BUS 290: Critical Thinking for Managers Text Table of Contents #4: What are the Reasons?

What Are the Reasons? Arguments intend to convince us to accept a conclusion – i.e., a position, claim, belief, etc. Why does the author want us to accept this conclusion? Reasons tell us why that conclusion should be accepted. Will Ferrell

Identifying the Reasons For each sentence ask: Does this sentence support the conclusion? Or does it make sense when you precede the sentence with: The conclusion is true because …

Reasons Reasons + Inferences  Conclusion The acceptability of a conclusion depends on the quality of the reasons (evidence) the validity of the inferences (logic)

Should the public be shown actual courtroom trials on television? It seems as though the system can easily be corrupted by having cameras in the courtroom. Victims are hesitant enough when testifying in front of a small crowd, but their knowledge that every word is being sent to countless homes would increase the likelihood that they would simply refuse to testify. There is little to no assumed innocence for the accused when their trial is put on television. People do not watch court television because they are concerned about our country’s ability to effectively carry out the proceedings of the judicial system; instead, they are looking for the drama in witness testimony: entertainment. Thus, leave the cameras out of the courtrooms, and let the public view sitcom drama based on the legal system.

Issue: Should court trials be televised to the public? Conclusion: Do not televise court trials. R1: Televising corrupts judicial system. SR1a: Fewer victims will testify. SR1b: Presumed innocence will disappear. R2: Public wants drama in witness’ testimony (i.e., entertainment) – not judicial process.

Inference Infer  deduce or conclude (information) from evidence and reasoning rather than from explicit statements (Oxford dictionary) Validity of inference does not refer to truth of premise or conclusion refers to the form of the inference i.e., how the inference is drawn A word about inference - induction vs. deduction induction – results in probable conclusion deduction results in certain conclusion

Valid Form of Inference All fruits are sweet. A banana is a fruit. Therefore, a banana is sweet. For the conclusion to be necessarily true, the premises need to be true.

Invalid Form of Inference Leading from true premises to a false conclusion. All apples are fruit. (correct) Bananas are fruit. (correct) Therefore, bananas are apples. (incorrect) Do you understand why this argument is invalid?

Validity of Inference When a valid argument is used to derive a false conclusion from false premises, the inference is valid because it follows the form of a correct inference. A valid argument with false premises may lead to a false conclusion: All tall people are Greek. (incorrect) John Lennon was tall. (correct) Therefore, John Lennon was Greek. (incorrect) Do you understand why this argument is valid?

Validity of Inference A valid argument can also be used to derive a true conclusion from false premises: All tall people are musicians (incorrect) John Lennon was tall (correct) Therefore, John Lennon was a musician (correct) Do you understand why this argument is valid?

Quality of Evidence Facts, examples, analogies, statistics, authorities, etc. Observations, beliefs, principles Later we will explore more thoroughly how to evaluate the quality of evidence