Logic And Critical Thinking (Hawassa University) PDF

CLICK HERE 🎠 GET PREMIUM Logic Hawassa University College Law And Governance LOGIC AND CRITICAL THINKING PHIL101 3crh  Course Description This course aims – To cultivate a critical attitude, both personally and professionally – Introduce the...

CLICK HERE 🎠 GET PREMIUM Logic Hawassa University College Law And Governance LOGIC AND CRITICAL THINKING PHIL101 3crh  Course Description This course aims – To cultivate a critical attitude, both personally and professionally – Introduce the nature and concepts of philosophy in general and logic in particular. – Nurturing the skills required to construct good arguments and ability to critically evaluate the arguments of others – Cultivate the habits of critical thinking and develop sensitivity to the clear and accurate use of language.  Learning Objectives On successful completion of this course, the students will be able to: – Understand the main concern of philosophy and the necessity of learning it; – Recognize the components and types of arguments; – Develop the skill to construct and evaluate arguments; – Understand the relationship between logic and language; – Recognize the forms of meanings of words and terms; – Comprehend the types, purposes and techniques of definitions; – Understand the concept, principles, and criteria of critical thinking  Contents CHAPTER ONE Meaning and Nature of Philosophy – Basic Features of Philosophy – Core Fields of Philosophy – Metaphysics and Epistemology – Axiology and Logic – Importance of Learning Philosophy CHAPTER TWO Basic Concepts of Logic: Arguments, Premises and Conclusions – Techniques of Recognizing Arguments. – Recognizing Argumentative Passages – Recognizing Non-argumentative Passages – Types of Arguments: Deduction and Induction. – Differentiating Deductive and Inductive Arguments.. – Evaluating Arguments – Evaluating Deductive Arguments: Validity, Truth, and Soundness – Evaluating Inductive Arguments: Strength, Truth, and Cogency CHAPTER THREE LOGIC AND LANGUAGE – Philosophy of Language – Debates and History of Philosophy of Language – Logic and Meaning – The Functions of Language: Cognitive and Emotive Meanings – The Intension and Extension of Terms – Logic and Definition – Meaning, Types, and Purposes of Definitions – Techniques of Definition – The Extensional (Denotative) Definitional Techniques – The Intentional (Connotative) Definitional Techniques – Criteria for Lexical Definitions  CHAPTER FOUR BASIC CONCEPTS OF CRITICAL THINKING – Meaning of Critical Thinking – Standards of Critical Thinking – Codes of Intellectual Conduct for Effective Discussion – Principles of Good Argument – Principles of Critical Thinking – Characteristics of Critical Thinking – Basic Traits of Critical Thinkers – Basic Traits of Uncritical Thinkers – Barriers to Critical Thinking – Benefits of Critical Thinking CHAPTER FIVE INFORMAL FALLACIES – Fallacy in General – The Meaning of Fallacy – Types of Fallacies – Informal fallacies – Fallacies of Relevance – Fallacies of Weak Induction – Fallacies of Presumption – Fallacies of Ambiguity and Grammatical Analogy – Fallacies of Ambiguity – Fallacies of Grammatical Analogy. CHAPTER SIX CATEGORICAL PROPOSITIONS – Standard-Forms of Categorical Proposition – The Components of Categorical Propositions – Attributes of Categorical Propositions: Quality, Quantity, and Distribution – Venn Diagrams and the Modern Square of Opposition – Representing Categorical Propositions in Diagrams – Squares of Opposition: Traditional and Modern Squares of Opposition – The Traditional Square of Opposition – Evaluating Immediate Inferences: Using Venn Diagrams and Square of Oppositions – Logical Operations: Conversion, Obversion, and Contraposition  Teaching and Learning Methods Presentation – lecture, – question and answer, – group discussion Independent learning (Reading assignment) Collaborative learning (group discussion, and debates) Methods of Assessment Mid-term Examination: 40% (it will cover chapter one and two at the end of week five) Final-term Examination: 60% (it will cover from chapter three to chapter six) Total: 100%  COURSE INTRODUCTION This course is a philosophical inquiry that takes argumentation and reasoning as its basic objects of investigation and attempts to introduce the fundamental concepts of logic and methods of logical argumentation and reasoning and critical thinking critical thinking is the reasonable, reflective, responsible, and skillful thinking that focuses on deciding what to believe or do.  Critical thinking helps to – Ask appropriate questions, – Gather relevant information, – Efficiently and creatively sort through this information, – Reason logically from this information, and – Come to reliable and trustworthy conclusions Generally, this course is designed to help you develop – The ability to construct reliable and logically defendable arguments and – Rationally evaluate the arguments of others  CHAPTER ONE INTRODUCING PHILOSOPHY Philosophy is the study of general and fundamental problems – concerning matters such as existence, knowledge, truth, beauty, law, justice, validity, mind, and language. Logic is a branch of philosophy which treated simultaneously as a field of study and as an instrument. It study arguments and the principles and methods of right reasoning As an instrument, it help us to formulate our own rational arguments and critically evaluate the soundness of others‘ arguments. Meaning and Nature of Philosophy It is difficult to define philosophy because philosophy has no a specific subject but it primarily deals with issues Etymologically, the word philosophy comes from two Greek words: philo and sophia, which mean love and wisdom, respectively. Thus, the literal definition of philosophy is “love of wisdom”. But this is not sufficient to understand philosophy Pythagoras was the first to use the word philosopher to call a person who clearly shows a marked curiosity in the things he experiences and analysis.  Philosophy refers to the development of critical habits, the continuous search for truth, and the questioning of the apparent. The best way to learn and understand philosophy is to philosophize; i.e. – To be confronted with philosophical questions, to use philosophical language, – To become acquainted with differing philosophical positions and maneuvers, – To read the philosophers themselves, and – To grapple with the issues for oneself.  The wisdom that philosophers seek is not the wisdom of the expertise or technical skills of professionals Philosophy involves reason, rational criticism, examination, For Socrates philosophy is a pursuit of wisdom, i.e. – The development of critical habits, – The continuous search for truth, and – The questioning of the apparent Therefore, philosophy is a rational and critical enterprise that tries to formulate and answer fundamental questions through:- – an intensive application of reason – an application that draws on analysis, comparison, and evaluation.  Philosophy has a constructive and critical side,  constructive side:- it attempts to formulate rational answers to certain fundamental questions concerning  the nature of reality,  the nature of value, and  the nature of knowledge and truth.  critical side-it deals with giving a rational critic, analysis, clarification, and evaluation of answers given to basic metaphysical, epistemological, and axiological questions. Philosophy is an activity. It is not something that can be easily mastered or learned in schools  Basic Features of Philosophy 1) Philosophy is a set of views or beliefs about life and the universe, (informal sense of philosophy or ―having a philosophy) 2) Philosophy is a process of reflecting on and criticizing our most deeply held conceptions and belief(the formal sense of – doing philosophy)  These two senses of philosophy-having and doing cannot be treated entirely independent of each other 3) Philosophy is a rational attempt to look at the world as a whole. Philosophy seeks to combine the conclusions of the various sciences and human experience into some kind of consistent worldview 4) Philosophy is the logical analysis of language and the clarification of the meaning of words and concepts. 5) Philosophy is a group of perennial/constant problems that interest people and for which philosophers always have sought answers.  Philosophy presses its inquiry into the deepest problems of human existence. e.g. -What is life and why am I here? -Where does knowledge come from, and can we have any assurances that anything is true? Philosophy is better seen as asking the right questions rather than providing the correct answers.  Generally, Philosophy is the various theories or systems of thought developed by the great philosophers, such as Socrates, Plato and Aristotle,  Core Fields of Philosophy Philosophy has different primary and secondary branches. This course deals only with the primary ones, namely – Metaphysics, – Epistemology, – Axiology, and – Logic.  Metaphysics Metaphysics is derived from the Greek words “meta” means beyond, upon or after and physika, means physics. Metaphysics studies the ultimate nature of reality or existence. It deal with issues of reality, cause and effect relationship, and other related issues. Some of the questions that Metaphysics primarily deals with includes: – What is reality? life? Time? – What is mind, and what is its relation to the body? – Is there a cause and effect relationship between reality and appearance? – Are human actions free, or predetermined by a supernatural force?  Metaphysical questions may be divided into four subsets or aspects. i) Cosmological Aspect:  It deals about the origin, nature, and development of the universe as an orderly system.  E.g. How did the universe originate and develop? Does its existence have any purpose? ii) Theological Aspect: Theology is that part of religious theory that deals with conceptions of and about God. what is God’s relationship to human?‖ iii) Anthropological Aspect: Anthropology deals with the study of human beings and asks questions like:- – What is the relation between mind and body? – Is mind more fundamental than body, with body depending on mind, or vice versa? – Are people born good, evil, or morally neutral? – Do they have free will, or are their thoughts and actions determined by their environment, inheritance, or a divine being? iv) Ontological Aspect: Ontology is the study of the nature of existence, or what it means for anything to exist. – Is reality orderly and lawful in itself, or is it merely orderable by the human mind? – Is it fixed and stable, or is change its central feature? – Is this reality friendly, unfriendly, or neutral toward humanity?‖  Epistemology Etymologically, epistemology ― Greek words episteme, meaning ―knowledge, understanding, and logos, meaning ―study of. Epistemology is referred to as ―theory of knowledge Epistemology studies about the nature, scope, meaning, source, and validity and possibility of knowledge. It deals with issues of knowledge, opinion, truth, falsity, reason, experience, and faith. Thus, epistemology covers two areas: the content of thought and thought itself. – What is knowledge? What does it mean to know? – What is the source of knowledge? Experience? Reason? Or both? – How can we be sure that what we perceive through our senses is correct? – What makes knowledge different from belief or opinion? – What is truth, and how can we know a statement is true?  