UGRC 150 Critical Thinking PDF 2021
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University of Ghana
2021
Dr. (Mrs.) Nancy Myles B. Gyamfi
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Summary
These lecture notes from the University of Ghana cover Critical Thinking and Practical Reasoning, focusing on how to evaluate claims and arguments. A variety of examples are provided for the purpose of analysis.
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UGRC 150: CRITICAL THINKING AND PRACTICAL REASONING G2 Main; G3 and G4 City LECTURE 1: THOUGHTS AS OBJECTS OF SCRUTINY Dr. (Mrs.) Nancy Myles B. Gyamfi Philosophy and Classics, (Humanities, U.G) June-, August 2021...
UGRC 150: CRITICAL THINKING AND PRACTICAL REASONING G2 Main; G3 and G4 City LECTURE 1: THOUGHTS AS OBJECTS OF SCRUTINY Dr. (Mrs.) Nancy Myles B. Gyamfi Philosophy and Classics, (Humanities, U.G) June-, August 2021 020-7301599 (WhatsApp/call) / [email protected] Introduction: Critical Thinking Dr. (Mrs.) Nancy Myles B. Gyamfi 2 ( 2021) A working definition Critical Thinking is the careful, deliberate determination of whether we should accept, reject, or suspend judgment about a claim and a determination of the degree of confidence with which to accept or reject it. The critical thinker is concerned about how well a belief or claim is supported by reasons(premises). Critical thinking helps to expose fallacies or errors in our reasoning. Dr. (Mrs.) Nancy Myles B. Gyamfi 3 ( 2021) Critical Thinking cont’d The critical thinker analyses (breaks- down into constituent parts) statements and arguments and then evaluates (judges) them to distinguish good (correct) from bad (incorrect) reasoning. Dr. (Mrs.) Nancy Myles B. Gyamfi 4 ( 2021) Critical Thinking cont’d The critical thinker does not ask questions, analyze or evaluate just for the sake of it. The aim is to respond to (solve) practical problems of existence. If not, then the whole act of thinking critically would be worthless. Thus, the course is Critical Thinking and Practical Reasoning. Dr. (Mrs.) Nancy Myles B. Gyamfi 5 ( 2021) Critical Thinking cont’d The course will equip you with concepts, methods, tools, principles and techniques for establishing and distinguishing logical truth (linguistic certainties) from empirical truth (observation-based contingencies). Dr. (Mrs.) Nancy Myles B. Gyamfi 6 ( 2021) Pause to think! Critically assess the following: 1. Witness at the law court: “Jail that bachelor because with my own eyes I saw him beat his wife mercilessly. I have video evidence….” 2. Question to the rain-maker: “So will it rain tomorrow?” Rain-maker: “it will either rain tomorrow or it will not rain tomorrow.” 3. Security officer to the boss: “She is the last person who left the office yesterday so she stole the laptop.” 4. “She is moral because she leads a morally upright life”. 5. As soon as she entered the room the lights went off. So, she caused the light-off. 6. My bachelor friend gave up his bachelors to fix bachelors. 7. The traffic was intense yesterday and the day before on that stretch, so I am not going by that route today because it will certainly be the same today. Dr. (Mrs.) Nancy Myles B. Gyamfi 7 ( 2021) Critical Thinking as topic-neutral ❖ Notice therefore that Critical Thinking is topic-neutral. That is, it transcends disciplines; cuts across disciplines; applies to all academic disciplines; every aspect of everyday life e.g. medicine, law, politics, religion, culture, military, … etc. Dr. (Mrs.) Nancy Myles B. Gyamfi 8 ( 2021) Why should we be critical thinkers? A critical thinker… 1. makes better decisions because s/he is less gullible 2. is clear about why s/he believes what s/he believes (not merely following the crowd) 3. is an effective communicator because s/he is trained to present a point of view in a clear, structured, reasoned way that convinces others; s/he can anticipate queries 4. is an invaluable problem-solver because s/he accommodates other views; examines, assesses and evaluates issues on merit. Critical Thinking Skills Open mindedness Inquiring mind - (question-asking) Analytic skills Evaluative skills Communicative skills Dr. (Mrs.) Nancy Myles B. Gyamfi 10 ( 2021) Course objectives The course aims at equipping you with concepts/tools/skills for: ✓Effective speaking; ✓Sound reasoning/analysis; ✓Conceptual clarity; ✓Recognizing, diagnosing and solving problems for the work environment and everyday life Dr. (Mrs.) Nancy Myles B. Gyamfi 11 ( 2021) UNIT 1: SENTENCE-SHAPED THOUGHT Introduction Humans are beings that think. Our thoughts are often captured or expressed in language. Since we may never know a person’s thought exactly, we depend on what a person says to determine what s/he had in mind. So “sentence shaped thought” means our thought shaped into sentence. UNIT 1 seeks to get students to understand the need and how to subject our thoughts (and that of others) to scrutiny(study). Dr. (Mrs.) Nancy Myles B. Gyamfi 12 ( 2021) Pause and note! As a critical thinker, say what you mean and mean what you say. For “out of the abundance of the heart (mind), the mouth speaks”. Notice the infinite regress associated with saying that you did not mean what you said. Why should I trust what you are saying now if you did not mean what you said earlier? Dr. (Mrs.) Nancy Myles B. Gyamfi 13 ( 2021) Unit 1: objectives At the end of Unit 1, the student will be able to ✓ distinguish a declarative from an imperative and an interrogative ✓ recognize sentence fragments and emotive expressions ✓ understand why declaratives alone have ‘truth-value’ ✓ identify the three (3) types of declaratives (statements): factual statements, value judgments and definitions ✓ distinction between sentences and statements ✓ implicit(covert) and explicit (overt) meanings of expressions (why some interrogatives are actually imperatives) Dr. (Mrs.) Nancy Myles B. Gyamfi 14 ( 2021) Unit 1 : Topics 1. Types of sentence-shaped thought - Interrogative; imperative; declarative 2. Recognizing sentence fragment and emotive expression 3. Types of declaratives - Factual statement; value judgment; definition 4. Distinguishing a sentence from a statement Dr. (Mrs.) Nancy Myles B. Gyamfi 15 ( 2021) Unit 1: Reading list and activity Read Unit 1 of Recommended Text – pages 4-12 Study the slides posted in resources and announcements Access the Video Lecture posted on the channel. Link copied to the resource tool Note open date for assessment one (week two) Dr. (Mrs.) Nancy Myles B. Gyamfi 16 ( 2021) UNIT 1 (topic one): Interrogatives Types of sentences that express our thoughts: 1. Interrogatives-(questions) are sentences expressed to seek information. Examples: 1. Is she your mother? 2. Did Kojo travel? 3. Which group are you in? 4. Is it raining at Legon? 5. Where is the Teaching Assistant? Note: Interrogatives are neither true nor false. So, they do not have a truth-value; they are not truth bearers. Dr. (Mrs.) Nancy Myles B. Gyamfi 17 ( 2021) Imperatives 2. Imperatives-(command, request, directive, instruction): Refer to sentences expressed to get someone to perform an action. Examples: 1. Take off your cap. 2. Raise your hand 3. Pass me the cheque book 4. Could you direct me to the library? NB: notice that E.g. 4 is explicitly interrogative but implicitly imperative. The speaker politely requests someone to perform an action. Imperatives have no truth-value; are not truth bearers!! Dr. (Mrs.) Nancy Myles B. Gyamfi 18 ( 2021) Declaratives Declarative-(statement, proposition, assertion): A sentence that conveys information which can be either true or false –(i.e. has a truth-value or is a truth bearer). Examples: 1.The exam has been cancelled. 2. Ghana has a new Speaker of Parliament. 3. A bachelor is sitting under the tree. 4. A bachelor is an unmarried adult male. 5. The bachelor has a good conscience. 6. She is a good friend. NB: Only declaratives can be either true or false (have a truth-value) Dr. (Mrs.) Nancy Myles B. Gyamfi 19 ( 2021) Unit 1, topic 2: recognizing sentence fragments and emotive expression Sentence fragment: These are incomplete sentences; they do not express complete thought. Examples: 1. If only I got to Ajo earlier (what then?) 2. Rice and stew (what has it done?) 3. The dean of students in the university of Ghana (what has s/he done?) 4. Morning dew (what about it?) NB. Sentence fragments have no truth value; are not truth bearers. Dr. (Mrs.) Nancy Myles B. Gyamfi 20 ( 2021) Emotive expression Emotive expressions are sentences that express feelings or exclamations. Examples: 1. Oh. What a day! 2. Wow!, Brilliant!, Awesome!, Bravo! Etc 3. Hey! Who do you think you are?! NB: Emotive expressions have no basis for rational evaluation. They have no truth-value and they are not truth bearers. Dr. (Mrs.) Nancy Myles B. Gyamfi 21 ( 2021) Unit 1, topic 3: Types of declaratives: 1. factual statement There are three (3) different types of declarative sentences: factual statements, value judgments and definitions. Factual statement: informs by objectively describing what is there through sense observation. E.gs. 1. That bachelor sitting under the tree is sleeping. 2. The president is taller than his opponent. 3. The car knocked down the boy 4. Ama is a girl. 5. Water boils at 100 degrees Celsius. NB: A statement may be factually true or factually false. Being factual does not mean it is true. It means the truth or falsity of the statement does not depend on the subject’s view-point but on the object itself. Dr. (Mrs.) Nancy Myles B. Gyamfi 22 ( 2021) Types of declaratives: 2. value judgment Value judgment: informs by subjectively prescribing or evaluating how something or someone should or ought to be. They do not state facts about the object but rather express the view point of the subject. E.gs. 1. That bachelor has a good conscience. 2. This knife has a good edge. 3. It is wrong to talk back at your supervisor. 4. Ama is a beautiful girl. 5. The wicked driver knocked down the innocent boy. 6. The president is more corrupt than his opponent. 