Chapter 1: Critical Thinking
Chapter Overview
Critical thinking is judicious (deliberate and thorough) thinking (correct reasoning) about what to believe and, therefore, what to do. It's a multi-dimensional skill. One gets better at it with practice. It involves understanding and then evaluating arguments for and against a particular claim.
Critical thinking is neither negative, passive, destructive, nor adversarial; it is not cold, calculating, and unfeeling; and it is neither intuitive, nor a matter of “common sense.”
Critical thinking enables us to provide evidence and reasoning for our opinions and actions. It thus enables us to be autonomous or independent — in control of our own lives. This is increasingly important as media conglomerates control what is said (and how it's said) and what is not said. Critical thinking also increases diversity of opinion and, thus, the quality of citizenship. It enables us to handle conflict without evasion or aggression. Critical thinking is based on rational thought which is superior to emotion, intuition, or faith as a basis for belief and action. Critical thinking skills can be applied not only to issues, but also to day-to-day decisions, as well as new or unfamiliar questions, ideas, and situations.
There are many reasons for why we don't normally engage in critical thinking: it's intrinsically hard, and the loss of diversity makes it harder, and we seem hard-wired to take the path of least resistance. Also, our society seems to encourage being non-judgmental (whether from etiquette, postmodernism, or relativism); and it discourages intellectualism. We are often manipulated into not thinking critically. Critical thinking often involves changing one's mind, which is something we may resist for a number of reasons; also, we tend to believe what we want to believe. Our emotions may get in the way; so too might our reluctance to take responsibility for our opinions and actions.
Chapter Objectives
By the end of this chapter, you should be able articulate in your own words:
- what is critical thinking
- why it's so important.
If you cannot do this, you will not do well in the course. So do not pass ‘GO' until…
Chapter 2: The Nature of Argument
Chapter Overview
An argument consists of one or more premises in support of a conclusion. Arguments are often implied rather than overtly articulated. Premises and conclusions may be stated outright; more often, they are assumed or implied. Unstated premises and conclusions, as well as the connections between them, should be identified in order to fully understand and critically assess the argument. Appeals to emotion, intuition, instinct, and faith are not arguments — they are not appeals to reason. An explanation is not an argument, but when the facts of the matter are in contention, one can make an argument for an explanation. A circular argument is an error in reasoning. A counterargument is an argument whose conclusion is counter to that of a given argument. The burden of proof is on the person making the claim, unless it's a negative claim. The more extraordinary the claim, the more extraordinary the proof must be. One cannot conclude that a claim is true simply because there is no evidence that it is false, and vice versa; that would be an appeal to ignorance. Facts are statements about the world as it is; such statements can be known to be true or false. Opinions are statements about the world as one thinks it is or should be or could be.
Arguments can be deductive or inductive. The conclusion of a deductive argument makes explicit what's already implicitly contained in the premises; it articulates the logical implications of the premises. The conclusion of an inductive argument goes beyond the information of the premises; it articulates new knowledge. When considering an argument, attention should focus on the reasoning (the premises and their relation to the conclusion), not on the conclusion; whether or not one accepts the conclusion should depend solely on the merit of argument that is made in support of that conclusion. For deductive arguments, if the premises are true, and the form is valid, the argument is sound — the conclusion necessarily follows from the premises. For inductive arguments, if the premises are true or at least acceptable, and relevant, and sufficient, the argument is strong — the conclusion probably follows from the premises. Deductive argument can be based on categorical logic or propositional logic; both involve the syllogism. Inductive argument includes generalization, analogies, general principles, and causal reasoning.
Chapter Objectives
By the end of this chapter, you should be able to:
- explain what an argument is
- appreciate the importance of unstated or assumed premises
- articulate the difference between an argument and appeals to emotion, intuition, instinct, and faith
- articulate the difference between arguments and explanations
- recognize a circular argument when you see/hear it
- say who has the burden of proof and understand the error of an appeal to ignorance
- articulate the difference between fact and opinion
- articulate the difference between a weak opinion and a strong opinion
- explain the difference between inductive argument and deductive argument
- explain what makes a sound deductive argument
- explain what makes a strong inductive argument.
Chapter 3: The Structure of Argument
Chapter Overview
Arguments can be constructed in various ways: single convergent, multiple-separate convergent, multiple-linked convergent, and divergent. And they can be multi-structured, with more than one of the preceding structures involved.
Chapter Objectives
By the end of this chapter, you should:
- understand that arguments consist of connected parts
- be able to diagram the arguments you come across.
Chapter 4: Relevance
Chapter Overview
In order for an argument to be considered a good argument, its premises must be relevant to its conclusion.
