Steps 1 and 2 must be
Figure out the premises
and conclusion. Put the argument in standard form: list the premises,
then the conclusion. State any relevant unstated premises.
Check CLARITY: Make sure
you know what all the statements mean.
- Any objectionable
- Any ambiguity
- Any problems
separating cognitive from emotive content?
- Any unfair
- Any problems
distinguishing collective and distributive usage?
Steps 3 and 4 may be done only after you have done steps
1 and 2. You can do step 4 before step 3 if you prefer.
Check LOGIC: Make sure
the premises support the conclusion. If the argument is deductive -- i.e.,
the arguer is claiming the conclusion must be true if the premises are true
-- make sure the arguer is right (i.e., make sure the conclusion really must
be true if the premises are true). If the argument is inductive -- i.e., if the
arguer is claiming that the conclusion is likely if the premises are true --
then make sure the arguer is correct (make sure the conclusion really is likely
if the premises are true). See “What is Bad Logic?”
- Any formal
- Any informal
NOTE: complex deductive
require formal techniques of symbolic logic to establish their validity or invalidity;
i.e., assessing their validity or invalidity is beyond the scope of “critical
thinking” classes. However, you can diagnose the validity or invalidity of a
large number of common ordinary-language arguments with the methods described
in “critical thinking” classes in Philosophy departments.
Check FACTS: Make sure the premises are all true or
- Any false or
- Any relevant
If an argument is clear,
omits no significant information, has good logic (no formal or informal fallacies),
and all true premises, then the argument is likely most excellent! Reasonable
people should accept its conclusion.