7. He is a good boxer. Dr. (Mrs.) Nancy Myles B. Gyamfi 23 ( 2021) Value judgment cont’d: moral and non-moral Value judgments come in two (2) forms: 1. Moral value Judgments: (a) Abortion is evil. (b) You should not talk back at your supervisor. 2. Non-moral value Judgments (c) He is a good boxer. (d) My phone has a good screen NB: Metaphors are also another way of expressing a value judgment. E.gs. 1. Ataa is a flower ( Ataa is weak; Ataa is beautiful) 2. My M.P is Mugabe (My M.P has stayed in power for so long…) Dr. (Mrs.) Nancy Myles B. Gyamfi 24 ( 2021) Types of declaratives: 3. definitions Definition: a definition is a sentence that informs by giving meaning (defining) to the word. E.gs.1. A bachelor is an unmarried man. 2. Pollination is the transfer of pollen grains from the anther to the stigma. 3. “Even number is any number that is divisible by two without a remainder”. NB a definition can be either true or false. If the meaning is correct then it is true. If not, then it is false. Dr. (Mrs.) Nancy Myles B. Gyamfi 25 ( 2021) Definitions cont’d: parts The parts of a definition are the definiendum and the definiens. E.g.: A bachelor is an unmarried adult male. In the definition above, a bachelor is the word being defined (i.e. the definiendum). A bachelor is an unmarried adult male. The part of the definition which gives the meaning is an unmarried adult male(i.e. the definiens). Dr. (Mrs.) Nancy Myles B. Gyamfi 26 ( 2021) UNIT 1, topic 4: distinguishing sentence from statement A sentence is a collection of words with a complete thought or meaning but a statement is a type of sentence that can be either true or false. That means there are some other sentences which do not have a truth-value. All statements are sentences but not all sentences are statements. A sentence can be a statement, a question or a command. E.gs. of sentences that are statements: 1. Nana is a graduate. 2. That is the Vice Chancellor. E.gs. of sentences that are not statements: 1. “Sit up!” 2. Why are you crying? Dr. (Mrs.) Nancy Myles B. Gyamfi 27 ( 2021) Recall and practice! Contrasting facts and values Refer to the recommended text references and exercises!! Dr. (Mrs.) Nancy Myles B. Gyamfi 28 ( 2021) End of lecture 1 Blessed week! Blessed week! Dr. Myles Dr. (Mrs.) Nancy Myles B. Gyamfi 29 ( 2021) UGRC 150: CRITICAL THINKING AND PRACTICAL REASONING G2 Main; G3 and G4 City LECTURE 2: DEFINITIONS, VERBAL DISPUTES & SUBSTANTIVE DISAGREEMENTS Dr. (Mrs.) Nancy Myles B. Gyamfi Philosophy and Classics, (Humanities, U.G) June - Aug, 2021 020-7301599 (WhatsApp/call) / [email protected] Definitions: connotation/denotation Every definition has two aspects: the meaning (connotation) of the word and the particular examples that the meaning refers to(denotation). Dr. (Mrs.) Nancy Myles B. Gyamfi 2 ( 2021) understanding connotation Look at the different connotations of the word chair - Chair is a furniture we sit on - Chair is the head of an institution - Chair is the person who steers the affairs of a meeting Note: The given connotation then will determine the specific denotation (particular instances or examples referred to) in each sentence above. Dr. (Mrs.) Nancy Myles B. Gyamfi 3 ( 2021) Pause & think! “The legislature agreed to table the motion for another day” “The rows and columns in the table are too complex” “Your breakfast is already on the table”. Notice the different connotations of the word ‘table’!! Dr. (Mrs.) Nancy Myles B. Gyamfi 4 ( 2021) Detecting equivocation! If more than one connotation of a word is used in the same context without any signal of the shift with the intention to manipulate or to persuade, the speaker is accused of committing equivocation. E.g.: I don’t see why women are always complaining that they do not enjoy the same freedom as men do. It is a free country; so what’s the problem? Everybody in Ghana here is free to do what they like. Dr. (Mrs.) Nancy Myles B. Gyamfi 5 ( 2021) E.gs. of equivocation Example 2: I don’t see how you can say you are an ethical person. It is so hard to get you to do anything; your work ethic is so bad. Example 3 Sure philosophy helps you argue better, but do we really need to encourage people to argue? There’s enough hostility in this world. Dr. (Mrs.) Nancy Myles B. Gyamfi 6 ( 2021) Types of Definitions: Lexical: dictionary Ostensive: pointing to (demonstrating) Operational: steps (or instruction) Stipulative: fiat (agreed upon by users, think of jargons) Theoretical: theory based (institutionalized) Real(Ideal, eliminative, essential): definiendum can replace definiens in all contexts of use. (Note: Overlaps in types of definitions. Discuss!!) Dr. (Mrs.) Nancy Myles B. Gyamfi 7 ( 2021) On definitions: open textured terms Open textured/open class concept: a word is open textured or essentially contestable if it has several connotations (meanings) and therefore any given meaning can be contested even within the same discipline. E.g. of such terms are family, justice, fidelity, democracy, etc.… Dr. (Mrs.) Nancy Myles B. Gyamfi 8 ( 2021) On definitions: well-defined terms Well-defined concept: a term is well-defined if its definition makes completely clear which objects or individuals, or properties are correctly called by that word. Its meaning is not contestable in the discipline in question! (Common in deductive studies like Maths and Logic) Refer to the definition of even number in the prescribed text Dr. (Mrs.) Nancy Myles B. Gyamfi 9 ( 2021) Problems with definitions Flaws(errors) in definitions include being broad, narrow, circular or vague. Note: one definition may be flawed in more than one way!! Broad: the definiens covers things that do not belong in the denotation of the word. Narrow: the definiens does not cover all the things that correctly belong in the denotation of the word. Circular: (begging the question/tautology): the definiens repeats the definiendum. Vague: the definiens does not specify adequately to determine what belongs to the word’s denotation. Trial questions! (Activity 4.1, unit 2) “Lady, efficiency is being efficient at what you do in this office please”. The meaning of evil is murder. A dinosaur is a pre-historical creature. “Development is to develop the nation and …” Religion is the opiate of the masses Volta ladies are snobs Note: some definitions can be both broad and narrow. See e,g 4 Dr. (Mrs.) Nancy Myles B. Gyamfi 11 ( 2021) UNIT 3: Types of discourse Your text identifies four types of discourse (a collection of expressions not a single expression as we have seen so far; passages): - argument, - narration, - instruction - rhetorical polemic. Dr. (Mrs.) Nancy Myles B. Gyamfi 12 ( 2021) Types of discourse 1. narrative Narrative: a discourse which only reports a sequence of events in order of their occurrence. Refer to examples in the text! Dr. (Mrs.) Nancy Myles B. Gyamfi 13 ( 2021) Types of discourse 2. instruction Instruction: a discourse which describes the process or sequence of things to do in a specified order to accomplish some desired effect. Dr. (Mrs.) Nancy Myles B. Gyamfi 14 ( 2021) Types of discourse 3. rhetorical polemic Rhetorical polemic: a passage that communicates (usually strong) feeling or persuasively vents an opinion. Dr. (Mrs.) Nancy Myles B. Gyamfi 15 ( 2021) Types of discourse 4. Argument Argument: a passage that contains a single conclusion that is presented as a logical consequence of reasons (premises/evidence)offered. ▪ Thus, hence, therefore, so, indicate conclusion ▪ Since, if, given that, provided, indicate premises (reasons/evidence). ▪ Refer to the text for examples!! Discuss during zoom Dr. (Mrs.) Nancy Myles B. Gyamfi 16 ( 2021) Understanding the technical meaning of argument An argument is NOT: The use of aggressive language or demeanour in an attempt to shout down or intimidate an opponent. ‘win at all costs’? Dr. (Mrs.) Nancy Myles B. Gyamfi 17 ( 2021) What is an argument? An argument simply means making a claim and giving reasons why that claim should be accepted. Dr. (Mrs.) Nancy Myles B. Gyamfi 18 ( 2021) argument cont’d An argument is a set of statements only one of which is the conclusion (claim) which one attempts to support, justify or prove with reasons(evidence). Every argument has two parts: Conclusion: the claim being made. Premise(s): the reason(s) or evidence intended to support the claim. Dr. (Mrs.) Nancy Myles B. Gyamfi 19 ( 2021) Examples of arguments (refer to activity 4.1, unit 3) 1. All students write exams Ama is a student So, she writes exams 2. Most Ghanaians are hospitable My mother is a Ghanaian Therefore, she is hospitable Note that sometimes if the premises are true it becomes necessary to accept the conclusion also. Dr. (Mrs.) Nancy Myles B. Gyamfi 20 ( 2021) Examples of arguments cont’d (refer to activity 4.1, unit 3) 3. Since the security man was the last person who left the building yesterday, he stole the project leader’s laptop. 4. Every registrar of UG is a member of Staff of UG. Mrs. Otoo-Ayeh is the registrar of the Faculty of Humanities of UG. Therefore, she is a member of Staff of UG. Dr. (Mrs.) Nancy Myles B. Gyamfi 21 ( 2021) examples of arguments cont’d 1) Bats are mammals, and they can fly. So, some mammals can fly. 2. The Administrator will arrive on time, since she’s never been late a day in her life. Both examples are arguments because both attempt to show that a conclusion is true by offering premises in support of it. Credit: Dr. Kwesi Dr. (Mrs.) Nancy Myles B. Gyamfi 22 ( 2021) Soundness & validity of arguments 1. All men are mortal. Socrates is a man. Therefore, Socrates is mortal. 