The first issue in epistemology is asking whether reality can even be known. In this regard, Skepticism(agnosticism) claiming that people cannot acquire reliable knowledge and that any search for truth is in vain. A second issue foundational to epistemology is whether all truth is relative, or whether some truths are absolute. – Is all truth subject to change? – Is it possible that what is true today may be false tomorrow? If the answer is “Yes” to the above questions, such truths are relative  A major aspect of epistemology relates to the sources of human knowledge. Central to most people‘s answer to that question is empiricism (Empirical knowledge i.e. knowledge obtained through the senses). However, data obtained from the human senses could be both incomplete and undependable. Fatigue, frustration, and illness could distort and limit sensory perception. In addition, there are sound and light waves that are inaudible and invisible to unaided human perception. In general, sensory knowledge is built upon assumptions that must be accepted by faith in the dependability of human sensory mechanisms. The advantage of empirical knowledge is that many sensory experiences and experiments are open to both replication and public examination.  A second important source of human knowledge is Reason(rationalism).it claim that the senses alone cannot provide universal, valid judgments that are consistent with one another Also rationalism claims that humans are capable of arriving at certain knowledge independently of sensory experience A third source of human knowledge is Intuition- i.e. the direct apprehension of knowledge that is not derived from conscious reasoning or immediate sense perception The weakness of intuition is that it is not a safe method when used alone. But it’s distinct advantage is helps to bypass the limitations of human experience.  A fourth influential source of knowledge is Revelation. It is the prime importance in the field of religion. It differs from all other sources of knowledge because it presupposes a transcendent supernatural reality that breaks into the natural order. Some people assert that a major disadvantage of revealed knowledge is that it must be accepted by faith and cannot be proved or disproved empirically. A fifth source of human knowledge, though not a philosophical position, is Authority. It comes from experts or has been sanctified over time as tradition. E.g. textbook, teacher, or reference work. If authoritative knowledge is built upon a foundation of incorrect assumptions, then such knowledge will surely be distorted(one sided).  Axiology The term Axiology stems from two Greek words- Axios, meaning ―value, worth, Logos, meaning ―reason/ theory/ symbol / science /study of. Axiology is the philosophical study of value(the worth of something).  What is a value?  Where do values come from?  How do we justify our values?  What is the relationship between values and knowledge? Axiology deals three areas, namely Ethics, Aesthetics, and Social/Political Philosophy.  1.Ethics It is also known as Moral Philosophy, and it deals with the philosophical study of moral principles, values, codes, and rules, It used as standards for determining what kind of human conduct/action is said to be good or bad, right or wrong. Ethics raises various questions including:  What is good/bad? right/wrong?  Is an action right because of its good end, or its right principle?  Are moral principles universal, conditional or unconditional?  What is the ultimate foundation of moral principles? The supernatural God? Human reason? Mutual social contract?  Why we honor and obey moral rules? For the sake of our own individual benefits?, or for the sake of others?  Ethics can be grouped into three broad categories: Normative ethics, Meta-ethics, and Applied Ethics. Normative Ethics It deals with moral rules, principles, standards and goals to evaluate conducts, actions and decisions. Consequentialism or Teleological Ethics, Deontological Ethics, and Virtue Ethics are the major examples of normative ethical studies. Meta-ethics It deals with investigation of the meaning of ethical terms, as good or bad and right or wrong than with what we think is good or bad and right or wrong. Moral Intuitionism/awareness, Moral Emotive, Moral Prescriptivism, Moral Nihilism, and Ethical Relativism are the main examples of meta-ethical studies  Applied Ethics It attempts to explain, justify, apply moral rules, principles, standards, and positions to specific moral problems, such as capital punishment, euthanasia, abortion, adultery, animal right, and so on.  Aesthetics Aesthetics is the theory of beauty. It studies about the particular value of our artistic and aesthetic experiences. It deals with beauty, art, enjoyment, sensory/emotional values, perception, and matters of taste and sentiment. The following are typical Aesthetic questions: – What is art? beauty? the relation between art and beauty and truth? – What is artistic creativity and how does it differ from scientific creativity? – Does art have any moral value, and obligations or constraints?  Social/Political Philosophy It studies about the value judgments operating in a civil society, be it social or political. It primarily deal with: – What form of government is best? – What economic system is best? – What makes an action/judgment just/unjust? – Does society exist? If it does, how does it come to existence? – How are civil society and government come to exist? – Are we obligated to obey all laws of the State? – What is the purpose of government?  Logic Logic is the study or theory of principles of right reasoning. It deals with formulating the right principles of reasoning; and developing scientific methods of evaluating the validity and soundness of arguments. The following are among the various questions raised by Logic: What is an argument; What does it mean to argue? What makes an argument valid or invalid What is a sound argument? What relation do premise and conclusion have in argument? How can we formulate and evaluate an argument? What is a fallacy?; What makes an argument fallacious?  Importance of Learning Philosophy “The unexamined life is not worth living”. philosophy provides us with the tools we need to critically examine our own lives as well as the world in which we live. philosophy can assist us to actualize ourselves by promoting the ideal of self-actualization. self-actualization is associated with self- fulfillment, creativity, self-expression, realization of one‘s potential, and being everything one can be. Although philosophy may not necessarily lead to this  There are many characteristics of self- actualization to whose achievement studying philosophy has a primordial contribution. 1) Intellectual and Behavioral Independence – we can learn how to develop and integrate our experiences, thoughts, feelings, and actions for ourselves, and thus how to be intellectually and behaviorally independent. 2) Reflective Self-Awareness – Philosophy helps critically examine the essential intellectual grounds of our lives 3) Flexibility, Tolerance, and Open-Mindedness: – we become more tolerant, open-minded, more receptive, and more sympathetic to views that contend or clash with ours. 4) Creative and Critical Thinking – we can learn how to refine our powers of analysis, our abilities to think critically, to reason, to evaluate, to theorize, and to justify. 5) Conceptualized and well-thought-out value systems in morality, art, politics, and the like: – studying philosophy provides us with an opportunity to formulate feasible evaluations of value; and thereby to find meaning in our lives.  CHAPTER TWO BASIC CONCEPTS OF LOGIC The word logic comes from Greek word logos, which means sentence, discourse, reason, truth and rule. Logic in its broader meaning is the science, which evaluates arguments and the study of correct reasoning. It could be also defined as the study of methods and principles of correct reasoning or the art of correct reasoning. Logic can be defined in different ways. – It is a science that evaluates arguments. – It is the study of methods for evaluating whether the premises adequately support or provide a good evidence for the conclusions. – It is a science that helps to develop the method and principles to evaluate the arguments of others and construct arguments of own.  Logic is the attempt to codify/organize the rules of rational thought.  Logicians explore the structure of arguments that preserve truth or allow the optimal extraction of knowledge from evidence. In logic, as an academic discipline, we study – Reasoning itself: – Forms of argument, – General principles and – Particular errors, – Methods of arguing. Logic can help us understand what is wrong or why someone is arguing in a particular way. Logic is the organized body of knowledge, or science that evaluates arguments.  The aim of logic is to develop a system of methods and principles that we may use as criteria for evaluating the arguments of others and guides in constructing arguments of our own.  Benefit of Studying Logic “Logic sharpens and refines our natural gifts to think, reason and argue” (C. S. Layman) The study of logic is one of the best ways to refine one‘s natural ability to think, reason and argue. The following are some of the major benefits that we can gain from the study of logic: It helps us to develop the skill needed to construct sound (good) and fallacy-free arguments of one‘s own and to evaluate the arguments of others It provides a fundamental defense against the prejudiced and uncivilized attitudes  It helps us to distinguish good arguments from bad arguments  It helps us to understand and identify the common logical errors in reasoning; It helps us to understand and identify the common confusions that often happen due to misuse of language It enables us to disclose ill-conceived policies in the political sphere, to be careful of disguises, and to distinguish the rational from irrational Thus, by studying logic, we able to increase our confidence when we criticize the arguments of others and when we advance arguments of our own. Generally, the goal of logic is to produce individuals who are critical, rational and reasonable both in the sphere of public and private life.  What is an Argument? Argument is a systematic combination of two or more statements, which are classified as a premise/premises and conclusion. From logical point of view, arguments is a group of statements(premise), which are claimed to provide support for, one of the other, the (conclusion). But an argument has a very specific meaning in logic. It does not mean, a mere verbal fight, as one might have with one‘s parent. Because :- First, an argument is a group of statements. That is, the first requirement for a passage to be qualified as an argument is to combine two or more statements. A statement is a declarative sentence that has a truth-value of either true or false Example:- a. Haile G/Selase is an Ethiopian athlete. b. Ethiopia was colonized by Germany. c. Ethiopia is a landlocked country Statement (a) and (c) are true, because they describe things as they are and “Truth” is their truth-value. Whereas statement (b) is false because it asserts what is not, and “Falsity” its truth-value. However, there are sentences that are not statements, and hence should be used to construct an argument. E.g. A. Would you close the window? (Question) B. Right on! (Exclamation) C. Give me your ID Card, Now! (Command) D. I suggest that you read philosophy texts. (Suggestion) E. Let us study together. (Proposal)  Unlike statements, none of the above sentences can be either true or false. Hence, none of them can be classified as statement. As a result, none of them can make up an argument. Second, the statements that make up an argument are divided into premise(s) and conclusion. That means, the mere fact that a passage contains two or more statements cannot guarantee the existence of an argument. Hence, an argument is a group statement, which contains at least one premise and one and only one conclusion. In other word an argument may contain more than one premise but only one conclusion.  