Informal Logical Fallacies (FYI)

[Shane Wahl]

(Dear moderators: you may place this where you like in the forums, though maybe some pinning is in order?)

 

Courtesy of Texas State's Philosophy Department:

http://www.txstate.edu/philosophy/resources/fallacy-definitions.html

 

Some important ones:

 

Straw Person

This fallacy occurs when, in attempting to refute another person's argument, you address only a weak or distorted version of it. Straw person is the misrepresentation of an opponent's position or a competitor's product to tout one's own argument or product as superior. This fallacy occurs when the weakest version of an argument is attacked while stronger ones are ignored.

Examples:

    Lloyd: Can you allow time for more class discussion? Prof. Schwartz: I don't want to give the entire class period over to some aimless bull session.
    Pro-choice is absurd. How could anyone support killing an innocent human being?
    Egalitarianism is wrong because it is the same as communism.
    Smith: We must have equal consideration for same sex couples as we do for heterosexual couples. It is unconstitutional to deny rights to these Americans. Jones: If you want men to be able to wear wedding dresses that's fine, but I don't want my tax dollars going to some ridiculous liberal idea.
    Debra: There is no logical or moral justification for the killing of animals for food. Animals are sentient creatures that deserve the same consideration as humans. Joe: Look, if you want to eat grass like a cow, Bon Appetit! Just let me have my hamburger.

False Dilemma

When you reason from an either-or position and you haven't considered all relevant possibilities you commit the fallacy of false dilemma.

Examples:

    America: Love it or leave it.
    Death is nothing to fear. It is either annihilation or migration.
    Be my friend or be my enemy.
    Are you a Republican or a Democrat?
    Since there is nothing good on TV tonight, I will just have to get drunk.

 

Irrelevant Authority

The fallacy of irrelevant authority is committed when you accept without proper support for his or her alleged authority, a person's claim or proposition as true. Alleged authorities should only be used when the authority is reporting on his or her field of expertise, the authority is reporting on facts about which there is some agreement in his or her field, and you have reason to believe he or she can be trusted. Alleged authorities can be individuals or groups. The attempt to appeal to the majority or the masses is a form of irrelevant authority. The attempt to appeal to an elite or select group is a form of irrelevant authority.

Examples:

    There is nothing to be learned from the East, for Gilbert Ryle, the great British philosopher once said, nothing but the sun rises in the East.
    Nobody is a better judge than public opinion.
    Pacifism is a good idea because the brilliant scientist Einstein advocated it.
    Mom, why can't I get my tongue pierced? Everyone else is doing it.
    Most of my friends say they stopped thinking about philosophy the minute they got through the semester, so I know this class is worthless.
  

Unwarranted Generalization

This fallacy occurs when we we make a generalization on the basis of insufficient evidence. This may occur when we rely on too small of a sample or an unrepresentative sample to support the generalization.

Example:

    Children of faculty are brats. I baby-sit for one of my professors and his children are spoiled and demanding.
    I was going to buy a new Honda, but my uncle had one back in the '70's and it was small and noisy and very uncomfortable. I don't think I want an uncomfortable car, so I'll buy something else.
    I know this will be a horrible class. They tell me the professor is old. Old professors are unable to talk with today's college students.
    My experience with my ex-wife was such a bad one that I have no intention of ever marrying again. In fact, I would not recommend marriage to anyone.
    It has been concluded from a recent study involving more that 100,000 people in Florida that 43 percent of the American people now spend at least two hours a day in some form of recreational activity.

 

Begging the Question

The fallacy of begging the question occurs when an argument's premises assume the truth of the conclusion, instead of supporting it. In other words, you assume without proof the stand/position, or a significant part of the stand, that is in question. Begging the question is also called arguing in a circle.

Examples:

    1. Erica: "How do you know that the bible is divinely inspired?" Pedro: "Because is says right in the third chapter of II Timothy that 'all scripture is given by divine inspiration of God.'"

    2. Celibacy is an unnatural and unhealthy practice, since it is neither natural nor healthy to exclude sexual activity from one's life.

    3. Thoughts are not part of the physical world, since thoughts are in their nature non-physical.

    4. Happiness is the highest good for a human being, since all other values are inferior to it.

    5. Of course smoking causes cancer. The smoke from cigarettes is a carcinogen.

 

[Mike Sixel]

Good luck, sir, good luck.

[diehardtwinsfan]

nice   Probably a sports bar discussion. 

[Craig Arko]

Plenty more animals in the zoo...

 

https://en.wikipedia.org/wiki/List_of_fallacies

 

Also, it's refreshing to remember that the first ideas to be subjected to critical thought are one's own.

[70charger]

 

 

Also, it's refreshing to remember that the first ideas to be subjected to critical thought are one's own.

 

HA ha ha ha hahahaha!

 

Oh wait. That wasn't a joke?

[Mike Sixel]

It was a valiant effort to remind people to not claim to be using logic, when they aren't......

[drjim]

 

Also, it's refreshing to remember that the first ideas to be subjected to critical thought are one's own.

 

I prefer to point out other people's logical fallacies while being blind to my own. World makes more sense that way.

[Craig Arko]

Let us not forget the kissing cousins of the fallacy; the paradox. The statistical paradoxes are particular;y entertaining.

 

https://en.wikipedia.org/wiki/List_of_paradoxes

[ashbury]

 

    America: Love it or leave it.

    Death is nothing to fear. It is either annihilation or migration.

    Be my friend or be my enemy.

    Are you a Republican or a Democrat?

USAFChief found the all purpose solution to this fallacy. "Yes."

[Craig Arko]

http://existentialcomics.com/comic/9

[Hosken Bombo Disco]

I recently mentioned that the sun rises in the East. 

 

But then, my political opponent released a damning, heavily-edited video making me look bad, with irrefutable proof that the sun rises in the West. 

 

People are up in arms about this, and the media doesn't know who to believe! 

 

The nightly news reporter fact-checked the television commercial with my original claim, and concluded that the truth lies somewhere in the middle.

 

[Craig Arko]

 

I recently mentioned that the sun rises in the East. 

 

But then, my political opponent released a damning, heavily-edited video making me look bad, with irrefutable proof that the sun rises in the West. 

 

People are up in arms about this, and the media doesn't know who to believe! 

 

The nightly news reporter fact-checked the television commercial with my original claim, and concluded that the truth lies somewhere in the middle.

Indeed, the Sun never rises. The Earth rotates.

[Hosken Bombo Disco]

 

Indeed, the Sun never rises. The Earth rotates.

 

and for my bluster,... isn't that the truth.

 

shows you how far you get by being "absolutely certain" about anything

[formerly33]

 

and for my bluster,... isn't that the truth.

 

shows you how far you get by being "absolutely certain" about anything

This reminds me of trying to convince my sister (among others) that you can't scientifically prove anything. A surprising number of people just can't seem to grasp the concept, so what do I do but launch into a lengthy argument trying to scientifically prove that you cannot scientifically prove anything.

[Mike Sixel]

 

This reminds me of trying to convince my sister (among others) that you can't scientifically prove anything. A surprising number of people just can't seem to grasp the concept, so what do I do but launch into a lengthy argument trying to scientifically prove that you cannot scientifically prove anything.

 

Ya, people REALLY struggle with this concept.

[Craig Arko]

http://rationalwiki.org/wiki/Proof

 

Although also be aware of and enjoy...

 

http://whatis.techtarget.com/definition/fuzzy-logic

 

Perhaps it turns out hat 'proof' really is only just for alcohol.