Covers what valid and fallacious reasoning is, and the common types of fallacious reasoning.

1. Author’s Reasoning:
Valid and Fallacious
English I
Beaulieu
Hall Dale High School
Monday, March 5, 14

2. Valid Reasoning
Claims must be backed with reasoning.
Reasoning should be based in logic.
Valid reasoning uses facts,
statistics, or personal
experience to support their
claim.
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3. Example
Becky tells her teacher that she is
allergic to pollen, every time she is
outside for recess her allergies act up,
and therefore the playground must have
a high pollen count.
This is valid because we see a logical
sequence based on true statements.
Monday, March 5, 14

4. Fallacious Reasoning
Fallacy is an argument that does not
provide the necessary support to back
up the given claims.
Fallacy is an error in reasoning.
Monday, March 5, 14

5. Most Common Types of
Fallacious Reasoning
Slippery Slope
Hasty Generalization
Post hoc ergo propter hoc
Genetic Fallacy
Circular Argument
Either/Or
Ad hominem Ad populum
Red Herring
Monday, March 5, 14

6. Slippery Slope
If A happens, then B, C, ......, X, Y, Z, will happen too.
If we ban Hummers because they
are bad for the environment,
eventually the government will ban
all cars, so we should not ban
Hummers.
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7. Hasty Generalization
A rushed conclusion before you have all the
relevant facts.
Even though it’s only the first
day, I can tell this is going to
be a boring course.
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8. Post hoc ergo propter
hoc
If A occurred after B, then B must have caused A.
I drank bottled water and now I
am sick, so the water must have
made me sick.
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9. Genetic Fallacy
Conclusion based on an argument that the
origins of a person, idea, institute, or theory
determine its character, nature, or worth.
The Volkswagen Beetle is an evil car
because it was originally designed by
Hitler’s army.
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10. Circular Argument
Restates the argument rather than actually proving it.
George Bush is a good
communicator because he speaks
effectively.
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11. Either/Or
Conclusion oversimplifies the argument by
reducing it to only 2 sides or choices.
We can either stop using cars
or destroy the earth.
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12. Ad hominem
Attack on the character of a person rather than
their opinions or arguments.
Green Peace’s strategies aren’t
effective because they are all
dirty, lazy hippies.
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13. Ad populum
An emotional appeal that speaks to positive (patriotism/
religion/democracy) or negative (terrorism/facism) concepts
rather than the real issue.
If you were a true American, you would
support the rights of people to choose
whatever vehicle they want.
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14. Red Herring
A diversionary tactic that avoids the key issues,
often by avoiding opposing arguments rather than
addressing them.
The level of mercury in seafood
may be unsafe, but what will
fishermen do to support their
families.
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15. Sources
http://knowyourmeme.com/memes/your-argument-is-
invalid
Author’s Reasoning Resource Handout
Monday, March 5, 14