************ CS Club Meets 5:00 Mondays - Library - 3rd floor - Humboldt Scholars Lab * (make two rights from the staircase and it should be on your left) * come anytime! * Contact att162@humboldt.edu (Andy Thorsen) with any questions about the club * Watch for events! * Join the CS Club Discord! -> email att162@humboldt.edu with your request ************ *********** * NEXT READING ASSIGNMENT - * CHAPTER 9 - CATEGORICAL LOGIC * probably starting to discuss on Monday ********** *========= * continuing our discussion of * some classic patterns for inductive arguments * inductive generalization * predictive argument * argument from authority * causal argument * statistical argument * argument by analogy * review: inductive generalization - attributing some characteristic to most or all members of a given class * continuing with: * predictive argument - says something about the future based on based on patterns seen in the past * It has rained over 2 inches a month in January for the last 10 Januaries. So, it will PROBABLY rain over 2 inches again this January. * argument from authority - cites some expert, authority, or eyewitness * Dentists say sugary gum causes more cavities. I chew a lot of sugary gum. So I will likely have more cavities. * statistical argument - uses some numerical evidence to support its conclusion * 85% of HSU students are from California. Ana is an HSU student. So Ana is probably from California. * argument by analogy - * analogy - a comparison of 2 or more things that are claimed to be alike in some RELEVANT aspect * argument by analogy - uses an analogy to support its conclusion * Newspapers are like weather reports. We don't blame weather reports when the weather is bad. Therefore, we shouldn't blame newspapers for bad news. ************ * so, how can we talk about the "goodness" or "badness" of a deductive or inductive argument? * there ARE some specific logical terms for some of this; * for a DEDUCTIVE argument, we can judge its [logical] VALIDITY can judge its [logical] SOUNDNESS * for an INDUCTIVE argument, we can judge its [logical] STRENGTH can judge its [logical] COGENCY * deductive VALIDITY - * is ONLY about the logical STRUCTURE of the argument * 2 questions to ask: * Does the conclusion follow from the premises? IF not, it is NOT a VALID argument * Is it possible that the conclusion could be false, even if its permise(s) are true? If not, it is not a VALID argument * deductive SOUNDNESS * for a VALID deductive argument, (after determining that a deductive argument is VALID), then and ONLY then can we ask whether it is SOUND * A SOUND deductive argument is a valid deductive argument that ALSO has TRUE premise(s) AND a logical, relevant connection to its TRUE conclusions * NOTE: a true conclusion is NOT enough to determine soundness -- for example, this is an argument with valid logic and a true conclusion, BUT it is not SOUND: All fruits are vegetables. Spinach is a fruit. Therefore, spinach is a vegetable. * Note -- if a deductive argument is invalid, it cannot be sound; AND, all sound arguments are valid, BUT not all valid arguments are sound...