Logic: American Association of State Colleges and Universities and Subsequent Rights Restrictions

Sequenced. Precise. Elegant. Clear. Hurleys A Concise incoming to reproducible systemal systemal system, 11th Edition How to bed an Origami Crane Make your own origami exsert exploitation these informations and the perforated sheet of paper accommodate in your countersign. 1. Start with a straightforwardly piece of paper, colo exit nerve up. sheepcote in half and open. thereof excavate in half the nigh separate way. 2. lead on the paper over to the white side. raft the paper in half, crease healthy and open, and then slew again in the otherwise(a) direction. 3. use the creases you shake up made, land the shed light on 3 corners of the manakin bulge to the bottom corner.Flat ecstasy model. The look-alikeic red crane on the cover of this parvenu magnetic variation of Hurleys, A Concise Introduction to system of system of logic symbolizes the qualities that see it the nearly successful logic text on the market. We capture elect origami to symboli ze this texts elaborated sequencing, precision, elegance, and clarity. About the Cover 4. lot top triangular flaps into the center and unfold. 5. fiddleclude top of model downwards, crease comfortably and unfold. 6. Open the uppermost flap of the model, manner of speaking it upwards and pressing the sides of the model inward at the same epoch. Flatten down, creasing well.Couple an icon steeped in tradition with a clean, recent design, and you get out quickly get a smell of the qualities that make this sensitive adaptation of Hurley the best yet. Along with instructions, each spic-and-span text includes a sheet of red paper so that you piece of tail stick the cover to life. This influence serves as a metaphor for the serve well of encyclopedism logic. It is ch all in allenging, petitions expend, tho heap be fun. Ideas for other slipway to create your own origami undersurface be prime at www. origami-resource-center. com. 7. braid model over and repeat Step s 4-6 on the other side. . keep mum top flaps into the center. 9. Repeat on other side. 10. Fold both legs of 11. inner(a) Reverse Fold the legs model up, crease along the creases genuinely well, then you provided made. unfold. Finished Crane. 12. Inside Reverse Fold unitary side to make a head, then fold down the wings. Source www. origami-fun. com copy cover 2010 Cengage acquirement. on the completely Rights Reserved. whitethorn non be copied, s send awayned, or duplicated, in firm or in subtract. holdable to electronic castigates, round trey troupe core whitethorn be stamp down from the eBook and/or eChapter(s). column fall over has deemed that each(prenominal) conquer subject ara does non materially repair the boilersuit cultivation experience. Cengage acquirement militia the indemnify to implant aside supererogatory gist at every m if sequent repairs restrictions dominate it. A C O N C I S E I N T R O D U C T I O N TO system of l ogic copy correctly 2010 Cengage tuition. in all Rights Reserved. whitethorn non be copied, s toiletned, or duplicated, in upstanding or in naval division. referable to electronic decents, near lead nearly society nitty-gritty whitethorn be curb from the eBook and/or eChapter(s). editorial refresh has deemed that every smothered suffice does non materially allude the boilers suit teaching experience. Cengage expertness militia the up repair to mutilate special bailiwick at either sequence if accomp whatsoevering functions restrictions have it. secure 2010 Cengage knowledge. altogether Rights Reserved. whitethorn non be copied, scanned, or duplicated, in entirely or in part. payable to electronic rights, almost(prenominal)(prenominal) 3rd semipolitical ships comp both field whitethorn be hold from the eBook and/or eChapter(s). editorial polish up has deemed that all(prenominal) check study does non materially need the ge neral encyclopedism experience.Cengage acquire reserves the right to get rid of surplus bailiwick at whatever firearm if posterior rights restrictions engage it. A C O N C I S E I N T R O D U C T I O N TO system of logic ELEVENTH EDITION PATRICK J. HURLEY University of San Diego Australia brazil Japan Korea Mexico Singapore Spain United country United hypothesises right of first publication 2010 Cengage cultivation. on the social unit Rights Reserved. whitethorn non be copied, scanned, or duplicated, in hale or in part. delinquent to electronic rights, much or less triad ships comp few(prenominal)(prenominal) capacity may be inhibit from the eBook and/or eChapter(s). editorial critique has deemed that whatsoever hold in substanceed does non materially equal the general education experience. Cengage training reserves the right to invite out additive field at any(prenominal) succession if posterior rights restrictions invite it. This is an electronic adaptation of the shanghai schoolbook. out-of-pocket to electronic rights restrictions, whatsoever tercet base political party core may be subdue. pillar reappraisal has deemed that any subdue cloy does not materially print the boilers suit encyclopedism experience.The publisher reserves the right to adjourn theme from this entitle at any conviction if accompanying rights restrictions select it. For valuable information on pricing, previous mutants, changes to certain editions, and alternate formats, divert shout www. cengage. com/highered to search by ISBN, author, title, or keyword for materials in your beas of fire. procure 2010 Cengage education. each Rights Reserved. whitethorn not be copied, scanned, or duplicated, in whole or in part. ascribable to electronic rights, rough triad party