fallacies Flashcards
Character or other irrelevant personal qualities of the opponent are presented as if they are evidence against her position, often coupled with insults. An abusive and extreme way to distract the audience from the topic of the debate.
argumentum ad hominem - direct attack: abusive
The position of the opponent is not criticised, rather (irrelevant) personal facts of the opponent are brought in in order to undermine her credibility and distract attention of the audience from the topic of the debate. Alternatively, doubt is cast on the opponent’s motives for arguing the way she does.
argumentum ad hominem - indirect attack: circumstantial
committing a pre-emptive ad hominem attack on the opponent, based on personal qualities irrelevant to the debate, before the opponent has been able to make her case. This may stall the debate, and leave the position of the attacker as the apparent winner.
argumentum ad hominem - indirect attack: poisoning the well
The attempt to counter an attack from the opponent by retorting the attack on the opponent herself, thus distracting the audience from the original issue.
argumentum ad hominem: tu quoque
Appeal to emotions of pity rather than rationality in order to support a proposition.
argumentum ad misericordiam (appeal to pity)
oversimplifying or pushing to the extreme the opponent’s thesis.
straw man
fallacy of irrelevance. Putting forward a proposition which might be true, but has no relation with the conclusion it is purported to support.
ignoratio elenchi
appeal to authority rather than rational arguments for the support or dismissal of a proposition.
argumentum ad verecundiam
a question Q is posed to the opponent, which implicitly assumes an affirmative or negative answer to one or more questions P1,…,Pn on which the validity of question Q depends.
plurium interrogationum (many questions fallacy)
Rather than justifying one’s own thesis, forcing the other person to disprove the thesis or to justify her own instead.
shifting the burden of proof
assuming as a premise of the argument its conclusion. The more premises the argument has, and the more convoluted it is, the more difficult to spot the circularity.
petitio principii
a fallacy which introduces a weak analogy between A and B in order to claim that since A has property P, then also B has property P.
false analogy
supporting the truth of a proposition by means of a generalization from a few cases which are either not representative of the variability of the whole population, or whose representativity has not been sufficiently argued for. A hasty generalization occurs whenever conclusions are made based on a sample which is too small to represent the whole population.
hasty generalization
a fallacy committed whenever one infers the conclusion that A must be the cause of B exclusively from the observation that A and B are in temporal succession. Temporal succession of events A and B is a necessary condition for A to be a cause of B, but it is not a sufficient condition.
post hoc ergo propter hoc
a fallacy committed whenever one infers the conclusion that A must be the cause of B exclusively from the observation that A and B exist or vary simultaneously. There may be an additional variable which causes both variations. Or it may just be chance.
cum hoc ergo propter hoc
arguing that there exists a causal chain of events C1,…,Cn leading from an event A to another event B which is usually considered bad in some way (morally or otherwise). This type of reasoning is not always a fallacy. The strength of the argument depends on the strength of the causal links C1; …;Cn. In general, the more causal links there are, the harder it is to justify the argument.
slippery slope
a conditional statement of the form “if P is the case, then Q must be the case” establishes P as a sufficient condition for Q to occur. Assuming that the conditional statement holds, claiming that P is false is, however, not sufficient to conclude that Q is also false; for instance, there might be other sufficient conditions enforcing the truth of Q, as in the sprinkler example before.
denying the antecedent
a fallacy committed whenever one concludes, from the observation that the truth of A logically implies the truth of B (so: A is a sufficient condition for B) and that B occurs, that A must also occur.
affirming the consequent
to deduce, from the fact that all of the component parts of a whole possess the property P, that the whole possesses P. Again, this is not always fallacious: it depends on the type of property considered. For example: “all the molecules composing my body are extended. Therefore, my body is extended.”
fallacy of composition
Deducing from the fact that the whole possesses P, that all of the component parts of the whole possess P.
fallacy of division
absence of evidence for a proposition does not constitute evidence for its contrary.
argumentum ad ignorantiam
inferring that a certain outcome of a random trial is more likely, given that a specific history of outcomes of previous, statistically independent random trials has been observed.
the gambler’s fallacy
arguing for a proposition P by assuming without support that either P or Q must be the case, and that Q must be rejected. The fallacy resides in the premise that either P or Q must be the case, neglecting other possible alternatives.
false dilemma (bifurcation fallacy)
threatening the opponent
argumentum ad hominem - ad baculum
