Crossfire: Fundamentals of Reasoning

1) define:

• deduction


• induction


• syllogism


• hypothetical syllogism


• chain argument


• antecedent


• consequent


• categorical syllogism


• valid (WARNING: remember, "valid" doesn't mean "true!")


• invalid


• sound


• unsound

2) distinguish deductive arguments from inductive arguments, and non-arguments like reports, opinions, illustrations, explanations, and conditional statements.

3) able to identify and evaluate (valid/invalid?) common patterns of deductive reasoning from a text:

a) be able to identify and evaluate hypothetical syllogisms

• chain argument


• affirming the antecedent (valid)


• denying the consequent (valid )


• affirming the consequent (invalid)


• denying the antecedent (invalid)

b) categorical syllogisms

4) Be able to tell whether an argument given to you is sound or unsound.

5) Know and be able to apply the common test for for deductive validity: "If you assumed the premises were all true, would the conclusion have to be true? If so, the argument is valid. If not, the argument is invalid."

5) Know that it is impossible to have true premises and a false conclusion if you have a valid deductive argument.

6) Know and be able to apply:

Indicator Word Test
Strict Necessity Test
Common Pattern Test

# posted by Beth B @ 8:02 PM