Chapter 3 Reality Assumptions This chapter will cover

Reality Assumptions Beliefs about what is true and factual about the world. • Based

Detecting Reality Assumptions Toulmin’s Model • Issue: Should we use the SAT or ACT

Toulmin’s Model Claim - Students should not apply to colleges at which SAT scores

Toulmin’s Model Claim Colleges should not use standardized test scores as a measure of

Toulmin’s Model Issue: Should trials and executions be televised Copyright © 2012 Pearson Education,

Toulmin’s Model Claim: Trials and executions should be televised Warrant Reason: Public has the

Reasoning Deductive Reasoning General statement to a specific instance Copyright © 2012 Pearson Education,

Reasoning Deductive • Aims for Certainty General to Specific Inductive • Gives us Probabilities

Deductive Reasoning Syllogism- a classic example • All men are mortal. (major premise) •

Deductive Reasoning Validity • Correct form makes an argument valid (logical). • Accurate content

Deductive Reasoning is content true? All students eat pizza. Claire is a student at

Deductive Reasoning is content true? All women are terrible drivers. Jane is a woman.

Deductive Reasoning Pattern of Deductive reasoning All As are Bs. m is A. Therefore,

Deductive Reasoning Categorical Statement All As are Bs. A B A statement in which

Conditional/hypothetical syllogism Modus ponens: ‘the way of affirmation’: the antecedent leads to the consequent.

Conditional/hypothetical syllogism Modus tollens: ‘denying the consequent. ’ If A, then B A B

Deductive Reasoning Questionable Premises All drivers who speed are subject to a fine. You

Deductive Reasoning Enthymeme • Key part is implied rather than directly stated. Copyright ©

Deductive Reasoning True Valid Sound Argument: Correct Form True Premises Invalid Unsound Argument: Incorrect

Deductive Reasoning Deductive reasoning can: • Uncover Reality Assumptions • Discover Truth and Make

Skill A critical thinker uses reasoning to discover truth and prevent stereotyping Copyright ©

Chapter 3: Reality Assumptions Checkup • Reality versus value assumptions • Validity in an

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Chapter 3: Reality Assumptions This chapter will cover • Reality assumptions • Patterns of deductive reasoning • Using deductive reasoning to test logic, discover truth, make decisions, avoid stereotyping, and understand argument. Copyright © 2012 Pearson Education, Inc. All rights reserved.

Toulmin’s Model Claim - Students should not apply to colleges at which SAT scores are 200 points higher than theirs. Reason Students will not likely succeed Based on Warrant (Reality Assumption) Scores are accurate predictions of how well a student is prepared Copyright © 2012 Pearson Education, Inc. All rights reserved.

Toulmin’s Model Claim Colleges should not use standardized test scores as a measure of success. Reason Test only predicts level of struggle for first year. Warrant (Reality Assumption) Based on Students success based on character qualities that are not measured by the tests. Copyright © 2012 Pearson Education, Inc. All rights reserved.

Toulmin’s Model Claim: Trials and executions should be televised Warrant Reason: Public has the right to have more information about the courts and the judicial system. Based on (Reality Assumption) Televising trials would inform the public about our judicial system. Warrant (Value Assumption) Freedom of information is an important value Copyright © 2012 Pearson Education, Inc. All rights reserved.

Deductive Reasoning Syllogism- a classic example • All men are mortal. (major premise) • Socrates is a man. (minor premise) • Therefore, Socrates is mortal. (conclusion) Copyright © 2012 Pearson Education, Inc. All rights reserved.

Deductive Reasoning Validity • Correct form makes an argument valid (logical). • Accurate content makes it true. • When the form is valid and the content is true, the argument is sound. Copyright © 2012 Pearson Education, Inc. All rights reserved.

Deductive Reasoning is content true? All students eat pizza. Claire is a student at CSU. Is form valid? • Therefore, Claire eats pizza. Is it sound? No Copyright © 2012 Pearson Education, Inc. All rights reserved.

Deductive Reasoning is content true? All women are terrible drivers. Jane is a woman. Is form valid? • Therefore, Jane is a terrible driver. Is it sound? Yes Copyright © 2012 Pearson Education, Inc. All rights reserved.

Deductive Reasoning Categorical Statement All As are Bs. A B A statement in which members of one class are said to be included in Another class. Copyright © 2012 Pearson Education, Inc. All rights reserved.

Conditional/hypothetical syllogism Modus ponens: ‘the way of affirmation’: the antecedent leads to the consequent. If A, then B A A Therefore, B Copyright © 2012 Pearson Education, Inc. All rights reserved. B

Conditional/hypothetical syllogism Modus tollens: ‘denying the consequent. ’ If A, then B A B Not A Therefore not B If I have strep throat, then the culture will be positive. But the culture is not positive. So, I don’t have strep throat. Copyright © 2012 Pearson Education, Inc. All rights reserved.

Deductive Reasoning Questionable Premises All drivers who speed are subject to a fine. You are speeding. Which premise can be contested? • Therefore, you are subject to a fine. Copyright © 2012 Pearson Education, Inc. All rights reserved.

Deductive Reasoning True Valid Sound Argument: Correct Form True Premises Invalid Unsound Argument: Incorrect Form, True Premises False Unsound Argument: Correct Form Untrue Premises Unsound Argument: Incorrect Form, Untrue Premises Copyright © 2012 Pearson Education, Inc. All rights reserved.

Deductive Reasoning Deductive reasoning can: • Uncover Reality Assumptions • Discover Truth and Make Decisions • Combat Prejudice and Stereotyping Copyright © 2012 Pearson Education, Inc. All rights reserved.

Chapter 3: Reality Assumptions Checkup • Reality versus value assumptions • Validity in an argument • What makes a deductive argument sound • What does deductive reasoning aim to establish Copyright © 2012 Pearson Education, Inc. All rights reserved.