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
