Logical fallacy
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***''[[Argumentum ad baculum]]'' — A subset of arguing from adverse consequences, the negative outcomes are being actualised by the one making the argument. Also a form of the style over substance fallacy (see below). | ***''[[Argumentum ad baculum]]'' — A subset of arguing from adverse consequences, the negative outcomes are being actualised by the one making the argument. Also a form of the style over substance fallacy (see below). | ||
**[[Slippery slope]] — If event A happens, it will lead downhill to further undesirable results. For example, "if we allow gays to get married, then we'll have to let men marry little kids". | **[[Slippery slope]] — If event A happens, it will lead downhill to further undesirable results. For example, "if we allow gays to get married, then we'll have to let men marry little kids". | ||
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| + | *[[Argumentum ad hominem fallacia rationis]] — The meta-fallacious argument that your opponent (or someone arguing for a similar point) has used logical fallacies, therefor the argument is wrong. | ||
*[[Special pleading]] — Demanding that your point of view is subject to different standards than all other points of view without any justification beyond "it's the only real support I have for my argument". | *[[Special pleading]] — Demanding that your point of view is subject to different standards than all other points of view without any justification beyond "it's the only real support I have for my argument". | ||
Revision as of 00:09, 19 July 2014
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Formal fallacies
Formal fallacies are those fallacies that violate a particular rule of propositional calculus, such as modus ponens. These fallacies can be determined to be invalid simply by the inspection of the form or structure of the argument - at heart, a formal fallacy contains some sort of non sequitur. This doesn't necessarily mean that a conclusion is wrong, but it does mean that we will need a better reason or argument to derive the conclusion.
For example, given the syllogism of A -> B, B -> C, A therefore C, it doesn't matter what A, B and C actually are. If the statement is incorrect because of the content of A, B or C, it would be an informal fallacy, not a formal fallacy because the logic works out. The difference can often be difficult to spot because we may have trouble splitting the content of an argument from its form.
Consider the following proposition:
- Some men are doctors.
- Some doctors are tall.
- Therefore, some men are tall.
We immediately want to say "yes" in response to this, and take the proposition to be correct because this is what reality reflects. However, this is actually an inference beyond what the logical set up allows us to make. Saying that "some men are tall" given the first two premises is a formal logical fallacy. Why this is so can be more easily highlighted by replacing "tall" with a different property, such as "are women" to yield:
- Some men are doctors.
- Some doctors are women.
- Therefore, some men are women.
This doesn't change the logical structure of the argument, but the fallacy is easier to spot because the content changes it to a more obvious absurdity. Arguments regarding the gender binary notwithstanding, of course.
Informal fallacies
Informal fallacies are arguments that, while not violating propositional calculus rules, are invalid because of the content of their argument. Informal fallacies are often characterised by the fact that there is a disconnect of some kind between their premises and conclusions. Inappropriate generalisations and argument from ignorance are forms or informal fallacies. These tend to be more numerous and slightly more interesting than formal fallacies.
Common examples
- Affirming the consequent — Believing that an effect proves a cause, i.e. A -> B, B, therefore A.
- Argument from ignorance — Basing the truth of a premise only on whether it has been proved to your satisfaction.
- Argument from incredulity — Literally "that's unbelievable = that's obviously not real". This kind of thinking would quickly put an end to virtually all quantum physics.
- Negative proof — Arguing that something must exist because there is no evidence it does not exist.
- One single proof — Dismissing all circumstantial evidence in favor of a single "smoking gun" that may not (and may not need to) exist.
- Argumentum ex culo — Various forms of making things up or lying.
- Ad hoc — Yanking shoddy explanations from where the sun don't shine in response to new information rather than from a coherent logical method. Often results in daisy-chaining various other fallacies.
- Argument by assertion — The belief that if you say something enough times, it eventually becomes true and therefore you win the argument.
- Bullshit — Placing your argument above the truth.
- Equivocation — Deliberately substituting the meaning of a given word in one context for another context that is inappropriate in order to make your argument.
- False analogy — Creating an analogy or metaphor, then extending it to prove one's point.
- False fallacy fallacy — Falsely claiming that a logically valid argument is fallacious.
- Generalisation from fictional evidence
- Moving the goalposts — Changing evidential requirements in an argument once they have been met, "what I really meant was..."
- Red herring — A group of fallacies which bring up a fact which is irrelevant to the issue, in an attempt to distract the opponent and/or audience.
- Straw man — Distorting an opponent's position for greater rhetorical flexibility.
- Argumentum ad hominem — Attacking the opponent directly rather than addressing the opponent's idea.
- Argumentum ad cellarium — attacking the opponent directly by accusing him of still being in "mom's basement"
- Bulverism — Rather than proving that an argument in favour of an opinion is wrong, a person instead assumes that the opinion is wrong, and then goes on to explain why the other person held it.
- Poisoning the well — Attempting to refute an argument based on the perceived veracity of the presenter.
- Tu quoque, where a criticism is falsely dismissed because its author is also guilty of the charge.
- Argumentum ad lapidem — Dismissing a statement as absurd without giving proof of its absurdity.
- Argumentum ad verecundiam — The Appeal to Authority; because someone famous/powerful/respected believes it, it must be true.
- Appeal to ancient wisdom — It's right because the Maya/Chinese/Hebrews said it thousands of years ago!
- Appeal to tradition — Just because it's always been that way doesn't mean it's the right way.
- Argumentum ad Hitlerum — Saying something is bad because Hitler did it.
