Logical Fallacies
A logical fallacy is an argumentative statement that appears to be valid but upon examination
has serious flaws; “errors in reasoning that lead to invalid conclusions.” Writers would be
encouraged to search their argument for these types of flaws and eliminate them.
Ad Hominem (to the man): the writer attacks the opponent’s character rather than the
argument.
Example: "I'm sure the good senator would have a better response to our fiscal proposition if
he'd spent more time studying the issues and less time cheating on his wife."
Bandwagon appeal: the writer validates a point by saying that "everyone believes this."
Example: "All right-minded people agree that Chrysler is a superior car company." (Bandwagon
usually uses 'in-group' tactics, suggesting that if you want to be right-minded, or smart, or
beautiful--you will do what other smart, beautiful people do.)
Begging the Question: the writer presents as truth that which is supposed to be proven by the
argument.
Example: All useless bills such as Reform BilI 13 should be repealed.
Either/Or Thinking: when the writer suggests that there are only two sides to an issue: right
and wrong.
Example: If colleges cancel need-based scholarships, underprivileged children will not be able
to attend college. (Many underprivileged children would still qualify for academic and ability-
based scholarships.)
False Analogy: an extended comparison used as proof that does not satisfy the argument
requirements because the two items being compared do not have a valid relationship.
Example: Putting teenagers in sex-education classes is like taking an alcoholic to a bar. (Are the
things being compared even similar? Does that prove anything?)
Generalization: conclusions are drawn from a sample that is too small.
Example: I have had two poodles. Both have attacked me. Poodles are vicious dogs.
Hypostatization: uses abstract concepts as if they were concrete reality.
Examples: "History has taught us... " or "Science has proven ..." (suggests that all scientists and
historians agree and that all people have learned the same lesson.)
Non Sequitur (it doesn’t follow): conclusion is not a logical result of the facts.
Example: She’s a good mathematician; she’ll make a good math teacher.
Post Hoc Thinking (post hoc, ergo propter hoc: after this, therefore because of this): this
fallacy occurs when one assumes that because one event follows another in time, the first event
caused the second.