2. All human beings have feathers. Socrates is a human being So, Socrates has feathers Dr. (Mrs.) Nancy Myles B. Gyamfi 23 ( 2021) Trial “It is important that UG actively encourages older people to remain within the work- force. Older people often have rare skills and useful attitudes that are wasted when they leave the work- force early. Moreover, staying on longer in full-time or part-time work is believed to be good for the health. Besides, it is unrealistic to expect savings and pensions to be sufficient to meet the needs of people retired for 40 years or more.” Dr. (Mrs.) Nancy Myles B. Gyamfi 24 ( 2021) Unit 3: Distinguishing verbal disputes from substantive disagreements Verbal dispute: when disputants seem to disagree because they are using the same words inconsistently. (That is, they actually are saying the same thing differently, so they are not disagreeing after all). ✓ This can be corrected by stipulating meaning. E.g. : Kofi- She is a nurse Kojo- No, She is a health worker instead. Dr. (Mrs.) Nancy Myles B. Gyamfi 25 ( 2021) substantive disagreements Substantive disagreement: when disputants disagree because each side subscribes to contrasting values or has in view different facts. (not subjective ‘feelings’!). This is an actual disagreement Arguments are meant to resolve such disagreements. But they may never be resolved E.g.: Kofi- She is a nurse because she has a certificate from the training school. Kojo- No, She is not really a nurse because she does not care for her patients! (Refer to text for egs.) Dr. (Mrs.) Nancy Myles B. Gyamfi 26 ( 2021) End of lecture 2 Effective marketing of the knowledge you acquire in your field of study depends on how well you DEFINE that content to suit your target audience at any point in time!! DEFINITIONS!!!!! Dr. (Mrs.) Nancy Myles B. Gyamfi 27 ( 2021) UGRC 150 CRITICAL THINKING & PRACTICAL REASONING Session 4 – CONTRASTING TYPES OF DISCOURSE Instructor: Dr. Richmond Kwesi Dept. of Philosophy & Classics, UG Contact Informaton: [email protected] College of Education School of Continuing and Distance Education 2020-2021 Academic Year Session Overview In Sessions 2 and 3 you were introduced to techniques for studying the meaning and diferent uses of individual sentences. But most of the time when we gather information we do not think about individual sentences one at a time in isolation from each other. In this Session you will apply these same techniques to scrutinise batches of sentences working together—in written passages and spoken conversations, where sentences are ordered in distinct ways for diferent purposes Sentences usually convey more than single bit of information or a single level of meaning at a time. We need to assess what is communicated both implicitly and explicitly, indirectly as well as overtly, in order to make correct evaluations and to draw correct conclusions from what we hear and read as critical thinkers and good practical reasoners. Dr. Richmond Kwesi Goals and Objectves Upon completion of this Session you will see where logical analysis belongs because you will be able to: distinguish between a verbal dispute and a substantive disagreement appreciate the deviations from literal interpretation required by metaphor, allegory and proverbial discourse recognise when ambiguity, vagueness, and equivocation require correction identify when a passage contains an argument rather than a narrative, a set of instructions, or self-asserting rhetorical polemic REQUIRED READING: UNIT 3 of the Textbook Dr. Richmond Kwesi Slide 3 TYPES OF DISPUTES VERBAL DISPUTES VS SUBSTANTIVE DISAGREEMENTS Dr. Richmond Kwesi Slide 4 Verbal Disputes and Substantve Disagreements To discover how correcting inconsistencies in the use of words can help to fx a disagreement that is steeped in confusion. Correcting a confusion does not always mean we can wipe away a disagreement by resolving people’s conficting views. Correcting confusion may involve instead forwarding the discussion to a productive level, either making clearer what the disagreement is about, or reaching a deeper, wider, or more complicated level of the disagreement. Sometimes disagreement is a good thing. Dr. Richmond Kwesi Slide 5 What is a dispute? A dispute may be defned as a disagreement or a controversy or diference of opinion between two or more people. Or Basically an argument between two or more people. For instance, if I say my grand mother was a good woman and you say she was a horrible woman then we can say there is a dispute in opinion about my grand mother. We will be contrastng these two types of disputes or disagreements. 1.Verbal disputes 2.Substantve disagreements Dr. Richmond Kwesi Slide 6 Verbal Disputes A verbal dispute is a disagreement which occurs as a result of diference in opinion about the meaning of a word and the dispute can be resolved easily when the meaning is clarifed. That is, when two parties to a dispute are interpreting a particular word diferently and that is what causes them to disagree with each other. A verbal dispute is therefore a disagreement which rests upon an inconsistency in the way the disputants are using the same words. Once the meanings of key words are clarifed so that both sides of the dispute are relying upon the same meanings, then either it becomes clear that there is no real diference of opinion, or it becomes clear instead what is the nature and quality of their disagreement. Dr. Richmond Kwesi Slide 7 Verbal Disputes Example 1: Liz: Kpanlogo is a traditonal folkloric dance that our Ga ancestors used to dance only at funerals for hundreds of years. Rich: NO! Kpanlogo is a neo-traditonal popular dance that the dance- band Otoo Lincoln and his group created in Bukom Square, Accra, around 1962. He relied on the old funeral dirges to build up a versatle form of popular dance which suits every occasion nowadays, including funerals. This is a verbal dispute because the dance “kpanlogo” is what is causing them to disagree. Dr. Richmond Kwesi Slide 8 Verbal Disputes Example 2: Liz: Kwame has new laptop. Rich: No, he does not. His brother gave him his old computer which he upgraded, and that computer is at least fve years old. So does Kwame have a “new” laptop? This depends on how one defnes “new”. So this is also a verbal dispute. Verbal disputes can be dissolved by means of a stpulatve defniton where the partes to the dispute fnally setle on a common usage or meaning of the word causing them to disagree in the frst place. Dr. Richmond Kwesi Slide 9 Substantve Disagreement On the other hand if the disagreement or dispute is about the expression of diferent opinions about facts or subscripton to contrastng values then the dispute in queston is considered as a substantve dispute or disagreement. Substantve disagreements can be pursued fruitully on logical grounds. Example: Liz: The US army personnel are helping Iraqi citzens because their presence maintains a peaceful and secure environment. Rich: No, these US soldiers are imposing martal law and have orders to target civilians so they pose a threat to Iraqi citzens. This is a substantve dispute since the only way we can know who is telling the truth is to check the facts on the ground. Dr. Richmond Kwesi Slide 10 Distnguishing between Verbal and Substantve Disagreements 1. Will the disagreement be resolved by all parties accepting a stipulative defnition? If so, then the participants in the argument were engaged in a verbal dispute. 2. Is the proposal of a stipulative defnition likely to be resisted by one or more of the parties in the dispute? If so, then there may be a substantive disagreement between the participants. Dr. Richmond Kwesi Distnguishing between Verbal and Substantve Disagreements 3. Once agreement is reached about the use of key words, is there still unfnished business and unresolved confict of opinion? Do the participants have good logical reasons for their diferent viewpoints? If so, then again we say they are engaged in a substantive disagreement 4. If people are still having a disagreement which cannot be resolved by improving their access to the facts, or by making more explicit the meaning of their words by appeal to a dictionary, or by appeal to a Dr. Richmond Kwesi Slide 12 EXERCISE: Determine whether the following disputes are Verbal or Substantve 1. Juror #3: It’s these kids—the way they are nowadays. When I was a kid I used to call my father, “Sir”. That’s right... “Sir.” You ever hear a kid call his father that anymore? Juror #8: Fathers don’t seem to think it’s important anymore. (From the movie 12 Angry Men) 2. Liz: I don’t think, I know. Rich: I don’t think you know, either. 3. Rich: Don’t ask her whether you should take the job or not—make your own decision. Liz: I am making my own decision—I have decided to ask her what I should do. Liz: 4.Richmond Dr. Kwesi The capital city of Korea is Seoul. EXERCISE: Determine whether the following disputes are Verbal or Substantve 5. Rich: Humans were created in the image of God. Liz: God doesn’t exist, so that can’t be true. 6. Liz: I don’t believe that any God exists. Rich: Wrong, everyone believes in God, since you have to believe in something. 7. Liz: Life begins at conception, when a distinct genetic defnition of a new organism is formed. Rich: Such life is not human, as humanity is the ability to reason and feel. Dr. Richmond Kwesi EXERCISE: Determine whether the following disputes are Verbal or Substantve 8. Liz: There is no “I” in “team”! Rich: There is in “win.” 9. Liz: C’mon, you have to believe the conspiracy happened or that it didn’t happen. Rich: No, actually, I have no belief about the topic at all. It might have happened, but I don’t reject it or accept it. Dr. Richmond Kwesi METAPHORS AND PROVERBS Dr. Richmond Kwesi METAPHORS AND PROVERBS Metaphors and proverbs involve vague use of language that carries many associatons. They are the type of sentences that can carry more than one meaning simultaneously and which also have diferent functons, depending on the circumstances. METAPHOR:- A fgure of speech in which a word or phrase is used to describe an object or acton with which it does not normally have an associaton in order to imply a connecton. PROVERBS:- They are phrases that embody some advice or commonly believed fact. They can also be referred to as axioms, truisms, clichés and adages. Dr. Richmond Kwesi METAPHORS AND PROVERBS Examples of metaphors and proverbs are; 1.Time is money.(metaphor) 2.Juliet is the apple of my eye.(metaphor) 3.Life is war.(metaphor) 4.Birds of a feather fock together.