Ethics/Deductive & Inductive Arguments
Invalid ALL Syllogism Type 2
All As are Bs All As are Cs Therefore, all Bs are Cs
Invalid ALL Syllogism Type 1
All As are Bs C is a B Therefore, C is an A
Valid ALL Syllogism
All As are Bs C is an A Therefore, C is a B
Valid Disjunctive Syllogism
Either p or q Not q Therefore, p
Valid Chain Argument
If p, then q If q, then r Therefore, if p, then r
Invalid Modus Tollens (negating the antecedent)
If p, then q Not p Therefore, not q
Valid Modus Tollens (negating the consequent)
If p, then q Not q Therefore, not p
Valid Modus Ponens (affirming the antecedent)
If p, then q p Therefore, q
Invalid Modus Ponens (affirming the consequent)
If p, then q q Therefore, p
Valid NONE Syllogism
No As are Bs C is an A Therefore, C is not a B
RUSTA criteria for inductive argument strength
Relevant evidence Up to date Sufficient sample size Trustworthy sources Accurate
Valid SOME Syllogism
Some As are Bs All As are Cs Therefore, some Cs are Bs
Invalid SOME Syllogism
Some As are Bs Some Cs are Bs Therefore, some As are Cs
Argument
a discourse in which some statements (premise/premises) are offered in support of another statement
conclusion
a statement that is supported by at least one other statement indicators include: so, thus, therefore, consequently, hence we may infer, . . .
premise
a statement that supports another statement indicators include: because, for, given that, the reasons are, . . .
Inductive arguments
are arguments in which true premises are intended to make the conclusion probable but do not guarantee that the conclusion is true
You too fallacy (ad hominem attack)
argument based on whether argument applies to the opponent
Strong inductive argument
argument in which it is probable, but not necessary, that if the premises are true then the conclusion is also true
Weak inductive argument
argument in which true premises do not make a true conclusion very likely
Unsound deductive argument
arguments that are either invalid or have at least one premise that is false
Uncogent inductive arguments
arguments that are either weak or have at least one false premise
ad hominem attack
attack on the person who advanced an argument resulting in the conclusion that the statement is false
False dilemma Fallacy
creates a situation in which only 2 alternatives are considered when in fact there is at least one additional option- usually the argument either (1) considers only extremes without taking into account any middle ground or (2) omits other alternatives without justification
Circumstantial ad hominem attack
instead of basing the conclusion on the merits of the premises, the conclusion is based on the opponent's circumstances
Distraction ad hominem attack
making opponent look inconsistent, self-serving, or contemptuous so we won't listen to him/her
appeal to force fallacy
occurs when a conclusion is defended by a threat to those who do not accept it
hasty generalization fallacy
occurs when a conclusion is drawn from too little evidence
straw man fallacy
occurs when an arguer misrepresents an opponent's view and then attacks his misrepresented version
Deductive arguments
reason from one statement to another by logical rules; they are arguments in which it is intended that true premises guarantee the truth of the conclusion
Cogent inductive arguments
strong arguments whose premises are also true
Valid deductive arguments
the true premises guarantee a true conclusion; the argument follows valid forms
Invalid deductive arguments
true premises do not guarantee a true conclusion; the argument follows an invalid form
Sound deductive argument
valid arguments that are also true