Argument always attempts to justify a claim. Therefore:- The claim that the statement attempts to justify is known as a conclusion of an argument; and  the statement or statements that supposedly justify the claim is/are known as the premises of the argument. An argument can be good or bad depending on the logical and real ability of the premise(s) to support the conclusion. Arguments can be divided into deductive and inductive arguments. A deductive argument is thought that the premises provide a guarantee of the truth of the conclusion.  In a deductive argument, the premises are intended to provide support for the conclusion that is so strong that, if the premises are true, it would be impossible for the conclusion to be false. A deductive argument is an argument in which the premises are claimed to support the conclusion in such a way that it is impossible for the premises to be true and the conclusion false. An inductive argument is a thought that the premises provide reasons supporting the probable truth of the conclusion. In an inductive argument, the premises are intended only to be so strong that, if they are true, then it is unlikely that the conclusion is false.  An inductive argument is an argument in which the premises are claimed to support the conclusion in such a way that it is improbable that the premises be true and the conclusion false. The difference between the two comes from the sort of relation the author or expositor of the argument takes there to be between the premises and the conclusion. If the author of the argument believes that the truth of the premises definitely establishes the truth of the conclusion due to definition, logical entailment or mathematical necessity, then the argument is deductive. If the author of the argument does not think that the truth of the premises definitely establishes the truth of the conclusion, but nonetheless believes that their truth provides good reason to believe the conclusion true, then the argument is inductive.  The deductiveness or inductiveness of an argument can be determined by – The particular indicator word it might use, – The actual strength of the inferential relationship between its component statements – Its argumentative form or structure. A deductive argument can be evaluated by its validity and soundness. An inductive argument can be evaluated by its strength and cogency Deductive argument can be valid if it is impossible for the premises to be true and the conclusion false. Deductive argument can be invalid if it is possible for the premises to be true and the conclusion false  Inductive argument can be strong , if it is improbable for the premises to be true and the conclusion false. Inductive argument can be weak, if it is probable for the premises to be true and the conclusion false. A deductive argument can be sound if it is valid and true. A deductive argument can be unsound if it fails to be valid and true. An inductive argument can be cogent/convincing if it is strong and probably true, An inductive argument can be uncogent if it fails to be strong and probably true.  What is premise Premise refers to the statement, which is claimed to provide a logical support or evidence to the main point of the argument, which is known as conclusion. It is a statement that set forth the reason or evidence, which is given for accepting the conclusion of an argument. Generally premise is claimed evidence. What is conclusion It is a statement, which is claimed to follow from the given evidence (premise). In other words, the conclusion is the claim that an argument is trying to establish. Example-1: All Ethiopians are Africans. (Premise 1) Tsionawit is Ethiopian. (Premise2) Therefore, Tsionawit is African. (Conclusion) Example-2: Some Africans are black.(Premise1)  Zelalem is an African. (Premise-2) Therefore, Zelalem is black. (Conclusion) In the above arguments, the first two statements are premises, because they are claimed to provide evidence for the third statement, whereas the third statement is a conclusion because it is claimed to follow from the given evidences. The claim that the premises support the conclusion, (and/or that the conclusion follow from the premises), is indicated by the word “therefore”  All arguments may be placed in one of two basic groups: – those in which the premises really do support the conclusion (good or well-supported arguments) – those in which they do not, even though they are claimed to. (bad or poorly-supported arguments) For example, in the above two examples in the first argument, the premises really do support the conclusion, they give good reason for believing that the conclusion is true, and therefore, the argument is a good one. But the premises of the second argument fail to support the conclusion adequately. Even if they may be true, they do not provide good reason to believe that the conclusion is true. Therefore, it is bad argument, but it is still an argument.  How Can We Distinguish Premises From Conclusion And Vice Versa? Sometimes identifying a conclusion from premises is very difficult The first technique that can be used to identify premises from a conclusion and vice versa is looking at an indicator word. Arguments contain certain indicator words that provide clues in identifying premises and conclusion. Some of conclusion indicators includes: – Therefore ,Wherefore, Accordingly, Provided that, It must be that, We may conclude, Entails that, Hence, It shows that, Thus , Consequently ,We may infer ,It implies that ,As a result ,So ,It follows that  In an argument, the statement that follows the indicator word can usually be identified as the conclusion. Example: – Women are mammals. – Zenebech is a woman. – Therefore, Zenebech is a mammal. Based on the above rule, the conclusion of this argument is “Zenebech is a mammal”. Because it follows the conclusion indicator word i.e. “therefore” and the other two statements are premises. If an argument does not contain a conclusion indicator, it may contain a premise indicator.  Here are some typical Premise Indicators: Since ,As indicated by, Because , wing to, Seeing that, Given that , As , For , In that ,May be inferred from , In, as much as , For the reason that In argument that contains any of the premise indicator words, a statement that follows the indicator word can usually be identified as a premise. Example: – You should avoid any form of cheating on exams because cheating on exams is punishable by the Senate Legislation of the University. Based on the above rule, the premise of this argument is “cheating on exams is punishable by the Senate Legislation of the University” because it follows the premise indicator word “because”,  One premise indicator not included in the above list is “for this reason”. This indicator is special in that it comes immediately after the premise it indicates and before the conclusion. In the middle place between the premise and the conclusion, “for this reason” can be both premise and conclusion indicator. The statement that comes before “for this reason” is the premise of an argument and the statement that comes after “for this reason” is the conclusion. Sometimes a single indicator can be used to identify more than one premise. Consider the following argument: – Tsionawit is a faithful wife, for Ethiopian women are faithful wives and Tsionawit an Ethiopian. The premise indicator “for” goes with both premises “Ethiopian women are faithful wives‘‘ and “Tsionawit is an Ethiopian”. By process of elimination, “Tsionawit is a faithful wife” is the conclusion.  Sometimes you may have an argument without conclusion and premise indicator word. When this occurs, the reader/ listener must ask himself or herself 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: – Our country should increase the quality and quantity of its military. Ethnic conflicts are recently intensified; boarder conflicts are escalating; international terrorist activities are increasing.  The main point of this argument is to show that the country should increase the size and quality of its military. The following is the standard form of this argument: – Ethnic conflicts are recently intensified. (P-1) – Boarder conflicts are escalating. (P-2) – International terrorist activities are increasing. (P-3) – Thus, the country should increase the quality and quantity of its military. (C)  If a statement has nothing to do with the conclusion or, for example, simply makes a passing comment, it should not be included within the context of the argument. Example: – Socialized medicine is not recommended because it would result in a reduction in the overall quality of medical care available to the average citizen. In addition, it might very well bankrupt the federal treasury. This is the whole case against socialized medicine in a nutshell. The conclusion of this argument is “Socialized medicine is not recommended” and the two statements following the word, “because‘” are the premises The last statement makes only a passing comment about the argument itself and is therefore neither a premise nor a conclusion.  Techniques of Recognizing Arguments  Not all passages that contain two or more statements are argumentative. There are various passages that contain two or more statements but are not argumentative.  Argumentative passages are distinguished from such kind of passages by their primary goal: proving something. Recognizing Argumentative Passages  In order to evaluate arguments we need to – understand the nature of arguments – understand what argument is not, because not all passages contain argument.  Two conditions must be fulfilled for a passage to purport to prove something: 1. At least one of the statements must claim to present evidence or reasons. 2. There must be a claim that the alleged evidence or reasons supports or implies something- that is, a claim that something follows from the alleged evidence.  