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FallaciesA fallacy is a deceptive argument which appears valid but is not. The word comes from the latin fallo which means I deceive.

Importance of Studying FallaciesCorrect methods of inference are better appreciated by contrasting them with erroneous ones. Ability to think correctly includes the ability to detect and avoid incorrect reasoning. It helps prevent confusion and aids us in decision making.

Categories of Fallacies Fallacies of Ambiguity Fallacies of Relevance The fallacies of ambiguity (or fallacies of language) are those arguments that contain ambiguous words or phrases whose meanings shift and change within the course of the argument.

Categories of FallaciesThe fallacies of relevance are those arguments whose premises are not relevant to the conclusion and therefore cannot possibly establish truth. However, the premises are often psychologically relevant to the conclusion which explains their seeming correctness and persuasiveness.

AMPHIBOLY - using a phrase whose meaning is ambiguous because the grammatical construction can be interpreted in various ways.

Examples: If Creosus wages war against the Persians, He will destroy a mighty kingdom. To be repaired: the rocking chair of an old lady with broken legs. Going up the stage, the crowd applauded the newly elected Prsident.

Fallacies of Ambiguity ACCENT Using ambiguously a word/phrase that has different meanings when accented differently. Examples: We should not speak ill of our friends. Midnight SALE 50% discount

Fallacies of Ambiguity EQUIVOCATION Using the different senses/meanings of a term in a single line of reasoning. Examples: What is natural is good To err is natural Therefore, to err is good

Fallacies of Ambiguity FIGURES OF SPEECH consists of inferring a meaning based on the similarity of word structure Examples: Anybody restless is not restful To be careless is not careful What is immaterial is not material Stevenson is a ghost writer but a ghost is a spirit Therefore, Stevenson is a spirit.

Fallacies of Ambiguity VICIOUS ABSTRACTION altering the logic or meaning of a statement by using vague or abstract terms.Examples: Vote Crisaldo The Peoples Choice Coke is the Real Thing The currency crisis will not have much effect anymore on the prices of goods; in fact there will be no price increases for the meantime.

Fallacies of Relevance ARGUMENTUM AD HOMINEM (Personal Attack) Abusive ignoring the issue by attacking the character or personality of the opponent Example: Those who are in favor of death penalty want vengeance pure and simple

Fallacies of Relevance Circumstantial ignoring the issue by citing the circumstances of another person (Is also called tu quoque which means youre another) Example: Mark Gil: Why were you late again in our class Mark Josep? Mark Joseph: Look whos talking. How about you? Youre always late in our class.

Fallacies of Relevance ARGUMENTUM AD POPULUM (Appeal to the interests and passions of the people) Example/s: Advertisements which associate certain products with things of which we are expected to approve strongly, or excite us favorably.

Fallacies of Relevance ARGUMENTUM AD MISERICORDIAM (Appeal to Pity) This student should be given a passing mark. You see he is troubled by serious family problems at present. His family cant afford to pay his tuition. Its the OFMs who pay for his tuition. If he fails, he might not be supported anymore.

Fallacies of Relevance ARGUMENTUM AD INVIDIAM (Appeal to Anger) I want him to face death penalty because he raped and brutally killed my wife. People like him should have no place in a civilized society like ours.

Argumentum Ad Baculum (Appeal to Force) Try voicing a contrary opinion next meeting and I will make sure you never get a decent job in town..

Argumentum Ad Verecundiam (Appeal to inappropriate authority) Examples:Advertisements that urge people to buy certain products. The doctrine of biological evolution cannot be true, for it contradicts the biblical account of creation, the church Fathers never accepted it and the Fundamentalists explicitly condemn it.

Argumentum Ad Iudicium (Appeal to Judgment)Assumes that conclusion is proven true because people in general believe it to be true. This is also appeal to customs or tradition. There is nothing wrong with Kaingin. Our forefathers have practiced it since time immemorial. Do you mean to tell me that they were wrong all the while?

Our exams should be postponed, Sir! The majority of the class have agreed to it. She is surely the best qualified for the position of mayor. She received more votes than any other mayor.

ACCIDENT Unnecessarily applying ageneral truth to particular cases. This fallacy assumes that what is true in general is true in particular. PNP is one of the most corrupt agencies of the government. Therefore, the Euro generals cannot be trusted. San Miguel is a very talented team. Samigue Eman, being a member of that Team must be a very talented player.

CONVERSE ACCIDENT (Hasty Generalization) drawing a general or universal conclusion from insufficient particular cases. This fallacy assumes that what is true in particular is true in general. Because every part of the machine is light in weight, therefore the whole machine is light in weight.

Singapore, Japan and Great Britain adopted a parliamentary form of government and became politically and economically stable. Therefore, any country that adopts a parliamentary government will be politically and economically stable.

Argumentum Ad Ignorantiam (Appeal to Ignorance) - assuming that the conclusion is true because its opposite cannot be proven.I believe there are living creatures in Mars called Martians. Nobody can furnish evidence to disprove my contention, So it must be true. Ghost cannot kill you cannot prove they do.

FALSE CAUSE (Post Hoc Ergo Propter Hoc) after this, therefore because of this mistaking a purely temporal sequence for a causal relationship.After he broke the bedroom mirror, bad luck attended his business ventures. I am convinced that breaking a mirror is bad luck.

COMPLEX QUESTION Asking a question in which some presuppositions are buried in that questionHave you already stopped gambling? Why did the government allow the peso to depreciate so much?

STRAW MAN Attacking a position that is different from, but similar to, an opponents real position, and concludes that the opponents real position has thereby been refuted. The opponent being attacked however is not the real opponent but an unreal opponent, a straw man who has been constructed by the attacker solely for the purpose of destruction.

What I object most about those people who oppose capital punishment is that they believe that the lives of convicted murderers are more important than the lives of the policemen and prison guards who protect us.

FALSE ANALOGY- drawing an analogy between two things where a relevant difference exists between them. It is evident that women should be elected to political office since government is similar to national housekeeping; and in this respect it is obvious that women have more experience than men.

CONTRARY TO FACT CONDITIONAL Altering a fact and then assuming that its consequent will also be altered. It falsely concludes from speculative hypothesis instead of arguing from actual facts.If the President did not choose the Speaker of the House as the administration bet, the administration party might have won the election. I met an accident because I took a short cut This morning on my way to work. If I had taken my regular route then I would have avoided the incident.

BEGGING THE QUESTION or VICIOUS CIRCLE This fallacy holds that the premises of the argument presuppose the truth of its conclusion. Arguer asserts as truth the answer to a question that is really at issue in the debate.Whiskey causes drunkenness because it is intoxicating. The reason that abortion is wrong is that It is wrong to kill babies who dont have any chance to represent themselves.