Logic final set 2.0 (Q39)

Argument

premises support conclusion

Premise

supporting reason

Conclusion

point being proven

Deductive argument

conclusion guaranteed true

Non deductive argument (Inductive)

conclusion probably true

Valid argument

true premises guarantee conclusion

Invalid argument

true premises could give false conclusion

Sound argument

valid + true premises

Strong argument

premises make conclusion likely

Weak argument

premises fail to make conclusion likely

Cogent argument

strong + true premises

Symbolize argument

replace statements with letters

Diagram argument

map support structure

Implicit premise

unstated support

Implicit conclusion

unstated final claim

Hook sentence

setup not argument

Conclusion indicator therefore

conclusion clue

Premise indicator because

premise clue

Conditional statement

if then statement

Antecedent

if part

Consequent

then part

Negation

opposite claim

Disjunction

either or claim

Conjunction

both claims together

Modus ponens form

If A then B A therefore B

Modus ponens clue

affirm first statement

Modus ponens valid or invalid

valid

Modus ponens diagram

conditional + A support B

What is this form?: If I study then I pass I study therefore I pass

Modus ponens

Modus tollens form

If A then B not B therefore not A

Modus tollens clue

deny second statement

Modus tollens valid or invalid

valid

Modus tollens diagram

conditional + not B support not A

What is this form?: If it rains ground is wet. The ground is not wet. There there is no rain.

Modus tollens

Hypothetical syllogism form

If A then B If B then C therefore If A then C

Hypothetical syllogism clue

chain conditionals

Hypothetical syllogism valid or invalid

valid

Hypothetical syllogism diagram

two conditionals support new conditional

What form is this?: If I sleep I dream, if I dream I remember. Therefore, if I sleep I remember.

Hypothetical syllogism

Disjunctive syllogism form

A or B not A therefore B

Disjunctive syllogism clue

remove one option

Disjunctive syllogism valid or invalid

valid

Disjunctive syllogism diagram

either or + negation support remaining option

What form is this?: Either movie or dinner, not movie. Therefore, dinner.

Disjunctive syllogism

Complex dilemma form

A or B If A then C If B then D therefore C or D

Complex dilemma clue

two paths two outcomes

Complex dilemma valid or invalid

valid

Complex dilemma diagram

disjunction + two conditionals —> new disjunction

What form is this?: Either study or sleep. If study pass. If sleep I’m rested. Therefore, pass or rested

Complex dilemma

Affirming the consequent form

If A then B B therefore A

Affirming the consequent clue

confirms result

Affirming the consequent valid or invalid

invalid

Affirming the consequent problem

other causes possible

Affirming the consequent diagram

conditional + B weakly support A

What form is this?: If I’m sick I cough. I’m coughing. Therefore, I’m sick

Affirming the consequent

Denying the antecedent form

If A then B not A therefore not B

Denying the antecedent clue

denies first part

Denying the antecedent valid or invalid

invalid

Denying the antecedent problem

B may happen another way

Denying the antecedent diagram

conditional + not A weakly support not B

What form is this?: If dog barks mail came. Dog’s didn’t bark. Therefore, no mail.

Denying the antecedent

Simple dilemma

one conclusion from two conditions

What form is this?: If hungry I eat. If starving I eat. I’m hungry or starving. Therefore, eat.

Simple dilemma

Conditional translation unless —> what is the order? : then / if

If, then

Unless I’m late I will attend class —> becomes. . .

If I’m not late then I will attend class.

Either or translation

disjunction form

If then translation

conditional form

Statistical generalization form

X percent of observed Fs are G. Therefore X percent of all Fs are G

Statistical generalization shortcut

sample to population

Statistical generalization diagram

observed cases support broad group claim

Statistical generalization strong factors

large unbiased sample

Statistical generalization weak factors

small biased sample

What generalization is this?: Three classmates cheat. Therefore most students cheat

Statistical generalization

Hasty generalization

weak broad claim from small sample

What generalization is this?: One rude tourist. Therefore, all tourists rude.

Hasty generalization

Biased sample

sample not representative

What sample is this?: Ski survey in snowy mountains.

Biased sample

Sample size

amount observed

Statistical application form

X percent Fs are G. X is F. therefore X is G

Statistical application shortcut

group statistic to individual

Statistical application diagram

percentage + category —> prediction

Statistical application strong factors

high percent relevant reference class

Statistical application weak factors

low percent weak reference class

Reference class

comparison group used

What class example is this?: 90% of swimmers fit. Mia is a swimmer. Therefore, Mia fits.

Reference class

Inference to best explanation form

observation, best explanation, therefore, probably true

Inference to best explanation shortcut

best explanation wins

Inference to best explanation diagram

evidence + comparison support hypothesis

What explanation is this?: The floor is wet because muddy paws dog probably made mess.

Inference to best explanation

Observation in explanation argument is a…

fact needing explanation

Hypothesis

proposed explanation

Comparison premise

challenges weaker explanations

Explanatory explanation

clearly explains evidence

This explanation is an example of a: explanation ignores paw prints

Explanatory weakness

Deep explanation

avoids new mysteries

What weakness is this?: Break in for cookies raises more questions.

Depth weakness

Powerful explanation

explains many cases

What weakness is this?: ghost only explains one event

Power weakness

Falsifiable explanation

testable claim

What weakness is this?: ghost cannot be tested

Falsifiable weakness