The first condition refers to premises as it tries to provide or claim to provide reasons or evidences for the conclusion; and the second condition refers to a conclusion The first condition expresses a factual claim, and deciding whether it is fulfilled often falls outside the domain of logic. Thus, most of our attention will be concentrated on whether the second condition is fulfilled. The second condition expresses what is called an inferential claim The Inferential Claim is a passage that expresses a certain kind of reasoning process- that something supports or implies something or that something follows from something. It is an objective feature of an argument grounded in its language or structure. An inferential claim can be either explicit or implicit. An explicit inferential claim – It exists if there is an indicator word that asserts an explicit relationship between the premises and the conclusions. e.g. Gemechu is my biological father, because my mother told so. the word “because” expresses the claim that evidence supports something. An implicit inferential claim  It exists if there is an inferential relationship between the statements in a passage, but the passage contains no indicator words. e.g. The genetic modification of food is risky business. Genetic engineering can introduce unintended changes into the DNA of the food-producing organism, and these changes can be toxic to the consumer.  The mere occurrence of an indicator word is by no means a guarantee for the presence of an argument.  Thus, we need to make sure that the existing indicator word is used to indicate a premise or a conclusion . Example: – Since Edison invented the phonograph, there have been many technological developments. – Since Edison invented the phonograph, he deserves credit for a major technological development. In the first passage the word “since” is used in a temporal sense. It means “from the time that.” Thus, the 1st passage is not an argument. In the second passage “since” is used in a logical sense, and so the passage is an argument. Therefore, in deciding whether a passage contains an argument one should try to insert mentally some indicators words among the statements to see whether there is a flow of ideas among the statements. Recognizing Non-argumentative Passages Non-argumentative passages are passages, which lack an inferential claim. for a passage to be an argument, it should contain not only premises and a conclusion but also an inferential claim or a reasoning process. Some of the most important forms of non-argumentative passages includes the following. 1. Simple Non-inferential Passages It contain statements that could be premises or conclusions (or both), but what is missing is a claim that any potential premise supports a conclusion or that any potential conclusion is supported by premises. It include statements of warnings, advice, belief or opinion, loosely associated statements, and reports. 2. Expository Passages It begins with a topic sentence followed by one or more sentences that develop the topic sentence. If the objective is not to prove the topic sentence but only to expand it or elaborate it, then there is no argument. Expository passages differ from simple non-inferential passages (such as warnings and pieces of advice) in that many of them can also be taken as arguments. If the purpose of the subsequent sentences in the passage is not only to flesh out the topic sentence but also to prove it, then the passage is an argument. If the topic sentence makes a claim that many people do not accept or have never thought about, then the purpose of the remaining sentences may be both to prove the topic sentence is true as well as to develop it, then the passage is an argument. 3. Illustrations It is an expression involving one or more examples that is intended to show what something means or how it is done. Illustrations are often confused with arguments because many illustrations contain indicator words such as “thus”. Example: – Chemical elements, as well as compounds, can be represented by molecular formulas. Thus, oxygen is represented by “O ”, water by “H O”, and sodium chloride 2 2 by “NaCl”. This passage is not an argument, because it makes no claim that anything is being proved. The word “thus” indicates how something is done - namely, how chemical elements and compounds can be represented by formulas.  Illustrations can be taken as arguments. Such arguments are often called arguments from example. Here is an instance of one: – Although most forms of cancer, if untreated, can cause death, not all cancers are life-threatening. For example, basal cell carcinoma, the most common of all skin cancers, can produce disfigurement, but it almost never results in death. 4. Explanations It is an expression that attempts to clarify, or describe such alike why something is happen that way or why something is what it is. Example: – Cows digest grass while humans cannot, because their digestive systems contain enzyme not found in humans.  Every explanation is composed of two distinct components: – Explanandum:- it is the statement that describes the event or phenomenon to be explained, – Explanans:- is the statement or group of statements that purports to do the explaining. In the above example, the explanandum is the statement “Cows digest grass while humans cannot” and the explanans is “their [cows‟] digestive systems contain enzyme not found in humans.” The purpose of explanans is to show why something is the case, whereas in an argument, the purpose of the premises is to prove that something is the case.  Moreover, in explanation, we precede backward from fact to the cause whereas in argument we move from premise to the conclusion. Thus, to distinguish explanations from arguments, first identify the statement that is either the explanandum or the conclusion However, some passages can be interpreted as both explanations and arguments. Example: – Women become intoxicated by drinking a smaller amount of alcohol than men because men metabolize part of the alcohol before it reaches the bloodstream, whereas women do not. Conditional Statements  They are an “if... then...” statements.  Every conditional statement is made up of two component statements.  antecedent (if-clause), The component statement immediately following the “if”  consequent (then-clause) the one following the “then”  However, there is an occasion that the order of antecedent and consequent is reversed.  Conditional statements are not arguments, because in a conditional statement there is no claim that either the antecedent or the consequent presents evidence  Also conditional statements are not evaluated as true or false without separately evaluating the antecedent and the consequent.  A conditional statement may serve as either the premise or the conclusion (or both) of an argument. examples: – If he is selling our national secretes to enemies, then he is a traitor. – He is selling our national secretes to enemies. – Therefore, he is a traitor.  The relation between conditional statements and arguments may now be summarized as follows: I. A single conditional statement is not an argument. II. A conditional statement may serve as either the premise or the conclusion (or both) of an argument. III. The inferential content of a conditional statement may be re-expressed to form an argument.  Conditional statements are especially important in logic (and many other fields) because they express the relationship between necessary and sufficient conditions. example – If X is a dog, then X is an animal. – If X is not an animal, then X is not a dog.  The first statement says that being a dog is a sufficient condition for being an animal, and the second that being an animal is a necessary condition for being a dog.  However, a little reflection reveals that these two statements say exactly the same thing.  Generally, non-argumentative passages may contain components that resemble the premises and conclusions of arguments, but they do not have an inferential claim.  However, some passages like expository passages, illustrations, and explanations can be interpreted as arguments; and the inferential contents of conditional statements may be re-expressed to form arguments.  Therefore, in deciding whether a passage contains an argument, you should look for three things: a) Indicator words such as “therefore,” “since,” “because,” and so on; b) An inferential relationship between the statements; and c) Typical kinds of non-arguments.  But the mere occurrence of an indicator word does not guarantee the presence of an argument. You must check that the conclusion is supported by one or more of the premises.  Also keep in mind that in many arguments that lack indicator words, the conclusion is the first statement. Differentiating Deductive and Inductive Arguments There are three factors that influence the decision about the deductiveness or inductiveness of an argument‘s inferential claim. These are: 1) The occurrence of special indicator words, 2) The actual strength of the inferential link between premises and conclusion, and 3) The character or form of argumentation the arguers use. Words like “certainly", 'necessarily”, “absolutely”, and “definitely” indicate that the argument should be taken as deductive. words like, “probable”, “improbable” “plausible” “implausible”, ‘‘likely", “unlikely” and “reasonable to conclude” suggest that an argument is inductive. The occurrence of an indicator word is not a certain guarantee for the deductiveness or inductiveness of an argument unless it is supported by the other features  If the conclusion actually does follow with strict necessity from the premises, the argument is clearly deductive  If the conclusion of an argument does not follow with strict necessity but does follow probably, it is usually best to interpret it as inductive argument. Example-1: – All Ethiopian people love their country. – Debebe is an Ethiopian. – Therefore, Debebe loves his country Example-2: – The majority of Ethiopian people are poor. – Alamudin is an Ethiopian. – Therefore, Alamudin is poor.  The character or form of argumentation the arguers use refers looking at some deductive or inductive argumentative forms. Instances of Deductive Argumentative Forms  Five examples of such forms or kinds of argumentation are arguments based on mathematics, arguments from definition, and syllogisms. Argument based on mathematics  Arguments in pure mathematics are deductive and arguments that depend on statistics are usually best interpreted as inductive.  Statistical arguments are based on random sampling of data gathering, it is impossible to arrive at absolutely certain conclusion.  Arguments based on definition It is an argument in which the conclusion is claimed to depend merely up on the definition of some words or phrase used in the premise or conclusion. example, Angel is honest; therefore, Angel tells the truth. Kebede is a physician; therefore, he is a doctor. Arguments based on Syllogisms Syllogisms are arguments consisting of exactly two premises and one conclusion. Syllogisms can be categorized into three groups; categorical, hypothetical, and disjunctive syllogism.  Categorical syllogism: It is consisting of exactly two premises and one conclusion and the statement begins with words like “all”,” “no” and “some”. Example: All Egyptians are Muslims. No Muslim is a Christian. Hence, no Egyptian is a Christian Hypothetical syllogism: It has a conditional statement for one or both of its premises. Example: – If you study hard, then you will graduate with Distinction. Disjunctive syllogism: it is a syllogism having a disjunctive statement. (i.e. an “either … or” statement.) e.g. Rewina is either Ethiopian or Eritrean. Rewina is not Eritrean. Therefore, Rewina is Ethiopian. Instances of Inductive Argumentative Forms  Some examples of such forms or kinds of argumentation are arguments based on predictions, analogy generalizations , authority, signs, and causal inferences  In Prediction the premises deals with some known event in the present or the past and the conclusions moves beyond this event to some event to relative future. For example, Certain clouds develop in the center of the highland, therefore, rain will fall within twenty-four hours.  