suffice may be stifled from the eBook and/or eChapter(s). pillar follow-up has deemed that any hold limit does not materially vi ew the boilers suit learning experience. Cengage Learning reserves the right to contain additive marrow at any sequence if posterior rights restrictions bear it. A Concise Introduction to logic, El unconstipatedth Edition vomit uprick J. Hurley Publisher Clark Baxter fourth-year Sponsoring Editor Joann Kozyrev Development Editor Florence Kilgo admirer Editor Nathan Gamache editorial Assistant Michaela henry Media Editor Diane Akerman polarityeting autobus gradation T.Haynes Marketing Coordinator Josh Hendrick Marketing communication theory Manager Laura Localio Content Project Manager Alison Eigel Zade Senior Art Director Jennifer Wahi write Buyer Paula vang Production Service elmwood Street Publishing Services congenital designer Yvo Riezebos Cover designer Jeff execration of CMB Design Partners Cover get a line Courtesy of Getty Images Red origami crane on white table (image number 85592979) type stationter Integra Softw be Services Pvt. 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Library of Congress view get along 2010924757 Student Edition ISBN-13 978-0-8400-3417-5 ISBN-10 0-8400-34 17-2 Wadsworth 20 Channel Center Street Boston, MA 02210 USA Cengage Learning is a star succeedr of customized learning solutions with o? e locations around the globe, including Singapore, the United Kingdom, Australia, Mexico, Brazil, and Japan. Locate your egressal anesthetic anaesthetic o? ce at international. cengage. com/ kingdom Cengage Learning products atomic number 18 re largessed in Canada by Nelson Education, Ltd. For your cable and learning solutions, visit www. cengage. com. Purchase any of our products at your local college store or at our like online store www. cengagebrain. com. Printed in the United offers of the adduces 1 2 3 4 5 6 7 14 13 12 11 10 secure 2010 Cengage Learning. each Rights Reserved. whitethorn not be copied, scanned, or duplicated, in whole or in part. due to electronic rights, more or less third party electrical capacity may be curb from the eBook and/or eChapter(s). editorial review has deemed that any curb center does not mater ially postulate the overall learning experience. Cengage Learning reserves the right to remove supererogatory content at any time if sequent rights restrictions conduct it. To All of the instructors, past and present, who have taught logic from this book. It is wrong endlessly, everywhere, and for any champion, to believe anything upon insufficient indicate. W. K. Clifford nada can be more all- measurable(a) than the art of positive debate match to true logic. Gottfried Wilhelm Leibniz procure 2010 Cengage Learning. All Rights Reserved. may not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, nearly third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially fall the overall learning experience. Cengage Learning reserves the right to remove excess content at any time if ensuant rights restrictions require it. Brief limit record xiii per cen tum IINFORMAL system of logic 1 2 3 raw material Concepts 1 spoken language Meaning and De? ition 78 Informal Fallacies 119 PART IIFORMAL logic 4 5 6 7 8 two-dimensional Propositions 197 mat Syllogisms 259 Propositional logic 310 natural deduction in Propositional Logic 380 pronounce Logic 442 PART IIIinducive LOGIC 9 10 11 12 13 14 simile and Legal and mora heelic debate 509 creator and Mills Methods 529 Probability 554 statistical teleph atomic number 53 circuit 571 theoretic/Scienti? c conclude 593 apprehension and bigotry 615 supplement Logic and Graduate-Level Admissions Tests 644 Answers to Selected Exercises 655 Glossary/Index 697 vi copyright 2010 Cengage Learning. All Rights Reserved.whitethorn not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially allude the overall le arning experience. Cengage Learning reserves the right to remove additive content at any time if succeeding rights restrictions require it. contents Preface xiii PART I? INFORMAL LOGIC 1 Basic Concepts operation 1. 1 7 1 1 14 33 1. 1 Arguments, Premises, and Conclusions 1. 2 Recognizing Arguments make 1. 2 25 1. 3 Deduction and Induction transaction 1. 40 1. 4 Validity, Truth, Soundness, Strength, Cogency 44 reckon 1. 4 53 1. 5 Argument Forms Proving in logicalness make 1. 5 63 57 1. 6 lengthy Arguments execution 1. 6 70 64 2 Language Meaning and De? nition 2. 1 Varieties of Meaning set 2. 1 83 78 78 88 2. 2 The Intension and Extension of Terms arrange 2. 2 92 2. 3 De? nitions and Their Purposes cause 2. 3 99 93 2. 4 De? nitional techniques utilization 2. 4 108 102 111 2. 5 Criteria for lexical De? nitions knead 2. 5 115 s level off secure 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part.Due to electronic r ights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if ulterior rights restrictions require it. 3 Informal Fallacies 3. 1 Fallacies in General elaborate 3. 1 121 119 122 138 119 3. 2 Fallacies of Relevance physical exercise 3. 2 133 3. 3 Fallacies of Weak Induction coiffe 3. 3 149 3. 4 Fallacies of Presumption, Ambiguity, and Grammatical Analogy 156 EXERCISE 3. 4 170 . 5 Fallacies in Ordinary Language EXERCISE 3. 5 185 178 PART II? FORMAL LOGIC 4 Categorical Propositions 197 4. 1 The Comp angiotensin-converting enzyments of Categorical Propositions 197 EXERCISE 4. 1 200 4. 2 Quality, Quantity, and Distribution EXERCISE 4. 2 204 200 4. 3 Venn Diagrams and the Modern red-blooded of foe 205 EXERCISE 4. 3 216 4. 4 Conversion, Obversion, and Contraposition EXE RCISE 4. 4 225 217 4. 5 The Traditional Squ be of Opposition EXERCISE 4. 5 234 227 4. 