(proverb) 5.When a palm-branch reaches its height, it gives way for a fresh one to grow. (proverb). Understanding metaphors and proverbs depends so much upon the situaton, mood, recepton, background knowledge or preparedness of listeners to appreciate and interpret the multplicity of the meaning of metaphors and proverbs. Individuals can read their own meanings into metaphors and proverbs. Dr. Richmond Kwesi METAPHORS AND PROVERBS Thus metaphors and proverbs cannot be relied upon to convey a single objectve meaning. They are useful in inspiring, motvatng, advising and to speak on topics that are socially powerful and highly charged. NB. To be very clear and straight-forward in conveying informaton it is usually best to avoid metaphorical and proverbial expressions. This is because their interpretatons are open-ended and indecisive. For instance, referring to Kwame as a lion, he might interpret it to mean that he is an animal and for that mater lives in the forest when you intend to mean that he is brave or courageous. Dr. Richmond Kwesi COMMON LINGUISTIC VICES VAGUENESS, EQUIVOCATION AND AMBIGUITY Dr. Richmond Kwesi What are Linguistc Vices? Linguistc vices refer to the bad ways in which we sometmes explain our thoughts. When we convey informaton to other people we make certain errors that distort the efectveness of the communicaton such that others misinterpret or misunderstand the informaton conveyed. The goal of declaratve speech is to be explicit and clear as possible in describing, prescribing, generalizing and predictng the states of afairs in the world. The vices we will be looking at are: Vagueness, Ambiguity, and Equivocaton. Dr. Richmond Kwesi 1. VAGUENESS When the component words of a statement have not been carefully considered such that more informaton need to be conveyed to tell exactly what in the world the words refer to then that statement is said to be vague. An expression is vague when there is: Lack of clarity or distinctness Lack of preciseness in thought or communication Inexplicitness or indeterminateness as to the meaning or denotation of the expression Unclarity as to what in the world the expression refers to Dr. Richmond Kwesi 1. VAGUENESS Examples: “My ofcials are monitoring this situaton very closely, and I can promise that we shall take all appropriate measures to ensure that the situaton is resolved in a way that is fair to all the partes involved.” What are “appropriate measures”? They could be anything or nothing. What does “fair to all the partes” mean? We have no clear idea. They could mean anything. Mom: What did you do at school today? Son: Stuf. He said he will be here any moment from now. We are sorry to say that we are looking for a younger person for the job. Temporarily out of service. We are unable to dispense money atDr. Richmond this Kwesi time. 2. EQUIVOCATION The use of more than one connotation of a word in the same context without any signal of the shift with the intention to manipulate or to persuade is called equivocation. The intended meaning of a word seems to shift back and forth between two or more distinct connotations without warning or indication Examples: 1.I don't see how you can say you are an ethical person. It is so hard to get you to do anything; your work ethic is so bad. 2.Sure philosophy helps you argue beter, but do we really need to encourage people to argue? There's enough hostlity in this world. Dr. Richmond Kwesi 2. EQUIVOCATION Examples Employer to Job Applicant: “In this job, we need someone who is responsible” Applicant: “Then I am the one you are looking for. In my last job every time anything went wrong, they said I was responsible” Can you spot the equivocation in this sign? Dr. Richmond Kwesi 3. AMBIGUITY When a word or phrase or an expression conveys more than one meaning then we say that the expression or word is ambiguous. Ambiguity can be lexical (a word) or structural (the whole sentence); that is, either the word or the whole sentence is open to more than one interpretaton. To disambiguate is to reveal the two meanings interpretatons Examples: 1.I rode a black horse in red pajamas. This could mean either the black horse was in red pajamas when you rode it but you intend to mean you were in a red pajamas when you rode the black horse 2.John took of his trousers by the bank. Did he do that by a building(fnancial insttuton) or by the edge of a river? 3.The passerby helps dog bite victm. Is the passerby helping a dog bite someone? Or is he helping a person biten by a dog? It’s not clear. Dr. Richmond Kwesi EXERCISE: Disambiguate the following expressions..... Dr. Richmond Kwesi EXERCISE: Disambiguate the following expressions..... Dr. Richmond Kwesi EXERCISE: Disambiguate the following expressions..... Dr. Richmond Kwesi Slide 3 EXERCISE: Disambiguate the following expressions..... 1. Drunk gets nine months in stolen laptop case 2. Military head seeks arms. 3. Prostitutes appeal to pope 4. Teacher strikes delaying WAEC candidates 5. Police squad helps rabid dog bite victim 6. Enraged billy goat injures farmer with cutlass 7. Miners refuse to work after death 8. Juvenile court to try shooting defendant 9 Stolen jewels discovered by tree 10. Two American oil tankers collide in the Gulf of Guinea; one dies 11. Two sisters reunited after 18 years in market stall Dr. Richmond Kwesi TYPES OF DISCOURSE REVEALED IN PASSAGES Dr. Richmond Kwesi Slide 31 DISCOURSE REVEALED IN PASSAGES A discourse is a unit of connected speeches or writngs longer than a sentence in the form of a passage either to covey an argument, narrate an event, give a set of instructons, or to make verbal – self assertons using rhetoric or polemic. The types of discourse revealed in passages are 1. Narratve 2. Instructon 3. Rhetorical polemic 4. Argument Dr. Richmond Kwesi 1. NARRATIVE This is a passage which reports a sequence of events in order of their occurrence. The sentences are ordered according to tme. Example: I was about fve years old when my sister informed me that I was too old to stll be riding a bike with training wheels. That was the tme I decided not to depend on them anymore. Even though I had some doubt, my sister and I went outside and started to take the litle wheels of my bike. Afer my bike went through the transformaton, I was now ready for the big moment. With buterfies in my stomach, I slowly got on the bike, and with my shaky hands, I gripped the handles tghtly. Meanwhile my sister was holding on to me to help keep my balance. I was so afraid that she would let go, yet I was determined to ride this bike on my own. Next with a litle push from her, I started to peddle. The faster my bike went the faster my heart raced. Finally I looked back nervously and notced that my sister let go of my bike a long tme ago. I was so excited that I accomplished freedom on my bike that I forgot to peddle. The next step I remember, I was lying on the ground, yet I did not care because of the adrenaline rush. I will never forget the exhilaratng moment and growing up stage of riding a bike without training wheels Dr. Richmond Kwesi 2. INSTRUCTION This is a passage that gives descripton or sequence of things to do in a specifed order; it might also provide a list of directves to follow to accomplish some desired efect, like a prescripton. Example. If you are from Legon campus and you want to go to Madina, get to the Okponglo juncton and wait for any of the commercial buses. Listen carefully to any of the bus conductors that mentons Madina. Get onboard one of the buses. As you sit down, you make your 1 Ghana cedi ready to be given to the conductor of the commercial bus and you tell him/her that you will get down at Madina. Dr. Richmond Kwesi 3. RHETORICAL POLEMIC This is a passage that communicates (usually strong) feeling or persuasively vents an opinion. Examples: What does the ECG think it is doing with the poor service of power supply. I wont pay any electricity bill again and let us see who will dare to take me to court. “We shall not fag or fail. We shall go on to the end, we shall fght in France, we shall fght on the seas and oceans, we shall fght with growing confdence and growing strength in the air, we shall defend our island…we shall never surrender.” Sir Winston Churchill. Dr. Richmond Kwesi 4. ARGUMENT An argument is NOT: The use of aggressive language or demeanour in an attempt to shout down or intimidate an opponent An attempt to ‘win at all costs’ Dr. Richmond Kwesi ARGUMENT A reason is a consideration that provides evidence that a belief is true, or very likely to be true. Reasons are said to “support,” “justify,” or “prove” beliefs by providing evidence for them. An argument is a set of statements presented to support/justify/prove a belief or claim with a set of reasons. Every argument has two parts: Conclusion: the belief being supported. Premise(s): the reason(s) intended to support the conclusion. Each reason is called a premise. Every argument has at least one premise. Dr. Richmond Kwesi ARGUMENT Belief/Claim: Richie is intelligent Why?: 1.AllAccra Aca boys are intelligent, And 2.Richie is an Accra Aca boy Argument: All Accra Aca boys are intelligent Richie is an Accra Aca boy Therefore, Richie is intelligent Dr. Richmond Kwesi ARGUMENT In each of the following arguments, there is a conclusion and at least one premise. Can you distinguish the premise(s) from the conclusion? 1) Bats are mammals, and they can fy. So, some mammals can fy. 2) The ofcer will arrive to the base on time, since she’s never been late a day in her life. 3) War is wrong because it involves killing innocent people, and that is always wrong. 