What You’ll Learn Here I. How to recognize arguments II. How to analyze arguments by 1. Recognizing the ultimate conclusion 2. Determining which other ideas are important 3. Seeing how these other ideas work together to support the ultimate conclusion Critical Thinking III. How to evaluate arguments by 1. Appreciating the structure of the argument The Very Basics 2. Evaluating the premises (at least as I see them) 3. Evaluating the inferences 4. Assessing the argument as a whole IV. How to construct arguments by Dona Warren 1. Deciding upon the ultimate conclusion Department of Philosophy 2. Constructing the chain of reasoning The University of Wisconsin – Stevens Point 3. Communicating the argument The Four Big Steps The Nature of Basics I. Recognizing Arguments • A few, relatively simple, skills II. Analyzing Arguments • Sometimes (and mistakenly) unappreciated III. Evaluating Arguments • The building blocks for any IV. Constructing Arguments more advanced activity • Admit of endlessly Note: It’s very important to sophisticated applications analyze before we evaluate. I. Recognizing Arguments First example An argument is a unit of reasoning that “Critical thinking is taught at many colleges attempts to prove that a certain idea and universities. Courses devoted to critical is true by citing other ideas as thinking are often offered by philosophy departments, but critical thinking skills are evidence. taught in every subject, from art to zoology.” “Is this passage trying to get me to believe something by making a case for its truth Not an argument. rather than by simply asserting it?” “Yes” = It’s an argument. “No” = It’s not an argument. 1 Second example II. Analyzing Arguments “Critical thinking helps people to reason 1. Identify the ultimate conclusion more easily and effectively and prevents 2. Determine which other ideas them from being easily taken in by shoddy arguments. These skills are essential to a are important. happy and productive life, so everyone 3. Determine how these other should study critical thinking.” ideas work together to support An argument. the ultimate conclusion. 1. Identify the Ultimate Conclusion 2. Determine What Other Ideas are Important The ultimate conclusion is the main An idea is important if it helps the idea that the argument is trying to argument to establish the truth of the prove. ultimate conclusion. Frequently, some of the sentences in a Sometimes, it’s unstated. passage that contains an argument don’t convey important ideas. 3. See How these i. Premise / Ultimate Conclusion Other Ideas Work Together Premise to Support the Ultimate Conclusion Inference Idea This is an idea This is the connection that that the holds between the idea(s) argument at the top of the arrow assumes to be Four Basic Patterns of Cooperation and the idea at the bottom true without of the arrow when the support. truth of the idea(s) at the Idea top is supposed to Combinations of Basic Patterns establish the truth of the Ultimate idea at the bottom. Conclusion (This is an argument diagram.) 2 For example: ii. Subconclusions “What’s your opinion of critical thinking? Critical Premise thinking helps us to understand how other people Idea think. Therefore, critical thinking is important.” Subconclusion Critical thinking helps us to This is an understand how other people Idea Inference intermediate idea Indicator think. on the way from the Expression premises to the (Conclusion ultimate conclusion. Indicator) Idea Critical thinking is important. Ultimate Conclusion For example: “What’s your opinion of critical thinking? Look at it this iii. Dependent Reasons way. Critical thinking helps us to understand the arguments that other people give. Thus, critical thinking helps us to understand how other people think. Therefore critical thinking is important.” Dependent Reasons Critical thinking helps us to understand the arguments that Neither idea can other people give. Idea + Idea support the conclusion alone but together they can Critical thinking helps us to understand how other people support the think. conclusion. Idea Critical thinking is important. For example: “Critical thinking helps us to understand how we iv. Independent Reasons think because in the process of assessing arguments, we clarify our own basic assumptions Inference Indicator and clarifying our own basic assumptions helps us Expression to understand how we think. I really enjoy teaching and studying critical thinking.” (Reason Independent Reasons Indicator) Each idea can support In the process of Clarifying our own basic Idea Idea the conclusion on its assessing arguments, we assumptions helps us to own. clarify our own basic + understand how we assumptions. think. This gives us independent lines Idea of reasoning. Critical thinking helps us to understand how we think. 