PHL131 Exam 1

What is a claim?

An assertion that can be true or false.

Does a claim have to be true to count as a claim?

No. A false assertion still counts as a claim.

What are two common types of nonclaims?

Questions and commands.

What is a factual claim?

A claim concerning something objectively true or false, independent of someone's preferences.

Does "factual claim" mean the claim is true?

No. Factual describes the type of claim, not whether the claim is true.

What is a nonfactual claim?

A claim concerning subjective or evaluative matters.

What is an opinion?

A belief or judgment.

Can an opinion be factual?

Yes. Opinions can be factual or nonfactual.

Can opinions differ in how well-reasoned they are?

Yes. They can be well supported or poorly supported.

Does saying "that's just your opinion" prove a claim is false?

No.

What is an issue?

A question raised about a claim.

When asked to identify an issue, what form should your answer take?

A question.

What is an argument?

A group of claims in which premises support a conclusion.

What is a premise?

A claim offered as support for a conclusion.

What is a conclusion?

The claim that the premises are intended to support.

Does an argument have to involve disagreement?

No.

What is an enthymeme?

An argument containing an unstated premise.

What is critical thinking?

Evaluating claims and reasoning using relevant criteria.

What is a mere opinion?

A position stated without supporting reasons.

What is a report?

A passage describing events or what someone said.

What is an explanation?

A passage explaining why an accepted event occurred.

What is the main difference between an explanation and an argument?

An explanation explains an accepted event. An argument gives reasons for accepting a conclusion.

What does an argument do?

Offers reasons to accept a conclusion.

Is a single conditional statement automatically an argument?

No. An if-then statement alone asserts a relationship.

What are common conclusion indicator words?

Therefore, so, hence, consequently.

What are common premise indicator words?

Because, since, on account of.

Does "because" always introduce a premise?

No. It can introduce a premise or an explanation.

Does "since" always indicate a premise?

No. It can also refer to time.

What is the first step when reconstructing an everyday argument?

State the main issue as a question.

What is the second step when reconstructing an argument?

State the author's conclusion as one declarative sentence.

What is the third step when reconstructing an argument?

List the supporting reasons separately.

What is the fourth step when reconstructing an argument?

Identify needed unstated premises and label them as unstated.

What should you avoid putting inside the conclusion when reconstructing an argument?

The supporting "because" clause.

What is a deductive argument?

An argument intended to establish that its conclusion must follow if its premises are true.

What is a valid argument?

An argument where no possible case has all true premises and a false conclusion.

What is an invalid argument?

An argument where at least one possible case has all true premises and a false conclusion.

What is a counterexample to an argument?

A case where all premises are true and the conclusion is false.

What is a sound argument?

A valid argument with all true premises.

What two conditions make an argument sound?

Validity and all true premises.

What must be true about the conclusion of a sound argument?

The conclusion must be true.

Can a valid argument have false premises?

Yes.

Can a valid argument have a false conclusion?

Yes, but at least one premise must be false.

Can a valid argument have all true premises and a false conclusion?

No.

Can an invalid argument have a true conclusion?

Yes.

Does a true conclusion prove an argument is valid?

No.

What property applies to claims, truth or validity?

Truth.

What property applies to arguments, truth or validity?

Validity.

What is an inductive argument?

An argument intended to make its conclusion probable rather than logically guaranteed.

How are inductive arguments evaluated?

As strong or weak.

Can a strong inductive argument have a false conclusion?

Yes.

What is inductive reasoning by analogy?

Two things share relevant features, so they probably share another feature.

What is an inductive generalization?

A sample has a characteristic, so the broader population probably has it too.

What is balance-of-considerations reasoning?

Several reasons are weighed together, sometimes mixing deductive and inductive support.

How many counterexamples are needed to prove a deductive argument invalid?

One.

What does "Everyone leaves at some point" fail to establish?

That everyone leaves at the same time.

What does ~P mean?

Not P.

What does P & Q mean?

P and Q.

What does P v Q mean?

P or Q.

What does P → Q mean?

If P, then Q.

What does // mean in an argument?

Therefore. It separates the premises from the conclusion.

What rule should you follow when assigning letters during symbolization?

Assign one letter to each complete basic claim and keep its meaning consistent.

Translate: If P, then Q.

P → Q

Translate: Q if P.

P → Q

Translate: P only if Q.

P → Q

Translate: P is sufficient for Q.

P → Q

Translate: P is necessary for Q.

Q → P

Translate: P if and only if Q.

(P → Q) & (Q → P)

Translate: P but Q.

P & Q

Translate: Neither P nor Q.

~(P v Q)

What is an equivalent form of ~(P v Q)?

~P & ~Q

Translate: Not both P and Q.

~(P & Q)

What is an equivalent form of ~(P & Q)?

~P v ~Q

Translate: Exactly one of P and Q.

(P v Q) & ~(P & Q)

For P → Q, which condition is sufficient?

P is sufficient for Q.

For P → Q, which condition is necessary?

Q is necessary for P.

What does a sufficient condition do?

Guarantees something.

What does a necessary condition mean?

It is required for something.

If being a dog is sufficient for being a mammal, how is this symbolized?

D → M

If being a mammal is necessary for being a dog, how is this symbolized?

D → M

Does being a mammal guarantee being a dog?

No.

What is the "only if" rule?

The words before "only if" go on the left side of the arrow.

Translate: I pass only if I study.

P → S

Translate: I pass if I study.

S → P

What is the difference between "P if Q" and "P only if Q"?

P if Q = Q → P. P only if Q = P → Q.

Translate: P unless Q.

~Q → P

What is an equivalent form of ~Q → P?

P v Q

Translate: I will attend unless I am sick.

~S → A

Does "I will attend unless I am sick" mean sickness guarantees absence?

No.

Translate: Jack will not go unless Sarah goes.

~S → ~J

What is another equivalent form of "Jack will not go unless Sarah goes"?

J → S

What is another equivalent disjunction for "Jack will not go unless Sarah goes"?

~J v S

What is the main connective?

The connective governing the entire formula.

What is the main connective of A & (B → C)?

&

What is the main connective of ~(A & B)?

The initial ~.

What is the main connective of ~(A v B) → ~(A & B)?

→

What is the main connective of (A → B) v C?

v

What should you ignore when finding the main connective?

Parentheses enclosing the entire expression.

Why are parentheses important in symbolization?

They determine the structure and meaning of the formula.

Translate: He will reject the results if he loses or the results are close.

(L v C) → R

What is the difference between "not both" and "exactly one"?

Not both allows neither to occur. Exactly one requires at least one and excludes both.