Critical Thinking Exam 2 (Ch. 3)

steps of assessing long arguments

(1) Ensure that you understand the argument (2) locate the conclusion (3) find the premises (4) diagram it to clarify logical relationships.

modus ponens

(affirming the antecedent) A valid argument form: If p, then q./p./Therefore, q.

The first step in investigating possible implicit premises is to:

Search for a credible premise that would make the argument valid.

two forms of argument

deductive and inductive

Because of the guarantee of truth in the conclusion, inductively strong arguments are said to be truth-preserving.

false

An independent premise offers support to a conclusion:

without the help of any other premises

truth-preserving

A characteristic of a valid deductive argument in which the logical structure guarantees the truth of the conclusion if the premises are true.

syllogism

A deductive argument made up of three statements--two premises and a conclusion.

invalid argument

A deductive argument that fails to provide conclusive support for its conclusion.

valid argument

A deductive argument that succeeds in providing conclusive support for its conclusion.

sound argument

A deductively valid argument that has true premises.

dependent premise

A premise that depends on at least one other premise to provide joint support to a conclusion. If a dependent premise is removed, the support that its linked dependent premises supply to the conclusion is undermined or completely cancelled out.

independent premise

A premise that does not depend on other premises to provide support to a conclusion. If an independent premise is removed, the support that other premises supply to the conclusion is not affected.

cogent argument

A strong inductive argument with all true premises

disjunctive syllogism

A valid argument form: Either p or q./Not p./Therefore, q./In the syllogism's second premise, either disjunct can be denied.

hypothetical syllogism

A valid argument made up of three hypothetical, or conditional, statements: If p, then q./If q, then r./Therefore, if p, then r.

inductive argument

An argument in which the premises are intended to provide probable, not conclusive, support for its conclusion.

deductive argument

An argument intended to provide logically conclusive support for its conclusion.

deductive

An argument intended to provide logically conclusive support its conclusion is:

conditional statement

An if-then statement; it consists of the antecedent (the part introduced by the word if) and the consequent (the part introduced by the word then).

weak argument

An inductive argument that fails to provide strong support for its conclusion.

strong argument

An inductive argument that succeeds in providing probable--but not conclusive--support for its conclusion.

strong

An inductive argument that succeeds in providingprobable, but not conclusive, logical support for its conclusion issaid to be:

affirming the consequent

An invalid argument form: If p, then q./q./Therefore, p.

denying the antecedent

An invalid argument form:If p, then q./Not p./Therefore, not q.

The invalid argument form known as denying the antecedent has this pattern:

If p, then q. Not p. Therefore, not q..

Modus ponens has this argument pattern:

If p, then q. p. Therefore, q..

The invalid argument form known as affirming the consequent has this pattern:

If p, then q. q. Therefore, p..

practice

The best way to learn how to assess long passages containing an argument is to:

antecedent

The first part of a conditional statement (If p, then q.) the component that begins with the word if.

consequent

The part of a conditional statement (If p, then q.) introduced by the word then.

A deductively valid argument cannot have:

True premises and a false conclusion.

two invalid forms of argument

denying the antecedent and affirming the consequent.

most important skill of critical thinking

evaluating an argument involves finding the conclusion and premises, checking to see if the argument is deductive or inductive, determining its validity or strength, and discovering if the premises are true or false

The argument form modus tollens is always invalid

false

The first statement in a conditional premise is known as the consequent.

false

argument diagrams

help you visualize the function of premises and conclusions and the relationships among complex arguments with several subarguments.

two valid forms of arguments

modus ponens (affirming the antecedent) and modus tollens (denying the consequent)

tautology

statement that's trivially true sentence must always be true by virtue of premises

modus tollens

tollens (denying the consequent) A valid argument form: If p, then q./Not q./Therefore, not p.

A sound argument is a good argument.

true

Only a small portion of a passage may contain statements that serve as the premises and conclusion

true

the first step in determining whether an argument is deductive or inductive is to find the argument's conclusion and then its premises.

true

the first step in evaluating a long passage is to study the text until you thoroughly understand it.

true