How to Coach Yourself and Others Beware of Manipulation

Formal syllogistic fallacies Syllogistic fallacies Logical fallacies that occur in syllogisms. Affirmative conclusion from a negative premise (illicit negative) When a categorical syllogism has a positive conclusion, but at least one negative premise. Fallacy of exclusive premises A categorical syllogism that is invalid because both of its premises are negative. Fallacy of four terms (quaternio terminorum) A categorical syllogism that has four terms. Illicit major A categorical syllogism that is invalid because its major term is not distributed in the major premise but distributed in the conclusion. Illicit minor A categorical syllogism that is invalid because its minor term is not distributed in the minor premise but distributed in the conclusion. Negative conclusion from affirmative premises (illicit affirmative) When a categorical syllogism has a negative conclusion but affirmative premises. Fallacy of the undistributed middle The middle term in a categorical syllogism is not distributed. Informal fallacies Informal fallacies Arguments that are fallacious for reasons other than structural (formal) flaws and which usually require examination of the argument's content. Argument from ignorance (appeal to ignorance, argumentum ad ignorantiam) Assuming that a claim is true (or false) because it has not been proven false (true) or cannot be proven false (true). The fallacy that since we don’t know (or can never know, or cannot prove) whether a claim is true or false, it must be false (or that it must be true). E.g., “Scientists are never going to be able to positively prove their theory that humans evolved from other creatures because we weren't there to see it! So, that proves the Genesis six-day creation account is literally true!” Sometimes this also includes “Either-Or Reasoning:” E.g., “The vet can't find any reasonable explanation for why my dog died. See! See! That proves that my neighbor poisoned him! There’s no other logical explanation!” A corrupted argument from logos. A fallacy commonly found in American judicial and forensic reasoning. See also "Argumentum ex Silentio." Argument from repetition (argumentum ad nauseam) Signifies that it has been discussed extensively until nobody cares to discuss it anymore. Argument from silence (argumentum ex silentio) Where the conclusion is based on the absence of evidence, rather than the existence of evidence. (see also, Argument from Ignorance). The fallacy that if sources remain silent or say nothing about a given subject or question this in itself proves something about the truth of the matter. E.g., "Science can tell us nothing about God, which proves God doesn't exist." Or "Science can tell us nothing about God, so you have no basis for denying that God exists!" Often misused in the American justice system, where remaining silent or "taking the Fifth" is often falsely portrayed as proof of guilt. E.g., "Mr. Hixel has no 52

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