Errors of relevance can involve considering the source of the argument instead of the argument itself, appealing to an inappropriate authority, or going off-topic.
Chapter Objectives
By the end of this chapter, you should be able to:
- articulate what exactly relevance is
- explain the many ways of being irrelevant (see the flashcards!)
- recognize when something is irrelevant.
Chapter 5: Language
Chapter Overview
Clarity is largely a matter of using precise diction (by avoiding vague words, ambiguous words, and exaggeration) and precise grammar, as well as detail. Beware of repetition that confuses the issue.
Loaded language (value- or emotion-laden words), as well as visual, aural, and other effects, may prevent us from thinking critically about what's being said.
Visual effects that get in the way of critical thinking include, for print, page placement, space allotment, and font type, and for images, camera angle, distance, lighting, and color, and for both, context (framing and sequence).
Aural effects that get in the way of critical thinking include voice pitch, pace, and tone, as well as soundtracks and sound effects.
Repetition also affects us in a non-rational way to accept what's being presented.
Definitions are important to keep an argument progressing on track. A good definition for the purposes of argument should specify genus and species, as well as necessary and sufficient conditions; it should be neither too broad, nor too narrow. Definitions can't be changed in the middle of an argument!
Chapter Objectives
By the end of this chapter, you should be able to:
- understand the importance of carefully choosing your words and crafting your sentences
- recognize and resist the effect of loaded language
- recognize and resist various visual effects
- recognize and resist various aural effects
- define your terms well
- recognize the error of equivocation.
Chapter 6: Truth and Acceptability
Chapter Overview
While philosophers typically leave the establishment of truth to others, our arguments, nevertheless, depend on truth. In order for a deductive argument to be sound and for an inductive argument to be strong, the premises of the argument must be true. A claim is verifiable if we can describe conditions under which we can show it to be true; a claim is falsifiable if we can describe conditions under which we can show it to be false. In some cases, we use the standard of acceptability instead of truth: when it is highly unlikely we can determine the truth, when it is impossible to determine the truth (prediction, causal reasoning), and when the claim is non-empirical. In order to decide whether a claim is acceptable, one can examine the arguments in support of the claim, ask whether the claim is plausible (possible, reasonable) or, further, whether it's probable, and ask whether it contradicts other claims known to be true and/or whether its implications are acceptable.
Four theories of truth are subjectivism, the coherence theory, the correspondence theory, and pragmatism.
Personal experience is an insufficient basis for generalizations because it is generally random and singular. Descriptions of personal experience may be flawed by interpretation and assumption, sensory perception deficit, environmental conditions, skill, emotional state, cognitive state, and memory inadequacies.
The scientific process seeks to avoid the weaknesses of personal experience as a way of knowing: it is methodical, it represents the experiences of more than one person, interpretations are carefully separated from observations, instruments are used by trained people in optimal conditions to minimize the subjective element of measurement (and results are replicated to ensure no mistakes were made), and claims are exposed to public scrutiny. The scientific process consists of the following steps: identify the issue of investigation; become familiar with relevant existing knowledge; develop a hypothesis, specifying conditions of verification or falsification; test the hypothesis by designing and conducting a reproducible experiment that will provide the specified conditions of verification or falsification, following established methods of investigation; formulate conclusions based on the evidence.
When evaluating personal testimony, the flaws mentioned above should be considered, as well as the person's credibility and any corroborating or contradicting evidence.
When evaluating the evidence provided by studies, several factors should be considered: the date of the study, the possibility of distorting bias, the tools and techniques used to obtain the evidence, consistency of the evidence with other established knowledge, replication of the study's results, the relationship between the results and the conclusions, and whether you're reading a first-hand or second-hand report. With regard to surveys, note what questions were asked and what questions were not asked, how the questions were ordered, how the questions were worded, who the respondents were, how many respondents there were, as well as when and how and by whom the survey was conducted, and, again, the relationship between the results and the conclusions. With regard to experiments, note what controls are required and whether they were established, the size and representation of the test group, and whether the instruments were appropriate. When evidence is presented in numbers, attention should be paid to whether absolute numbers or percentages are given, the possibility of fake precision, whether averages are means, modes, or medians, the margin of error, the level of confidence, whether comparisons are complete, and the accuracy of graphic representations.
When evaluating sources, consider whether the source is qualified, impartial, and thorough, whether the material has undergone independent examination before publication/posting, and whether the material is original or second-hand (a quote or a summary).
When evaluating images, consider inconsistencies in lighting, sharpness, perspective and scale. Also look for anachronisms and other contradictions to established fact, and consider the possibility that missing context may be misleading.
