Analyzing & Interpreting Arguments:
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Arguments contain premises that give reasons for accepting a conclusion.
Conclusions are problematic statements; premises are unproblematic statements
Premises and conclusions are sometimes implied
Arguments should not be confused with other forms:
exposition, illustration, description, explanation, etc.
Indicator words can often help with identifying premises and conclusions
since, because, for, as, given that, etc. often indicate premises
therefore, thus, consequently, as a result, etc. often indicate conclusions
Cogent (valid and convincing) Reasoning:
Arguments are generally considered cogent based on three primary criteria being satisfied:
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Reasonableness: there is known good evidence for the truth of all premises
Relevancy: premises provide logically, factually, or causally related evidence for conclusion
Sufficiency: premises, taken as a whole, provide enough evidence to support the conclusion
(NOTE: the validity of an argument does not necessarily guarantee that it is true)
Deductive Argument Forms:
Syllogisms: (“the putting together of ideas”)
 All syllogisms contain three statements (two are premises and one is the conclusion)
Categorical Syllogisms:
 contain three categorical propositions (indicator words: “all, some or no”)
 categorical propositions come in 4 forms (universal/particular affirmative/negative)
 valid categorical syllogisms contain 3 subject/predicate terms (major, minor, middle)
 Valid forms must satisfy all 6 rules of validity; breaking just one rule makes them invalid
Conditional Syllogisms:
 contain one or more conditional (if…then) statements
 antecedent follows if; consequent follows then; “If (antecedent), then (consequent)”
Pure Conditional (Hypothetical) Syllogism: “If A then B. If B then C. If A then C.”
Mixed-Conditional Syllogisms:
Modus Ponens – Latin: “the way of putting in place”
(aka: affirming the antecedent) “If A then B. A. Therefore, B.”
Modus Tollens – Latin: “the way of taking away”
(aka: denying the consequent) “If A then B. Not B. Therefore, Not A.”
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Note that the following invalid mixed-conditional forms represent opposite relationships
Denying the Antecedent:
Asserting (Affirming) the Consequent:
“If A then B. Not A. Therefore, Not B.”
“If A then B. B. Therefore, A.”
Disjunctive Syllogism: “A or B. Not A. Therefore, B.” (variation: Not B. Therefore A)
Dilemma:
 Contains a conditional premise and a disjunctive premise, and either a simple statement for its
conclusion (simple dilemma) or a disjunction for its conclusion (complex dilemma)
Counterdilemma: a dilemma whose conclusion is opposed to the conclusion of the original
Inductive Argument Forms:
Inductive Generalization: conclusion expresses a pattern or principle derived from its premises
Induction by Enumeration: asserts a generalization about an entire class based on a sample
Statistical Induction: similar to IbE, but uses statistical evidence to assert a ratio of occurrences
Reasoning by Analogy: based on comparison, asserts that a pattern of similarities will continue
Causal Connection: establishes a cause-effect relationship based on prior events and patterns
Higher Level Induction: draws on more general knowledge to claim outcomes in particular cases
Properties of deductively valid arguments:
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Deductive arguments follow strict rules of form and structure
Conclusions are drawn from information contained in the premises
If the premises are true, then the conclusion must be true
True premises cannot move to false a conclusion because of structural limitations
Conditionals (if-then statements) are often used in deductive argument forms
Properties of inductively valid arguments:
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Inductive forms and structures can be less limited and more varied
Conclusions can go beyond information contained in the premises
Inductions often assert probabilities and likelihoods rather than certainties
Conclusions are based on learned experience, patterns and regularities
True premises do not guarantee true conclusions
Fallacious Reasoning:*
Arguments that are considered fallacious can fit into one of these three fallacy categories:
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Questionable Premise: premises are not warranted or justified
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questionable premise / questionable statement
(improper) appeal to authority
inconsistency
“straw man”
false dilemma / either-or fallacy
begging the question
tokenism
Suppressed (Overlooked) Evidence: relevant information has been excluded
Invalid Inference: stated premises do not justify accepting the conclusion
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ad hominem – latin: “to the person”
guilt by association
two wrongs make a right
o common practice
o traditional wisdom
irrelevant reason
equivocation
appeal to ignorance
composition
division
slippery slope
hasty conclusion
small sample
unrepresentative sample
questionable cause
questionable analogy
questionable statistics
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questionable uses of statistics
* Avoid false charges of fallacy and Quibbling (being overly critical of others’ reasoning)