4) Humankind was created by aliens from another planet. A wise man once told me so. All four examples above are arguments. All of them attempt to show that a conclusion is true by ofering premises in support of it. However, you probably noticed that most of them are not good arguments. Dr. Richmond Kwesi ARGUMENT Bats are mammals, and they can fy. So, some mammals can fy. [Premise 1] Bats are mammals, and [Premise 2] they can fy. [Conclusion] So, some mammals can fy. The ofcer will arrive to the base on time, since she’s never been late a day in her life. [Conclusion] The ofcer will arrive to the base on time, since [Premise] she’s never been late a day in her life. NOTE: A syllogism is an argument with two premises Dr. Richmond Kwesi ARGUMENT War is wrong because it involves killing innocent people, and that is always wrong. [Conclusion] War is wrong because [Premise 1] it involves killing innocent people, and [Premise 2] that is always wrong. Humankind was created by aliens from another planet. A wise man once told me so. [Conclusion] Humankind was created by aliens from another planet. [Premise] A wise man once told me so. Identfy the premise(s) and conclusion.... We must resist all forms of government censorship. Freedom of speech and expression are essential to a democratic form of government. As soon as we allow some censorship, it won't be long before censorship will be used to silence opinions critical of the government. Dr. Richmond Kwesi Identfy the premise(s) and conclusion.... Witches are real. They are mentioned in the Bible. There are many people today who claim to be witches. And historical records reveal that there were witches in Salem, Massachusetts (Vaughn 2010: 25). Dr. Richmond Kwesi Slide 3 FINDING ARGUMENTS Tips for fnding arguments: 1) Find the conclusion frst. Whenever you read or hear something and you’re not sure if it contains an argument, ask yourself “What claim is the author/speaker trying to persuade me to believe?” That claim will be the conclusion. 2) After identifying a possible conclusion, fnd the premises. If an argument is present, there should be a conclusion that the author is trying to convince you of and reasons (premises) ofered to show that the conclusion is true. If there are no premises, there is no argument. Dr. Richmond Kwesi FINDING ARGUMENTS 3) Look for indicators—words or phrases typically followed by a premise or conclusion. (Indicators are not always used!) Points of caution: (1) The lists below are not complete! (2) Some arguments contain no indicators at all! Premise Indicators Conclusion Indicators because, since, for, so, therefore, thus, as, after all, the hence, ergo, implies reason is that, in light that, it follows that, of the fact that, accordingly, based on the fact consequently, we that, etc. may infer that, etc. Dr. Richmond Kwesi Slide 3 EXERCISES.... “The university ought to raise the retrement age from 65 to 75. People are living longer than they used to, and many academics are stll productve even afer 70. Why, Dr Morgan discovered the cure for the common cold when she was 72! Older academics have a great deal of expertse that can beneft younger members of staf. If academics know they are going to be forced out at 65, they may feel unhappy about their jobs. So academics are likely to be less productve if the retrement age stays as it is.” 1. What is the main conclusion of the argument? 2. What are the main premises of the argument? 3. Write out any sub-conclusions of the argument. Dr. Richmond Kwesi EXERCISES.... Identfy whether the passage is or is not an argument; if a passage is an argument, state its main conclusion. a)The tger, whose populaton is estmated at about 6000, may become extnct in the next decade, according to some claims. b)Of all the animals commonly eaten in the Western world, the pig is without doubt the most intelligent. The natural intelligence of a pig is comparable and perhaps even superior to that of a dog; it is possible to rear pigs as companions to human beings and train them to respond to simple commands much as a dog would. (Peter Singer, Animal Liberaton) c)Since animals are sentent, and can feel both pleasure and pain, we ought to take their interests into account; we should not harm animals for no good reason. Most humans can thrive on a plant-based diet, so eatng meat is unethical. We should always try to act ethically, so we should all avoid eatng meat. Dr. Richmond Kwesi EXERCISES.... Identfy whether the passage is or is not an argument; if a passage is an argument, state its main conclusion. I.I’m not sure a bad person can write a good book. If art doesn’t make us better, then what on earth is it for? (Alice Walker) II.Let us weigh the gain and the loss in wagering that God is. Let us estimate these two chances. If you gain, you gain all; if you lose, you lose nothing. Wager, then, without hesitation that He is. (Blaise Pascal). III.Is the arrow-maker less benevolent than the maker of armour of defense? And yet the arrow-maker’s only fear is lest men should not be hurt, and the armour-maker’s only fear is lest men should be hurt. So it is with the priest and the cofn maker. The choice of profession, therefore, is a thing in which great caution is required. (Menicus) Dr. Richmond Kwesi End of Session Dr. Richmond Kwesi UGRC 150 CRITICAL THINKING & PRACTICAL REASONING UNIT 5 – THE NORMATIVE AND THE EMPIRICAL Instructor: Dr. Richmond Kwesi Dept. of Philosophy & Classics, UG Contact Information: [email protected] Session Overview Think of an example where someone is criticizing on moral grounds the legitimacy or justness of a civil statute or a law. Imagine a situation where there seem to be a conflict between something that is an accepted practice on legal grounds but is regarded as unacceptable on moral grounds. These examples and situations illustrate that there must be more than one sense we attribute to the notion of law. To avoid being fooled by switching connotations without indication, this session introduces the critical thinker to the different senses of law. Required Reading: UNIT 5 Dr. Richmond Kwesi Review: Factual statements vs Value Judgements Factual statements are expressions that describe the way the world is. What this means is that, they give a report of the way the world is as we experience them with our senses. We call them EMPIRICAL because they are expressions derived from experience or observations and they are verifiable. Value judgments on the other hand are expressions that prescribe or evaluate the way the world or things or someone should or ought to be. We call them NORMATIVE because they state standards or norms to prescribe or evaluate an action or behavior or something. Dr. Richmond Kwesi The Normative and the Empirical The distinction between factual statements and value judgements, therefore, helps us to understand general claims of two kinds: normative principles—which indicate how things must be or how they should be—vs. empirical generalisations—which supposedly report how things are in fact. Rules or laws of Logic and Critical thinking are normative, in the sense that they capture how we ought to think and not how we actually do think Dr. Richmond Kwesi The Different Senses of ‘Law’ Dr. Richmond Kwesi LAW There is no one definition for the word ‘law’ but rather different notions. Depending on the context of usage, the word law can mean a natural law, civil law, customary law, moral law, law of reasoning, mathematical law or divine law. Law is a system of rules or general principles that govern the nature of things, or the way individuals are supposed to behave. Laws are expressed in the form of statements. Some laws are descriptive and others are prescriptive. Dr. Richmond Kwesi 1. NATURAL LAW Natural laws also called scientific laws refer to statements that express laws about nature (living things, rivers, celestial bodies etc.) They are defined as statements that aim to describe the regularities or uniformities in the patterns of event or features of things we observe around us. They are formed based on our past experiences. For instance, we observe that at any point in time when a fish is taking out of water for a maximum of five minutes, it dies so we conclude that “all fish survive in water” as a statement that expresses an attribute or a property that applies to all fish any where, anytime. Dr. Richmond Kwesi NATURAL LAW..... EXAMPLES NB 1. Every planet moves around the Natural law statements sun in an elliptical orbit. have no exceptions and are 2. All metals expand when therefore called law-like. heated. But there is no way to be 3. Any physical object that goes absolutely certain that such up must come down. statements will always be 4. All green plants use sunlight for true. So they are called law- photosynthesis. like because maybe 5. All fish live in water. someday counterevidence 6. Every human being breath will make them false. oxygen. Dr. Richmond Kwesi NATURAL LAW.... Natural laws are disguised predictions. They predict about future realities. The statement “all metals expand when heated” means that “if you come across any metallic object and you heat it then expect it to expand.” But what if you discover a new metal and it does not expand upon heating it, then it will make the statement “all metals expand when heated” to be false. Scientific laws always depend upon evidence, and they are predictions. They may turn out to be false so we call them law- like statements or hypothesis NB: Since they describe regularities and uniformities in the patterns of events around us they are EMPIRICAL. Dr. Richmond Kwesi NATURAL LAW.... This sense of natural law in terms of scientific law makes natural law an empirical concept Natural law as a normative concept is about rules for how humankind should fit in with a divinely ordained natural order of things. - This sense of natural law works on the presumption that rationally organized and legitimized social conduct follows from a larger picture of the universe - Hence, we can say things like a particular action is unnatural or that it does not cohere with the laws of nature Dr. Richmond Kwesi 2. CIVIL LAW AND STATUTORY LAW CIVIL LAWS AND STATUTORY LAWS are man-made laws that represent the legal instruments that governments of states use to regulate the behavior of citizens. They prescribe how citizens ought to behave in specific circumstances. They are laws backed by force since they come with sanctions. NB: They are prescriptive statements since they express what one should do or must not do, so they are NORMATIVE. Dr. Richmond Kwesi CIVIL LAW AND STATUTORY LAW Examples NB 1. Commercial laws If these laws are broken by 2. Tax laws individuals, the individuals are 3. Constitutional statutes rather punished. Violations do not make the laws falsified and 4. Land tenure regulations for that matter must be changed. 