Presentation is loading. Please wait.

Presentation is loading. Please wait.

Phil 148 Fallacies of Relevance and Vacuity. Fallacies of Relevance When we give reasons to believe a claim, it is understood (or conversationally implied)

Similar presentations


Presentation on theme: "Phil 148 Fallacies of Relevance and Vacuity. Fallacies of Relevance When we give reasons to believe a claim, it is understood (or conversationally implied)"— Presentation transcript:

1 Phil 148 Fallacies of Relevance and Vacuity

2 Fallacies of Relevance When we give reasons to believe a claim, it is understood (or conversationally implied) that those reasons ought to be relevant. – sometimes irrelevant premises are a form of deceit – sometimes irrelevant premises are mistaken for relevant ones

3 Ad-hominem “arguments” The most basic definition of an Ad-hominem argument is an argument directed at the person presenting the argument rather than the argument itself. Sometimes this is a more legitimate move than at other times. These cases will be difficult to distinguish, but relevance will be the key factor. What follows are several varieties of Ad-hominem arguments.

4 Deniers Deniers deny the truth of what is said by a person on the basis of what the denier claims about that person. – Louie often testifies in court for money, so we should not believe what he said today in court. – Larry doesn’t know anything about politics. He voted for Ross Perot twice! His prediction of an Obama win is surely false.

5 Silencers Silencers revoke a person’s right to speak in a given circumstance without necessarily negating the truth of what they say. – When this is used as an excuse not to entertain the merits of the argument, it represents the fallacy – When this is used for a recognized and relevant purpose (like non-senators not being able to propose senate legislation) it is legitimate.

6 Dismissers As characterized in the text, the dismisser points out an agent’s self-interest in a claim that the agent makes. – To go counter to the text a bit, this is seldom legitimate counterargument. A person’s interest in a state of affairs that they advocate does not negate the desirability of that state of affairs to others. – we need further facts about someone’s integrity before we accuse them of intentional deception.

7 Inconsistency: When a person’s opinions are inconsistent over time (or inconsistent with their behavior, as in the tu quoque “argument”), we might be inclined to dismiss everything they say. – This should not be the case. People change their minds from time to time, and sometimes do not themselves follow what they know to be good advice. Unless a person is much more inconsistent than would be regarded as normal, inconsistency is not an independent reason to reject their claims.

8 Genetic fallacy: Whenever a view is rejected because of its causal, historical, or group origins, the genetic fallacy has been committed. Many things that are true were first proposed by odd groups of people or for odd reasons. The origin of a claim is seldom relevant to the truth of the claim.

9 Appeals to Authority In general, there is nothing wrong with appealing to authority to increase confidence in the truth of one’s claims. The problem arises when the appeal is to an irrelevant authority. This happens more often than one might think.

10 Questions to ask about appeals to authority: 1.Is the authority cited an authority in the area under discussion? 2.Is this the kind of question that can be settled by expert opinion? 3.Has the authority been cited correctly? 4.Can the authority be trusted to tell the truth? 5.Why is appeal to authority being made at all?

11 Appeals to authorities that are always irrelevant What many people think is true is not necessarily the case. Assuming that the popularity of a belief is relevant to the truth of the belief is the fallacy of appealing to popular opinion. The fact that a claim has been held for a long time also provides no reason to believe the claim is true. This is the fallacy of appealing to tradition.

12 Emotional Appeals When a person’s emotions are being manipulated to get them to assent to or deny something, this is fallacious reasoning. There are as many names for these as there are names for emotions. – wow, that student has a tough time at home, you should give them a break on some of these test questions. (appeal to pity) – Choosy moms choose Jif (apple polishing)

13 Fallacies of Vacuity Fallacies of vacuity result when a person’s argument is just uninformative. Again, this can be the result of either deception or confusion. These fallacies are fallacies because they fail to provide reasons for believing what they purport to support.

14 Circular reasoning The simplest way of characterizing circular reasoning is when the explanation just is the thing being explained (but usually in different words). – The reason that cigarettes are hard to give up is that they contain nicotine, which is addictive.

15 Begging the Question This is subtly different from circular reasoning in that circular premises just are the conclusions (though sometimes restated) while premises in question-begging arguments are distinct from their conclusions, but cannot be believed without believing the conclusion.

16 Self-sealers Self-sealers are arguments or explanations who have all of their proof built in already. The reason that this is a fallacy of vacuity is because any argument that can’t be wrong in any circumstances doesn’t tell us anything useful. The worst thing that one might say about a proposed scientific explanation is that “it’s not even wrong” (January 2006 Astronomy Magazine, Bob Berman “Tangled up in Strings”)

17 Three kinds of self sealers Universal discounting: The person can always explain away counterevidence with the self- sealing feature of the argument or explanation. Ad-hominem: The person can level a personal attack on their critics which will apply to a person just for being a critic. Definition: When words are stipulated in such ways as to make someone’s position true by definition.

18 Test Preview: Validity versus Strength Evaluating analogical arguments Evaluating generalizations Evaluating explanations (SA) Evaluating correlations NCT and SCT Vagueness evaluation Kinds of Ambiguity Identifying and evaluating different Slippery Slope arguments (SA) Distinguishing different kinds of definitions (SA) Identifying chapter fallacies Distinguishing different sorts of ad-hominem attacks Evaluating arguments for fallacies of vacuity (SA)


Download ppt "Phil 148 Fallacies of Relevance and Vacuity. Fallacies of Relevance When we give reasons to believe a claim, it is understood (or conversationally implied)"

Similar presentations


Ads by Google