1.8, Evaluation: Fallacies (2)

Notes taken from ‘Argumentation: Analysis, Evaluation, Presentation’, by Frans van Eemeren et al.

1, Violations of the Starting Point Rule
Rule 6: No party may falsely present a premise as an accepted starting point, or deny a premise representing an accepted starting point.
… It makes no sense to have a discussion with someone who will not commit himself to any starting points (some minimum of facts, beliefs, norms, and value hierarchies)… Explicit agreements about common starting points are rare. Parties normally operate on the assumption that they share certain starting points…
… Sometimes a proposition is temporarily accepted as true in order to test its acceptability or even to demonstrate that it is unacceptable because it has untenable consequences…
The antagonist violates Rule 6 if he questions either a proposition that was agreed on as a common starting point or one that the protagonist, based on verifiable background information, may rightly assume the antagonist to be committed to…
The protagonist violates Rule 6 if he acts as though a certain proposition was accepted as a starting point when that is not the case…
Fallacy of asking many questions: For example, asking “Who have you quarraled with today?” instead of properly splitting the question in two: “Have you quarrelled with anyone today?” and “Who have you quarrelled with?”
Fallacy of circular reasoning (or begging the question or petition principii): In defending their standpoints the protagonist uses an argument that amounts to the same thing as the standpoint…

2, Violations of the Argument Scheme Rule
Rule 7: A standpoint may not be regarded as conclusively defended if the defence does not take place by means of an appropriate argument scheme that is correctly applied.
Some argument schemes are rarely acknowledged to be sound…
Populist fallacy (argumentum ad populum): A variation of argumentation based on a symptomatic relation… It is claimed the standpoint should be accepted because so many people agree with it…
Confusing facts with value judgments (argumentum ad consequentiam): Inappropriately appealing to a causal relation… In support of a standpoint with a factual proposition, an argument is advanced that is normative because it points out undesirable effects of the standpoint: “It is (not) true, because I (don’t) want it to be true.”
… If an argument scheme is correctly applied, then all critical questions corresponding to this scheme can be satisfactorily answered…
Fallacy of abuse of authority (argumentum ad verecundiam): A proposition is presented as acceptable because some person or written source that is inappropriately presented as an authority says that it is so…
Fallacy of hasty generalisation (secundum quid): Generalising on the evidence of too few observations…
Fallacy of false analogy: The two things compared must really be comparable and there must be no special circumstances that invalidate the comparison.
Fallacy of post hoc ergo propter hoc (“After this, therefore, because of this”): Sometimes a cause-and-effect relation is based on no more than the fact that the one thing preceded the other.
Fallacy of the slippery slope: The mistake here is to wrongly suggest that adopting a certain course of action will inevitably be going from bad to worse, when in fact there is no evidence that such an effect will occur…

3, Violations of the Validity Rule
Rule 8: The reasoning in the argumentation must be logically valid or must be capable of being made valid by making explicit one or more unexpressed premises.
Affirming the consequent and denying the antecedent: Invalid counterparts of the modus ponens and modus tollens types of reasoning. The mistake made in both of these forms of invalid reasoning is that a sufficient condition is treated as a necessary condition.
Fallacy of division: Assuming every property of the whole also applies to each of the component parts.
Fallacy of composition: Treating the whole as a simple sum of the separate parts. If a stew is composed of ingredients each of which by itself is delicious, this is no guarantee that the stew will also be delicious.

4, Violations of the Closure Rule
Rule 9: A failed defence of a standpoint must result in the protagonist retracting the standpoint, and a successful defence of a standpoint must result in the antagonist retracting his or her doubts.
Fallacy of refusing to retract a standpoint that has not been successfully defended: A protagonist who has not managed to successfully defend the standpoint must be prepared to give up this standpoint.
Fallacy of refusing to retract criticism of a standpoint that has been successfully defended: If the protagonist has succeeded, then the antagonist must be prepared to retract the criticism of the standpoint.
Fallacy of concluding that a standpoint is true because it has been defended successfully: When inflated consequences are attached to the successful attack or defence. Successful protagonists are entitled to expect the other party to retract their doubts about the standpoint, but no more than that… If protagonists conclude that they have now proved that their standpoint is true, then they are going too far. The only thing they have shown is that their standpoint, based on the agreed-on starting points, can be successfully defended…
Fallacy of concluding that a standpoint is true because the opposite has not been successfully defended (argumentum ad ignorantiam): The failure of a defence does not warrant the conclusion that the standpoint has been shown to be false or that the opposite standpoint is true… This ignores the possibility of a “middle course”…

5, Violations of the Usage Rule
Rule 10: Parties must not use any formulations that are insufficiently clear or confusingly ambiguous, and they must interpret the formulations of the other party as carefully and accurately as possible.
Fallacy of unclarity or fallacy of ambiguity: Any time a party makes use of unclear or ambiguous language to improve his or her own position in the discussion. These fallacies occur not only by themselves, but also – even often – in combination with violations of other discussion rules…
Structural unclarity at the textual level: Unclarity related to the structure of larger pieces of text, resulting from “illogical” order, lack of coherence, obscure structure, and so on…
Unclarity at sentence level: Four main types can be distinguished, and this is demonstrated by the statement “Charles is a kleptomaniac”:
(1) Implicitness – “Are you warning me or just informing me?” The listener is not sure what the communicative function of the speech act is because the context and situation allow for more than one interpretation.
(2) Indefiniteness – “Charles? Charles who?” Seeks clarification of the propositional content. The listener cannot determine who the speaker is referring to; the reference is unclear.
(3) Unfamiliarity – “A kleptomaniac? What’s that?” Also indicates unclarity in the propositional content, but this time it is the predication that is problematic…
(4) Vagueness – “What do you mean, he’s a kleptomaniac? Do you mean once upon a time he stole something, or do you mean he makes a habit of stealing things?” The listener attempts to obtain a clearer idea of what the speaker means by “kleptomaniac”, thereby reducing the vagueness of this term...
Ambiguity has to do with the fact that words and phrases (and questions) can have more than one meaning…