3 Combinations of the For example: Four Basic Patterns “Critical thinking is important since it helps us to understand how other people think. It’s also For “What’s your opinion of critical thinking? Look important because it helps us to understand how example: at it this way. Critical thinking helps us to we think.” understand how other people think because it helps us to understand the arguments that other people give. Hence critical thinking is Critical thinking helps us to Critical thinking helps us important. In addition, in the process of understand how other people to understand how we assessing arguments, we clarify our own basic think. think. assumptions, and clarifying our own basic assumptions helps us to understand how we think, so critical thinking helps us to Critical thinking is important. understand how we think. I really enjoy teaching and studying critical thinking.” Combinations of the Four Basic Patterns III. Evaluating Arguments In the process Clarifying our of assessing own basic Critical thinking arguments, we assumptions •A good argument establishes the truth of helps us to clarify our own + helps us to its ultimate conclusion and gives its audience understand the basic understand how arguments that good reason to think that the ultimate assumptions. we think. other people give. conclusion is true. ☺ •A bad argument either doesn’t establish the Critical thinking helps Critical thinking helps us to understand how us to understand how truth of its ultimate conclusion or else other people think. we think. doesn’t give its audience good reason to think that the ultimate conclusion is true. Critical thinking is important. III. Evaluating Arguments 1. Appreciate the Structure of the Argument 1. Appreciate the Structure of • A good argument must have at the Argument least one good line of reasoning. 2. Evaluate the Premises • A good line of reasoning must 3. Evaluate the Inferences have all good premises and all 4. Assess the Argument good inferences. 4 For example: 2. Evaluate the Premises Idea ☺ Idea Idea ☺ 1. “Is this premise true?” ☺ ☺ ☺ - Here, we think with our own head. Idea Idea Idea 2. “Would most members of the argument’s audience, including people who don’t already Idea ☺+ Idea Idea ☺+ Idea ☺ Idea ☺+ Idea ☺ believe the ultimate conclusion, believe this ☺ ☺ ☺ premise?” - Here, we try to view the premise through Idea Idea Idea someone else’s eyes. 3. “Does the argument’s audience have good reason Idea Idea ☺ Idea Idea ☺ to believe this premise?” ☺ ☺ ☺ ☺ • If one answer is “no,” the premise is bad. Idea Idea • If all answers are “yes,” the premise is good. For example: For example: Plausibly true and acceptable to audience. “Sometimes believing the truth isn’t very useful, but Can be believed only many people think that we should try to believe the False by someone who truth anyway. Such people maintain that it’s more already believes the ☺ ultimate conclusion important to have true beliefs than useful ones. Are Most We can’t know these people right? Well, first of all, philosophers philosophers for certain that think that our beliefs are think that useful beliefs are more important than useful true. beliefs are Anything true beliefs and anything that most philosophers more that most Having true think must be right. Second, having true beliefs is important philosophers beliefs is less important than less important that having useful beliefs. And finally, than true + think must be It’s pointless to beliefs. right. having useful even try to since we can’t know for certain that our beliefs are beliefs. believe the truth. true, it’s pointless to even try to believe the truth.” It’s more important that our beliefs be useful than that they be true. (Unstated) 3. Evaluate the Inferences The Bob Method Bob is a perfectly gullible, perfectly Reason (R) Reason (R) rational fellow. The inference is valid = If R were true e.g. Your then C would have to be true as well. ☺! neighbor is a Bob believes R. Martian. How likely is Bob to believe C? The inference is good = If R were true ≠ then C would probably be true as well. ☺ • If Bob is compelled to believe C, the inference is valid. ☺! Conclusion (C) e.g. Your • If Bob is inclined but not The inference is bad = Even if R were neighbor is an compelled to believe C, the Conclusion (C) true, C could very easily be false. extraterrestrial. inference is good. ☺ • If Bob is not at all inclined to believe C, the inference is bad. 5 The Bob Method For example: Bob is a perfectly gullible, perfectly ☺ Reason (R) rational fellow. Most We can’t know philosophers Weak inference for certain that e.g. Your think that Bob believes R. our beliefs are neighbor is a useful true. Martian. beliefs are Anything How likely is Bob to believe C? more that most Having true important philosophers beliefs is less than true + think must be important than It’s pointless to beliefs. right. having useful even try to beliefs. believe the truth. Conclusion (C) The Bob Method helps us to see the ☺ world as someone who accepts certain ☺! e.g.