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Learn how persuasive discourse works and how to construct persuasive arguments. Explore the motivations behind persuasion and the importance of good argument structures. Discover how to identify premises, conclusions, and missing elements in arguments.
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BBI3420 / 3436 ARGUMENTS
Persuasive Discourse • Why do they want to persuade? • Authors • Advertisers • Prosecutors • Politicians • Perspective employees
Persuasive Discourse • Why do they want to persuade? • Authors: the truth of particular ideas • Advertisers: consumers to buy products • Prosecutors: convince the jury that the accused is guilty • Politicians: the electorate to vote for them • Perspective employees: employers to hire them
Persuasive Discourse: Arguments • Argument: a form of reasoning in which one draws a conclusion based upon particular pieces of evidence. • Bierman and Assali (1996), “…a sequence of statements in which statements, called premises, are given as reasons or evidence for the truth of a statement, called the conclusion” (p. 33).
Persuasive Discourse: Arguments • In persuasive communications, arguments are very important because a speaker has to convince the listeners. • The speaker should be able to construct arguments that have good argument structures
Critical thinking is primarily about the evaluation of arguments. • Definition of an argument: • a set of statements of which it is claimed that one of those statements (the conclusion) is supported by the others (the premises). • a reason or reasons offered for or against something
ARGUMENT = CONCLUSION (assertion) + PREMISES = THESIS STATEMENTS + SUPPORTING DETAILS
Example – A Simple Argument • Lawyers earn a lot of money. (Premise) • I want to earn a lot of money. (Premise) • I should become a Lawyer. (Conclusion)
Sometimes some arguments have unstated premise and conclusion. • In this case, inference indicators signal the occurrence of the premise and conclusion.
Example: [Premise] “You can’t check books out of the library without an ID card. So [conclusion] Bill won’t be able to check any books out” The word ‘so’ is the inference indicator to signal the conclusion.
Identifying Premises & Conclusions
Identifying the conclusion • An argument's conclusion is what the person making the argument is ultimately trying to convince you of, i.e., the person's point. • To identify the conclusion of an argument 'what does the person making the argument want me to walk away thinking?' (If the answer is 'nothing', then you're not dealing with an argument.)
Identifying the conclusion • Location • Logical Indicator of words • Analysis of the content of the paragraphs
Identifying the conclusion Location • The thesis of the paragraph, section or article is often the conclusion. • Usually at the beginning, at the end or both
Identifying the conclusion Location When the city reconstructs our street next autumn, it should not widen it. I live on a hill and my current driveway is very steep where it connects with the street. If the city widens the street, my driveway will be so steep that I will scrape my tailpipe and bumper on the asphalt, ruining my car and gouging the new street. Keep the street that same width!
Identifying the conclusion Logical Indicator of words • Try putting the word "therefore" before each of the statements in turn. The statement that fits best will be the conclusion. • Lawyers earn a lot of money. • I want to earn a lot of money. • I should become a Lawyer.
Some Conclusion Indicator Words: • Look for conclusion indicator words, such as: therefore, consequently, as a result, thus, it follows that, so, which shows that, hence, accordingly
Identifying the Premises • Every argument must also consist of at least one premise. • A premise is a statement that is meant to support the conclusion. Ideally, a premise provides a good reason for believing the conclusion. • (justification)
Some Premise Indicator Words: • To identify premises, it often easiest to look for premise indicator words, words that are often used to introduce a claim as a premise such as: because, since, as, for, given that, as, judging from, seeing that
Missing Premises and Conclusions: • People don't always come out and say what their point is. Similarly people may not always explicitly mention all the premises they are working with. • As a result, we must be prepared to identify both missing premises and missing conclusions (i.e., conclusions or premises that are not explicitly stated by the arguer, but that are implicit in what the arguer does say).
Missing Premises and Conclusions: • Apply all our background knowledge about the probable intentions of the author. • Use an important principle of interpretation called the Principle of Charity tells you always to interpret an argument so as to make its reasoning the best possible.
Missing Premises and Conclusions: • "8:30 is too early to go to bed. All my friends are allowed to stay up till 9:30.“ • If we were to put an inference indicator into this argument, which indicator would we choose and where would we put it? There are two main choices:
Missing Premises and Conclusions: • "8:30 is too early to go to bed. All my friends are allowed to stay up till 9:30.“ • A: "8:30 is too early to go to bed, therefore all my friends are allowed to stay up till 9:30.“ • B: "8:30 is too early to go to bed, because all my friends are allowed to stay up till 9:30." Which is the better reading: A or B?
Exercise 1 Make a will. Otherwise, the state will determine who gets your stuff.(Andrew Tobias, "Isn't It Time You Faced the Future?" 2001) Identify the premise(s) and conclusion of this argument.
Exercise 2 Because she could not see so far, the children were able to play in safety. Identify the premise(s) and conclusion of this argument.
Exercise 3 The main reason I believe Australia should have nothing to do with SDI (Star Wars) research is that the whole plan is discredited. Hardly any scientists of note support it … Find the first word of the conclusion
Exercise 3 8:30 is too early to go to bed. All my friends are allowed to stay up till 9:30. Identify the premise(s) and conclusion of this argument.