- Argumentum ad populum or bandwagon — Arguing for a point based on popularity rather than merit.
- Galileo gambit — If someone is going against the tide of popular thinking, they must be right because the likes of Galileo were right, while in reality, Galileo was right because he had evidence.
- Balance fallacy — Giving equal weighting to both sides of an argument, even if one really doesn't deserve the time.
- Begging the question — Assuming the conclusion as part of the premise (similar to circular reasoning).
- Confusing correlation for causation — The number of pirates on the seas has gone down, this correlates with global temperatures rising. So, do pirates cause global cooling?
- Post hoc, ergo propter hoc — Saying that because event A happened before B, A must have caused B.
- Texas sharpshooter fallacy — A data mining fallacy and pattern recognition error where the arguer makes an ad hoc conclusion from a set of unrelated data without looking for corroborating data.
- Composition and division — A pair of fallacies confusing what is true of a part with what is true of the whole.
- Association fallacy — Associating the values of one group with the values of another due to superficial or coincidental similarities.
- No True Scotsman — Excluding an inconveniently misbehaving member of a class to defend the class as a whole.
- Overgeneralisation — Taking a few specifics and making a general rule out of them, without the few specifics adequately representing the entire group.
- Spotlight fallacy — Assuming aspects of a group from aspects from a smaller observed part of the group.
- Denying the antecedent — If A implies B, and not-A, therefore not-B.
- False cause — Presuming that a real, or perceived, relationship between things, means that one is the cause of the other.
- False dilemma — Portraying two options as the only possibilities, with no middle ground (see Pascal's wager for an example).
- Genetic fallacy — Judging something good or bad, on the basis of where it comes from, or from whom it comes. The genetic fallacy, despite its name, has nothing to do with the science of genetics.
- Intuition pump — Deliberately abusing a thought experiment to prove a fallacious point.
- Loaded question — Asking a question, which has an assumption built into it, so that it can't be answered without appearing to agree to the assumption, or else appearing evasive by questioning the assumption. To be distinguished from a Leading question, which is not a fallacy, but is a way of suggesting the desired answer by how the question is phrased. "Are you still beating your wife?" is a loaded question, for it assumes that at one time you did beat your wife; while "You weren't beating your wife, were you?" is a leading question, for it suggests the simple answer no.
- My enemy's enemy — Supporting someone because you've a mutual enemy with them.
- Nirvana fallacy — Claiming that a realistic solution is useless because it is not as good as an idealized perfect solution.
- Non sequitur — Arguably the most fundamental logical fallacy, this is claiming A implies B when it doesn't.
- Pathetic fallacy — This is not a fallacy, but a metaphor, the term being due to John Ruskin, for the assigning animate qualities to inanimate objects: happy skies , babbling brook.
- Presupposition — Making an implicit assumption as part of an argument.
- Reification — Treating an abstraction as a real thing, e.g. treating the test score called "intelligence" as an innate part of a person.
- Reductio ad absurdum — Following a chain of thought to its absurd or contradictory conclusion. Sometimes worthwhile, but oftentimes fallacious.
- Argument from adverse consequences — Arguing against a point based on expected negative outcome.
- Argumentum ad baculum — A subset of arguing from adverse consequences, the negative outcomes are being actualised by the one making the argument. Also a form of the style over substance fallacy (see below).
- Slippery slope — If event A happens, it will lead downhill to further undesirable results. For example, "if we allow gays to get married, then we'll have to let men marry little kids".
- Argument from adverse consequences — Arguing against a point based on expected negative outcome.
- Argumentum ad hominem fallacia rationis — The meta-fallacious argument that your opponent (or someone arguing for a similar point) has used logical fallacies, therefor the argument is wrong.
- Special pleading — Demanding that your point of view is subject to different standards than all other points of view without any justification beyond "it's the only real support I have for my argument".
- Style over substance fallacy — Using language or rhetoric (ethos or pathos) to enhance the appeal of an argument, but not its validity.
- Argumentum ad baculum — Also an argument from adverse consequences, this is attempting to intimidate an opponent (baculum is Latin for "stick").
- Argumentum ad nauseam — The belief that something becomes true if repeated often enough to make you vomit.
- Emotional appeal — evaluating an argument based on its emotional consequences rather than logical ones.
- Definist fallacy — Insisting that definitions are required before an argument can begin, also known as the Socratic fallacy. Or using persuasive/dictionary definitions in a debate, when the matter at hand is not about a dictionary definition. Or as the generic fallacy behind the naturalistic fallacy (good and natural are defined as identical), as proposed by William Frankena.[1]
See also
External links
- Appeal to Authority Breakdown
- The Fallacy Files
- A list of fallacious arguments
- 42 Fallacies for Free
- 5 Ways Common Sense Lies to You Every Day
- The Art of Being Right: 38 Ways to Win An Argument, Arthur Schopenhauer demonstrates how to use logical fallacies to beat your rhetorical opponent.
- Top 25 Creationist Fallacies - A well made 25 minute video.
- Your Logical Fallacy Is
Footnotes
- ↑ http://www.jstor.org/stable/2250706 For information on the author, see the Wikipedia article William Frankena
| Articles about logical fallacies | |||||
|---|---|---|---|---|---|
| Formal fallacies | |||||
| Affirming the consequent | Denying the antecedent | ||||
| Informal fallacies | |||||
| Red herrings | |||||
| Conditional fallacies | |||||
| Fallacious argument styles | |||||