An argument from analogy is an argument that depends on the existence of an analogy or similarity between two things or state of affairs. Example: The Encyclopedia Britannica has an article on culture. The Encyclopedia Americana, like Britannica, is an excellent work. Therefore, the Americana probably also has an article on culture.  An inductive generalization (An argument based on statistics) is an argument that proceeds from the knowledge of selected sample to some claim about the whole group. Example: There are 45 students in this class. I have evaluated the answer sheets of 20 students and all of them scored above 85%. It implies that all students of this class are smart.  An argument from authority is argument based on citation, interview, or witness of a person who has a better position or access to the required qualification. Example: According to Ato Tewodros who is a lawyer in Hawassa city, Kebede committed murder because an eye witness testified to that effect under oath.  An argument based on signs is an argument that proceeds from the knowledge of a certain sign (may be it is a traffic sign, a trademark, a cautionary mark, a symbol,) to a knowledge of the thing or situation symbolized by the sign. Example: The package material says that “keep it out of the reach of children.” Therefore, this package must consist of some sort of medicine An argument based on causation is an argument that proceeds from the knowledge of a cause to knowledge of the effect, or conversely, from the knowledge of an effect to the knowledge of a cause. Example: The cloud is becoming dark and the thunder is roaming. So, let us go home quickly, the rain is inevitable.  From the knowledge that a bottle of water had been accidentally left in the freezer overnight, someone might conclude that it had frozen (cause to effect). Conversely, after tasting a piece of chicken and finding it dry and tough, one might conclude that it had been overcooked (effect to cause). Because specific instances of cause and effect can never be known with absolute certainty, one may usually interpret such an argument as inductive.  We have to take into consideration that deductive argument not always proceeds from the general to the particular and inductive arguments proceed from the particular to the general.  This is because there are some deductive or inductive arguments that proceed from the general to the general or from the particular to the particular or even from the particular to the general.  For example, here is a deductive argument that proceeds from the particular to the general: – Three is a prime number. Five is a prime number. Seven is a prime number. Therefore, all odd numbers between two and eight are prime numbers. Here is an inductive argument that proceeds from the general to the particular: All emeralds previously found have been green. Therefore, the next emerald to be found will be green. Here is an deductive argument that proceeds from particular to general The members of Mohammed’s family are Kedija, Kemal and Leyla. Kedija wears glasses. Kemal wears glasses. Leyla wears glasses. Therefore, all members of Mohammed’s family wear glasses.  CHAPTER THREE LOGIC AND LANGUAGE Philosophy of Language According to Semiotics(the study of sign processes in communication), language is the manipulation and use of symbols in order to draw attention to signified content. Philosophy of language is the reasoned inquiry into the nature, origins, and usage of language. Philosophy of language has been concerned with four central problems: the nature of meaning, language use, language cognition, and the relationship between language, logic and reality. It poses questions like – What is meaning? How does language refer to the real world? – Is language learned or is it innate? – How does the meaning of a sentence emerge out of its parts?  Ordinary language serves various functions in our day-to-day life. These functions are almost unlimited. Thus, among other things, individuals use language:  To tell stories,  to ask questions,  to guess at answers,  to form hypotheses,  to launch verbal assaults,  to tell jokes,  to give directions,  to sing songs,  to issue commands and to greet someone and so on.  In general, language has three linguistic functions namely, expressive (emotive), directive and cognitive (informative) function.  Of these functions of language, the cognitive function of language is a relevant and an important for logic A. Expressive (Emotive) Function  It is a function of language which is important for individuals to express their feelings or emotions. Both positive and negative feelings. examples  She is smart —  I like my English teacher  I hate him.  I dislike Abebe.  B. Directive Function  It gives direction to the speaker or writer in order to pass orders, commands or instructions to others. Examples:  What is your name? —  Leave me alone!  Do not close that door! — Give me your pen! C. Cognitive (Informative) Function  It used to convey information about the world’s objective realities. For Example: Ethiopia has its own prestigious airlines. (True) The capital city of the regional state of Afar is Hawassa. (False) Lake Tana is found in Amhara region. (True)  The reason why we study about definitions is  words have meanings.  Meanings are conveyed through definitions  Some times the meaning of certain words in the argument is vague or ambiguous.  On the other hand logic evaluates arguments, and an argument consists of a group of statements, and statements are made up of words.  Meaning of term  Term is any word or arrangement of words that may serve as the subject of a statement.  Terms consist of proper names, common names, and descriptive phrases. Proper Names Common Names Descriptive Phrases Ayele house The first president of Ethiopia John Person The king of England South Ethiopia Animal Those who study hard Words that are not terms include verbs, non- substantive adjectives, adverbs, prepositions, conjunctions, and all non-syntactic arrangements of words. Examples dictatorial, run quickly, above and beyond, moreover, craves, cabbages, into again, the forest.  The Intension and Extension meaning of Terms  The intentional meaning, is also known as connotation, refers to the qualities or attributes that the term connotes.  The extensional meaning, is also called denotation, consists of the members of the class that the term denotes. Examples:  “Inventor” means a person who is, clever, intuitive, creative and imaginative.  “Inventor” means such as Thomas Edison, Alexander Graham Bell, and Samuel F.B. Morse.  The meaning of the first example is based on its attributes, qualities or essential characteristics.  The meaning of the second example is based on its class members. This is because this sentence provides lists of individuals who are the member of the class of the term being defined - inventor The denotation of a term remains the same from person to person. For example, The denotation (extensional meaning) of human being refers to all human being in the universe, on which everybody agrees. This term either constantly fluctuating as some human beings die and others are born or it is presumably constant because it denotes all human beings, past, present, or future. Denotation of a term doesn’t remain the same from time to time? For example, ‘the current king of Ethiopia. Is there any king in Ethiopia now? No. Therefore, this term denotes an empty extension. An empty extension is said to denote: the empty or “null” class - the class that has no members. You may recognize from the above example that emperor Haile Sillasie was the king of Ethiopia in the past. Therefore, ‘the current king of Ethiopia’, changed over the passage of time. Thereby, things that do not have current objective reference include myth, spiritual realities, extinct (died out) creatures, historical events, and so on do not have extension. For instance, Dinosaur, Dragon, Satan, fictional and mythical stories, etc. They do not have objective references that could serve as a living testimony for their existence. Our knowledge of these things is based on their properties and but not based on their living class members’ characteristics. However, the intentional meaning of a term serves as the criteria for deciding what the extension consists of. That is why intentional meaning determines extensional meaning.  Example: Satan is an evil sprit that causes people to suffer. Dinosaur is an extinct reptile of the Mesozoic era. Terms may be put in the order of depending on the increase or decrease of attributes and sets of things added to the term being defined. Increasing intension, increasing extension, decreasing intension, and decreasing extension If the member of a class of things decrease, then the attribute of particular objects increase. The order of decreasing intension is the reverse of that of increasing intension but not always. If the member of a class size gets larger with each consecutive term, then the attribute of the particular object decreases. Decreasing extension is the reverse of this order. Example: – Increasing Intension: Africa, East Africa, Ethiopia, Addis Ababa. – Decreasing Intension: Addis Ababa, Ethiopia, East Africa, Africa. – Increasing Extension: Addis Ababa, Ethiopia, East Africa, Africa. – Decreasing Extension: Africa, East Africa, Ethiopia, Addis Ababa.  Definitions and Their Purposes  Many logicians define the term ‘definition’ as a group of words that assigns a meaning to some words or group of words. Accordingly, every definition consists of two parts: the definiendum and the definiens. The Latin term definiendum is the word or group of words that is supposed to be defined, and the Latin term definiens is the word or group of words that does the defining or gives a meaning to the definiendum. Example: diffident means lacking confidence in oneself. In this definition, the term ‘‘diffident’’ is the definiendum, and everything that comes the word “means” (lacking confidence in oneself; characterized by modest reserve) is the definiens. The most important objective of definition is to provide meaning for the terms that are not clearly understood in the context of other terms. Purposes of Definitions in logic Definition helps us To avoid confusion or misleading use of words and phrases; To avoid obscurity(insignificance),unintelligibility(un clearness), subjectivity(bias) , and complexity of words; To introduce new words and to persuade(ecourage) others; To avoid useless controversies, disputes, disagreements and conflicts over the meaning of terms ,words, phrases and passages which considered as an argument; To prevent incorrect reasoning; and to develop the ability to reason logically. There are five different types of definitions, namely, Stipulative, Lexical, Précising, Theoretical, and Persuasive Definitions. A. Stipulative Definition Stipulative definition assigns a meaning to a word for the first time. This may involve either creating a new word or giving a new meaning to an old word. The purpose of a stipulative definition is to introduce unusual or unfamiliar words, which have no pervious meaning in the language. Stipulative definition is used to introduce new meanings to some newly discovered phenomenon or things in the area of archeological findings, and innovations, such as new modes of behaviors, new kinds of fashion clothes, new dances, new food inventions, etc Example:  A few years ago the attempt was made at a certain zoo to crossbreed male tiger and female lion by biologists. As a result of this, the offspring was born from male Tiger and female lion. Thus, this suggests a need for assigning a new name.  