6 Venn Diagrams and the Traditional Stand denominate 239 EXERCISE 4. 6 245 4. 7 Translating Ordinary Language evokements into Categorical Form 246 EXERCISE 4. 254 viii table of contents Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 5 Categorical Syllogisms 259 5. 1 Standard Form, Mood, and Figure 259 EXERCISE 5. 1 264 5. 2 Venn Diagrams EXERCISE 5. 277 266 280 288 292 5. 3 reins and Fallacies EXERCISE 5. 3 286 5. 4 Reducing the Number of Terms EXERCISE 5. 4 291 5. 5 Ordinary Language Argu ments EXERCISE 5. 5 294 5. 6 Enthymemes 295 EXERCISE 5. 6 297 5. 7 Sorites 301 EXERCISE 5. 7 304 6 Propositional Logic EXERCISE 6. 1 319 310 6. 1 Symbols and description 310 6. 2 Truth Functions EXERCISE 6. 2 332 323 6. 3 Truth Tables for Propositions 335 EXERCISE 6. 3 341 6. 4 Truth Tables for Arguments EXERCISE 6. 4 347 344 6. 5 Indirect Truth Tables 350 EXERCISE 6. 5 358 6. 6 Argument Forms and Fallacies EXERCISE 6. 6 371 360 confine ixCopyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 7 immanent Deduction in Propositional Logic 380 7. 1 Rules of Implication I 380 EXERCISE 7 . 1 386 7. 2 Rules of Implication II 391 EXERCISE 7. 396 7. 3 Rules of Replacement I 401 EXERCISE 7. 3 407 7. 4 Rules of Replacement II EXERCISE 7. 4 419 414 7. 5 qualified test copy EXERCISE 7. 5 430 427 7. 6 Indirect Proof EXERCISE 7. 6 436 432 438 7. 7 Proving Logical Truths EXERCISE 7. 7 440 8 Predicate Logic 442 8. 1 Symbols and Translation 442 EXERCISE 8. 1 449 8. 2 Using the Rules of Inference EXERCISE 8. 2 460 451 8. 3 Change of Quanti? er Rule EXERCISE 8. 3 467 464 468 8. 4 conditional and Indirect Proof EXERCISE 8. 4 472 8. 5 Proving In severeness EXERCISE 8. 5 479 474 481 8. 6 Relational Predicates and Overlapping Quanti? ers EXERCISE 8. 6 489 . 7 Identity 492 EXERCISE 8. 7 501 x Contents Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. Part III INDUCTIVE LOGIC 9 Analogy and Legal and honourable Reasoning 509 9. 1 Analogical Reasoning 9. Legal Reasoning 9. 3 Moral Reasoning EXERCISE 9 520 509 512 516 10 Causality and Mills Methods 10. 2 Mills Five Methods 531 10. 3 Mills Methods and Science EXERCISE 10 546 529 529 10. 1 Cause and infallible and Sufficient Conditions 540 11 Probability 554 11. 1 Theories of Probability 11. 2 The Probability coalescency EXERCISE 11 567 554 557 12 statistical Reasoning 571 12. 1 Evaluating Statistics 571 12. 2 Samples 572 576 12. 3 The Meaning of Average 12. 4 dispersion 578 12. 5 Graphs and Pictograms 12. 6 Percentages 586 EXERCISE 12 588 583 13 Hypothetical/Scienti? c Reasoning 593 13. The Hypothetical Method 593 13. 2 Hypothetical Reasoning Four causes from Science 596 Contents xi Copyright 2010 Cengage L earning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 13. 3 The Proof of Hypotheses EXERCISE 13 607 02 13. 4 The dubious Acceptance of Hypotheses 604 14 Science and Superstition 14. 2 Evidentiary Support 14. 3 Objectivity 14. 4 Integrity EXERCISE 14 615 615 14. 1 Distinguishing Between Science and Superstition 616 621 625 630 631 14. 5 Concluding Remarks Appendix Logic and Graduate-Level Admissions Tests 644 Answers to Selected Exercises Glossary/Index 697 655 xii Contents Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. Preface The most quick benefit derived from the study of logic is the skill needed to construct sound short letters of bingles own and to evaluate the lines of others. In accomplishing this goal, logic instills a sensitivity for the formal comp oneness and only(a)nt in language, a organic command of which is indispensable to clear, e? ective, and importationful communication.On a broader scale, by focusing maintenance on the requirement for resolves or licence to musical accompaniment our views, logic adds a organic falsifying against the prejudiced and uncivilized attitudes that peril the foundations of our democratic society. Finally, by means of its attention to discrepancy as a fatal ? aw in any theory or point of view, logic proves a useful doohickey in disclosing ill-conceived policies in the political sphere and, ultimately, in distinguishing the rational from the irrational, the flat coatable from the insane. This book is written with the aim of securing these bene? s. all(prenominal) Book Has a Story When I ? rst began teaching introductory logic numerous old age ago, I selected a text that was widely used and highly regarded. Yet, my educatees a expert deal had a hard time arrest it. The book tended to be overly boring and the main points were oftentimes lost amid a welter of detail. Also, I found that much of the books content was further peripherally related to the native conceits of logic. Using this book provided the happy and un judge reply that my students always came to class so they could construe me explain the textbook. entirely aft(prenominal) I weary of doing this, I decided to writ e a textbook of my own that would address the de? ciencies of the one I had been using. Speci? cally, my goal was to write a book in which the main points were always presented up front so students could not possibly miss them, the prose was clear and uncomplicated, and intemperance verbiage and peripheral subject calculate was avoided. To accomplish these and other related goals, I incorporated the pursuit pedagogical devices relevant and up-to-date examples were used extensively end-to-end the book. Key call were introduced in courageous face type and de? ed in the glossary/index. Central concepts were illustrated in graphic boxes. Numerous exercisestoday there are over 2,600were include to perfect student skills. legion(predicate) exercises were drawn from real-life sources such as textbooks, unexampledspapers, and magazines. Typically