Sec 1.2 Flashcards
What is a premise?
Evidental claims for conclusion. Reaons to accept conclusion.
What is an argument?
A group of sentences containing 1 or more premises and conclusion.
What is a conclusion?
What you’re trying to prove.
What is a enthymeme?
An argument with unstated premises or conclusion.
What is inference?
Compilation of evidence to conclusion.
Define a deductive argument.
Structure for argument guaranteeing the truth of conclusion. Deductive arguments CAN NEVER have: TRUE premises and FALSE conclusions.
How is valid defined?
Premise logically entails the conclusion.
1.) All fish have 8 legs.
2.) Prof Nulty is a fish.
Conclusion: Prof Nulty has 8 legs.
How is sound defined?
An argument is sound when both valid and all premises have to be true.
1.) All humans are mammals.
2.) Prof Nulty is a human.
Conclusion: Prof Nulty is a mammal.
What is an inductive argument?
Makes a conclusion highly probable.
How is strong defined?
When premises make the conclusion highly likely to be true.
1.) Prof Nulty said the quiz is Thurs.
2.) When professors say there will be a quiz, there will be a quiz.
Conclusion: There will be a quiz on Thurs.
How is cogent defined?
When an argument is both strong and has true premises.
1.) I had coffee this morning.
Conclusion: Therefore its likely I drank something this morning.
Valid argument forms for deductive arguments?
Affirming the antecedent, denying the consequent, hypothetical syllogism, disjunctive syllogism.
Invalid argument forms for deductive arguments?
affirming the consequent and denying the antecedent.
Structure for affirming the antecedent?
If p, then q.
Is p.
Therefore, q.
VALID
1.) If birds have wings, then birds can fly.
2.) Birds have wings.
Therefore birds can fly.
Structure for denying the consequent?
If p, then q.
not q.
Therefore, not p.
VALID
If it’s raining, then the ground will be wet.
The ground is not wet.
Therefore it is not raining.
Structure for hypothetical syllogism?
If p, then q.
If q, then r.
Therefore, if p, then r.
VALID
If I drink too much, I will get bad grades.
If i get bad grades, I will get kicked out of school.
Therefore if I drink too much, I will get kicked out of school.
Structure for disjunctive syllogism?
Either p or q.
Not p.
Therefore, q.
VALID
Sam either walked or biked here.
Sam did not walk here.
Therefore Sam biked here.
Structure for affirming the consequent?
If p, then q.
q.
Therefore, p.
INVALID
1.) If Chicago is the capital of Illinois(p), then Chicago is in Illinois(q).
2.) Chicago is in Illinois(q).
Conclusion: Therefore, Chicago is the capital of Illinois (p).
Structure for denying the antecedent?
If p, then q.
Not p.
Therefore, not q.
INVALID
1.) If Joe is a bachelor (p), then Joe is a male (q).
2.) Joe is not a bachelor.
Conclusion: Joe is not a male
Valid forms for Inductive arguments?
Enumerative induction, analogical induction, hypothetical induction.
What is a enumerative induction?
Generalization from a small sample size.
X% of observed members of A are B.
Therefore, X% of the entire group of A are B.
What is a analogical induction?
Used to compare 2 things. More similiar , the more probable the conclusion.
If Object 1 has properties A, B, C and Z etc.
Object 2 has properties A, B, C etc.
Therefore, object B probably has property Z.
What is a hypothetical induction (abduction)?
Inference to the best possible explanation.
Sky is falling versus the law of gravity.