So, they may call the new offspring ‘‘Tigon’’ taking the first three letters from tiger (tig) and the last two letters from lion (on).  Another use of stipulative definitions is to set up Secret Codes. It was (and still is) common to give a secret code for the military invasion. Examples:  ‘‘Operation Barbarosa’’ was the name the code Germans gave to the invasion of Russia;  ‘‘Operation Desert Storm’’ was the code name given to the military invasion of Iraq.  “Operation Sun Set” was the code name given to the military victory of Ethiopia armed force against Eritrea, which is the most recently.  B. Lexical Definition A lexical definition is used to report the meaning that a word already has in a language. Dictionary definitions are all the best examples of lexical definitions. The purpose of a lexical definition is to eliminate ambiguity that would arise over the improper use of word to its context. A word is ambiguous if it has more than one meaning. Some words that are subjected to ambiguous usage are: “light”, “bank”, “sound”, “right” , “race”, ‘‘mad’’, “defuse” , “humanity” ,etc. Examples:  ‘‘Light,’’ can mean light in weight or radiant energy.  ‘‘Bank’’ can mean a finical institution or the edge of river.  A word is vague  If it is so imprecise and unclear, that is, it is impossible to tell about the applicability of the word.  If it is impossible to tell whether the word applies to them or not.  Words such as “love”, ”happiness”, “peace”, “fresh”, “normal”, “rich”, ”poor”, “polluted” etc are vague words.  It is difficult to draw a line or a boundary between the things to which those words apply or do not apply.  We can not tell with any degree of precision who rich is or how we counted as rich.  C. Précising Definition A précising definition provides a more precise, specific, exact and restricting meaning to a term. Its use is to reduce vagueness of the term. For example, the word ‘poor’ is a vague word. Suppose you are an administrator of one humanitarian organization and want to give a direct financial assistance to the poor. Therefore, we may define Poor as: “Poor” means a person having a monthly income of less than Birr 150. This is an example of a précising definition. Précising definition used to clarify a highly systematic context such as science, mathematics, medicine or law. Examples:- ‘‘force’’, ‘‘energy’’, ‘‘acid’’, ‘‘element’’, ‘‘number” “equality’’, ‘‘contract’’, and ‘‘agent’’ A précising definition differs from a stipulative definition in that Stipulative definition involves a purely arbitrary assignment of meaning The assignment of meaning in a précising definition is not at all arbitrary. Care must be taken that the meaning in a précising definition is appropriate and legitimate for the context within which the term is to be employed.  D. Theoretical Definition A theoretical definition assigns a meaning to a word by suggesting a theory that gives a certain characterization to the entities that the term denotes. In other words, it gives us the way of seeing or conceiving (imagining) theoretical (that is, non- experimental or non- practical) entity. Fore example there is no any way to see or view “heat” except in theoretical way. Not all theoretical definitions are associated with science. Many terms in philosophy, such as ‘‘substance’’, ‘‘form’’, ‘‘cause’’, ‘‘change’’, ‘‘idea’’, ‘‘good’’, and ‘‘mind’’, have been given theoretical definitions. Most of the major philosophers in history have given these terms their own peculiar theoretical definitions, examples:  ‘‘Good’’ means the greatest happiness of the greatest number provided the underpinnings for his utilitarian theory of ethics.  “Substance” means something that up supports different qualities.  “Justice” means to give each individual what he or she deserves his or her due.  E. Persuasive Definition  The purpose of Persuasive definition is:  persuading or convincing listeners or readers over a certain issue;  changing or influencing the attitude of others towards one’s own point of view and to win the acceptance of audience.  The method employed to develop persuasive definition is to use emotionally charged or value laden words and phrases for the purpose of inciting, striving or arousing the emotion of audiences to make them to accept the definition.  This definition may exaggerate or diminish the definiendum.  Here are some examples of opposing pairs of persuasive definitions:  ‘‘Abortion’’ means the ruthless murdering of innocent human beings.  ‘‘Abortion’’ means a safe and established surgical procedure whereby a woman is relieved of an unwanted burden.  Techniques of Definition and Their Relation with Kinds of Definitions 1. Techniques of Extension (Denotative) Definitions  Extensional definitions provide meaning to a term by listing examples to the term which is being defined - definiendum. It is indicating the members of the class  There are at least three ways of indicating the members of a class:  by pointing physically to them,  by naming them individually, and  by naming them in groups.  Thus, based on this we identify three different kinds of definitions, namely, demonstrative or ostensive definitions, enumerative definitions, and definition by subclass respectively Demonstrative (Ostensive) Definition  It assigns a meaning to a term by pointing physically to the thing or object to be defined.  It is probably the most primitive form of definition. This definition might be either partial in a sense that when we point to only some part of things or complete  Therefore, ostensive definition attempts to define a term by showing the object physically.  Examples: ‘‘Chair’’ means this and this and this—as you point to a number of chairs, one after the other.  ‘‘House’’ means this one—using a picture demonstrating a house. Demonstrative definitions differ from the other kinds of definitions in that the definiens is constituted at least in part by a gesture—the gesture of pointing. Since the definiens in any definition is a group of words, however, a gesture, such as pointing, must count as a word. While this conclusion may appear strange at first, it is supported by the fact that the ‘‘words’’ in many sign languages consist exclusively of gestures.  Enumerative Definition  It the members of the class that the definiendum denotes individually.  It assigns a meaning to a term by naming individually the members of the class the term denotes. Like demonstrative definitions, they may also be either partial or complete.  It is carried out through listing some or all of the objects or entities symbolized by the definiendum. Examples:  ‘‘Actor’’ means a person such as Nick Nolte, Al Pacino, or Richard Gere.  “Athlete” means a person such as Hail G/sillassie, Kenensia Bekele, Derartu Tulu, etc. Definition by Subclass  A definition by subclass assigns a meaning to a term by naming subclasses of the class denoted by the term.  Definition by subclass assigns a meaning to a term by naming either partial or complete. Examples:  ‘‘Tree’’ means an oak, pine, elm, spruce, maple, and the like.  ‘‘Flower’’ means a rose, lily, daisy, geranium, zinnia, and the like.  “Professional person” means a person such as a doctor, or an architect.  2. Techniques of Intentional (Connotative) Definitions  Intentional or connotative definition provides a meaning to a term by describing the essential characteristics or features possessed by the term being defined.  Kinds of intentional definitions includes:  Synonymous Definition,  Etymological Definition,  Operational Definition, and  Definition by Genus and Difference.  A. Synonymous Definition A synonymous definition is one in which  The definiens is a single word that connotes the same attributes as the definiendum.  The definiens connotes exactly the same attributes as the definiendum. Examples:  ‘‘Physician’’ means doctor.  ‘‘Intentional” means willful.  ‘‘Observe’’ means see. Therefore, we can interchangeably use the definiens and the definiendum of synonymous definitions.  B. Etymological Definition  An etymological definition assigns a meaning to a word by revealing the word’s root or ancestry in both its own language and other languages. That is why most ordinary English words have ancestors either in Old or Middle English as well as are derived or come from some other language such as Greek, Latin, or French, etc. Examples: The word “Democracy” is derived from the two Greek words, ’demos’ and ‘crates’, which means people and power respectively.  The English word ‘‘License’’ is derived from the Latin verb licere, which means to be permitted, and The English word ‘‘Captain’’ derives from the Latin noun caput which means head.  C. Operational Definition  It assigns a meaning to a word by specifying certain experimental procedures and it is carried out by performing the actions, operations, activities and procedures that the word implies.  It can be identified by words “if and only if” which is equivalent to ‘necessary and sufficient condition.’ Examples:  One substance is ‘‘Harder than’’ another if and only if one scratches the other when the two are rubbed together.  A solution is an ‘‘Acid’’ if and only if litmus paper turns red when dipped into it. D. Definition by Genus and Difference  It assigns a meaning to a term by identifying two things: one ‘genus’ term and one or more ‘difference’ words. In logic, ‘‘genus’’ means a relatively larger class, and ‘‘species’’ means a relatively smaller subclass or smaller of the genus. For instance, if you may speak ‘animal’ as a genus, and ‘mammal’ as species or if you take ‘mammal’ as genus and ‘feline’ can be species. Again, if you take ‘feline’ as genus, ‘tiger’ (which is the subclass of the class of cat family), can be the species. Where as the ‘‘specific difference,’’ or ‘‘difference” is the attribute or attributes that distinguish the various species within a genus. For example, the specific difference that distinguishes tigers from other species in the genus feline (a cat family) would include the attributes of being large, striped, ferocious (aggressive), and so on. Therefore, these aforementioned qualities of tiger are called the ‘specific difference’ or simply ‘difference’ of tiger. When the genus is qualified, we get the ‘species’ (that is, the word to be defined).  A definition by genus and difference is easy to construct.  The step is Simply select a term that is more general than the term to be defined, and then narrow it down so that it means the same thing as the term being defined. Example Species Difference Genus Ice means frozen water. Husband means married man. Mother means female parent Tiger means a large, stripped and ferocious feline  Lexical definitions are typically definitions by genus and difference, but they also often include etymological definitions.  