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Moral Reasoning. What is moral reasoning?. Moral reasoning is ordinary critical reasoning or critical thinking applied to moral arguments. Critical Thinking. The careful, systematic evaluation of statements and arguments. Critical Thinking. Reasoning Well Involves Arguments.
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Moral Reasoning What is moral reasoning? Moral reasoning is ordinary critical reasoning or critical thinking applied to moral arguments.
Critical Thinking The careful, systematic evaluation of statements and arguments.
Reasoning Well Involves Arguments • Argument does not mean a verbal dispute.
Arguments • An Argument Is One or More Statements, Called Premises, Attempting to Prove Another Statement, Called a Conclusion
Statements and Arguments The statement that is being supported by the others is the conclusion. The supporting statements are called premises.
Logic:The study of the formal principles of reasoning Arguments
Deductive Argument: the truth of the premises guarantees the truth of the conclusion Arguments
Example (Valid): 1. If it snows, then it is cold (premise) 2. It snows (premise) 3. Therefore, it is cold (conclusion) VALID DEDUCTIVE ARGUMENT: The argument is in the proper form Deductive Arguments
Example (Invalid): 1. If it snows, then it is cold (premise) 2. It is cold (premise) 3. Therefore, it snows (conclusion) Deductive Arguments
INVALID : The argument is not in the proper form. Informal testing for deductive validity: Can You Think of a counter example? If yes, the argument is invalid. Deductive Arguments
Deductive Arguments Example: 1. If it snows, then it is cold (premise) 2. It is not cold (premise) 3. Therefore, it does not snow (conclusion)
Deductive Arguments Example: 1. If it snows, then it is cold (premise) 2. It does not snow (premise) 3. Therefore, it is not cold (conclusion)
If Tom Cruise is a bulldog then he has four legs (Premise) Tom Cruise is a bulldog (Premise) Therefore, Tom Cruise has four legs (Conclusion) Is the Argument Valid? Have we proven that Tom Cruise has four legs? Deductive Arguments
Deductive Arguments • If it is determined that the argument is valid it must next be determined if the argument is sound. • A sound argument is a valid argument with true premises.
If Tom Cruise is a bulldog then he has four legs Tom Cruise is a bulldog Therefore Tom Cruise has four legs Is the Argument Sound? Deductive Arguments
Arguments Inductive Argument: the truth of the premises makes the truth of the conclusion more probable
Inductive Arguments Examples: 1.All observed emeralds have been found to be green 2.Therefore, the next observed emerald will be green. 1.In the past, sugar cubes have dissolved in water 2.Thus, this sugar cube will dissolve in water. 1.70% of BCCC students in the sample are from Bristol 2. Hence, 70% of BCCC students are from Bristol
Inductive Arguments Strong Inductive Argument: Gives probable support to its conclusion such that, if its premise is true, its conclusion is also likely to be true. Ninety percent of Students at BCCC have perfect SAT scores. Therefore, John (a student at BCCC) probably has a perfect SAT score.
Inductive Arguments Weak Inductive Argument: : Does not give probable support to its conclusion, and even if its premise is true, its conclusion is not more likely to be true One percent of Students BCCC have perfect SAT scores. Therefore, John (a student at BCCC) probably has a perfect SAT score.
Inductive Arguments If it is determined that an inductive the argument is strong it must next be determined if the argument is cogent. A cogent inductive argument is a strong argument with true premises.
Inductive Arguments Ninety percent of Students at BCCC have perfect SAT scores. Therefore, John (a student at BCCC) probably has a perfect SAT score. Is the Argument Strong? Is the Argument Cogent?
Many times arguments have one or more unstated premises that need to be added to support the conclusion. Sally’s dog is a bloodhound therefore it has a keen sense of smell Unstated Premises
It is February, so I will dress warmly Drugs should not be legalized Unstated Premises
Analyzing Arguments Reconstruct the Argument • 1. Find the conclusion. • 2. Find the premises • 3. Find any unstated premises
Conclusion: * Defendant should be acquitted Premise(s): * The glove doesn't fit the defendant (premise - stated) Unstated premises: * If evidence does not fit the defendant, then the defendant should be acquitted (premise - unstated) * The glove is evidence (premise - unstated) “The glove doesn’t fit so you must acquit”
Analyzing Arguments • Evaluate the argument • 1. Is the argument valid? • (Can I think of a counter example?) • 2. Are the premises true?
1. Is the argument valid? (Can I think of a counter example?) 2. Are the premises true? If evidence does not fit the defendant, then the defendant should be acquitted The glove is evidence The glove doesn't fit the defendant Therefore, defendant should be acquitted Evaluating the Argument
Logical Fallacies • Mistakes in logic when presenting our arguments. Formal Fallacy: An invalid argument Informal Fallacy: Type of bad reasoning that can only be detected by examining the content of the argument.
Begging the Question Assuming what you are trying to prove “Capital punishment is wrong because it is immoral” Informal Fallacies
Ad Hominem Attack Attack on your opponent rather that his or her argument “The only reason that you think Capital punishment is wrong is because you are a bleeding heart liberal” Informal Fallacies
Informal Fallacies Straw Man: Misrepresenting someone’s claim or argument so it can be more easily refuted Actual statement: • “We should liberalize the laws on selling alcohol in PA.” Straw-man characterization: • “No. Any society with unrestricted access to intoxicants loses its work ethic and goes only for immediate gratification.”
Red Herring: Sidetracking the argument with an irrelevant issue “Honda makes the best cars” --- “No they don’t their workers are treated poorly” Informal Fallacies
Hasty Generalization: Drawing general conclusions from a small sample “A number of professional athletes have been convicted of crimes therefore all professional athletes are criminals” Informal Fallacies
Every moral argument should offer at least one premise that is a moral statement. A moral statement is a statement affirming that: An action is right or wrong A person is good or bad A person’s motive or character is good or bad “Capital punishment is wrong” “Harry should not lie” Moral Arguments
Moral Arguments Every moral argument should offer at least one premise that is a non-moral statement. A non-moral statement is a statement affirming that something is true or false, without assigning a moral value to it. • “Many people think that Capital punishment is wrong” • “Harry did not lie”
Bad arguments all share one of the following two problems: A conclusion that doesn’t follow from its premises. At least one false premise. Avoiding Bad Arguments
Barack Obama is a good president Barack Obama is a bad president Arguments