Logical Fallacies

Logical fallacies are arguments that don’t work
 They seem convincing, but fail under close examination
What do logical fallacies do?
Fail to provide evidence
Make jumps in logic
Divert attention from the real issues
OVERALL: They damage your ethos
Imagine you’re a reader with an opposing view
 What points would you criticize?
Bad words: always, never, and everyone
 Sweeping generalizations lead to overstating a case
Generalization. A conclusion about an entire group
based on a sample that’s neither large enough nor truly
 Having met several Texans, I can tell you that they are all
Non sequitur. No clear connection between a conclusion
and its support. Latin for “it does not follow.”
 Congress will surely approve the education bill, since they
already passed the voting reform bill.
 Rabbits are a symbol of the American Dream because Lennie
and George work on a ranch.
Forced Hypothesis. The explanation is forced because
there’s not enough evidence. It often ignores
alternative explanations or counter-arguments.
 Ex. Everyone clapped after Sophia’s recital, so she must be an
excellent pianist.
Slippery Slope. You cannot permit something because it
leads to extreme consequences.
 Ex. If we allow the government to legalize marijuana, it will
next legalize cocaine and heroin. Before long, our kids will all
be addicted to hard drugs.
Begging the Question or Circular Reasoning. The claims
of an argument assume the conclusion is true.
 Ex. Using a cell phone while driving is hazardous, so it should
be completely outlawed.
▪ This argument doesn’t offer proof that driving while using a phone is
dangerous, but simply asserts that it is and expects readers to agree.
Red Herring. An irrelevant topic is introduced, diverting
attention from the relevant debate.
 Ex. The government cannot begin to improve education until
it balances the budget.
Straw Man. An argument that distorts the opposition.
 Ex. People who oppose this education bill want us to go back
to the age of one-room school houses. Obviously, we live in a
different era.
▪ The author exaggerates the opposing side’s position, creating a “straw
man.” A man made of straw is easy to defeat.
Ad Populum. An argument that appeals to an audience’s
presumed shared values. Latin for “to the people.”
 Ex. As good Texans, we want what’s best for our beloved state,
which is why we can all agree that Cowboy Bob is the best
candidate for governor.