5. Rules for electoral process. The laws still remain and 6. Criminal laws in response to rape, sanctions are carried out. This is stealing, murder, manslaughter, what makes it different from assault. natural laws. The sanctions 7. Human rights laws, traffic laws, attached are what makes interstate laws etc. them laws to be obeyed by all citizens. Dr. Richmond Kwesi CIVIL LAW AND STATUTORY LAW Example: 1992 Constitution of Ghana: Article 276 (1) A chief shall not take part in active party politics; and any chief wishing to do so and seeking election to parliament shall abdicate his stool or skin. Notwithstanding clause (1) of this article and paragraph (c) of clause (3) of article 94 of this constitution, a chief may be appointed to any public office for which he is otherwise qualified. Dr. Richmond Kwesi 3. CUSTORMARY LAW ▪ The laws, practices, customs of indigenous and local communities which are intrinsic and central part of the way of life of these communities. ▪ Customary laws are embedded in the culture and values of a community or society, they govern acceptable standard of behaviour and are actively enforced by members of the community. ▪ Most customary laws deal with standards of the community that have been long-established in a given locale ▪ Generally, customary laws are not written, but are transmitted through oral tradition and practice. Dr. Richmond Kwesi CUSTORMARY LAW Just like the civil laws or Examples statutory laws, they are man- made and also have sanctions 1.Taboos like incest, not farming or fishing on a particular day. attached to them to regulate behaviors of members of a 2.The traditional customary marriage. particular community, clan or lineage. The system of 3.Acknowledgements of chiefs as traditional custodians of lands. authority that enforces the customary laws are Chiefs, 4.Traditional inheritance system clan heads etc. and marriage system. etc NB CUSTOMARY LAWS ARE ALSO NORMATIVE. Dr. Richmond Kwesi CUSTORMARY LAWS and CULTURAL NORMS Customary laws are distinguished from cultural norms, social rules and conventions in the sense that the latter are not laws and they do not have sanctions attached to them in case of any violation. Examples of cultural norms are wearing of certain kinds of apparel in certain public and private circumstances, dietary rules, worship behavior, observance of public holidays and public ceremonies etc. NB: Cultural norms or social rules are the commonly adhered practices in a society that normally do not attract any severe form of punishment or sanction. Dr. Richmond Kwesi 4. MORAL LAW a general rule of right living; especially, such a rule or group of rules conceived as universal and unchanging and as having the sanction of God's will, of conscience, of man's moral nature, or of natural justice as revealed to human reason Morally good law NOT same as cultural norm – [there would be no way to criticize any cultural norm as being immoral] Morally good law NOT same as being legal – [then there would have been no way to challenge apartheid law on moral grounds] Moral Laws are presumed to be universal, transcending ones culture, religion, constitution or society. Dr. Richmond Kwesi MORAL LAW Examples. 1.It is morally wrong to steal. 2.It is wrong to kill. 3.It is morally right to respect other people’s views. 4.To legalize segregation is morally wrong. NB: MORAL LAWS ARE ALSO NORMATIVE. Dr. Richmond Kwesi Quotes for reflection..... Spend some time to reflect on what some prominent people have said about moral law….. Dr. Richmond Kwesi Quotes for reflection..... Spend some time to reflect on what some prominent people have said about moral law….. Dr. Richmond Kwesi Quotes for reflection..... Spend some time to reflect on what some prominent people have said about moral law….. Dr. Richmond Kwesi Quotes for reflection..... Spend some time to reflect on what some prominent people have said about moral law….. Dr. Richmond Kwesi 5. LOGICAL LAW LOGICAL laws are the principles or rules for thinking that are required in order to move from statements that are accepted as true, to further statements which by all means will necessarily also be true since they follow from the premises that were assumed to be true from the outset. They guide us in distinguishing good reasoning from bad reasoning. They are deductive in nature. Since they guarantee that if your starting point( assumptions or premises) are true then your final conclusion will also be true. Example: If all As are Bs and every B is a C then every A is a C Example: the law of excluded middle (or the principle of excluded middle) states that for any proposition, either that proposition is true, or its negation is true. Dr. Richmond Kwesi 6. MATHEMATICAL LAW WHAT ARE THEY Examples 1. Laws of addition, subtraction, division, These are laws that regulate multiplication. AND the way operations in 2. Never divide by zero, Laws of indices mathematics ought to be are all general rules of mathematical done. practices. We have rules for 3. Every even number is the sum of two mathematical practices and odd numbers, is an example of a descriptive laws that descriptive law that summarizes the results of mathematical practice for summarize the results of all time. mathematical practice for all NB. Mathematical laws are time. also NORMATIVE. Dr. Richmond Kwesi 7. DIVINE LAW WHAT IS IT. EXAMPLES These are laws whose contents 1. The ten commandments of come from a particular Christians. religious doctrine. 2. The sharia law of the The authority of such laws Muslims. come from a supreme being,(deity, God, god) 3. Some religions practice monogamous marriage They are prescriptive in nature while others practice so they are also NORMATIVE. polygamous marriage. They are subject to revelation NB DIVINE LAWS are as the means by which they are binding only on the made available to man and can practitioners of religion. be changed. Dr. Richmond Kwesi END OF SESSION Dr. Richmond Kwesi UGRC 150: CRITICAL THINKING AND PRACTICAL REASONING LECTURE 4: Deduction versus Induction (Unit 6) Dr. (Mrs.) Nancy Myles B. Gyamfi Philosophy and Classics, (Humanities, U.G) June -Aug, 2021 020-7301599 (WhatsApp/call) / [email protected] 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 1 Outline CONTRASTING DEDUCTIVE AND INDUCTIVE ARGUMENTS – Particular and general statements Reference class and attribute class – Types of generalizations – Universal generalizations as disguised conditionals DEDUCTIVE ARGUMENT AND INDUCTIVE ARGUMENT 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 2 Outline Cont’d FOUR VALID SYLLOGISTIC PATTERNS Understanding syllogisms Understanding negation – Modus Ponens (affirming the antecedent) – Modus Tollens (negating the consequent) – Disjunctive Syllogism – Hypothetical Syllogism FORMAL FALLACIES – Fallacy of affirming the consequent – Fallacy of negating the antecedent – False hypothetical syllogism VALID ARGUMENT AND SOUND ARGUMENT 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 3 Deduction vs. Induction These terms describe two types of arguments. (two ways of reasoning; two ways of supporting a claim with evidence(s)) Deductive argument: If the premises are true, then the conclusion is also necessarily true already. Inductive argument: The conclusion may not necessarily follow(may not be true) even if the premises are true. Recall premises and conclusion! 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 4 Recall Argument Argument: a passage that contains a single conclusion that is presented as a logical consequence of reasons (premises/evidence) offered. ▪ Thus, hence, therefore, so, indicate conclusion ▪ Since, if, given that, provided, indicate premises (reasons/evidence). ▪ Refer to the text for examples!! Discuss during zoom 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 5 COMPARE TWO TYPES OF ARGUMENTS Deductive 1. All students write exams Ama is a student So, she writes exams Inductive 2. Most Ghanaians are hospitable My mother is a Ghanaian Therefore, she is hospitable 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 6 Discuss types of argument cont’d – Inductive argument 3. Since the security man was the last person who left the building yesterday, he stole the project leader’s laptop. – Deductive argument 4. All mangoes are fruits My pen is not a fruit So, it is not a mango 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 7 CORRECT DISTINCTION: DEDUCTIVE AND INDUCTIVE ARGUMENTS Deductive argument: an argument is deductive when the truth of the premises guarantee(proves) the truth of the conclusion. In a deductive argument, if the premises are assumed to be true, then the conclusion is necessarily true. In a valid deductive argument, it is impossible for the premises to be true, and the conclusion false at the same time. If not, you create a contradiction!!! 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 8 CONTRASTING DEDUCTION AND INDUCTION It is wrong to say deductive arguments move from general premises to particular conclusions while inductive move from particular to general. That is ambiguous!!! Note that deduction is topic-neutral but induction depends on subject matter! Deduction is about form/pattern/structure but induction is about content. See text for more examples! 