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Post Hoc/Faulty Causality/Non-Sequitur Logical Fallacies

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Fabio Hickenlooper

on 12 November 2013

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Transcript of Post Hoc/Faulty Causality/Non-Sequitur Logical Fallacies

Logical Fallacies
The Crucible
Danforth is committing the fallacy

"DANFORTH: A little while ago you[Mary Warren] were inflicted. Now it seems you afflict others; where did you find this power?" Act 3, page 116

Danforth is falsely concluding that because the girls act afflicted that Mary is afflicting them.
That school is big. The classroom must be big.
She drives a BMW. She must be rich.
She's wearing red shoes. Her favorite color must be red.
My neighbor's cat is aloof and mean. Cats are nasty creatures.
I lived in a house without a basement. That house flooded. Houses without basements will definitely flood.
-Your Dictionary(.com)
Non-Sequitur is an argument in which its conclusion does not follow its premise, whether the argument is true or not.

In Latin it means "does not follow."
The Crucible

"HALE: Mr. Corey, exactly what complaint were made on your wife?

GILES: That bloody mongrel Walcott charge her. Y'see, he buy a pig of my wife four or five year ago, and the pig died soon after. So he come dancin' in for his money back. So my Martha, she says to him, "Walcott, if you haven't the wit to feed a pig properly, you'll not live to own many," she says. Now he goes to court and claims that from that day to this he cannot keep a pig alive for more than four weeks because my Martha bewitch them with her books!" Act Two, Page 72
Faulty Causality/Post Hoc(,Ergo Propter Hoc)
Post Hoc is when you say that two things are connected, just because one event follows the other.

In latin, it literally means: "after this, therefore because of this."

"Suppose Jill, who is in London, sneezed at the exact same time an earthquake started in California. It would clearly be irrational to arrest Jill for starting a natural disaster, since there is no reason to suspect any causal connection between the two events."

Or if your computer crashes shortly after you download a new program. It would be committing a Post Hoc fallacy to say the software ruined your computer.
-The Nizkor Project (nizkor.org)
The fallacy is a post hoc.
Walcott is committing it.
Walcott is committing the fallacy by assuming that since his pigs won't live very long
Martha said something, that they keep dying
Martha said what she did. It could just be coincidence.
Google Images/Melissa's Blog
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