Dear Ways of Knowing People,
This is just a starter list for informal fallacies: a self-explanatory
"to
do" list of reasoning mistakes to avoid. If you want to pursue
any of them in more depth (doing so is optional, but may be useful to
you), then click here for
an excellent site that provides more detailed information.
I. Fallacies of Relevance:
- Argument from Ignorance
Arguing that a proposition is true simply on the basis that it has
not been proven false (& vice versa).
Ex: No one has ever proven that the Loch Ness monster doesn't
exist; therefore, it does exist.
- Appeal to Inappropriate Authority
The appeal to parties having no legitimate claim to authority in the
matter at hand.
Ex: I play a doctor on TV, and I recommend this brand of
aspirin,
so you should buy it.
- Argument Against the Person (Ad Hominem)
Directing one's attack not at a conclusion, but rather at the person
who asserts or defends it.
Ex: Everyone knows that the mayor has a son who's a drug addict;
therefore, you should just disregard her arguments about the
legalization
of marijuana.
- Appeal to Pity
Appealing not to rational argument and evidence but rather to the
emotional
response of the audience.
Ex: I know I failed all my exams in here and my attendance was
bad, but please, Prof. Smith, you've just got to give me an "A" or it
will
break my parents heart and they may die of the strain.
- Appeal to Force
Attempting to persuade someone by force or threat rather than by reason
and argument.
Ex: Give me that swing or I'll call my daddy and he'll beat
up your daddy.
- Irrelevant Conclusion
When an argument purports to establish a conclusion that is
misleadingly
irrelevant to its premises.
Ex: Theft and robbery have been increasing at an alarming rate.
Therefore, we must reinstate the death penalty immediately.
- Straw Man
Attacking a weakened or distorted representation of your opponent's
argument.
Ex: Mr. Lu has argued against prayer in public schools.
Obviously,
he advocates atheism. But atheism is what they have in Russia, and it
works
hand in hand with communism. Mr. Lu is wrong!
II. Fallacies of Ambiguity:
- Equivocation
When the same term appears to be used consistently but in fact relies
on several different meanings.
Ex: Good steaks are rare these days, so don't order yours well
done.
- Amphiboly
Arguments that rely on statements that are amphibolous, or of
indeterminate
meaning.
Ex: Walking up O'Connell St., the statue comes into view.
Apparently
that statue gets around!
III. Others:
- Complex Question
Deceptively combining two or more questions into a single one. A
"trick"
question.
Ex: Have you stopped beating your children yet, Mr. Smith?
- False Cause
Occurs when the link between premises and conclusion depends on
improbable
or non-existent cause.
Ex: Every time the mascot danced during halftime, the team won.
Let's keep that mascot dancing!
- Slippery Slope
A variety of false cause - rests upon alleged chain reaction that is
unlikely to occur.
Ex: Let naughty children go unpunished just once, and you'll
start them on the road to crime & jail.
- False Dichotomy
Committed when disjunctive (either...or) premise hides other
alternatives.
Ex: The choice is yours: the spotted owl, or economic
prosperity.
- Begging the Question
Takes several forms: "circular reasoning", and assuming in premise(s)
what's to be shown in conclusion.
Ex: I know God exists because the Bible says he does, and the
Bible is true because it's God's word.
- Accident
Committed when a general rule is applied to a case it was never
intended
to cover.
Ex: Anyone who cuts another person with a knife is a criminal.
Therefore, arrest that surgeon now!
- Hasty Generalization
Arguing from a small and/or non-representative example of a group to
what's true of group as whole.
Ex: John's blue car rusted out after only two years, therefore
my blue car will do the same.
- Composition
Erroneously transferring attributes from the parts to the whole (i.e.,
what's true of parts is true of whole.)
Ex: Each atom in this piece of chalk is invisible. Therefore,
the chalk is invisible.
- Division
Erroneously transferring attributes from the whole to the parts (i.e.,
what's true of whole is true of parts.)
Ex: The completed jigsaw puzzle is circular in shape.
Therefore,
each piece of the puzzle is circular.