Fallacy谬误.docx

1、Fallacy谬误Ad HominemDescription of Ad HominemTranslated from Latin to English, Ad Hominem means against the man or against the person.An Ad Hominem is a general category of fallacies in which a claim or argument is rejected on the basis of some irrelevant fact about the author of or the person presen

2、ting the claim or argument. Typically, this fallacy involves two steps. First, an attack against the character of person making the claim, her circumstances, or her actions is made (or the character, circumstances, or actions of the person reporting the claim). Second, this attack is taken to be evi

3、dence against the claim or argument the person in question is making (or presenting). This type of argument has the following form:1 Person A makes claim X.2 Person B makes an attack on person A.3 Therefore As claim is false.The reason why an Ad Hominem (of any kind) is a fallacy is that the charact

4、er, circumstances, or actions of a person do not (in most cases) have a bearing on the truth or falsity of the claim being made (or the quality of the argument being made).Example of Ad Hominem4 Bill: I believe that abortion is morally wrong.Dave: Of course you would say that, youre a priest.Bill: W

5、hat about the arguments I gave to support my position?Dave: Those dont count. Like I said, youre a priest, so you have to say that abortion is wrong. Further, you are just a lackey to the Pope, so I cant believe what you say.Ad Hominem Tu QuoqueAlso Known as: You Too FallacyDescription of Ad Hominem

6、 Tu QuoqueThis fallacy is committed when it is concluded that a persons claim is false because 1) it is inconsistent with something else a person has said or 2) what a person says is inconsistent with her actions. This type of argument has the following form:1 Person A makes claim X.2 Person B asser

7、ts that As actions or past claims are inconsistent with the truth of claim X.3 Therefore X is false.The fact that a person makes inconsistent claims does not make any particular claim he makes false (although of any pair of inconsistent claims only one can be true - but both can be false). Also, the

8、 fact that a persons claims are not consistent with his actions might indicate that the person is a hypocrite but this does not prove his claims are false.Examples of Ad Hominem Tu Quoque4 Bill: Smoking is very unhealthy and leads to all sorts of problems. So take my advice and never start.Jill: Wel

9、l, I certainly dont want to get cancer.Bill: Im going to get a smoke. Want to join me Dave?Jill: Well, I guess smoking cant be that bad. After all, Bill smokes. 5 Jill: I think the gun control bill shouldnt be supported because it wont be effective and will waste money.Bill: Well, just last month yo

10、u supported the bill. So I guess youre wrong now. 6 Peter: Based on the arguments I have presented, it is evident that it is morally wrong to use animals for food or clothing.Bill: But you are wearing a leather jacket and you have a roast beef sandwich in your hand! How can you say that using animal

11、s for food and clothing is wrong!Appeal to AuthorityAlso Known as: Fallacious Appeal to Authority, Misuse of Authority, Irrelevant Authority, Questionable Authority, Inappropriate Authority, Ad VerecundiamDescription of Appeal to AuthorityAn Appeal to Authority is a fallacy with the following form:1

12、 Person A is (claimed to be) an authority on subject S.2 Person A makes claim C about subject S.3 Therefore, C is true.This fallacy is committed when the person in question is not a legitimate authority on the subject. More formally, if person A is not qualified to make reliable claims in subject S,

13、 then the argument will be fallacious.This sort of reasoning is fallacious when the person in question is not an expert. In such cases the reasoning is flawed because the fact that an unqualified person makes a claim does not provide any justification for the claim. The claim could be true, but the

14、fact that an unqualified person made the claim does not provide any rational reason to accept the claim as true.When a person falls prey to this fallacy, they are accepting a claim as true without there being adequate evidence to do so. More specifically, the person is accepting the claim because th

15、ey erroneously believe that the person making the claim is a legitimate expert and hence that the claim is reasonable to accept. Since people have a tendency to believe authorities (and there are, in fact, good reasons to accept some claims made by authorities) this fallacy is a fairly common one.Si

