This document defines and provides examples of common logical fallacies to avoid in arguments. It discusses 12 types of fallacies: appeal to pity, attacking the person, argument from ignorance, appeal to popularity, prejudicial language, slippery slope, false dilemma, begging the question/circular reasoning, appeal to authority, anonymous authority, straw man, and lack of citations. The document encourages identifying fallacies in one's own arguments and those of others to strengthen logical reasoning.

1. FALLACY
“…arguments, like men,
are often pretenders.”
~Plato

2. In forming an argument
you may appeal to:
1. Ethos = appeal to ethics or morality
2. Pathos = appeal to pity or the emotions
3. Logos = appeal to reason

3. Logic is where fallacies occur
 Fallacies are common errors in reasoning that
will undermine the logic of your argument.
 Fallacies can be either illegitimate arguments
or irrelevant points, and are often identified
because they lack evidence that supports their
claim.
 Avoid these common fallacies in your own
arguments and watch for them in the
arguments of others.

4. Appeal to Pity
(Argumentum ad Misericordiam)
 A fallacy committed when pity is appealed to
for the sake of getting a conclusion accepted.
 But Mr. Gonzalez, I have failed 2326 four times in a row.
Don’t you think I deserve to pass it this time around? How
many times do I have to fail it before I pass it?
 Officer, I know I was speeding, but I just paid for a speeding
ticket just last month. Can you give me a break?

5. Attacking the person
(Argumentum ad Hominem)
 This is an attack on the character of a
person rather than her/his opinions or
arguments.
 Green Peace's strategies aren't effective because
they are all dirty, lazy hippies

6. Argument from ignorance
(Argumentum ad ignorantiam)
 This occurs when it is argued that a
proposition is true simply on the basis that
it has not been proven false, or that it is
false because it has not been proven true.
 There must be ghosts because no one has ever
been able to prove that there aren’t any.
 Since you cannot prove that there is water on
Mars, then there must be water on Mars.

7. Appeal to popularity
(Argumentum ad Populum)
 “Jumping on the bandwagon”
 The attempt to win popular assent to a
conclusion by arousing the emotions and
enthusiasms of the multitude, rather than
by appeal to relevant facts.
 Since so many people are now using tattoos,
it follows that everyone should get one before
Christmas.

8. Prejudicial language
 Charged, loaded or emotive terms are
used to attach value or moral goodness
to believing in a particular proposition.
 Very different from loaded language.
 Any good Catholic would agree that
abortion is tantamount to murder.
 Any reasonable IRS agent will agree that
our income tax is way too high.

9. Slippery slope
 On the basis of a sequence of several
unacceptable premises, an
illegitimate conclusion is drawn.
 You should never gamble. Once you
start gambling you will find it hard to
stop. Soon you are spending all your
money on gambling, and eventually you
will turn to a life of crime.

10. False dilemma
(either/or)
 A limited number of options (usually two)
is given while in reality there are more
options.
 Putting issues or opinions into “black and
white” terms
 America: Love it or leave it.
 Every person is either wholly good or wholly
evil.

11. Begging the question &
Circular Reasoning
 The conclusion that the writer should
prove is validated within the claim.
 He is an unjust man. Thus, it may be asserted
that he is an unfair man.
 George Bush is a good communicator
because he speaks effectively.

12. Appeal to authority
 An authority is appealed to for testimony in
matters outside the province of that authority’s
special field.
 An appeal to the opinion of a great physicist like
Einstein to settle a political or economic argument
would be fallacious. He may be an authority in science,
but not government.
 President Bush has stated that walking is the best
exercise for your heart.

13. Anonymous authority
 The authority appealed to is not specified.
The authority is anonymous or unknown
and thus unreliable.
 Government experts have reported that anthrax has
been found in 95% of federal government buildings.

14. Straw Man
 This move oversimplifies an opponent's
viewpoint and then attacks that hollow
argument.
 People who don't support the proposed state
minimum wage increase hate the poor.

15. Citations
 “Logical Fallacies”. Purdue Online Writing Lab. 2011.
http://owl.english.purdue.edu/owl/resource/659/03/
 “Fallacy”. South Texas College. 2011.
http://www.southtexascollege.edu/dev-
english/PowerPoint/gonzalez/1302/Fallacies.ppt