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