Operational definition can serve as the method for constructing stipulative, lexical, précising, and persuasive definitions, but it could not be used to produce a complete lexical definition.  Synonymous definition may be used to produce only lexical definitions.  Synonymous definition cannot be used to produce stipulative definitions because the definiendum must have a meaning before a synonymous definition.  Also Synonymous can not be used to construct précising, theoretical, and persuasive definitions because the definiens of synonymous definitions contains no more information than the definiendum.  In other words, the definiens of a synonymous definition adds nothing new to the definiendum.  Criteria for Lexical Definitions Rule1:A Lexical definition should match to the standards of proper grammar.  A definition should be grammatically correct. Definitions that are grammatically incorrect create disagreements and disputes among individuals over the meaning of terms.  Examples: Consider the following definitions that are grammatically incorrect are as follows:  Vacation is when you don’t have to go to work or school.  Furious means if you’re angry at someone.  The corrected versions are:  ‘‘Vacation’’ means a period during which activity is suspended from work or school.  ‘‘Furious’’ means a condition of being angry.  Rule 2:A lexical definition should convey or communicate the essential meaning or characteristics of the word being defined. Thus, a correct definition attempts to point out the attributes that are essential to the designation of things as the members of the relevant group. Example: ‘‘Human being’’ means a featherless biped.  This definition fails to says nothing about the important attributes that distinguish human beings from the other. A correct and adequate definition would be “Human being” means “the rational animal that has the capacity to reason and to speak” and not as a featherless biped.  Rule 3: A lexical definition should be neither too broad nor narrow. If a definition is too broad, the definiens includes too much; if it is too narrow, the definiens includes too little. In other words, a good or correct definition should be proportionate, that is, the extent of the defining word (definiens) should be equal to the extent of word to be defined (definiendum),  A definition is too broad if the definiens applies to things to which the definiendum does not. In a too broad definition, the definiendum is less than the definiens. A definition is too narrow if the definiendum applies to things to which the definiens does not. In a too narrow definition the definiendum is greater than the definiens. Examples: The following definitions are broad  ‘‘Birds’’ means any warm-blooded animals having wings.  “Pen” means an instrument used for writing. In the first example, the phrase “any warm-blooded animal having wings” would include bats, and bats are not birds. In the second example, the phrase “an instrument used for writing “ includes things like chalk, pencil, marker, pen, etc. Examples: The following definitions are narrow ‘‘Bird’’ means warm-blooded, feathered animal that can fly. “Gun” means a tool used in the battle for defending the enemy. These two definitions would be too narrow. The first definition would exclude ostriches, which cannot fly. In the second definition the term gun is defined using a few attributes, that is, the definiens fails it include different attribute of gun.  Rule 4: A lexical definition should avoid circularity A circular definition presents the meaning of a word: either by using the same word with the same meaning in the definiens, or by using grammatical variation of the same word (the definiendum) in the definiens. Examples: ‘‘Religious ’’ means any one engaged in religious activity. ‘‘Scientist’’ means anyone who engages in science. A circular definition cannot provide any useful additional information to the word being defined or their definiendum becomes visible in the Rule 5: A lexical definition should not be negative when it can be affirmative. Of the following two definitions, the first one negative, and the second affirmative: Example ‘‘Concord’’ means the absence of discord. “Concord’’ means harmony. Thus, definition should explain what a term does mean rather than what it does not mean.  Some words, however, are intrinsically negative. For them, a negative definition is quite appropriate. Example ‘‘Bald’’ means lacking hair. ‘‘Darkness’’ means the absence of light.  “Death” means the end of life  Rule6:A lexical definition should not be expressed in figurative, obscure, vague, or ambiguous language. A definition is figurative when it involves and based on metaphors. A metaphor is a word or a phrase used in the imaginative way. A definition is figurative when it also tends to paint a picture (describes the thing in a particular way) instead of exposing the essential meaning of a term. Example1: If you define ‘architecture’ as frozen music, you are expressing it in figurative language. Example 2: If you define ‘camel’ as ship of the desert you are also expressing it in figurative language. A definition is Obscure if its meaning is hidden as a result of defective or inappropriate language or expression. One source of obscurity is excessively technical language. Examples  ‘‘Bunny’’ means a mammalian of the family Leporidae of the order Lagomorpha whose young are born furless and blind. ‘‘Bunny’’ means a rabbit. The problem lies not with technical language as such but with needlessly technical language. Because ‘‘bunny’’ is very much a no technical term, no technical definition is needed. A definition is vague if it lacks precision or if its meaning is unclear—that is, if there is no way of telling exactly what class of things the definiens refers to.  Example: ‘‘Democracy’’ means a kind of government where the people are in control. This definition fails to identify the people who are in control, how they exercise their control, and what they are in control of.  A definition is ambiguous if it lends itself to more than one different interpretation. Example: ‘‘Triangle’’ means a figure composed of three straight lines in which all the angles are equal to 1800.  Does this mean that each angle separately is equal to 1800 or that the angles taken together are equal to 1800?  Rule7:A lexical definition should avoid affective terminology.  Affective terminology is an expression that influences others positively or negatively. It includes Sarcastic and facetious (inappropriate) language and any other kind of language that is liable to influence attitudes. Examples: ‘‘Communism’’ means that ‘‘brilliant’’ invention of Karl Marx and other foolish political visionaries.  The intended meaning is the opposite of what is meant by brilliant. This is what we call a sarcastic use of language. Dear learner, again look at the following examples:  “Ethiopia” is a country of illiterate and hungry people.  “Africans” are uncivilized and have no history.  Rule 8: A lexical definition should indicate the context to which the definiens pertains. A reference to the context is important definiendum means different meanings in the different context. Examples: ‘‘Strike’’ means (in baseball) a pitch at which a batter swings and misses. ‘‘Strike’’ means (in fishing) a pull and a line made by a fish in taking the bait. In the above definitions at term “strike” has two different meanings in the different contexts given above (baseball and fishing).  CHAPTER FOUR 4.1.BASIC CONCEPTS OF CRITICAL THINKING 4.1.1. Meaning of Critical Thinking  Critical thinking can be defined as A wide range of cognitive skills and intellectual dispositions needed to effectively identify, analyze, and evaluate arguments and truth claims. Involving or exercising skilled judgment or observation i.e. Thinking clearly and intelligently. A wide range of cognitive skills and intellectual dispositions needed to effectively identify, analyze, and evaluate arguments and truth claims.  Critical thinking is a process or journey that helps us  To arrive at the most useful, helpful, and most likely destinations when evaluating claims for scientific truth  To formulate and present convincing reasons in support of conclusions; and  To make reasonable, intelligent decisions about what to believe and what to do.  Critical thinking, thus, is thinking clearly, thinking fairly, thinking rationally, thinking objectively, and thinking independently  Therefore, the aim of critical thinking is to arrive at well-reasoned, considered, and justifiable conclusions.  The American philosopher, John Dewey, has defined critical thinking as an active, persistent, and careful consideration of a belief or supposed form of knowledge  ‘active’ ,refers think things through for yourself, raise questions yourself, find relevant information yourself and so on, rather than learning in a largely passive way from someone else.  ‘persistent’ and ‘careful consideration’-- Dewey contrasting critical thinking with the kind of unreflective thinking we all sometimes engage in.  For example, we sometimes jump to a conclusion or make a quick decision without thinking about it.  What Dewey is saying, to express it in a more familiar language, is that what matters are the reasons we have for believing something and the implications of our beliefs. Edward Glaser defined critical thinking as: 1.An attitude of being disposed to consider in a thoughtful way the problems and subjects that come within the range of one’s experience; 2.Knowledge of the methods of logical enquiry and reasoning; and 3.Some skill in applying those methods. Robert Ennis-defined critical thinking as reasonable, reflective thinking that is focused on deciding what to believe or do. So ‘deciding what to... do’, or decision-making is an important part of critical thinking in Ennis’s conception.  For Richard Paul Critical thinking is Mode of thinking about any subject, content or problem – in which the thinker improves the quality of his or her thinking by skillful thinking and imposing intellectual standards upon them. Paul associates critical thinking with reflecting on thoughts.  Michael Scriven has defined critical thinking as skilled and active interpretation and evaluation of observations and communications, information and argumentation.  interpretation‘ of texts, speech, film, graphics, actions and e body language helps to construct and select the best alternatives evaluating the truth, probability or reliability of claims. Evaluation is the process of determining the merit, quality, worth, or value of something‘ According to Scriven to be critical, thinking has to meet certain standards like clarity, relevance, reasonableness and so on. Critical thinking is sometimes referred to as ‘criticocreative’ thinking. This word is the combination of two words: critical and creative. This is because critical thinking is a kind of evaluative thinking – which involves both criticism and creative thinking – and particularly concerned with the quality of reasoning or argument that is presented in support of a belief, or a course of action.  Standards of Critical Thinking To identify a critical thinking from the uncritical, we refer to some standards. The most important intellectual standards are clarity, precision, accuracy, relevance, consistency, logical correctness, completeness, and fairness. 