inFact with Brian Dunning inFact with Brian Dunning


Logical Fallacies 2

Think you know how to use and recognize logical fallacies in arguments? Here's how. Part 2.

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In this second of three videos, we're going to look at some common ways people use language to make a point when their argument is weak. One of these is the use of:

Weasel Words

Cleverly chosen words that are hoped will make you think they say more than they do.

Our product supports a healthy immune system.

"Supports" doesn't really mean anything.

Enjoy up to 50% off today!

Yeah, I'll probably be out there on the dance floor.

The Straw Man Argument

is a way to rephrase your opponent's point of view, into something that's absurd and much easier to argue against. Very, very common.

I'm tired of all this homework.

Lazy, you never want to do any homework at all! You'd fail all your classes.

You just want me to do it 24 hours a day! That would be ridiculous.

Both sides are exaggerating the other to a ridiculous degree.

The Loaded Question

is two questions rolled into one, attempting to force the acknowledgement of a point:

One last question: Did you enjoy killing him?


Oh, so you did kill him!

There was never any opportunity to answer No.

Shall I nudge you for breakfast?

If your argument is weak, start off by:

Poisoning the Well

Use phrases that suggest your point of view is already the accepted one:

The acknowledged quack Carl Sagan buried the role of kundalini energy in the creation of the universe.

I acknowledge that; don't you?

And now we're going to hear those same old rejected arguments that we should vaccinate against diseases.

Rejected by who? Poisoning the well is also employed by those who name government programs:

The Patriot Act. Don't like it? You're not a patriot!!

No Child Left Behind. Don't like it? You hate children!!

One technique often used by conspiracy theorists is:

Proof by Verbosity

where the sheer number of words gives the false impression of the subject having been thoroughly researched.

The chain of command on 9/11 was all messed up. Bush, Cheney, and Rumsfeld were all somewhere other than where they were supposed to be. NORAD and the FAA all gave different reasons for air defense failures. How could an inexperienced pilot make it past Andrews Air Force Base to hit the Pentagon? Flight 93 was clearly shot down, according to the debris trail. Prominent members of government were given secret warnings not to fly on 9/11. And what made Building 7 fall down, since it was undamaged? It could only be explosives. Insider trading happened at the stock market, proving that the government tried to profit from 9/11 and planned it in advance. If the FBI hadn't obstructed the investigation, everyone would know that the World Trade Center was destroyed by a controlled demolition, since all the debris were quickly disposed of before anyone could examine it.

Listen for all of these next time you have a debate with someone. In the next episode we're going to look at some fallacious arguing techniques, and you'll want to listen for those too.

— Brian Dunning

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References & Further Reading

Kahane, Howard; Cavender, Nancy. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life. Belmont: Thomson Higher Education, 2006. 155-156.

Morier, Dean; Keeports, David. "Normal science and the paranormal: The effect of a scientific method course on students' beliefs." Research in Higher Education. 1 Jul. 1994, Volume 35, Number 4: 443-453.

Porter, Burton Frederick. The Voice of Reason: Fundamentals of Critical Thinking. New York: Oxford University Press, 2002.

Sagan, Carl; Druyan, Ann. The Demon-Haunted World: Science as a Candle in the Dark. New York: Random House, Inc., 1996.

Urdan, Timothy C. Statistics in Plain English. Mahwah: Lawrence Erlbaum Associates, Inc., 2005.

Walton, Douglas. Informal Logic: A Pragmatic Approach. New York: Cambridge University Press, 2008.


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