4.1 4.2 4.3 Reading and Lecture notes
4.1 4.2 4.3 Reading and Lecture notes Philos 1500
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This 9 page Class Notes was uploaded by Kaitlyn Herbst on Friday February 13, 2015. The Class Notes belongs to Philos 1500 at Ohio State University taught by Peter Celello in Spring2015. Since its upload, it has received 159 views.
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Chap 41 Fallacies of lrrelevance 1500 Intro to Logic Vocab Fallacy a psychologically persuasive error inreasoning Formal fallacy an error in reasoning that involves the explicit use of an invalid form Informal fallacy an error in reasoning that does not involve the explicit use of an invalid form Fallacies of irrelevance use of premises that are logically irrelevant to their conclusions But premises may seem relevant for psychological reasons Summary of Fallacies Involving Irrelevant Premises Argument Against the Person Ad Hominem Fallacy Premises Instead of providing a rational critique of a statement or argument attack the person who advances it Conclusion The Statement is false or dubious or the argument is unsound or uncogenU Abusive ad hominem involves direct personal attack Circumstantial ad hominem involves an attempt to discredit an argument or view by calling attention to the circumstances or situation of those who advance it Tu quoque charges opponent with hypocrisy or inconsistency The Straw Man Fallacy Premises A misrepresentation of the view is false Conclusion The view itself is false Appeal to Force ad baculum fallacy Premises You can avoid Harm by accepting this statement Conclusion This statement is true Appeal to the People ad populum fallacy Premises You will be accepted or valued if you believe this statement Conclusion This statement is true Appeal to Pity ad misericordiam fallacy Premises You have reason to pity this person or group Conclusion You should do X for the bene t of the person or group although doing it is not called for logically by the reason given Appeal to Ignorance ad ignorantiam fallacy Premises This statement has not been proven true Conclusion This statement is false or may be reasonably believed false Premises This statement has not been proven false Conclusion This statement is true or may be reasonably believed true Red Herring Fallacy ignorantia elenchi Premises Something relevant to the topic at hand is described Conclusion A distracting but often unnoticed change of subject occurs Notes and Examples Argument Against the Person Ad Hominem Fallacy Ad hominem Latin phrase means quotagainst the manquot Attacking the person who advances an argument or asserts a statement instead of providing a rational critique of the argument or statement itself 0 Not always use outright verbal abuse Involve attempt to discredit an opponent o Suggesting opponent39s judgment is distorted by some factor or circumstances 0 Person offering ad hominem often trying to distract listenerreader from original argument 0 Personal criticisms not always ad hominem o If relevant to conclusion presidential candidates should they be elected o Arguments by authority Abusive ad hominem Most blatant form 0 Direct personal attack 0 Insult or allegation that the arguer has a moral aw Example 5 Jones argues for vegetarianism He says it is wrong to kill animals unless you really need them for food and that as a matter of fact nearly everyone can get enough food without eating meat But jones is just a nerdy intellectual So we can safely conclude that vegetarianism remains what it has always beennonsense jones39s argument is not rationally critiqued jones himself is criticized Ifjones is actually a quotnerdy intellectualquot 0 Not show jones39s argument is flawed 0 Not show that vegetarianism is nonsense Personal attack is irrelevant to soundness of argument and vegetarianism Circumstantial ad hominem Involve attempt to discredit an opponent by calling attention to circumstances or situation of those who advance it o Suggesting opponent39s judgment is distorted Example 6 Ms Fitch argues in favor of equal pay for equal work She says it doesn39t make sense to pay a person more for doing the same job just because he is male or Caucasian But since Ms Fitch is a woman it s to her personal advantage to favor equal pay for equal work After all she would get an immediate raise if her boss accepted her argument Therefore her argument is worthless Attempts to discredit by showing the arguer has something to gain if her conclusion is accepted 0 By seIf doesn39t show the arguers reasoning is flawed Tu quoque Means quotyou tooquot Attempt to suggest the opponent is hypocritical Example 7 Dad tells me I shouldn39t lie He says ying is wrong because it makes people stop trusting one another But I39ve heard my Dad lie Sometimes he calls in quotsickquot to work when he isn39t really sick So lying isn39t actually wrong Dad just doesn39t want me to lie Might succeed in embarrassing or discrediting opponent Logical error should be clear upon re ection In general the fact that some people violate a moral rue doesn39t show the rule is incorrect Straw Man Fallacy Arguer attacks a misrepresentation of the opponent39s view 0 Describe something that sounds like opponent39s view but is easier to knock down and refute Can be very effective if audience is unaware the misrepresentation has taken place 0 Results from not honoring Principle 4 from Chap 2 BE fain and charitable in interpreting an argument c When a view or argument is alleged to involve assumption that it does not involve Sometimes a persuasivebiased de nition used Example 9 These evolutionists believe that a dog can give birth to a cat How ridiculous Appeal to Force ad baculum fallacy Bacuum is Latin for quotstaffquot 0 Conclusion is defended by a threat to the wellbeing of those who do not accept it Threat may be explicit or