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A little logic


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A little logic

  1. 1. Created by Simpo PDF Creator Pro (unregistered version) UFOs – Unidentified Flying Objects Ufology – is a neologism coined to describe the collective efforts of those who study reports and associated evidence of unidentified flying objects (UFOs). Ufologist – A ufo investigator is called a ufologist Ufo Sightings- Some eye witnesses to the UFOs Roswell Incident- called the Roswell UFO crash 1947 UFO Conspiracy – Worldwide UFO cover Ups and related theories Alien- An extra-terrestrial being is called an alien
  2. 2. Created by Simpo PDF Creator Pro (unregistered version) The Nature and Scope of LogicNote: The examples are reprinted from With Good Reason: An Introduction to InformalReasoning by S. Morris Engel (St. Martin’s Press, 1986). Many of the explanations come fromthe same source. Logic is the study of argument. Not “argument” in the sense of a quarrel,but an “argument” in the sense of a piece of reasoning in which one or morestatements are offered as support for some other statements.There are two components of an argument: the premise(s) and the conclusion(s) conclusion- the statement being supported in the argument (generally preceded by words like therefore, hence, consequently etc.) premise- the reasons given in support of the conclusion (generally preceded by words like because, for, since etc.) “This is so (conclusion) because that is so (premise).” “This is so and this is so (premises), therefore that is so (conclusion).”Exercises: Distinguish between the premise(s) and conclusion by marking them. * There are no UFOs in the area. We haven’t seen one all day. * All Democrats oppose capital punishment; Senator Wellstone opposes it; he must be a Democrat. * Since all rational beings are responsible for their actions, and since all human beings are rational, it follows that all human beings are responsible for their actions. * Tom must have left already. He doesn’t answer his phone. * Smith ought to exercise more. It would be good for his condition.
  3. 3. Created by Simpo PDF Creator Pro (unregistered version) Many types of communications are not arguments. Questions are notarguments, nor are announcements, complaints, compliments, or apologies. Suchcommunications are not arguments because they make no effort to persuade byoffering reasons in support of their claims. This does not mean that such passagesare bad arguments; it simply means that they are not arguments at all. They fulfillother legitimate, and often necessary, functions.Exercises: Label whether each of these are “arguments” or “non-arguments”. * Back in the 1980s there was an actor named Gary Coleman. I believe he was a short guy. I think he was popular for a couple of years. What happened to him? “Argument” or “non-argument”? * The main issue is life is not the victory but the fight. The essential thing is not to have won but to have fought well. (Baron Coubertin, founder of the modern Olympics. “Argument” or “non-argument”? * You shouldn’t have legislation against a thing that the majority of the population does. And today the majority speeds. Speeding should be legalized. “Argument” or “non-argument”? In the context of argument, an element is “suspect” if it is made to carrymore weight that it is capable of doing. We need to ask such questions as: Are thefacts cited in support of a conclusion sufficient as such in support? Are theyrelevant? Are the illustrations apt? To what degree? Is the wording clear so thatwe know what the author intends? The following exercises will consider “suspectelements”.Exercises: Read each quote and briefly answer the question that follows. * In a press conference on May 13, 1982 President Reagan said the following regarding missiles carried by submarines and bombers: “You are dealing there with a conventional type of weapon or instrument, and those instruments can be intercepted. They can be recalled if there has been a miscalculation.” Was Reagan referring to the submarines or missiles when he said “they”?
  4. 4. Created by Simpo PDF Creator Pro (unregistered version) What did his critics contend? What do you think Reagan claimed? * When on September 27, 1984, a terrorist zig-zagged an explosive-laden truck around concrete barriers and set off a blast that once again killed many people at the still unfinished and poorly secured American embassy in Beirut, President Reagan responded as follows to critics: “Anyone that’s ever had their kitchen done over knows that it never gets done as soon as you wish it would.” Is this an apt illustration? Is the analogy meaningful? Inappropriate? * You shouldn’t have legislation against a thing that the majority of the population does. And today the majority speeds. So speeding should be legalized. Is it really the case that we should not have legislation against something the “majority does”? Would this apply if the majority were prejudiced? An argument’s structure may be misleading or deceptive because it hasmissing components. Such arguments may appear sounder that they are becausewe are unaware of important assumptions made by them and on which they rest.Such assumptions need to be dug out, if hidden, or made explicit, if unexpressed. It will be easier to find missing components of an argument if we rememberthat many arguments consist of a statement of a general principle, the citing of acase of it, and a conclusion which infers that what is true of the general principle istrue of the case in question. Consider this classic example: All men are mortal. (the general principle) Socrates is a man. (the case) Socrates is mortal. (the conclusion)
  5. 5. Created by Simpo PDF Creator Pro (unregistered version) http://www.simpopdf.comExercises: Supply the missing elements in these arguments. If you can, identifywhich “part” of the argument was missing (i.e. general principle, case, orconclusion). * These are natural foods and therefore good for you. * “Yon Cassius has a lean and hungry look; such men are dangerous.” * This must be a good book; it was chosen by the Book-of-the-Month-Club. * The speaker criticizes free enterprise; he must be a communist. * We do not want a democracy in this land, because if we have a democracy a majority rules. (Rev. Charles Staley)A question to consider: Is logic an art or a science?This is enough for now. Try to have this done for the next class session, andwe will discuss the examples.