every third exercise was answered in the back of the book so students could check their work. xiii Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. Chapters were organized so that earlier ingredients provided the foundation for later ones. later on sections could be skipped by instructors opting to do so. fundamental rules and tables were printed on the inside covers for ready access. In its ? rst edition, the book was so well acquire that plans were quickly begun for a atomic number 42 edition.With the extent of that and later editions, the book grew to incorporate legion(predicate) new holds Venn diagrams for syllogisms were presented in a myth and more e? ective way using color to constitute t he relevant areas. parley exercises were include to depict the commission of fallacies in real life. Predicate logic was protracted to include relational predicates and identity. The Eminent Logicians feature was introduced to elevate the human element it presented the lives of historically prominent logicians. Truth Trees and full of life cerebration and Writing were written as supplements. Learning Logic, a multimedia political platform that includes an additional 2,000 exercises and that practically teaches the get over by itself, was include in the package. A series of videos relations with topics that students ? nd di? cult, including the concept of validity, indirect trueness tables, and natural deduction, were o? ered with the polish edition. I am convinced that with each accompanying edition the book has be get into a more e? ective teaching tool. I am as well convinced that the veritable, el even soth edition, is the best and most accurate one to date. par venue To This Edition Five new biographical vignettes of prominent logicians are introduced.The new logicians include Ruth Barcan Marcus, Alice Ambrose, Ada Byron (Countess of Lovelace), Willard Van Orman Quine, and Saul Kripke. Six new converse exercises are introduced to dish out a? rm the relevance of formal logic to real-life. They can be found in branchs 5. 6, 6. 4, 6. 6, 7. 3, 7. 4, and 8. 2. The end-of-chapter summaries now get on in bullet format to make them more useful for student review. some new and improved exercises and examples appear by and throughout the book. In Section 1. 4, the link amidst inductive reason out and the principle of the consonance of nature is explained.Cogent inductive short letters are those that parcel out with this principle, while weak ones violate it. much(prenominal) violations are always accompanied by an element of surprise. xiv Preface Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. The connection between the Boolean bandstand and the Aristotelian standpoint is explained more completely. The empiric fallacy as it occurs in prompt inferences is explained in greater detail. All inferences that pluck this fallacy have a universal joint enter and a particular completion. The signification of universal and particular are broad to cover dictations that are given as phony. A new exercise set is introduced in Section 4. 5 that involves test immediate inferences for soundness. An improved de? nition of the main mover of a combine argumentation is given. A new subsection is introduced in Section 6. 5 giving preliminary instruction on how to work backward from the fairness set of the simple mesmerisms to the rightfulness economic taxs of the operators. A new exercise set provides practice with this technique. Section 7. 1 has been rewritten, express the strategy of laborious to ? nd the shoemakers last in the set forth. Margin of error in Chapter 12 is now explained in harm of level of expectation. A more enlightening table illustrates this change. A complete list of all improvements is given at the start out of the instructors Manual. berth to the Student call up that you are interviewing for a job. The psyche crosswise the desk asks about your strengths, and you reply that you are energetic, enthusiastic, and unstrained to work long hours. Also, you are seminal and innovative, and you have life-threatening bearership skills. Then the interviewer asks about your flunkes. You hadnt anticipated this question, but aft(prenominal) a moments t hought you reply that your reason out skills have never been very acceptable. The interviewer quickly responds that this weakness could create big problems. Why is that? you ask. Because reasoning skills are internal to good judgment. And without good judgment your creativity pass on lead to projects that make no reek. Your leadership skills depart direct our other employees in circles. Your devotion leave alone undermine everything we have finish up until now. And your operative long hours will make things even worse. But go int you think there is some position in your company that is right for me? you ask. The interviewer thinks for a moment and then replies, We have a competitor on the other side of town. I hear they are hiring right now. Why dont you apply with them? The point of this little dialogue is that good reasoning skills are essential to doing anything right. The business person uses reasoning skills in writing a report or preparing a presentation the scie ntist uses them in intention an experiment or clinical trial, the division manager uses them in maximizing prole e? ciency, the lawyer uses them in piece an argument to a judge or jury. And thats where logic comes in. The chief champion-valued function of logic is to develop good reasoning skills. In fact, logic is so central that when the liberal arts computer program of studies was theorise ? fteen hundred years Preface v Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. ago, logic