Fallacy 오류

사진1. 누가봐도 잘못 끼워진 조각처럼 오류는 확실하게 논증의 틀렸음을 입증하는데 쓰일 수 있다.

 

"그건 진짜 틀렸다." 라고 말할수 있는 상황

오류란, 논리학에서 일반적으로는 옳지 않은 추리를 가리키나, 특히 옳은 듯이 겉으로만 보이려는 옳지 않은 추론(推論)을 말한다. 오류는 논리적 형식상에서 논증구조가 잘못되어 발생하거나 혹은 비형식상 명제의 내용에서 비롯되기도 한다. 누군가가 말하는 논증이 아래와 같은 패턴을 보인다면 잘못된 추론이라고 답변할수 있다. 하지만 charity자애를 가지면서 상대의 의도를 악의적으로 폄하하지 말자.

 

Fallacy	Basic Description	Example	Notes
Formal Fallacies
Denying the antecedent 전건부정	For an implication P → Q, denying the antecedent is to state ¬P and conclude ¬Q (¬P → ¬Q), which is not true.	If it rains, he always bring an umbrella. It’s not raining, so he wouldn’t bring an umbrella.	Denying the antecedent can be seen as an erroneous application of modus tollens (denying the consequent), which is a valid deductive rule.
Affirming the consequent 후건긍정	For an implication P → Q, affirming the consequent is to state Q and conclude Q (Q → P), which is not true.	If I drink coffee, my heart will bounce fast. My heart bounce fast, so I drank coffee.	Affirming the consequent can be seen as an erroneous application of modus ponens (affirming the antecedent), which is a valid deductive rule.
Existential fallacy 실존적 오류	While there is no member of a class, one presume that there is any. If P exist → Q. Q⊂R=(Q→R). R exist. Therefore, P exist	All time travelers can notice when was the first time traveler invitation party in the history. Therefore, some of the attender of that party would be time travelers.	The conditional statement does not require existence of P. If P is not exist, the statement does not guarantee the truth value of Q.
Affirming a disjunct 논리합 긍정의 오류	Concluding that one disjunct of a logical disjunction(P V Q) must be false(~Q) because the other disjunct is true(P).	He ate pizza or curry for dinner. He ate pizza for dinner. So he did not ate curry for dinner.	Affirming the disjunct can be seen as an erroneous application of Disjunctive syllogism (denying a disjunct), which is a valid deductive rule.
Illicit major 부당주연의 오류	A⊂B=(A→B), !(C⊂A)=!(C→A). Therefore, !(C⊂B)=!(C→B). ABC ~AVB, C&~A, tf, C&~B 111        1       0             0 110        1       0             0 101        0       0            1 100        0       0            0 011        1       1            0  F 010        1       0            0 001        1       1            1  T 000        1       0            0 Invalid. Something not A but B&C exist.	All rice cakes are foods. No candies are rice cakes. Therefore, no candies are food.	Illicit major is a formal fallacy committed in a categorical syllogism(A→B, C→A. Therefore, C→B) that is invalid because its major term is undistributed in the major premise but distributed in the conclusion.
Informal Fallacies
Slippery slope 바늘도둑이 소도둑 된다	A series of implications in which one or more causal links has questionable strength and so the conclusion is implausible.	If you don’t study right now, you will do poorly on your next exams. Doing poorly early on means you will always lag behind your class. Lagging behind means you won’t go to a good university, and then your job will be terrible. To avoid that, study right now.	The slippery slope fallacy has a deductively valid structure. The flaw is with the chain of unlikely events within the premises.
Genetic fallacy 발생학적 오류	The genetic fallacy is a fallacy of irrelevance in which arguments or information are dismissed or validated based solely on their source of origin rather than their content.	Some serious murderer have played FPS games. Therefore, teenagers should avoid FPS games.	Genetic accounts of an issue may be true, and they may help illuminate the reasons why the issue has assumed its present form, but they are not conclusive in determining its merits.
ad hominem 인신공격	One of red herring fallacies. Attacking the arguer instead of the argument.	He is a jaywalker. So we cannot trust his word!	This avoids genuine debate by creating a diversion to some irrelevant but often highly charged issue.
two wrongs make a right	Assuming that, if one wrong is committed, another wrong will rectify it.	Your son punched my son. So I will punch you. Because that’s fare, and it’s right.	Its antithesis, "two wrongs don't make a right", is a proverb used to rebuke or renounce wrongful conduct as a response to another's transgression.
tu quoque 너도 마찬가지다	Stating that a position is false, wrong, or should be disregarded because its proponent fails to act consistently in accordance with it.	You are one of rich person. So you can not represent poor people.	In the sense of distraction, this fallacy blames other person’s behavior. This specious reasoning is a special type of ad hominem attack.
Bandwagon 편승의 오류 (Argumentum ad populum 군중에 호소)	A proposition is claimed to be true or good solely because a majority or many people believe it to be so.	Lyric : “Anybody knows that wheat and barley grow on the field.”	If what major people believe is false, it is simply false, no matter how much people believe.
red herring 논지무시	Introducing a second argument in response to the first argument that is irrelevant and draws attention away from the original topic.	We have to stop eating meat. Because, as a high class species, we have to respect their lives.	It may be either a logical fallacy or a literary device that leads readers or audiences toward a false conclusion.
false dichotomy 거짓 이분법	Two alternative statements are given as the only possible options when, in reality, there are more.	Unless you choose your side whether right or left, you cannot tell you care about politics.	The source of the fallacy lies not in an invalid form of inference but in a false premise. This premise has the form of a disjunctive claim: it asserts that one among a number of alternatives must be true. It oversimplifies the choice
appeal to ignorance 무지에의 호소	One of relevance fallacies. Assuming that a claim is true because it has not been or cannot be proven false, or vice versa.	We still don’t know how to get to the extrasolar planet. Therefore, there is no alien. (or there is alien)	This represents a type of false dichotomy in that it excludes the possibility that there may have been an insufficient investigation to prove that the proposition is either true or false. In debates, appealing to ignorance is sometimes an attempt to shift the burden of proof.
hasty generalization 성급한 일반화	Basing a broad conclusion on a small or unrepresentative sample.	Some people who has long eyebrows, also has luck of wealth. Therefore, if who has long eyebrows, also must has luck of wealth.	It represent week induction. It is similar to a proof by example in mathematics. It is an example of jumping to conclusions.
questionable cause 의심스러운 원인	Its primary basis is the confusion of association with causation, either by inappropriately deducing (or rejecting) causation or a broader failure to properly investigate the cause of an observed effect.	I have a jinx that if I cheer for a soccer team, that team always loose.	The two events may coincide, but have no causal connection. This fallacy includes Circular cause and consequence, Correlation implies causation, and etc.