implicit 0 Not fallacious to mention harm that something causes while offering an argument Example 12 MrJones you helped us import the drugs For this the Boss is grateful But now you say you39re entitled to 50 percent of the pro ts The Boss says you39re entitled to 10 Percent Unless you see things the Boss39s way you39re going to have a very nasty accident So you39re entitled to 10 percent Got it quotnasty accidentquot has no logical bearing on conclusion Appeal to the People ad populum fallacy o Popuum is Latin for quotpeoplequot or quotnationquot 0 Attempt to persuade a person or group by appealing to the desire to be accepted or valued by others Example 18 Ms Riley are you saying that President Bush mad a moral error when he decided to go to war with Iraq I can39t believe my ears That39s not how Americans feel Not true Americans anyway You are an American aren39t you MsRiley Appeal to Pity ad misericordiam fallacy o Misercordiam is Latin for quotpityquot Attempt to support a conclusion by evoking pity in audience when statement evoking pity are not logically related to the conclusion Example 21 You have heard that my client was seen in the vicinity of the crime scene on the day of the murder But look at his narrow shoulders and frightened eyes This is a man a boy really more sinned against than sinning Appeal to Ignorance ad ignorantiam fallacy Either The claim that a statement is true simply because it hasn39t been proven false or the claim that a statement is false simply because it hasn39t been proven true Example 23 After centuries of tying no one has been able to prove that reincarnation occurs So at this point I think we can safely conclude that reincarnation does not occur 24 After centuries of trying no one has been able to show that reincarnation does not occur Therefore reincarnation occurs Noseeum I do not see them I see perceive no X39s So there are no X s Red Herring Fallacy ignorantia elenchi Most general fallacy of irrelevance Any argument in which the premises are logically unrelated to the conclusion Often premises focus on topic of discussion but conclusion is irrelevant to that topic Example 27 Your friend Margie says that Tasters Choice coffee tastes better than Folgers Apparently she is ignoring the fact that tasters Choice is made by Nestle and Nestle is the company that manufactured that terrible baby formula for Third World countries Thousands of babies died when the dry milk formula was mixed with contaminated water Obviously your friend was mistaken 28 There is a good deal of talk these days about the need to eliminate pesticides from our fruit and vegetables But many of these foods are essential to our health Carrots are an excellent source of vitamin A broccoli is rich in iron and oranges and grapefruits are high in vitamin C Chap 42 Fallacies Involving Ambiguity 1500 Intro to Logic Vocab Fallacies involving ambiguity contain ambiguous words phrases or statements or involve a subtle confusion between two closely related concepts mmary of Fallacies Involving Ambiguity Equivocation Premises contain a key word or phrase that is ambiguous Conclusion is reached not by valid logical inference but by trading on the ambiguity of the key work or phrase Amphiboly Premises contain a sentence that is ambiguous due to faulty structure ex grammar punctuation Conclusion is reached not by valid logical inference but by trading on the structural ambiguity Composition Premises the parts or members have attribute X Conclusion the whole or group has attribute X Division Premises the whole or group has attribute X Conclusion the parts or members have attribute X Equivocation Occurs when two or more meanings of a word or phrase are used in a context in which validity requires a single meaning of that word 0 Makes it sound as if one wordphrase is being used but actually more than one meaning Example from text 29 Only man is rational But no woman is a man Hence no woman is rational Man rsthumans secondmale humans Super cial appearance of validity 30 Only humans are rational No woman is a male human So no woman is rational Rewrite of 29 0 Shows the two meanings have no logical linkage between premises and conclusion 32 I agree with Christians in their claim that God is love But unlike Christians lam not afraid to draw the obvious logical consequence Love is God 0 quotisquot has the attribute of vs is identical with Amphiboly Double meaning due to sentence structure Often Missing comma Dangling modi er Ambiguous antecedent of a pronoun Examples from text 35 One morning I shot an elephant in my pajamas How he got into my pajamas I39ll never know 39 Prof Warren gave a lecture on homicide in Tiffany Hall room 208 I gather that a lot of people have been murdered in that room Composition Two similar types 0 Can39t know if an argument commits fallacy of composition unless one examines the content of the argument An invalid inference from the nature of the parts to the nature of the Whole 43 Each of the parts of this airplane is very light Therefore the airplane itself is very light 44 Each player on the football team is outstanding Hence the team itself is outstanding Each part of X has attribute Y therefore X itself has attribute Y An in valid inference from attributes of members of a group to attributes of the group itself 46 Elephants eat more than humans So elephants taken as a group eat more than humans taken as a group Division Reverse of fallacy of composition 0 Can39t know if an argument commits fallacy of division without examining the content of the argument Invalid inference from the nature of the Whole to the nature of the parts or from the nature of a group to the nature of its members Examples from text 48 The airplane is heavy So each of its parts is heavy 50 Grizzly bears are rapidly disappearing So Freddy the grizzly bear at the 200 must be rapidly disappearing