was selected as one of the original seven liberal arts. Logic extends to this day a cen tral component of a college or university education.From a more pragmatic angle, logic is important to earning a good score on any of the several tests required for access to graduate professional schoolsthe LSAT, GMAT, MCAT, and so on. Obviously, the designers of these tests avow that the ability to reason logically is a prerequisite to success in these ? elds. The concomitant in the back of the book charters taste questions and cues on answering them. Also, logic is a useful tool in relieving what has come to be called math anxiety. For whatever reason, incalculable students today are terri? ed of any form of reasoning that involves abstract symbols.If you give to be one of these students, you should ? nd it relatively easy to master the use of logical symbols, and your newly found comfort with these symbols will carry over into the other, more di? cult ? elds. To improve your performance in logic, I strongly urge you to take proficient advantage of a multimedia program c alled Learning Logic. This is an interactive tutorial that teaches the essentials of this textbook in a very user-friendly way. However, your figurer must be provide with loudspeakers or headphones, because the audio component is essential.Learning Logic is procurable both on CD and online at the Logic CourseMate site. If the CD version or a passcode for the website did not come with your textbook, it can be purchased separately through your campus bookstore if your instructor has say it. You can overly order it directly at www. cengagebrain. com. In addition to Learning Logic, an eBook and other quizzes and self-study material are getable on the Logic CourseMate site. Also available online through the Logic CourseMate site are design video lectures on key topics. The videos include pointers on how to work the pertinent exercises in the textbook.They cover topics such as the concept of validity, conversion, obversion, and contraposition, indirect truth tables, and natural de duction. If, as you work through the content of this book, you learn a subject that you have fuss understanding, one of these videos may solve the problem. Additionally, a set of audio summaries for each chapter in the book is available. These are designed so that you can download them onto your iPod, mp3 player, or computer and listen to them before taking a test. Because pro? ciency in logic involves exploitation a kill, it helps to work through the practice problems in Learning Logic and the exercises in the textbook more than once. This will help you see that good reasoning (and perverting reasoning, too) follows sure patterns whose identi? cation is crucial to success in logic. As you progress, I think you will ? nd that learning logic can be lots of fun, and working with the online resources should enhance your overall learning experience. mark off to the Instructor With this eleventh edition, Learning Logic is available both on CD and online. The CD comes free ifordered with a new book, or it can be ordered separately at www. engagebrain. com. Online, Learning Logic it is available through the Logic CourseMate site, a password protected website (www. cengage. com/sso). This website o? ers the bene? t of being able to check a students time on task, that is, how much time the student has played out using a particular supplement. Critical Thinking and Writing and Truthtrees are available free on the website, and they can to a fault be selected as modules in a custom version of the textbook. The videos, which cover topics students often have trouble with, are also available on Logic CourseMate.This edition also features Aplia, one of the Cengage Learning CourseMaster digital solutions. Aplia established a name for itself in the ? eld of economics, where it o? ers interactive online preparedness xvi Preface Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, som e third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience.Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. assignments with incessant feedback to students. Providing automatic grading, Aplia increases student effort and keeps students accountable for course material while adding no additional paperwork to the instructors workload, go away instructors with more time to prepare lectures and work with students. As Aplia expands its o? erings to include additional subjects, it has won widespread acclaim from thousands of instructors across numerous disciplines. Now, Aplia o? ers its signature bene? s to logic students and instructors with a program speci? cally designed to enhance student engagement. The Aplia assignments build on the exercises in this textbook, and they conform to the language, style, and structure of the book. let me now turn to alternate ways of approaching the textbook. In general, the material in each chapter is arranged so that certain later sections can be skipped without a? ecting subsequent chapters. For example, those wishing a brief treatment of natural deduction in both propositional and predicate logic may want to skip the last three sections of Chapter 7 and the last four (or even ? e) sections of Chapter 8. Chapter 2 can be skipped altogether, although some may want to cover the ? rst section of that chapter as an introduction to Chapter 3. Finally, Chapters 9 through 14 direct only reasonably on earlier chapters, so these can be handle in any order one chooses. However, Chapter 14 does depend in part on Chapter 13. eccentric person of Course Traditional logic course Recommended material Chapter 1 Chapter 3 Chapter 4 Chapter 5 Chapter 6 Sections 7. 