China Debate Education Network

The Quality of Arguments:Fallacies

Criteria for Logical Assessment of Arguments• Standard of Acceptability

• Standard of Relevance

• Standard of Sufficiency

RSA Triangle

• This entire approach to fallacies is borrowed from Ralph H. Johnson and J. Anthony Blair. Logical Self Defense.

Standard of Acceptability

• This standard applies to the evidence on which the argument is constructed.

• Is the evidence acceptable to the audience? • Three criteria for acceptability– Is the evidence common knowledge? – Is the evidence supported elsewhere? In an

acceptable source? From a qualified authority?– Is the evidence supported by a cogent sub-

argument?

Standard of Relevance

• This standard applies to the links drawn between the evidence and claim.

• Does the link have any relationship the evidence and the claim. In other words, does the link, to any degree, assist the arguer in transferring the acceptability of the evidence to the claim?

• This is a minimal standard of the quality of the link between evidence and claim.

Standard of Sufficiency

• Sometimes a claim is relevant to the claim but still not sufficient.

• Is the relationship between evidence and claim strong enough to convince a reasonable audience?

• Does the link fully transfer the acceptability of the evidence to the claim?

• Sufficiency varies from situation to situation.

ARS as Related to the Structure of Argument

Three Basic Fallacies

• Problematic premise: arguments that for any reason fail to fulfill the acceptability requirements.

• Irrelevant reason: an argument fails to minimally satisfy the criteria of relevance.

• Hasty conclusions: all evidence and links taken together fail to meet the test of sufficiency.

Basic Fallacy #1: Problematic Premise

• Begging the question

• Fallacy of incompatibility

Problematic PremiseBegging the Question

• When an arguer introduces evidence that is essentially the same as the claim.

• Free speech is good for the society because it is conducive to the interests of the community.

Problematic PremiseFallacy of Incompatibility

• Fallacy that occurs when – An arguer makes a statement that is at odds to another

statement made by the arguer.– An arguer’s statement is incompatible with some action

that the arguer as performed• Examples– An arguer says at one time (in Beijing) that a policy is good

at another time (in Xi’an) says the policy is bad– Radio talk show host Rush Limbaugh said “If people are

violating the law by doing drugs they should be convicted” and punished.” Yet Limbaugh admitted to being addicted to prescription drugs obtained through multiple doctors.

Basic Fallacy #2:Irrelevant Reason

• Argument ad hominem• Straw person fallacy• Red herring• Poisoning the well• Guilt by association• Appeal to fear• Appeal to popularity• Appeal to tradition

Irrelevant ReasonAd Hominem

• When a debater attacks the person rather than his or her argument.

• Not all attacks on the person are irrelevant and thus are not fallacious

• Examples– Fallacious: Attacking a candidate for President of

the debate club for failing a math examination.– Not fallacious: Attacking a candidate for the

Ministry of Health for cheating on medical exams.

Irrelevant ReasonStraw Person

• A debater construes an argument to be other than what it is then attacks this misconstrued version of the argument rather than the real version.

• Example: Someone opposing the death penalty argues that the death penalty risks executing an innocent person. The straw person response might be: “you’re suggesting we open the doors of our prisons and let everyone out to avoid wrongfully convicting anyone.”

Irrelevant ReasonRed Herring

• An argument that attempts to shift the focus of discussion to a different and irrelevant argument. In other words, it tries to sidestep the issue.

• The issue of gay marriage was introduced prior to the 2004 U.S. presidential election to take the focus off of the U.S. economy and the war in Iraq.

Irrelevant ReasonAdditional Fallacies

• Poisoning the well: discredit a person in advance of their argument. “Dr. Summers is a Republican. We can only expect her to be against Affirmative Action.”

• Guilt by Association: A person’s argument is attacked not directly, but on the basis of people with whom the person is associated. “How can you possibly support Ms. Yang. After all, she is an she is seen in the company of gay people.”

Irrelevant ReasonAdditional Fallacies

• Appeal to fear: attempting to take the focus off the argument by shifting the focus solely on the basis of fear. “If you vote for my opponent, we should all build bomb shelters because we will be attacked.”

• Appeal to popularity: Using the popularity of someone or something to justify a favorable evaluation. “Most Serbs support President Boris Tadic. So should you.”

Irrelevant ReasonAdditional Fallacies

• Appeal to tradition: an attempt to argue for an action on the grounds of tradition rather than on the actual merits of that action. “The U.S. has allowed citizens to possess guns for the past 200 years so we should continue to do so for the next 200 years.

Basic Fallacy #3Hasty Conclusion

• Hasty generalization• Fallacious slippery slope arguments• Two wrongs fallacy• Improper appeal to practice• Fallacy of composition• Fallacy of division• Post hoc fallacy• Faulty analogy

Hasty ConclusionsHasty Generalization

• A fallacy of reasoning by example that occurs when the examples selected are either insufficient in number or are not representative.

• I have five students in my class from Harbin and they are all failing. I suppose Harbin does not produce good students.

Hasty ConclusionsFallacious Slippery Slope Arguments• A debater tries to connect a series of events in

a causal chain that ends in calamity. • The argument is fallacious only if the causal

chain is improperly supported. Thus, all slippery slope arguments are not fallacies.

• “If we restrict ownership of semiautomatic weapons, politicians will then think about banning handguns, then shortly all firearms including hunting rifles and gun collections will be banned.”

Hasty ConclusionsTwo Wrongs Fallacy

• The two wrong fallacy is a misplaced appeal to consistency.

• “Two wrongs don’t make a right.”• How can the state justify capital punishment

when the act of capital punishment is the same as murder.

Hasty ConclusionsAdditional Fallacies

• Improper appeal to practice: This argument assumes a person is justified in doing something that is common practice even if that practice is clearly wrong. “Why should I pay women equal wages? Other businesses pay men more than women.”

• Fallacy of composition: the evidence is drawn from a part of a whole but the conclusion is about the whole. “Tim Howard, the keeper for Manchester United, is a superb keeper. Therefore, Manchester United is one of the best football teams in Europe.”

Hasty ConclusionsAdditional Fallacies

• Fallacy of division: The evidence is drawn from the whole, but the conclusion is about the part. “Harvard is an excellent university, therefore Law Professor Lawrence Tribe must be an excellent Professor.”

• Post hoc fallacy: the assumption that because one thing precedes another, the first must have caused the first. “After Barak Obama was elected, the U.S. economy went into recession. Therefore Obama was the cause of the recession.”

Hasty ConclusionsAdditional Fallacies

• Faulty analogy: this fallacy occurs when two events are compared to each other but are not similar in terms of the comparison.

• Abortion practices are just like Hitler’s murder of six million Jews.

Fallacies:Some Concluding Thoughts

• Fallacies are about the quality of an argument’s construction, not its truth.– An argument free of fallacies is not necessarily a

true argument. – An argument is not necessarily false just because

it contains a fallacy. • Arguments are not either categorically “good”

or “bad.” They exist on a continuum from more -or-less good to more-or-less bad.