Informal Fallacies Flashcards
These involve flawed reasoning caused by such things as a misleading emphasis on a word or phrase, shifting meanings of words with an argument, incorrect inferences from parts to wholes – and vice versa.
Fallacies of ambiguity
Arises from faulty grammar such as omission of punctuation marks or incorrect positioning of words or phrases.
Amphiboly
Example: “one morning I shot of elephant in my pyjamas. How we got in my pyjamas I’ll never know.”
Arise when words or sentences are taken out of context and given visual or verbal emphasis that they were not meant to have.
The fallacy of Accent
Example: Fly to Australia for $89 – one-way fare, not including tax, surcharges, transfers, etc.
Arises when a key term or word in an argument changes meaning during the course of the argument.
The fallacy of equivocation.
Example: A feather is light. Whatever is light cannot be dark. Therefore a feather cannot be dark.
Arises when characteristics of a group are inferred from characteristics of its individual parts or members.
The fallacy of composition.
Example: since every human must die, the human race will one day die.
Arises by incorrectly inferring characteristics of the individual parts of a set or group from the characteristics of the group as a whole.
The fallacy of division
Example: Cambridge University is a great university and since Sharon went to Cambridge University she must be great to.
All such arguments contain unstated assumption that it is flawed. In the most obvious cases, conclusions are arrived on the basis of a single instance.
Fallacies of presumption
Any form of argument in which the conclusion appears as one of the premises. Also known as petitio principii, or arguing in a circle.
The fallacy of Begging the question.
Example: we know that the Buddha was enlightened because he said so, and enlightened beings never lie.
An argument which is presented with only two alternatives where in reality others may exist. Sometimes known as the “black and white fallacy” or the “excluded middle” it presents an “either…or” situation when there are in fact other options.
The fallacy of bifurcation.
Examples: there are two types of people in the world: the wealthy and the losers. Do you want to be wealthy or a loser?
You either love them or you hate them.
You’re either with me or against me.
Incorrectly highlighting the similarity of two things.
The fallacy of false analogy.
Example: a nuclear power plant is safer than eating, because 500 people choke to death on food every year.
Children and adults are similar because they are both human. Adults are allowed to smoke cigarettes. Therefore, children should be allowed to smoke.
An argument that suggests events are causally connected when in fact no causal connection has been convincingly established. Post hoc, ergo propter hoc, meaning “after this, therefore because of this”.
The fallacy of false cause.
Examples:
The USSR collapsed after instituting state atheism. Therefore we must not Institute state atheism for the same reasons.
The wealthiest town had the lowest incidence of obesity, well the poorest had the highest. This goes to show that poverty is the cause of obesity.
This fallacy occurs with the error of assuming that what is true under certain conditions is true under all conditions.
Also called dicto simpliciter occurs when a general rule is applied to a particular situation in which the features of that particular rule are inapplicable.
The fallacy of sweeping generalisation.
Examples:
Jogging is healthy exercise so Craig should take it up as it will be good for his heart condition.
My parents have told me to always tell the truth so I will tell Aunt Thelma that her new hairstyle looks awful.
This fallacy occurs when a generalisation or principle is drawn on the basis of too small a sample or an uncommon case. It may also occur because of laziness or sloppiness. It is very easy to simply leap to a conclusion; much harder to gather an adequate sample and draw a justified conclusion.
The fallacy of hasty generalisation.
Examples:
I’ll never trust another Australian because it was an Australian who stole my watch when I left it in the changing room.
This fallacy consists of objecting to something on the grounds of the unwarranted assumption that it will ultimately lead to a bad consequence that in turn will lead to another bad inconsequence and so on. It claims that we must stop the first action in order to prevent the catastrophic slide.
The fallacy of the slippery slope.
Examples:
If I make an exception for you then I have to make an exception for everyone.
Pornography should not be banned. Once they’ve banned one form of literature, it will never stop. Next thing you know, they will be burning all types of books.
This fallacy occurs when an opponent’s views are misrepresented and weakened in order to make it easier to criticise. The idea behind the name of this fallacy is that instead of engaging in debate with your real opponent you set up a position not held by your opponent, and then set about destroying the argument as if it were your opponent’s.
The straw man fallacy.
Examples:
Some members of parliament say that the air force should not purchase any more fighter aircraft. I disagree entirely. I can’t understand why they would want to leave us totally defenceless like that.
