Chapter 7

Insubstantial criticism #4

Who is to say premise 2 is reasonable?

Can your own observations and sensory experiences, as well as your memories and the things you have heard or read, be relevant to the assessment of the premise?

Yes

3 ways to evaluate conditionals

a. Q must be true if P is true b. Q is probably true if P is true c. There is no connection between P and Q

Compound sentences

combining two or more simpler sentences

Example of #2

1. All professional athletes are male. 2. Bob Dylan is a professional athlete 3. Bob Dylan is male.

2 Basic ways an argument can go wrong

1. Either the proposed reasons are not properly connected to the conclusion and the argument is ill-formed. 2. Proposed reasons are not worthy of our acceptance.

Evaluating specific types of premises.

1. Specific Factual claims 2. Generalizations 3. Compound sentences

Universal Generalizations

All As are Bs

Criticisms for universal generalization

Alls As are not Bs. One A is not B.

Insubstantial criticism #2

Argument has not proven that all argument's premises are true.

Criticisms for 'All'

At least one counterexample

Only criticism you can make for valid argument is...

At least one of the premises are not reasonable to believe (or false).

If 2 arguments are competing arguments then...

Both can be weak or One can be strong and one can be weak

Types of Compound Sentences

Conjunctions, Dis-junctions, and conditionals.

Criticism for Conjunction

Criticize either P or Q

Basic Rule of Argument Evaluation #3

Direct criticisms at individual premises

Only criticism you can make for cogent argument...

Directed at premises or argument is defeated

Exclusive Interpretations of Dis-junction

Dis-junction are true if and only if exactly one of them is true P or Q but not both

Inclusive Interpretations of dis-junctions

Dis-junction is true if both of them are true, as well as one of them. P or Q or both

Basic Rule of Argument Evaluation #2

Do not accept an argument simply because you believe the conclusion

Basic Rule of Argument Evaluation #6

Do not object to intermediate conclusions of compound arguments.

Basic Rule of Argument Evaluation #5

Don't accept competing arguments.

Basic Rule of Argument Evaluation #1

Don't criticize an argument by denying its conclusion

Dis-junctions

Either P or Q

Insubstantial criticism

Fails to identify a real flaw in the argument

When critiquing a cogent argument, a single counterexample is sufficient to refute the non-universal generalization. T/F?

False

You should accept every well-formed argument whose conclusion is true. T/F?

False - When evaluating arguments, we shouldn't accept or reject an argument based on our beliefs about whether a conclusion is true or false. Instead, we must focus on the elements outlined in question #1.

Let's imagine you are faced with competing arguments and that you can't identify a flaw in either of the two arguments. In such cases, it's best to suspend judgment about both. T/F?

False? Whenever a person considers any proposition, that person must believe the proposition, or disbelieve the proposition, or suspend judgment about the proposition. A person cannot at any time have more than one of these attitudes toward one proposition

Sufficient Condition

If A is true, then B must be true (If A then B)

Necessary Condition

If B is true, then A must be true (If A then B)

Conditionals

If P then Q

Cogent arguements

If premises are true, and argument is undefeated, then the conclusion is at least probably true.

Valid argument

If premises are true, then conclusion is true as well.

Belief Principle

Impossible for you to believe both a statement and its denial

Non-universal generalizations.

Most As are Bs.

Criticism for non-universal generalization

Most US presidents are male. Criticism - More than 50% of US president are female.

Can both competing arguments be strong?

No - there must be something wrong with at least one of the arguments.

Criticism for 'some' and 'few'

None

Criticism for 'several'

None, anything less than several

Basic Rule of Argument Evaluation #4

Only reasonable to reject the argument on the basis of a substantial criticism

Conjunctions

P and Q... And

Insubstantial criticism #3

Premise 2 is merely an opinion, no a fact, and so no evidence is relevant to the truth or to falsify of it.

Insubstantial criticism #1

Premise 2 might be false. . . The possibility that a premise is false is not an adequate criticism. Ex. ) Maybe that is not true.

Well formed argument is....

Premises provide good support for the conclusion.

Although a clear and specific counterexample is the best criticism of a universal generalization, pointing out that there is no evidence supporting a generalization and that there are counterexamples to relevantly similar generalizations can be a good criticism. T/F?

True

It is a good policy to replace conditional statements by generalizations when you can. T/F?

True

Some arguments are weak because the conjunction of premises is unreasonable to accept, even though each premise by itself is fairly reasonable. T/F

True