Common errors of truth include the either/or fallacy, the fallacy of composition, the fallacy of division, and the gambler's fallacy. Suppressed evidence results in an incomplete truth, so it is not an error of truth per se; it is more an error of sufficiency.
Chapter Objectives
By the end of this chapter, you should be able to:
- explain the difference between verifiability and falsifiability
- explain when the standard of acceptability is used instead of the standard of truth
- summarize the four theories of truth: subjectivism; coherence; correspondence; pragmatism
- explain the many ways in which personal experience is limited (as a basis for generalization)
- explain why the scientific process is better than personal experience as a way of knowing
- explain the difference between a control group and an experimental group
- appreciate the value of replication
- list the steps of the scientific process
- evaluate personal testimony
- evaluate studies
- evaluate surveys
- evaluate experiments
- evaluate evidence presented with numbers
- evaluate sources
- evaluate images
- recognize the either/or fallacy
- recognize the fallacy of composition
- recognize the fallacy of division
- recognize the gambler's fallacy
- appreciate the possibility of suppressed evidence.
Chapter 7: Generalization, Analogy, and General Principle
Chapter Overview
The strength of an inductive argument depends on the truth or acceptability, relevance, and sufficiency of its premises. Sufficiency (sometimes called adequacy) refers to the degree of support provided by the premises for the conclusion; the more sufficient the support, the stronger the argument (that is, the more probable the conclusion). Additional information may be required before a conclusion is deemed to have sufficient support.
Generalization can be defined as making a general claim based on specific evidence. All it takes is one counterexample to disprove a generalization that is a universal statement; in that case, revision of qualifier, rather than outright rejection of the generalization, may be possible.
The two important elements of generalizations are quantities and qualities. The larger the sample (proportionally speaking) and the more representative the sample (the more similarities there are between the sample and the target population), the stronger the argument. Almost all errors of generalization are errors of overgeneralization — of scope, frequency, or certainty — involving a sample that is insufficient in size or unrepresentative (or both).
An argument by analogy involves reasoning from one situation to an analogous, or similar, situation. The strength of an argument by analogy depends on whether there are sufficient relevant similarities and no relevant dissimilarities. Errors of argument by analogy include weak or false analogies.
An argument by application of general principle involves reasoning from a general principle to a particular instance of that general principle. The strength of this kind of argument depends on the acceptability of the general principle and the applicability of the general principle to the particular instance. An error of argument by application of general principle is the misapplication of a general principle.
Chapter Objectives
By the end of this chapter, you should be able to:
- explain what sufficiency is (in the context of argument)
- provide an example of a generalization and provide a counterexample to disprove it
- explain the role of sample size and representation in generalization
- recognize the three kinds of overgeneralization
- recognize and evaluate arguments by analogy
- recognize and evaluate arguments by general principle.
Chapter 8: Inductive Argument: Causal Reasoning
Chapter Overview
Claims of causation can never be established by direct experience; they can only be inferred. Correlation (mere association in time or space) does not imply causation. A cause need not be close in time or space to its effects. It is important to consider both direct and indirect causes. It is also important to distinguish between necessary and sufficient causes. An effect may have more than one cause, and these contributing causes may be independent or interactive. A cause and its effect may also interact with each other. Mill's methods provide ways to determine causation.
An explanation is an accounting for a given phenomenon or occurrence. Knowledge and creativity are required to come up with alternative explanations. A good explanation:
- accounts for all of the relevant facts,
- doesn't create more puzzles than it solves,
- is testable, enabling you to make predictions,
- doesn't contradict established knowledge.
Arguments advocating a certain plan or policy implicitly involve causal reasoning; to the extent a plan or policy proposes or includes the causal processes that would lead to the stated goal of the plan or policy, the achievement of that goal is likely.
Errors in causal reasoning include mistaking correlation for causation, post hoc ergo propter hoc, failing to consider a common cause, failing to consider additional causes, reversing cause and effect, failing to consider a reciprocal causal relation, and the slippery slope.
Chapter Objectives
By the end of this chapter, you should be able to:
- distinguish between correlation and causation
- distinguish between direct and indirect causes
- distinguish between necessary and sufficient causes
- explain and use Mill's four methods of determining causation
- articulate the four elements of a good explanation
- identify errors in causal reasoning.
