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1. Logical fallacy: An argument that is structurally invalid because its

premises do not suffice to logically determine the truth of its

conclusion; error in reasoning; faulty argumentation.

a. Conditional fallacies (Invalid conditional forms)

•Affirming the consequent: if P then Q; Q; Therefore, P

•Denying the antecedent: if P then Q; Not P; Therefore,

not Q

b. Quantifier scope fallacy: The mistake of inferring a specific

statement from its unspecific version; misordering a universal

quantifier and an existential quantifier, resulting in an invalid

inference; mistaken reasoning that what is true for all/every/each

(universal quantifier) of something is also true for some/a/the/one

(existential quantifier) of that thing. (EXAMPLES IN BOOK)

c. Equivocation: A fallacy that involves changing the definition of

terms in different premises or conclusions of a single argument.

(EXAMPLES IN BOOK)

2. Evidential fallacy: An argument that fails to show its conclusion to be

reasonably likely because the state of information is too weak to

support the conclusion. / Failure to make conclusion reasonable

even in inductive or heuristic terms.

a. Argument from ignorance: We have no evidence that P; Therefore,

it is not the case P