CLASSIC FLAWS Flashcards
If you ride a wild horse, you’re of an adventurous sort. All adventurous sorts desire the thrill of the new. So, if you desire the thrill of the new, then you are an adventurous sort.
Bad conditional reasoning
Fatigue syndrome is associated with low blood magnesium levels. Malabsorption of magnesium is associated with some types of fatigue. Therefore, raising blood magnesium levels would cure chronic fatigue syndrome.
Bad causal reasoning
Each of the elements of Garelli’s recently completed design for a university library is copied from a different one of several historic libraries. The design includes various features from classical Greek, Islamic mogul, and Romanesque structures. Since no one element in the design can be considered original it follows that the design of the library cannot be considered original.
Whole-to-Part
Leanna was very clever on her shark paper, so Leanna must be very clever in general.
Over generalization
A Survey of alumni from the 1960 class at Aurora University yielded puzzling results. When asked to indicate their academic rank, half of the respondents indicated they were in the top 25% of the graduating class.
Survey problems
Two groups are enrolled in a study on exercise and health outcomes. Group one exercises and group 2 does not. Group one ends the study with better health outcomes than group one. Therefore exercise is responsible for good health.
False starts
Despite best efforts of astronomers, no one has yet succeeded and exchanging messages with intelligent life on other planets, or other solar systems. In fact, no one has managed to prove that any kind of extraterrestrial life exists. Thus there is clearly no intelligent life anywhere, but on earth.
Possibility does not equal certainty
Bank deposits are credited on the date of the transaction when made before 3 PM Alicia knows the transaction was made before 3 PM so she must know the deposit will be credited for the date of the transaction
Implication
Commentator: because of teacher hiring freezes the quality of education in that country will not improve. Thus it will surely deteriorate.
False dichotomy
Student representative: our university is expelling a student who verbally harassed his roommate, thus penalizing the student for doing what he has a right to do: speak his mind!
Dean: So what you’re saying is the university should endorse verbal harassment.
Strawman
John says the herbal drink won’t work to cure my sinus infection, but John works for Big Pharma, so he has to protect his own interests. Therefore the herbal drink is probably an effective cure.
Ad Hominem
Explaining string theory is pointless. Sure, explaining complex concepts, may seem like a worthy aim, but in this case, since it will never work, there’s no point in doing so.
Circular Reasoning
Samantha: my new workout plan is fantastic. My arms have never been stronger so maybe I should intervene in a complex foreign political conflict.
Equivocation
Most people believe yawning is most powerfully triggered by seeing someone else yawn. This belief about yawning is widespread not only today, but also has been common place in many parts of the world in the past if we are to believe historians of popular culture. thus, seeing someone else yawn must be the most irresistible cause of yawning there is.
Appeal fallacy - invalid appeal to public opinion
Office manager: We need the best paper for the office. I will not order recycled paper, which could be inferior.
Stationary supplier: recycled paper is not necessarily inferior. From the beginning, the finest paper was made from rags only when demand increased in the 1850s did paper manufacturers switch to wood fiber, which was more readily available.
Irrelevant
It’s common for people to mistakenly believe left-handed people are more prone to accidents than right handed people. But this is just a myth, as indicated by the fact that more household accidents are caused by right-handed people than left-handed people.
Percentages do not equal numbers
Tariq sold 1000 more yo-yos today than he did yesterday therefore his share of the market percentage must have risen considerably.
Percentages do not equal numbers
Current efforts to recapture the grizzly bear on the loose at Sunbird acres, are misguided. Sure, the bear did maul a number of residents. But consider this: bears have long been appreciated by zoologists and the general public as beautiful creatures. The beauty of the grizzly bear has been documented extensively as in literalbearsI’mjealousof.tumblr.com.
Irrelevant
Over 50% of UK residents believe in the supernatural. Therefore, at least in the UK, ghosts and seances must be real.👻
Appeal Fallacies - Invalid Appeal to Public Opinion