Categorical Logic
Chapter Overview
There are four kinds of categorical statement, and in some cases, their conversions, obversions, and contrapositives are logically equivalent (these cases are in regular type):
| Conversion | Obversion | Contrapositive | |||
|---|---|---|---|---|---|
| A | Universal Affirmative: | All A are B. | = All B are A. | = No A are non-B. | = All non-B are non-A. |
| I | Particular Affirmative: | Some A are B. | = Some B are A. | = Some A are not non-B. | = Some non-B are non-A. |
| E | Universal Negative: | No A are B. | = No B are A. | = All A are non-B. | = No non-B are non-A. |
| O | Particular Negative: | Some A are not B. | = Some B are not A. | = Some A are non-B. | = Some non-B are not non-A. |
“All As are Bs” and “Some As are not Bs” are contradictories; “Some As are Bs” and “No As are Bs” are also contradictories.
“All As are Bs” and “No As are Bs” are contraries.
“Some As are Bs” and “Some As are not Bs” are subcontraries.
One can use diagrams or rules in order to determine whether categorical syllogisms are valid. In the first case, if the syllogism is valid, the conclusion will be apparent in any diagram that results from the two premises. In the second case, the syllogism is valid if none of the following rules are broken:
- The syllogism must have three, and only three, terms.
- The middle term must be distributed in at least one of the premises.
- Any term that is distributed in the conclusion must be distributed in the premise in which it occurs.
- The syllogism can't have two negative premises.
- If one of the premises is negative, then the conclusion must be negative — and vice versa.
- If both premises are universal, the conclusion must be universal.
Chapter Objectives
By the end of this chapter, you should be able to:
- recognize the four kinds of categorical statements, their conversions, obversions, and contrapositives — especially when they appear in ordinary language
- recognize contradictories
- recognize contraries
- recognize subcontraries
- determine whether categorical syllogisms are valid or invalid.
Propositional Logic
Chapter Overview
There are four kinds of propositions:
- Conjunction: p and q
- Disjunction: p or q
- Negation: Not-p
- Conditional: If p, then q.
One can use truth tables in order to determine whether arguments using propositional logic are valid.
Chapter Objectives
By the end of this chapter, you should be able to:
- identify conjunctions, disjunctions, negations, and conditionals when they appear in ordinary language
- identify standard forms as valid or invalid
- determine whether arguments involving propositional logic are valid or invalid.
Thinking Critically About Ethical Issues
Chapter Overview
The word ‘ethics’ refers to matters of right and wrong. The word ‘morality’ refers to a particular system of ethical beliefs or principles. In ethics there is no truth of the matter. While this can be a source of frustration ending in defeat, it need not be: rather than trying to make the single right decision, focus on simply making better decisions, more carefully considered decisions. Getting to the point where at least you're asking all the right questions is a worthy achievement. Ethically speaking, most of us are quite undeveloped; we haven't updated our childhood training. This is unfortunate because as adults, we have to deal with a lot of ethical issues that our childhood morality simply isn't up to. Many ethical arguments attempt to establish a general principle that can then be used as a guide for decisions about moral right and wrong. Some of the commonly used general principles for moral decision-making do not stand up under critical scrutiny: appeals to intuition or gut feeling, conscience, legality, doing to others what you'd want done to you, and not hurting others.
Values-based reasoning about ethical issues involves determining whether an action is right or wrong according to whether or not the action in question conforms to certain values. Some values are not that easy to define. Deciding which values to endorse depends on the basis for your values. The main problem for those who use a values-based approach to ethical issues is deciding what to do when values collide — which values take precedence over which other values?
Rights-based reasoning about ethical issues involves determining whether an action is right or wrong according to whose and which rights are upheld or violated by the act in question. One must establish which rights one has, the grounds for having those rights (are they natural, god-given, or acquired rights?), and whether they can be lost. The main problem with a rights-based approach is that of competing rights: which rights and/or whose rights trump?
Consequence-based reasoning about ethical issues involves determining whether an action is right or wrong according to its consequences. The strengths of this approach are that it seems to encourage comparison, a consideration of alternatives. Also, it takes a long-term, far-reaching view, a view in which everyone counts equally; and it provides a clear way out of moral conflicts. Its weaknesses include our inability to determine consequences, the irrelevance of intent, and its endorsement of ‘the ends justify the means.’
Two errors common in reasoning about ethical issues are the is/ought fallacy and the arbitrary line fallacy.
Chapter Objectives
By the end of this chapter, you should be able to:
- always know what is the right thing to do (just kidding)
- distinguish between ethics and morality
- recognize which approaches to ethical issues are inadequate
- deliberate about an ethical issue using a values-based approach
- deliberate about an ethical issue using a rights-based approach
- deliberate about an ethical issue using a consequence-based approach
- recognize the is/ought fallacy
- recognize the arbitrary line fallacy.