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 9 TYPES OF VALID DEDUCTIVE ARGUMENTS Your textbook lists 4 types of VALID deductive syllogistic arguments, but there are more: 1.Modus Ponens (affirming the antecedent) 2. Modus Tollens (denying or negating the consequent) 3. Disjunctive Syllogism 4. Hypothetical Syllogism See examples from text! Note: A syllogism is a form of deductive argument with two premises and one conclusion 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 10 Understanding particular vs general statements Every statement (proposition) has two parts : the reference class and the attribute class. e.g. That man is a bully. ‘That man’ is the reference class (since ‘that man’ is specific, countable and finite, we describe this statement as a particular statement) e.g. Men are bullies. ‘Men’ is the reference class (since ‘men’ is not specific, not countable and is infinite, we7/12/2021 describe this statement asMyles Dr. (Mrs.) Nancy a generalization) Gyamfi 11 Types of generalizations universal and statistical Universal/lawlike generalization: The attribute applies to all members of that infinite reference class. (No one is exempted!) E.g. Men are bullies. Statistical generalization: The attribute applies only to a subset of the infinite reference class. (some are exempted but the class is still infinite, therefore a generalization). E.g. Some men are bullies. NOTE: The reference class tells you whether a statement is general or particular; as well as the type of generalization 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 12 Practice! particular vs. general statements: See pg. 191 1. The disease is contagious. verifiable 2. Few Ghanaians are allergic to pineapples. confirmable 3. The liquid in that ball is poisonous. verifiable 4. Green tables are scarce these days. confirmable 5. Kofi is the new SRC president. verifiable 6. All voters prefer a recount of ballots. confirmable 7. All the voters interviewed said they will prefer a recount of the ballot. verifiable 8. No student registers unless forced. confirmable 9. None of the students in that class registered for the course. verifiable 10. 80% of all retailed stones are not real diamonds. confirmable 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 13 NOTE: Universals are either affirmative or negative Universal Affirmative Ghanaians are hospitable. Most Christians worship on Sundays. Alcoholics are womanizers. Few Ghanaians approve of same-sex marriage. Universal negative No man is perfect. No cat is a dog No goats require vaccinations 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 14 Universal generalizations as disguised conditionals Note: any universal generalization is actually a disguised conditional which has an antecedent and a consequent. All men are bullies is the same as if x is a man then x is a bully. Every student cheats is the same as if x is a student then x cheats 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 15 Universal generalizations as disguised conditionals cont’d We can clearly determine the antecedent and the consequent of our statement when written as a conditional (if…then statement). Antecedent: the ‘if clause’ Consequent: the ‘then clause’ E.g. If x is a man then x is a bully. (antecedent is x is a man; consequent is x is a bully) E.g. If x is a student then x cheats. (antecedent is x is a student; consequent is x cheats) 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 16 Universal negations as conditionals For the expression “No man is perfect”, the conditional form reads thus: “if x is a man, then x is not perfect’. For the expression, “No cats are dogs”, the conditional form reads thus: “if x is a cat, then x is not a dog” For the expression, “No humans have feathers”, the conditional form reads thus: “if x is a human then x has no feathers ” 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 17 A note on syllogism A syllogism simply refers to a deductive argument with two premises and a conclusion. All the valid forms we will study are syllogisms. 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 18 A note on interpreting negation Note: if the original statement is a negation, then its negation will be positive, and vice versa. E.g. the negation of the statement “Kofi is not a student” is “Kofi is a student”, while the negation of the statement “Kofi is a student” is “Kofi is not a student”. This note is useful for affirming and denying antecedent and consequent. 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 19 Types of valid deductive forms (valid syllogistic forms) Modus Ponens (affirming the antecedent) All mangoes are fruits This thing is a mango So it is a fruit Modus Tollens (negating the consequent) All mangoes are fruits This thing is not a fruit So, this thing is not a mango 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 20 valid deductive forms cont’d Hypothetical Syllogism All mangoes are fruits All fruits are edible So, all mangoes are edible Disjunctive Syllogism You either save at Barclays or Stanchart You do not save at Barclays Therefore, you save at Stanchart 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 21 Formal/Syllogistic FALLACIES Formal fallacies simply refer to an error in the form of deduction (i.e. you do not deduce according to the correct form or pattern) 1. The fallacy of affirming the consequent. When you affirm the consequent instead of the antecedent. All Xs are Ys This thing is a Y So, this thing is an X 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 22 Formal fallacies cont’d 2. The fallacy of denying or negating the antecedent. When you negate the antecedent instead of the consequent. All Xs are Ys This thing is NOT an X So, this thing is NOT a Y 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 23 Formal fallacies cont’d 3. False hypothetical syllogism: If two different antecedents share a common consequent, it does not mean the two antecedents are the same or identical. “E.g. Every table is a furniture. Every chair is a furniture. So, every table is a chair.” That is a fallacy!!! All Xs are Ys All Zs are Ys So, all Xs must be Zs 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 24 Compare! VALID FORM ITS INCORRECT FORM (FALLACY) MODUS PONENS (affirming the antecedent) Affirming the consequent Heavy smokers have lung issues Heavy smokers have lung issues Kofi is a heavy smoker Kofi has lung issues So, he has lung issues So, he is a heavy smoker MODUS TOLLENS(denying the consequent) Denying the antecedent Heavy smokers have lung issues Heavy smokers have lung issues Kofi does NOT have lung issues Kofi is NOT a heavy smoker So, he is NOT a heavy smoker So, he does NOT have lung issues HYPOTHETICAL SYLLOGISM False Hypothetical Syllogism All mangoes are fruits. All mangoes are fruits All fruits are edible All bananas are also fruits So, all mangoes are edible So, all mangoes are bananas 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 25 Recall! Validity vs. Soundness of a deductive argument Valid and true premises = sound 1. All men are mortal. Socrates is a man. Therefore, Socrates is mortal. Valid but false premises = not sound 2. All human beings have feathers. This table is a human being So, this table has feathers 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 26 SOUND ARGUMENT A sound argument must first be valid and then its premises must be true. 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 27 END OF LECTURE 4 (UNIT 6) BLESSED, SAFE WEEK!! 7/12/2021 Dr. (Mrs.) Nancy Myles Gyamfi 28 UGRC 150: CRITICAL THINKING AND PRACTICAL REASONING Inductive Reasoning in the Sciences and Everyday Life; Causal Reasoning (Units 7 & 9) Dr. (Mrs.) Nancy Myles B. Gyamfi Philosophy and Classics, (Humanities, U.G) June-Aug, 2021 020-7301599 (WhatsApp/call) / [email protected] OUTLINE Basic principles of Inductive Reasoning. Verifiable and confirmable statements. Enumerative Induction: Law-like and Statistical Hypothesis Causal Reasoning and the notion of causation J. S. Mill’s Methods of Causal Reasoning Some Causal Fallacies Dr. (Mrs.) Nancy Myles Gyamfi 2 Recall Induction Unlike deduction, in inductive arguments… the premises provide some reasons or evidence to believe the conclusion will be probably true (Not certain). the premises do not prove or guarantee the truth of conclusion; (i.e., no logical relationship between premises and the conclusion) the conclusion does not necessarily follow from the premises The meanings of the content or information provided matters in confirming the degree of likelihood of truth of conclusion based on the strength of evidence presented Note: conclusion may be false even if it is assumed that the premises are true, and no contradiction will be created Dr. (Mrs.) Nancy Myles Gyamfi 3 Induction cont’d The more evidence you have that corroborate (support) the conclusion, the higher the degree of confirmation. But confirmation is not proof! – (confirmed does not mean certainty) Types of inductive arguments: arguments based on sampling, analogy, causal reasoning, enumerative induction. Dr. (Mrs.) Nancy Myles Gyamfi 4 Examples of inductive arguments 1. 80% of politicians are lawyers. Mr. Kofi is a politician So, he is a lawyer 4. Two out of five women like rich men. 2. Few Ghanaians are hostile to So, women like rich men. foreigners. Dede is a Ghanaian. 5. The security man was the last person who left the building last night. Thus, she is not hostile to So, he is responsible for the theft. foreigners. 