logical error per se, is it?

POWELL:
According to my understanding of logical terminology, the non sequitur fallacy is not a formal fallacy (a fallacy because the form is wrong) like affirming the consequent, but it's expected to be an unsound argument. Informal fallacies, such as the deductive appeal to authority, are fallacies of soundness rather than fallacies of form. Informal fallacies are fallacious not necessarily because the deductive arguments are invalid (they might have a valid form), but because the deductive arguments are expected to be unsound because of the content.

John Powell

[John Powell]

1) Tautology

POWELL:
What is logically fallacious about a circular argument?

Upon whose authority are you claiming that my circular argument is logically fallacious?

THEMUSICMAN:
2) Appeal to unknown experts.

POWELL:
Then let me revise it.

According to the logical expert authorities you rely upon, TheMusicMan, the circular argument is logically fallacious, therefore the circular argument is logically fallacious.

Now, what is the logical fallacy in that revised argument?

THEMUSICMAN:
Frozen water is ice.
Ice is hard.
Water that is not frozen isn't hard.

Therefore frozen water is ice.

POWELL:
Deductively non fallacious since the argument is sound. If you disagree then post your appeal to authority or reasoning sans appeal to authority.

It's my understanding that, although frozen water is ice by definition, it's not necessarily the case that ice is frozen water since there are kinds of ice that aren't water.

John Powell

[themuzicman]

POWELL:
What is logically fallacious about a circular argument?

No foundation.

Upon whose authority are you claiming that my circular argument is logically fallacious?

Mine.

POWELL:
Then let me revise it.

According to the logical expert authorities you rely upon, TheMusicMan, the circular argument is logically fallacious, therefore the circular argument is logically fallacious.

Now, what is the logical fallacy in that revised argument?

Tautology. Trivially true.

POWELL:
Deductively non fallacious since the argument is sound. If you disagree then post your appeal to authority or reasoning sans appeal to authority.

It's my understanding that, although frozen water is ice by definition, it's not necessarily the case that ice is frozen water since there are kinds of ice that aren't water.

John Powell

Um... assuming the conclusion?

Michael

[John Powell]

POWELL:
What is logically fallacious about a circular argument?

TheMusicMan:
No foundation.

POWELL:
The truth of the circular premise guarantees the truth of the circular conclusion so the circular argument form is valid. The premise I proposed is true so the argument is sound. What more is required for a deductive argument to avoid logical fallacy than to be expected to be sound? That it also be persuasive?

POWELL:
Upon whose authority are you claiming that my circular argument is logically fallacious?

TheMusicMan:
Mine.

POWELL:
Wouldn't that be an appeal to authority?

POWELL:
Then let me revise it.

According to the logical expert authorities you rely upon, TheMusicMan, the circular argument is logically fallacious, therefore the circular argument is logically fallacious.

Now, what is the logical fallacy in that revised argument?

THEMUSICMAN:
Tautology. Trivially true.

POWELL:
What is logically fallacious about being trivially true?

POWELL:
Deductively non fallacious since the argument is sound. If you disagree then post your appeal to authority or reasoning sans appeal to authority.

It's my understanding that, although frozen water is ice by definition, it's not necessarily the case that ice is frozen water since there are kinds of ice that aren't water.

John Powell

TheMusicMan:
Um... assuming the conclusion?

Michael

POWELL:
Do you dispute the truth of the conclusion or the validity of the inference?

Do you expect any rational person to dispute the truth of the conclusion or the validity of the inference?

John Powell

[Captain Ochre]

Here are two of mine to consider:

1. I exist therefore I exist.

Not fallacious, unless it represents an enthymeme (trying to convince the person who doesn't think you exist that you exist). If used as an enthymeme, then it begs the question via vicious circularity, which is a fallacy.
Ambiguity is the friend of the deceiver.

2. According to expert authorities of logic, the circular argument is a logical fallacy, therefore the circular argument is a logical fallacy.

We should just stick with "The circular argument is a logical fallacy, therefore the circular argument is a logical fallacy."

Appeal to authority may be perfectly legitimate in inductive reasoning. Since authorities are not always infallible, the argument is deductively fallacious. The argument is a non sequitur since the conclusion is worded too strongly.

John Powell is pedantic, therefore John Powell is pedantic.

Convinced, Powell?

[John Powell]

POWELL:
Here are two of mine to consider:

1. I exist therefore I exist.

CAPN OCHRE:
Not fallacious, unless it represents an enthymeme (trying to convince the person who doesn't think you exist that you exist). If used as an enthymeme, then it begs the question via vicious circularity, which is a fallacy.
Ambiguity is the friend of the deceiver.

POWELL:
It's a valid argument and the premise is true so it's a sound argument too. So, it's not logically fallacious. To be persuaded that the conclusion is true via the argument the reader would need to be persuaded that the premise is true. The same kind of thing applies to sound modus ponens form arguments.

POWELL:
2. According to expert authorities of logic, the circular argument is a logical fallacy, therefore the circular argument is a logical fallacy.

CAPN OCHRE:
We should just stick with "The circular argument is a logical fallacy, therefore the circular argument is a logical fallacy."

Appeal to authority may be perfectly legitimate in inductive reasoning. Since authorities are not always infallible, the argument is deductively fallacious. The argument is a non sequitur since the conclusion is worded too strongly.

POWELL:
Ok.

CAPN OCHRE:
John Powell is pedantic, therefore John Powell is pedantic.

Convinced, Powell?

POWELL:
I will be persuaded to accept the conclusion once you persuade me to accept the premise. The same kind of thing applies to modus ponens form arguments.

John Powell