1. Clarity: refers to clear understanding of concepts and clearly expressing them in a language that is free of obscurity and vagueness. 2. Precision: refers a matter of being exact, accurate and careful. Most ideas are vague and obscures though we think we have precise understanding of them. 3. Accuracy: refers to correct/genuine information.  Decision based on wrong and false information will likely to result in distorting realities.  4. Relevance: refers to the connections of ideas Critical thinkers carefully choose only the information that has logical relation with the ideas at hands 5. Consistency:- refers to the quality of having the same opinions or standards. Logic tells us that if a person holds inconsistent beliefs, at least one of those beliefs must be false. There are two kinds of inconsistency that should be avoided. Logical Inconsistency, which involves saying or believing inconsistent things (i.e., things that cannot both or all be true) about a particular matter. Practical Inconsistency, which involves saying one thing and doing another.  6. Logical Correctness:- When the combinations of thoughts are mutually supporting and make sense in combination, the thinking is logical.  To think logically is to reason correctly, therefore we need to use accurate and well supported beliefs. 7. Completeness: Deep and complete thinking are more preferable than shallow and superficial thinking. Thinking is better when it is deep rather than shallow, thorough rather than superficial. 8. Fairness :- Refers open minded, impartial, and free of distorting biases and preconceptions. – Principles of Good Argument 1. The Structural Principle  An argument should meet the fundamental structural requirements of a well-formed argument.  In other words, it should be formed in such a way that  The conclusion either follows necessarily from its premises, in the case of deductive arguments, or  The conclusion Follows probably from its premises, in the case of inductive arguments.  2. The Relevance Principle An argument should set forth only reasons whose truth provides some evidence for the truth of the conclusion. The premises of a good argument must be relevant to the truth or merit of the conclusion. 3. The Acceptability Principle The reasons set forth in support of a conclusion must be acceptable.  4. The Sufficiency Principle  An argument should attempt to provide relevant and acceptable reasons of the right kind, that together are sufficient in number and weight to justify the acceptance of the conclusion. 5. The Rebuttal Principle  An argument should be with effective rebuttal to all anticipated serious criticisms that may be brought against it.  –Principles of Critical Thinking 1. The Fallibility Principle  Each participant in a discussion of a disputed issue should be willing to accept the fact that he or she is imperfect.  One must acknowledge that one’s own initial view may not be the most defensible position on the question. 2. The Truth Seeking Principle  Each participant should be committed to the task of seriously searching for the truth  One should be willing to examine alternative positions seriously and look for insights in the positions of others.  3. The Clarity Principle It requires that the formulations of all positions, defenses, and attacks should be free of any kind of linguistic confusion and clearly separated from other positions and issues. 4. The Burden of Proof Principle This principle requires that the burden of proof for any position usually rests on the participant who sets forth the position. If an opponent asks the proponent should provide an argument for that position.  5. The Principle of Charity If a participant’s argument is reformulated by an opponent, it should be carefully expressed in its strongest possible version that is consistent with what is believed to be the original intention of the arguer. If there is any question about the argument, the arguer should be given the benefit of any doubt in the reformulation and/or, when possible, given the opportunity to amend it.  6. The Suspension of Judgment Principle This principle requires that if no position is defended by a good argument, or if two or more positions seem to be defended with equal strength, one should suspend judgment about the issue. If practical considerations seem to require a more immediate decision, one should weigh the relative benefits or harm connected with the consequences of suspending judgment and decides the issue on those grounds. If suitable evidence is so lacking that one has no good basis for making a decision either way, it may be quite appropriate to suspend judgment on the matter and wait until there is more of a basis for decision. 7. The Resolution Principle An issue should be considered resolved if the argument is a structurally sound uses relevant and acceptable reasons provide sufficient grounds to justify the conclusion and include an effective rebuttal to all serious criticisms and/or the position it supports.  Characteristics of Critical Thinking Basic Traits of Critical Thinkers There are some dispositions and attitudes, skills and abilities, habits and values that every critical person should manifest. Critical thinkers:  Are honest with themselves, acknowledging what they don't know, recognizing their limitations, and being watchful of their own errors.  Regard problems and controversial issues as exciting/stimulating challenges.  Strive for understanding, keep curiosity alive, remain patient with complexity, and are ready to invest time to overcome confusion.  Base judgments on evidence rather than personal preferences, deferring judgment whenever evidence is insufficient.  They revise judgments when new evidence reveals error.  Are interested in other people's ideas even when they tend to disagree with the other person.  Recognize that extreme views (whether conservative or liberal) are seldom correct, so they avoid them, practice fair-mindedness, and seek a balance view.  Practice restraint(controlling) their feelings rather than being controlled by them, and thinking before acting.  – Basic Traits of Uncritical Thinkers Some traits of uncritical thinkers includes:- Believe they know more than they do, ignore their limitations, and assume their views are error-free. Regard problems and controversial issues as nuisances or threats to their ego. Are inpatient with complexity and remain confused than make the effort to understand. Base judgments on first impressions and gut/instinctive reactions. And tend to follow their feelings Are preoccupied with themselves and their own opinions, and Are unwilling to pay attention to others' views. At the first sign of disagreement, they tend to think, "How can I refute this?“ Ignore the need for balance and give preference to views that support their established views.  Key intellectual traits of critical thinkers and the relevant traits of uncritical thinkers First, critical thinkers have a passionate drive for clarity, precision, accuracy, and other critical thinking standards while uncritical thinker’s are unclear, imprecise, and inaccurate. In addition to this, critical thinkers are sensitive to ways in which critical thinking can be skewed by egocentrism, sociocentrism, wishful thinking, and other impediments, while uncritical thinkers often fall prey to egocentrism, sociocentrism, relativistic thinking, unwarranted assumptions, and wishful thinking.  Second, critical thinkers are skilled at understanding, analyzing, and evaluating arguments whereas uncritical thinkers often misunderstand or evaluate unfairly  Critical thinkers reason logically, draw appropriate conclusions from evidence and data, while uncritical thinkers are illogical, and draw unsupported conclusions  Third, critical thinkers are intellectually honest with themselves, acknowledging what they do not know and recognizing their limitations while uncritical thinkers pretend they know more than they do and ignore their limitations.  Furthermore, critical thinkers listen open-mindedly to opposing points of view, whereas uncritical thinkers are closed-minded, and resist criticisms. Fourth, critical thinkers base their beliefs on facts and evidence while uncritical thinkers often base beliefs on mere personal preferences or self-interests. Critical thinkers are aware of the biases and preconceptions that shape the way they perceive the world, whereas uncritical thinkers lack awareness of their own biases and preconceptions. Fifth, critical thinkers think independently and are not afraid to disagree with group opinion whereas uncritical thinkers tend to engage in “groupthink” uncritically following the beliefs and values of the crowd. Moreover, critical thinkers have the intellectual courage to face and assess fairly ideas that challenge even their most basic beliefs whereas uncritical thinkers fear and resist ideas that challenge their basic beliefs.. Finally yet importantly, critical thinkers pursue truth despite obstacles or difficulties whereas uncritical thinkers are often relatively indifferent to truth and lack curiosity.  Barriers to Critical Thinking Egocentrism, Sociocentrism, Unwarranted Assumptions and Stereotypes, Relativistic Thinking and Wishful Thinking are some of the barriers to Critical Thinking 1. Egocentrism Egocentrism is the tendency to see reality as centered on oneself. Egocentrics are selfish, self-absorbed people who view their interests, ideas, and values as superior to everyone else’s. Two common forms Egocentrism are self-interested thinking and the superiority bias. Self-interested thinking is the tendency to accept and defend beliefs that harmonize with one’s self-interest. Almost no one is immune to self-interested thinking. For example, most doctors support legislation making it more difficult for them to be sued for malpractice because they do not want to punish for mistakes committed in the workplace.  superiority bias (also known as illusory superiority or the better-than average effect) is the tendency to overrate oneself - to see oneself as better in some respect than one actually is. 2. Sociocentrism  It is group-centered thinking and it can hinder rational thinking by focusing excessively on the group.  It can distort critical thinking in many ways. Two of the most important types of Sociocentrism are group bias and conformism.  Group bias is the tendency to see one’s own group (nation, tribe, sect, peer group, and the like) as being inherently better than others.  Most people absorb group bias unconsciously, usually from early childhood.  Conformism refers to our tendency to follow the crowd unthinkingly to authority or to group standards of conduct and belief. 3. Unwarranted Assumptions and Stereotypes  An assumption is something we believe to be true without any proof or conclusive evidence. Almost everything we think and do is based on assumptions.  If the weather report calls for rain, we take an umbrella because we assume that  the meteorologist is not lying,  the report is based on a scientific analysis of weather patterns,  the instruments are accurate, and so forth.  4. Relativistic Thinking  Relativism is the view that truth is a matter of opinion. It is strongest challenges to critical thinking.  There is no objective or absolute standard of truth.  There are two popular forms of relativism: subjectivism and cultural relativism. A. Subjectivism  It is the view that truth is a matter of individual opinion.  Whatever