17. 4 Informal logic course, critical reasoning course Chapter 1 Chapter 2 Ch apter 3 Chapter 4 Sections 5. 15. Sections 5. 55. 6 Sections 6. 16. 4 Section 6. 6 Chapter 9 Chapter 12 Chapter 13 Chapter 14 Writing Supplement Section 5. 4 Section 5. 7 Section 6. 5 Chapter 10 Chapter 11 Course emphasizing modern formal logic Chapter 1 Sections 4. 14. 3 Section 4. 7 Sections 6. 16. 5 Chapter 7 Chapter 8 Truth Tree Supplement nonmandatory material Chapter 2 Sections 7. 57. 7 Chapters 914 Chapter 3 Sections 4. 44. 6 Sections 5. 15. 2 Section 5. 7 Section 6. 6 Preface xvii Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part.Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. Acknowledgements For their reviews and su ggestions leading to this eleventh edition I want to thank the avocation Kevin Berry Scott Calef Gabriel Camacho Loren Cannon Victor Cosculluela Thompson gent Thomas J.Frost Paul Gass Alexander star sign Courtney Hammond Merle Harton Anthony Hanson Ron Jackson William Jamison Sandra Johanson Richard Jones Russel Jones William Lawhead Stephen Leach Keane Lundt Erik Meade Ian MacKinnon Allyson depend upon Seyed Mousavian Madeline Muntersbjorn Herminia Reyes Frank Ryan Eric Saidel Stephanie Semler Janet Simpson Aeon Skoble Joshua Smith Paula Smithka Krys Sulewski Brian Tapia William Vanderburgh Mark Vopat David Weise Shannon Grace Werre Katherine D.Witzig Stephen Wykstra Ohio University Ohio Wesleyan University El Paso friendship College Humboldt severalise University Polk postulate College University of Portland Biola University/Long brim city College Coppin assign University Clayton state of matter University Cuyamaca College Edward water College West Valley College Clayt on verbalize University University of Alaska anchorage ground cat valium River participation College Howard University University of okeh University of manuscript UTPA Massachusetts College of Liberal Arts southern Illinois UniversityEdwardsville The University of Akron Keene land College University of Alberta University of Toledo San Diego State University Kent State University George upper-case letter University Radford University Su? olk County community of interests College Bridgewater State College Central bread University University of gray disseminated multiple sclerosis Edmonds partnership College Foothill College Wichita State University Youngstown State University Gonzaga University Edmonds society College Southwestern Illinois College Calvin College Of course any errors or omissions that may remain are the result of my own oversight. eighteen Preface Copyright 2010 Cengage Learning. All Rights Reserved.May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. Those who have contributed reviews and suggestions leading to the ten previous editions, and to whom I express my continue thanks, are the by-line James T. 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Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 1 Basic Concepts 1. 1 1. 2 1. 3 1. 4 1. 5 1. Arguments, Premises, and Conclusions Recognizing Arguments Deduction and Induction Validity, Truth, Soundness, Strength, Cogency Argument Forms Proving Invalidity Extended Arguments 1. 1 Arguments, Premises, and Conclusions Logic may be de? ned as the organized dust of knowledge, or science, that evaluates arguments. All of us clangor arguments in our day-to-day experience. We read them in books and newspapers, hear them on television, and formulate them when communication with friends and associates. The aim of logic is to develop a system of regularitys and principles that we may use as criteria for evaluating the arguments of others and as guides in constructing arguments of our own.Among the bene? ts to be expect from the study of logic is an increase in con? dence that we are making sense when we criticize the arguments of others and when we advance arguments of our own. An argument, in its most basic form, is a assemblage of statements, one or more of which (the antecede) are claimed to provide turn out for, or reasons to believe, one of the others (the consequence). All arguments may be placed in one of two basic groups those in which the set forth really do support the final stage and those in which they do not, even though they are claimed to. The former are said to be good arguments (at least(prenominal) to that extent), the latter bad arguments.The purpose of logic, as the science that evaluates arguments, is thus to develop methods and techniques that quit us to distinguish good arguments from bad. As is apparent from the given definition, the term argument has a very specific meaning in logic. It does not mean, for example, a sheer verbal ? ght, as one baronhave with ones parent, spouse, or friend. Let us examine the features of this de? nition in Additional resources are available on the Logic CourseMate website. 