Identify the inference indicator: • Indian Classical music is very difficult to play because it requires you to improvise in a very sophisticated fashion. • While many people realise that global warming will change the nature of our agricultural practices, very few people realise the extent of the changes that are coming. Thus most people in agriculture are quite complacent about their current ways of doing things.
Identify the inference indicator: • Indian Classical music is very difficult to play because it requires you to improvise in a very sophisticated fashion. • While many people realise that global warming will change the nature of our agricultural practices, very few people realise the extent of the changes that are coming. Thus most people in agriculture are quite complacent about their current ways of doing things.
Identify the inference indicator: • Australia has only sufficient water resources to permanently sustain a population of 15 million. This means that the current Australian population is much too large. • Suppose I agree with you that economic prosperity is not fairly distributed among all the world's people. It doesn't follow that I have a moral duty to do something about it. I am not personally responsible for the plight of the world's poor. I didn't impoverish them, so I am not morally bound to help them.
Identify the inference indicator: • Australia has only sufficient water resources to permanently sustain a population of 15 million. This means that the current Australian population is much too large. • Suppose I agree with you that economic prosperity is not fairly distributed among all the world's people. It doesn't follow that I have a moral duty to do something about it. I am not personally responsible for the plight of the world's poor. I didn't impoverish them, so I am not morally bound to help them.
Diagramming Arguments Congruent and Linked Arguments
Kinds of Argument Structures • 4 major argument types • Simple Arguments • Convergent Support Arguments • Linked Support Arguments • Complex/Extended Arguments
Simple arguments • Simple arguments have one "layer" of premise. That is, no premise also functions as a conclusion. • 1. Single Support Arguments • Example: • I think I should buy this used Toyota Corolla. Why? They're practically giving it away. • P1: They're practically giving it away. • MC: I think I should buy this used Toyota Corolla.
Simple Argument • The gods have all the very best qualities. Intelligence is one of the very best qualities. Therefore the gods are intelligent. • *As you can see “the gods have all the very best qualities and intelligence is one of the very best qualities” are both the premises and ” therefore the gods are intelligent” is the conclusion. Both of the premises are true and therefore support and prove the conclusion to be true.*
Convergent Support Arguments • If a premise can stand on its own, that is, if it adds to the likelihood of the conclusion being true on its own, and there is more than one premise like this, we have a convergent argument. • Example: • I think I should buy this used Toyota Corolla. It is in good shape, it gets good mileage, and besides, it is within my budget. • P1: The car is in good shape • P2: It gets good mileage • P3: It is within my budget • MC: I should buy this used Toyota Corolla
Convergent Argument • Nuclear power plants should not be built, because they are dangerous. And, the power from these plants is not essential. Finally, these plants are not fair to future generations. • *This is a perfect example of an convergent argument. Although the claim is not supported with evidence this does not disregard that the other two claims which are very much relevant to to the topic but they do not support the fact that “Nuclear power plants should not be built, becuase they are dangerous.”
Linked Support Arguments • We link premises when it is clear that a premise by itself will not lead to the conclusion. It is a question of relevance. • Example: • I think I should buy this used Toyota Corolla. I need a car, and I like this one. • P1: I need a car • P2: I like this car • MC: I should buy this used Toyota Corolla • Note that neither premise can stand by itself. Could the argument be, "I need a car, therefore I should buy this used Toyota Corolla."? No, because we might ask, why this car? Could it be "I like this car, therefore I should buy this used Toyota Corolla."? No - just because you like a car doesn't mean you should buy it. Both premises are needed together.
Divergent Argument • “It is going to rain, so we will get wet and the game will get canceled.” • *This is an example of a divergent argument. Although it is awkwardly phrased it still stands true that what is being said in the statement is in fact true. Another way to really clarify the premise and conclusion would be to say the following “Due to the fact that it is going to rain we will get we and the game will get cancelled.”*
An Argument • An argument = a set of statements connected by a special relationship of justification; the statements provide evidence for the main claim
Independent Premises • Falsity of one doesn’t cancel support the other provides.- independent proof. • You shouldn’t buy a T.V. that costs over $300. This costs $450. It is also too big for your room. Don’t buy this T.V.
Dependent Premises • Falsity of one can cancel support for others-interconnected. • These premises cannot stand alone to provide proof.
Example of Dependent • No floor with 2x4 joists on two foot centers is strong enough. This floor has 2x4 joists on two foot centers. So, this floor is not strong enough.
Convergent Arguments • In convergent arguments, the premises provide different and independent reasons for the claim. Each can support the claim by itself.
Example-Convergent • Nuclear power plants should not be built, because they are dangerous. And, the power from these plants is not essential. Finally, these plants are not fair to future generations.
Linked Arguments • Linked argument- one in which the reasons are dependent on one another for their strength. They cannot stand alone.
Linked Argument • There is reason to think the suspect is linked to this crime. The shots were fired from a jaguar; jaguars are not usual to this area; and the suspect owns a white jaguar.
Argument Diagramming • Identify each claim and number them. • Provide missing parts if needed. • Determine relation of claims and diagram.