16、nce this sort of reasoning is fallacious only when the person is not a legitimate authority in a particular context, it is necessary to provide some acceptable standards of assessment. The following standards are widely accepted:4 The person has sufficient expertise in the subject matter in question

17、. Claims made by a person who lacks the needed degree of expertise to make a reliable claim will, obviously, not be well supported. In contrast, claims made by a person with the needed degree of expertise will be supported by the persons reliability in the area.Determining whether or not a person ha

18、s the needed degree of expertise can often be very difficult. In academic fields (such as philosophy, engineering, history, etc.), the persons formal education, academic performance, publications, membership in professional societies, papers presented, awards won and so forth can all be reliable ind

19、icators of expertise. Outside of academic fields, other standards will apply. For example, having sufficient expertise to make a reliable claim about how to tie a shoe lace only requires the ability to tie the shoe lace and impart that information to others. It should be noted that being an expert d

20、oes not always require having a university degree. Many people have high degrees of expertise in sophisticated subjects without having ever attended a university. Further, it should not be simply assumed that a person with a degree is an expert.Of course, what is required to be an expert is often a

21、matter of great debate. For example, some people have (and do) claim expertise in certain (even all) areas because of a divine inspiration or a special gift. The followers of such people accept such credentials as establishing the persons expertise while others often see these self-proclaimed expert

22、s as deluded or even as charlatans. In other situations, people debate over what sort of education and experience is needed to be an expert. Thus, what one person may take to be a fallacious appeal another person might take to be a well supported line of reasoning. Fortunately, many cases do not inv

23、olve such debate.5 The claim being made by the person is within her area(s) of expertise. If a person makes a claim about some subject outside of his area(s) of expertise, then the person is not an expert in that context. Hence, the claim in question is not backed by the required degree of expertise

24、 and is not reliable.It is very important to remember that because of the vast scope of human knowledge and skill it is simply not possible for one person to be an expert on everything. Hence, experts will only be true experts in respect to certain subject areas. In most other areas they will have l

25、ittle or no expertise. Thus, it is important to determine what subject area a claim falls under.It is also very important to note that expertise in one area does not automatically confer expertise in another. For example, being an expert physicist does not automatically make a person an expert on mo

26、rality or politics. Unfortunately, this is often overlooked or intentionally ignored. In fact, a great deal of advertising rests on a violation of this condition. As anyone who watches television knows, it is extremely common to get famous actors and sports heroes to endorse products that they are n

27、ot qualified to assess. For example, a person may be a great actor, but that does not automatically make him an expert on cars or shaving or underwear or diets or politics.6 There is an adequate degree of agreement among the other experts in the subject in question. If there is a significant amount

28、of legitimate dispute among the experts within a subject, then it will fallacious to make an Appeal to Authority using the disputing experts. This is because for almost any claim being made and supported by one expert there will be a counterclaim that is made and supported by another expert. In such

29、 cases an Appeal to Authority would tend to be futile. In such cases, the dispute has to be settled by consideration of the actual issues under dispute. Since either side in such a dispute can invoke experts, the dispute cannot be rationally settled by Appeals to Authority.There are many fields in w

30、hich there is a significant amount of legitimate dispute. Economics is a good example of such a disputed field. Anyone who is familiar with economics knows that there are many plausible theories that are incompatible with one another. Because of this, one expert economist could sincerely claim that

31、the deficit is the key factor while another equally qualified individual could assert the exact opposite. Another area where dispute is very common (and well known) is in the area of psychology and psychiatry. As has been demonstrated in various trials, it is possible to find one expert that will as

32、sert that an individual is insane and not competent to stand trial and to find another equally qualified expert who will testify, under oath, that the same individual is both sane and competent to stand trial. Obviously, one cannot rely on an Appeal to Authority in such a situation without making a fallacious argument. Such an argument would be fallacious since the evidence would not warrant accepting the conclusion.It is important to keep in mind that no field has complete agreement, so some degree of dispute is acceptab