1 Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 1 greater detail. First of all, an argument is a group of statements. A statement is a disapprobation that is either true or falsein other words, typically a declarative sentence or a sentence component that could stand as a declarative sentence. The following sentences are statements Chocolate truffles are loaded with calories. Melatonin helps discharge jet lag. Political candidates always tell the complete truth.No wives ever cheat on their husbands. Tiger Woods plays golf and maria Sharapova plays tennis. The first two statements are true, the fleck two false. The last one expresses two statements, both of which are true. Truth and fickleness are called the two possible truth values of a statement. Thus, the truth value of the ? rst two statements is true, the truth value of the second two is false, and the truth value of the last statement, as well as that of its components, is true. unconnected statements, many senten ces cannot be said to be either true or false. Questions, proposals, suggestions, commands, and exclamations normally cannot, and so are not unremarkably classi? ed as statements.The following sentences are not statements Where is Khartoum? Lets go to a movie tonight. I suggest you get contact lenses. Turn off the TV right now. wild (question) (proposal) (suggestion) (command) (exclamation) The statements that make up an argument are divided into one or more exposit and one and only one conclusion. The premises are the statements that set onwards the reasons or evidence, and the conclusion is the statement that the evidence is claimed to support or imply. In other words, the conclusion is the statement that is claimed to follow from the premises. present is an example of an argument All shoot down stars are celebrities. Halle Berry is a scoot star.Therefore, Halle Berry is a celebrity. The ? rst two statements are the premises the third is the conclusion. (The claim that the premises support or imply the conclusion is indicated by the word therefore. ) In this argument the premises really do support the conclusion, and so the argument is a good one. But consider this argument slightly spud stars are men. Cameron Diaz is a film star. Therefore, Cameron Diaz is a man. In this argument the premises do not support the conclusion, even though they are claimed to, and so the argument is not a good one. angiotensin converting enzyme of the most important tasks in the abstract of arguments is being able to distinguish premises from conclusions.If what is thought to be a conclusion is really a premise, and vice versa, the subsequent analysis cannot possibly be correct. Manyarguments 2 Chapter 1 Basic Concepts Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed tha t any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. contain indication words that provide clues in identifying premises and conclusion. some typical conclusion index numbers are therefore wherefore thus consequently we may infer therefore we may conclude it must be that for this reason so entails that hence it follows that implies that as a result 1 Whenever a statement follows one of these forefingers, it can ordinarily be identi? ed as the conclusion. By process of elimination the other statements in the argument are the premises. Example tormented prisoners will say anything just to disengage the pain. Consequently, torture is not a trustworthy method of interrogation. The conclusion of this argument is pain is not a reliable method of interrogation, and the premise is Tortured prisoners will say anything just to relie ve the pain. Premises Claimed evidence Conclusion What is claimed to follow from the evidenceIf an argument does not contain a conclusion indicator, it may contain a premise indicator. Some typical premise indicators are since as indicated by because for in that may be inferred from as given that seeing that for the reason that in as much as owing to Any statement following one of these indicators can usually be identi? ed as a premise. Example with child(p) mothers should never use unskilled drugs, since the use of these drugs can jeopardize the development of the fetus. The premise of this argument is The use of these drugs can jeopardize the development of the fetus, and the conclusion is Expectant mothers should never use recreational drugs. In reviewing the list of indicators, note that for this reason is a conclusion indicator, whereas for the reason that is a premise indicator. For this reason (except Section 1. 1 Arguments, Premises, and Conclusions 3 Copyright 2010 Cenga ge Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 1 hen followed by a colon) means for the reason (premise) that was just given, so what follows is the conclusion. On the other hand, for the reason that announces that a premise is about to be stated. Sometimes a single indicator can be used to identify more than one premise. Consider the following argument It is vitally important that state of nature areas be preserved, for wild provides essential habitat for wildlife, including endangered species, and it is a natural kip down from the stress of daily life. The premise indicator for goes with bot h Wilderness provides essential habitat for wildlife, including endangered species, and It is a natural retrogress from the stress of daily life. These are the premises. By method of elimination, It is vitally important that wilderness areas be preserved is the conclusion. Some arguments contain no indicators. With these, the reader/listener must ask such questions as What single statement is claimed (implicitly) to follow from the others? What is the arguer trying to prove? What is the main point in the passage? The answers to these questions should point to the conclusion. Example The length program deserves change magnitude expenditures in the years ahead. Not only does the national excuse depend on it, but the program will more than pay for itself in terms of technological spinoffs.Furthermore, at current funding levels the program cannot carry through its anticipated potential. The conclusion of this argument is the ? rst statement, and all of the other statements are prem ises. The argument illustrates the pattern found in most arguments that lack indicator words the intend conclusion is stated ? rst, and the remaining statements are then o? ered in support of this ? rst statement. When the argument is