3. Yaa is a woman and she cheated. Practice: Activity 1.5 (pp. 148-149) distinguishing deduction from Ajo is a woman and she cheated. induction. Discuss at tutorial! Mansa is also a woman and she cheated. Therefore, believe me when I tell you Dr. (Mrs.) Nancy Myles Gyamfi 5 that women are cheats. Example of an enumerative induction Premises: I dated Ama and she cheated I dated Yaa, she also cheated I dated Mansa, she cheated I dated Afi, she cheated I have just dated Zainab and she cheated All the women I have dated cheated Conclusion: So, all women are cheats Premises (verifiable statements) are listed or enumerated to show the several instances that support the generalized conclusion or hypothesis (which is not verifiable but is only confirmable). Dr. (Mrs.) Nancy Myles Gyamfi 6 Two kinds of enumerative inductive Enumerative induction 1: argument with many verifiable premises (enumerating the premises like a list) and a law-like hypothesis as conclusion. Enumerative induction 2: argument with many verifiable premises (enumerating the premises like a list) and a statistical hypothesis as conclusion. Dr. (Mrs.) Nancy Myles Gyamfi 7 …with a law-like hypothesis as conclusion (Unit 7, section 3) Premise 1: Gold expanded when heated. Premise 2: Silver expanded when heated. Premise 3: Bronze expanded when heated. Premise 4: Copper expanded when heated. Premise 5: Aluminum expanded when heated. Premise 6: Platinum expanded when heated. Premise 7: Brass expanded when heated. Premise 8: Lead expanded when heated. Premise 9: Iron expanded when heated. Premise 10: Zinc expanded when heated. Summary of premises: All the metals tested so far expanded when heated. Conclusion: All metals expand when heated. Dr. (Mrs.) Nancy Myles Gyamfi 8 …with a statistical hypothesis as conclusion (Unit 7, section 3) Premises: I dated Ama and she cheated I dated Yaa, she also cheated I dated Mansa, she cheated I dated Afi, she cheated I have just dated Zainab & she cheated All the women I have dated cheated Conclusion: So, most women are cheats Dr. (Mrs.) Nancy Myles Gyamfi 9 CONFIRMATION IS NOT PROOF!! Note: - Inductive arguments aim at confirming the given hypothesis, while - Deductive arguments aim at proving the given conclusion - The evidence of an inductive argument only confirms but it does not prove the truth of the hypothesis. Confirmation is not proof! Hypothesis is the same as the conclusion of inductive arguments whether statistical or law-like Dr. (Mrs.) Nancy Myles Gyamfi 10 Verifiable vs. confirmable statements ❖A statement is verifiable if it has a finite (specific, countable) reference class (particular statement) and is therefore directly testable. E.g., That man is a bully. ❖A statement is confirmable if it has an infinite (non-specific, uncountable) reference class (general statement) and is therefore indirectly testable. E.g., Men are bullies. Dr. (Mrs.) Nancy Myles Gyamfi 11 Recall particular vs general statements Every statement (proposition) has two parts : the reference class and the attribute class. e.g. That man is a bully. ‘That man’ is the reference class (since ‘that man’ is specific, countable and finite, we describe this statement as a particular statement) e.g. Men are bullies. ‘Men’ is the reference class (since ‘men’ is not specific, not countable and infinite, we describe this statementDr.as (Mrs.)a generalization) Nancy Myles Gyamfi 12 Recall! Types of generalizations universal and statistical Universal/lawlike generalization: The attribute applies to all members of that infinite reference class. (No one is exempted!) E.g. Men are bullies. Statistical generalization: The attribute applies only to a subset of the infinite reference class. (some are exempted but the class is still infinite, therefore a generalization). E.g. Some men are bullies. NOTE: The reference class tells you whether a statement is general or particular; as well as the type of generalization Dr. (Mrs.) Nancy Myles Gyamfi 13 verifiable evidence & confirmable hypothesis Particular statements have finite reference class, they are directly testable and therefore useful as evidence(premise). We describe such statements as verifiable statements. Generalizations or general statements have infinite reference class, they are indirectly testable and therefore useful as hypothesis (conclusion). We describe such statements as confirmable statements. Note: It’s all about the reference class!! Dr. (Mrs.) Nancy Myles Gyamfi 14 Practice! verifiable vs. confirmable statements: See pg. 191 1. The disease is contagious. verifiable 2. Few Ghanaians are allergic to pineapples. confirmable 3. The liquid in that bowl is poisonous. verifiable 4. Green tables are scarce these days. confirmable 5. Kofi is the new SRC president. verifiable 6. All voters prefer a recount of ballots. confirmable 7. All the voters interviewed said they will prefer a recount of the ballot. verifiable 8. No student registers unless forced. confirmable 9. None of the students in that class registered for the course. verifiable 10. 80% of all retailed stones are not real diamonds. confirmable Dr. (Mrs.) Nancy Myles Gyamfi 15 Degrees of confirmability: statistical vs. law-like hypothesis Examples of statistical hypotheses 1. Some Americans are allergic to pineapples. Note: 2. 80% of all retailed stones are not real diamonds. statistical 3. Most Christians worship on Sundays. hypotheses 4. Few Africans approve of same-sex marriage are easier to confirm 5. Two out of every ten men are egoistic. therefore less Examples of law-like hypotheses valuable to 1. No cat is a dog the empirical 2. All voters prefer a recount of ballots. scientist compared to 3. No student registers unless forced. law-like 4. Ghanaians are hospitable hypothesis 5. Alcoholics are womanizers Dr. (Mrs.) Nancy Myles Gyamfi 16 Note: degrees of confirmability Statistical hypotheses are easier to confirm than law-like hypothesis. That makes statistical hypothesis less valuable to the empirical scientist. Law-like hypotheses are easier to falsify, therefore they are more valuable to the empirical scientist! Dr. (Mrs.) Nancy Myles Gyamfi 17 Why falsifiability is valuable to the empirical scientist When a theory is falsified then the empirical scientist can be certain that it is not true. But when a theory is confirmed, it only means there is currently evidence that corroborates the likelihood of the theory being true. But the empirical scientist cannot be certain that a confirmed theory is certainly true because there is always the possibility that we may encounter a counter-factual. So, law-like generalizations are more valuable, next is statistical generalization, then verifiable statements Dr. (Mrs.) Nancy Myles Gyamfi 18 Scientific statements as: (testable, falsifiable) To be scientific is to be capable of being true or false. That is to say, to be testable. (it makes sense to re-search only if what we found earlier could turn out to be false). So uncertainty is a virtue in science! Therefore, a statement that cannot be false is a pseudo-scientific statement (it is not a genuine scientific statement). E.g. Tautologous statements like “Tomorrow it will rain or it will not rain” and “she is pregnant or she is not pregnant” are always true, therefore pseudo-scientific! Falsifiability (able to be false) is a sign that the statement is scientific. It is valued by the scientist!!! Verifiable or confirmable Dr.statements are testable/scientific 19 (Mrs.) Nancy Myles Gyamfi Empirical content, degrees of falsifiability and predictive power The more general a statement is the more empirical content it has; The more empirical content a statement has, the higher its predictive power; The more predictive power a statement has, the easier it is to falsify; The easier it is to falsify a statement, the more valuable it is to the scientist! Dr. (Mrs.) Nancy Myles Gyamfi 20 Some conclusions on unit 7! Therefore, - universal generalizations have more empirical content, - followed by statistical generalization, - then particular statements. (Pseudo scientific statements do not have empirical content or predictive power and are not falsifiable). Practice exercises in text!! Unit 5.1 and 5.2 Dr. (Mrs.) Nancy Myles Gyamfi 21 Cont’d A valuable empirical information must be falsifiable to be scientific. A statement that is not falsifiable cannot be a verifiable or confirmable statement. A statement that is absolutely true has no empirical content (pseudo-scientific statement). Dr. (Mrs.) Nancy Myles Gyamfi 22 Compare degrees of falsifiability, empirical content, predictive power, scientific value TRY!! 1. The earth’s orbit around the sun is elliptical. 2. All the planets that were discovered by Kepler before 1620 AD have elliptical orbits. 3. All planets have elliptical orbits. Dr. (Mrs.) Nancy Myles Gyamfi 23 TRY! a) Heavy smokers are prone to cancer b) Most heavy smokers are prone to cancer c) That heavy smoker is prone to cancer. d) Either that heavy smoker is prone to cancer or he is not. 1. Which has the least predictive power?...................... 2. Which has the most empirical content?....................... 3. Which is/are pseudo-scientific?................................... 4. Which is easiest to falsify?..................................... 5. Which is/are directly testable?......................................... 6. Which would you call verifiable?.................................... 7. Which is absolutely true regardless?............................................................. 8. Which is tautologous and therefore empty of empirical content?.......................... 9. Which would you call hypothetical or confirmable?...................................... 10. Which would you use as evidence/data or observation statement?............................... Dr. (Mrs.) Nancy Myles Gyamfi 24 UNIT 9: CAUSAL REASONING (cause-and-effect based) It is commonplace to seek the cause or causes of things: covid-19, climate change, flooding, destroyed relationship, decline in spirituality, sore friendship, etc. Again, causal (not casual) arguments are also inductive (a matter of probability not proof or certainty!) Dr. (Mrs.) Nancy Myles Gyamfi 25 Different connotations (meanings) of the word ‘cause’ (Unit 9, activity 1.1 & 1.2) Cause as … Proximate condition: (nearest to the effect) Agent: (person or entity with intention) Necessary condition: (must be present for the effect to occur) Sufficient condition: (if present then effect; but other condition(s) can yield that effect) Individually necessary, jointly sufficient condition: if alone necessary but together with other conditions they become sufficient for the occurrence of the effect. E.g. sunlight, water etc for photosynthesis to take place. Probabilistic: (likelihood) Note! So far as we are dealing with empirical evidence, no effect can lay claim to only one single cause Dr. (Mrs.) Nancy Myles Gyamfi 26 J. S. Mill’s 4 methods of causal reasoning To improve our explanation of the possible cause(s) of an effect, J. S. Mill proposes four (4) methods of causal reasoning. (these are inductive, not deductive!). 1. Method of agreement: (that is, if in the series of tests, wherever the suspected cause is present, the ef