Logical Fallacies: Or, How to Really Fail at Argumentation “Logic is the beginning of wisdom, not the end.” – Dr. Spock, Star Trek

Logical fallacy #1 “Despite the women's movement in the ‘70s, women still do not receive equal pay for equal worth. Obviously, all such attempts to change the status quo are doomed to failure.” “Despite the women's movement in the ‘70s, women still do not receive equal pay for equal worth. Obviously, all such attempts to change the status quo are doomed to failure.” -University of Notre-Dame Writing Program, -University of Notre-Dame Writing Program,

Logical fallacy #1 Hasty generalization: leaping to a conclusion; unrepresentative Hasty generalization: leaping to a conclusion; unrepresentative

Logical fallacy #2 “Bill Clinton wants television programs to show ratings in order to protect children from adult material, a surprisingly moral position for an adulterer.” “Bill Clinton wants television programs to show ratings in order to protect children from adult material, a surprisingly moral position for an adulterer.” -University of Notre-Dame Writing Program, -University of Notre-Dame Writing Program,

Logical fallacy #2 Ad hominem: Attacking the person rather than the issue Ad hominem: Attacking the person rather than the issue

Logical fallacy #3 Because math scores went down after Sierra Verde became a feeder school for Mountain Ridge, those students must have caused a decline in the scores. Because math scores went down after Sierra Verde became a feeder school for Mountain Ridge, those students must have caused a decline in the scores.

Logical fallacy #3 Post hoc: false cause; assumed cause-effect relationship that may not be accurate Post hoc: false cause; assumed cause-effect relationship that may not be accurate

Logical fallacy #4 “It is ridiculous to have a gay and lesbian studies program and a department for the study of Native American culture; we don’t have a straight studies program or a department for Caucasian culture.” “It is ridiculous to have a gay and lesbian studies program and a department for the study of Native American culture; we don’t have a straight studies program or a department for Caucasian culture.” -University of Notre-Dame Writing Program, -University of Notre-Dame Writing Program,

Logical fallacy #4 False analogy: analogy is too weak; the analogs are too different to be worthy of comparison False analogy: analogy is too weak; the analogs are too different to be worthy of comparison

Logical fallacy #5 Millions of minorities simply drop out of school before their senior year anyway, so there is no need to fund minority- based college scholarships. Millions of minorities simply drop out of school before their senior year anyway, so there is no need to fund minority- based college scholarships.

Logical fallacy #5 Non sequitur: Something that does not follow; an illogical conclusion that does not follow the premise Non sequitur: Something that does not follow; an illogical conclusion that does not follow the premise

Logical fallacy #6 “We may support this petition for a gender studies major, or we may turn our backs on progress, reject the petition, and suffer the consequences.” “We may support this petition for a gender studies major, or we may turn our backs on progress, reject the petition, and suffer the consequences.” -University of Notre-Dame Writing Program, -University of Notre-Dame Writing Program,

Logical fallacy #6 Either/or fallacy: an oversimplification of the issues which leaves only 2 diametrically opposed viewpoints Either/or fallacy: an oversimplification of the issues which leaves only 2 diametrically opposed viewpoints

Logical fallacy #7 I’m not a doctor, but I play one on TV and I use Bayer Asprin. I’m not a doctor, but I play one on TV and I use Bayer Asprin.

Logical fallacy #7 Appeal to questionable authority: Just what it says— the use of faulty, overtly biased or otherwise questionable sources Appeal to questionable authority: Just what it says— the use of faulty, overtly biased or otherwise questionable sources

Logical fallacy #8 “We could improve the undergraduate experience with coed dorms since both men and women benefit from living with the opposite gender.” “We could improve the undergraduate experience with coed dorms since both men and women benefit from living with the opposite gender.” -University of Notre-Dame Writing Program, -University of Notre-Dame Writing Program,

Logical fallacy #8 Begging the question: the premise is merely an assumption so the conclusion won’t necessarily be true Begging the question: the premise is merely an assumption so the conclusion won’t necessarily be true

Logical fallacy #9 “The opposition claims that welfare dependency leads to higher crime rates -- but how are poor people supposed to keep a roof over their heads without our help?” “The opposition claims that welfare dependency leads to higher crime rates -- but how are poor people supposed to keep a roof over their heads without our help?” -Logical Fallacies and the Art of Debate, -Logical Fallacies and the Art of Debate,

Logical fallacy #9 Red herring: an irrelevant topic is introduced to divert attention from the topic at hand. Red herring: an irrelevant topic is introduced to divert attention from the topic at hand.

Logical fallacy #10 "The current Chancellor of Germany was in the Hitler Youth at age 3. With that sort of background, his so called 'reform' plan must be a facist program." -The Nizkor Project, fallacy.htmlg "The current Chancellor of Germany was in the Hitler Youth at age 3. With that sort of background, his so called 'reform' plan must be a facist program." -The Nizkor Project, fallacy.htmlghttp://

Logical fallacy #10 Genetic fallacy: a line of "reasoning" in which a perceived defect in the origin of a claim or thing is taken to be evidence that discredits the claim or thing itself. It is also a line of reasoning in which the origin of a claim or thing is taken to be evidence for the claim or thing. Genetic fallacy: a line of "reasoning" in which a perceived defect in the origin of a claim or thing is taken to be evidence that discredits the claim or thing itself. It is also a line of reasoning in which the origin of a claim or thing is taken to be evidence for the claim or thing.

Logical fallacy #11 “Arnold Killembetter’s movie True Garbage is the greatest movie of all time. No movie has made as much money as it did.” “Arnold Killembetter’s movie True Garbage is the greatest movie of all time. No movie has made as much money as it did.” -The Skeptic’s Dictionary, -The Skeptic’s Dictionary,

Logical fallacy #11 Ad populum: the appeal to the popularity of a claim as a reason for accepting it. Ad populum: the appeal to the popularity of a claim as a reason for accepting it.

Logical fallacy #12 "Senator Jones says that we should not fund the attack submarine program. I disagree entirely. I can't understand why he wants to leave us defenseless like that." -The Nizkor Project, man.html "Senator Jones says that we should not fund the attack submarine program. I disagree entirely. I can't understand why he wants to leave us defenseless like that." -The Nizkor Project, man.htmlhttp://

Logical fallacy #12 Straw man: a deliberate misrepresentation of another’s argument. Straw man: a deliberate misrepresentation of another’s argument.

Others to know “Sob story” = appeal to pity “Sob story” = appeal to pity Equivocation = deliberately using ambiguous or misleading words Equivocation = deliberately using ambiguous or misleading words Circular reasoning – relies on its own premise to prove itself Circular reasoning – relies on its own premise to prove itself "Only an untrustworthy person would run for office. The fact that politicians are untrustworthy is proof of this.“ "Only an untrustworthy person would run for office. The fact that politicians are untrustworthy is proof of this.“