restructured match to logical principles, however, the conclusion is always listed after the premises P1 P2 P3 C The national defense is dependent on the set program. The space program will more than pay for itself in terms of technological spinoffs.At current funding levels the space program cannot fulfill its anticipated potential. The space program deserves increased expenditures in the years ahead. When restructuring arguments such as this, one should remain as virtually as possible to the original version, while at the same time tending to the requirement that premises and conclusion be complete sentences that are meaningful in the order in which they are listed. Note that the ? rst two premises are included within the scope of a single senten ce in the original argument. For the purposes of this chapter, compound arrangements of statements in which the various components are all claimed to be true will be considered as separate statements.Passages that contain arguments sometimes contain statements that are neither premises nor conclusions. Only statements that are actually intended to support the conclusion should be included in the list of premises. If, for example, a statement 4 Chapter 1 Basic Concepts Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. erves merely to introduce the general topic, or merely makes a passing comment, it should not be taken as part of the argument. Examples The claim is often made that malpractice lawsuits movement up the cost of health care. But if such suits were outlawed or badly restricted, then patients would have no means of recovery for injuries caused by negligent doctors. Hence, the handiness of malpractice litigation should be maintained intact. vast federal deficits push up interest rates for everyone. Servicing the debt gobbles up a huge portion of the federal budget, which lowers our well-worn of living. And big deficits also weaken the value of the dollar. For these reasons, Congress must make a determined effort to cut overall spending and raise taxes.Politicians who ignore this man imperil the future of the nation. 1 In the ? rst argument, the opening statement serves merely to introduce the topic, so it is not part of the argument. The premise is the second statement, and the conclusion is the last statement. In the second argument, the ? n al statement merely makes a passing comment, so it is not part of the argument. The premises are the ? rst three statements, and the statement following for these reasons is the conclusion. Closely related to the concepts of argument and statement are those of inference and proposition. An inference, in the narrow sense of the term, is the reasoning process expressed by an argument.In the broad sense of the term, inference is used interchangeably with argument. Analogously, a proposition, in the narrow sense, is the meaning or information content of a statement. For the purposes of this book, however, proposition and statement are used interchangeably. Note on the History of Logic The person who is generally credited as the pay off of logic is the ancient Greek philosopher Aristotle (384322 b. c. ). Aristotles predecessors had been interested in the art of constructing convincing arguments and in techniques for refuting the arguments of others, but it was Aristotle who ? rst devi sed systematic criteria for analyzing and evaluating arguments.Aristotles chief accomplishment is called syllogistic logic, a large-hearted of logic in which the fundamental elements are terms, and arguments are evaluated as good or bad depending on how the terms are arranged in the argument. Chapters 4 and 5 of this textbook are given up mainly to syllogistic logic. But Aristotle also deserves credit for originating modal logic, a kind of logic that involves such concepts as possibility, necessity, belief, and doubt. In addition, Aristotle catalogued several informal fallacies, a topic treated in Chapter 3 of this book. later Aristotles death, another Greek philosopher, Chrysippus (280206 b. c. ), one of the founders of the Stoic school, substantial a logic in which the fundamental elements were whole propositions.Chrysippus treated every proposition as either true or false and developed rules for determining the truth or insincerity of compound propositions from the truth or untruth of their components. In the course of doing so, he displace the foundation for the truth functional description of the logical connectives presented in Chapter 6 of this book and introduced the notion of natural deduction, treated in Chapter 7. Section 1. 1 Arguments, Premises, and Conclusions 5 Copyright 2010 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. 1 For thirteen hundred years after the death of Chrysippus, relatively little seminal work was done in logic. The physician Galen (a. d. 129ca. 199) developed the theory of the compound unconditional syllogism, but for the most part philosophers con? ned themselves to writing commentaries on the works of Aristotle and Chrysippus. Boethius (ca. 480524) is a noteworthy example. The ? rst major logician of the marrow Ages was Peter Abelard (10791142). Abelard reconstructed and re? ed the logic of Aristotle and Chrysippus as communicated by Boethius, and he originated a theory of universals that traced the universal mention of general terms to concepts in the discernment rather than to natures existing outside the mind, as Aristotle had held. In addition, Abelard distinguished arguments that arevalid because of their form from those that are valid because of their content, but he held that only formal validity is the perfect or conclusive variety. The present text