Say What? Finding the Logic Behind Good Arguments

1. Say What? Finding the Logic Behind Good Arguments

2. On your own paper, answer the following question. Hold onto it, we’ll get to it in a moment… What is one thing which you must know for CERTAIN? What is one thing you can accept a “probably” or “likely” answer to?

3. Objectives • Define the key terms you need to understand argumentation. • Learn key “marker” words that indicate premise and conclusion. • Practice finding parts of an argument in several passages. • Listen and record two premises and two conclusions from the courtroom scene in the movie, A Few Good Men.

4. To understand arguments and logic, you have to speak the language. • Define each of the key terms in the next few slides. Feel free to add any illustrations that may help you remember the definitions. These terms will be on your quiz on Friday.

5. Argument A conclusion together with the premises that support it. Classic Example: • All men are mortal. (Premise) • Socrates is a man. (Premise) • Therefore, Socrates is mortal. (Conclusion)

6. Premise A reason offered as support for another claim

7. Conclusion The claim being supported by a premise or premises.

8. Valid Argument An argument in which the premises genuinely support the conclusion. Example: All students in Mrs. Watson’s first hour are sophomores. Mrs. Watson teaches English. Therefore, Mrs. Watson must teach English to sophomores.

9. Unsound Argument An argument that has at least one false premise. Example: If the streets are wet, it must have rained recently.The streets are wet this morning, therefore, it must have rained. (WHY is the premise wrong?)

10. Deductive Argument An argument whose premises make its conclusion certain Example: Bergen is either in Norway or Sweden. If Bergen is in Norway, then Bergen is in Scandinavia. If Bergen is in Sweden, the Bergen is in Scandinavia. Therefore, Bergen is in Scandinavia. **Red=Premise Blue=Conclusion**

11. Inductive Argument an argument whose premises make its conclusion likely Example: It has snowed in Massachusetts every December in recorded history.Therefore, it will snow in Massachusetts this coming December.

12. Premise Marker Words • Since • Because • For • As • Follows from • As shown by • Inasmuch as • As indicated by • The reason is that • May be inferred from • May be derived from • May be deduced from • Given that

13. Conclusion Marker Words • Therefore • Hence • So • Accordingly • Consequently • Proves that • As a result • Thus • For this reason • For these reasons • It follows that • I conclude that • Which shows that • Which means that • Which entails that • Which implies that

14. Practice…Identify the Premise and Conclusion in this argument. “Since pain is a state of consciousness, a ‘mental event,’ it can never be directly observed.” (source: Peter Singer, “Animal Liberation,” 1973) Premse: Pain is a state of consciousness, a “mental event” Conclusion: Therefore, since pain happens inside the mind, it cannot be observed.

15. And the answer is… Premise: Pain is a state of consciousness, a “mental event” (The marker word was SINCE.) Conclusion: Therefore, since pain happens inside the mind, it cannot be observed. (The marker word was THEREFORE.)

16. It’s your turn now. • With your small group, read through the first five arguments in your logic handout. Underline the premises and circle the conclusions. You have 7 minutes.

17. Argument in the movies The witness on the stand, played by Jack Nicholson, is Col. Jessup. The lawyer, played by Tom Cruise, is Lt. Kaffee. 1. Listen carefully for the premises of the arguments that Lt. Kaffee uses to question Col. Jessup. Write down all the marker words that you hear. 2. How does Col. Jessup refute the arguments? 3. What do YOU think is the truth? Can you handle it?