Logical Fallacies

Logical FallaciesWhat is a Fallacy?A Fallacy is an error of reasoning. An argument whose premises do not support its conclusion is one whose conclusion could be false even if all the premises were true. In such cases, the reasoning is bad, and the argument is said to be fallacious. Fallacies include typical errors that arise in common discourse. Each fallacy is a type of false argument, an instance of a typical mistake. An argument in which mistake of a given type appears is said to commit that fallacy.

Classification of Fallacies: Aristotle identified 13 fallacies. Nevertheless, there is no determinable number of fallacies but for this course we are focusing on the most common types of fallacies. For convenience, they are divided into two groups here:

I. Fallacies of Relevance

II. Fallacies of Ambiguity

Fallacies of Relevance: When an argument relies on premises that are not relevant to its conclusion, and that therefore cannot possibly establish the truth, the fallacy committed is one of relevance. These are of several types.

The Argument from Ignorance/ Argument Ad Ignorantiam: When it is argued that the proposition is true simply on the basis that it has not been proved false, or that it is false because it has not been proved true. Examples: i) In a criminal court, it is argued that any accused person is presumed innocent until proven guilty. But can it imply that a person is innocent if he/she is not guilty? Logically it seems to be an example of an argument from ignorance. But this special case centers around a presumed definition of innocent as absence of factual errors or any other reasonable doubt as specified by Judicial systems. So, the court in this special context may rightly claim that the only verdict possible in case of no proof beyond a reasonable doubt is not guilty. In all other cases any such appeal is fallacious.ii) The argument that there is no global warming is certainly occurring because nobody has demonstrated conclusively that it is not. But failing to prove the global warming theory false is not the same as proving it true.

The Appeal to Inappropriate Authority/ Argument Ad Verecundiam: Whenever the truth of a proposition is asserted on the basis of the authority of any one who has no special competence in that sphere, the appeal to misplaced authority is the fallacy committed. Examples: i) In advertising testimonials, one is urged to make a given choice like buying a particular automobile, a beverage, a soap/detergent, a cellphone etc because a particular cricketer or a movie star endorses it. However, they may have no expertise in the matter at hand.

ii) Citing a Physicist like Edward Teller whose competence lies in technical design or construction of weapons in determining political goals or resorting to Alexander Solzhenitsyns fiction in determining a political dispute.

It is likely that even an expert can be mistaken. If any authority A, asserts that a proposition p is true then it depends on what p asserts, on what is the relation between A and p, If As judgment has some value as evidence for regarding the truth of p? These considerations are an attempt to make a well reasoned argument irrespective of the fact that even relying on an expert can turn into an error in some cases.

Complex Question: Asking a question in such a way as to presuppose the truth of some conclusion buried in that question. The question is likely to be rhetorical, no answer being genuinely sought. When a question is accompanied by the aggressive demand that it be answered yes or no, there is reason to suspect that the question itself is deliberately complex. A single speaker may craftily pose the question answer it, and then go on to use the conclusion that has been deliberately buried within it. Or the question may be posed and the fallacious assumption drawn, while the answer to the question remains unstated, only suggested or presumed.

This argument is usually intended to trap the respondent into acknowledging something that he or she might otherwise not want to acknowledge. Example: Have you stopped cheating on exams? Let us suppose the respondent answers "yes" to the question. The following arguments emerge: You were asked whether you have stopped cheating on exams.You answer "yes". Therefore, if follows that you have cheated in the past.On the other hand, let us suppose that the respondent answers "no" to the question. We then have the following arguments: You were asked whether you have stopped cheating on exams.You answered "no." Therefore, you continue to cheat. The questions is really two questions:

Did you cheat on exams in the past? If you did cheat in the past, have you stopped now?If respondent does not identify a complex question when one is put to him/her, one may answer quite innocently and be trapped by a conclusion that is supported by no evidence at all; or, they may be tricked into providing the evidence themselves. The correct response lies in resolving the complex question into its component questions and answering each separately.

Argument Ad Hominem/ Argument against the person: A fallacious attack in which the thrust is directed, not at a conclusion, but at the person who asserts or defends it. To contend that the proposals are bad because they are asserted by radicals or extremists is one such example. When argument ad hominem takes the form of attacking the source or the genesis of the opposing position- which is not relevant to its truth, it may then be called Genetic fallacy. E.g: Labelling the one who argues as being of a certain persuasion: a chauvinist, a left-winger, misogynist etc. to invoke an attitude of disapproval

In the circumstantial form of ad hominem fallacy, an irrelevant connection between the belief held and the circumstances of those holding the belief is sought that gives rise to the mistake. E.g.: insisting someone to hold a belief merely because of the persons nationality, employment, political affiliation, etc.The circumstances of one who makes a claim have no bearing on the truth of that claim.

Accident and Converse Accident: When we apply a generalization to individual cases that it does not properly govern, we commit the fallacy of accident. Example:Germans are Nazis. The premise above could be used in an argument concluding that all Germans or current Germans should be held responsible for the actions of the Nazis. Instead of theclaim: Some Germans are Nazis. On the other hand, when we apply a principle that is true of a particular case to the great run of cases, we commit the fallacy of converse accident. Example: Did you see that teenager run that red light? Teenage drivers are really pathetic." (converse accident fallacy)

False Cause: Any reasoning that relies on treating the cause of a thing what is not really its cause is considered as a fallacy of false cause. The most common form is the error of concluding that an event is caused by another simply because it follows the other. Since we know that mere temporal succession does not establish a causal connection, it becomes a fallacy. Example: "Napoleon became a great emperor because he was so short."If this were a causal inference, then all short people would become emperors.

Begging the question/ Petitio Principii: To beg the question is to assume the truth of what one seeks to prove, in the effort to prove it. A petitio principii is always valid but always worthless too. Example: When a questionably true premise, which is needed to make the argument valid, is completely ignored:Murder is morally wrong. This being the case, it follows that abortion is morally wrong.

The questionable premise that is ignored is, "Abortion is a form of murder." The argument begs the question, "How do you know that abortion is a form of murder?" The premise that is stated, of course, is indisputably true, and the phrase "This being the case" makes it appear that the stated premise is all that is needed.Appeal to emotion/ Argument ad populum: Such argument replaces the laborious task of presenting evidence and rational argument with expressive language and other devices calculated to excite enthusiasm, excitement, anger or hate. Examples: Hate speeches, Speeches of Adolf Hitler in which he invokes the love of country to manipulate his audience, Associating advertised products with emotions that command attention like automobiles with romance, etc.

The appeal to pity/ Argument ad misericordium: A special case of appeal to emotion, in which altruism and mercy of the audience are appealed to. Example: "I should receive an 'A' in this class. After all, if I don't get an 'A' I won't get the fellowship that I want. Our emotional responses are not always a good guide to truth; emotions can cloud, rather than clarify, issues. We should base our beliefs upon reason, rather than on emotion, if we want our beliefs to be true.The appeal to force/ argument ad baculum: The appeal to force to cause the acceptance of some conclusion. Example: If I succeed in threatening you, then you will want to raise my salary.

Irrelevant Conclusion/ Ignoratio Elenchi: When an argument purporting to establish a particular conclusion is instead directed to proving a different conclusion. The premises miss the point; the reasoning may seem plausible in itself yet the argument misfires as a defense of the conclusion in dispute. Examples: Such an argument is sometimes framed in highly emotional language like:

Im all for women having equal rights, said Bullfight Association President Paco C. But I repeat, women shouldnt fight bulls because a bull fighter is and should be a man. ( San Francisco Chronicle, 28th March 1972)