Understanding Arguments and Fallacies in Critical Thinking

Wisdom

Good Judgment

Fair-mindedness

Considering Other Views Fairly

Intellectual Courage

Willing to Risk for Truth

Intellectual Perseverance

Don't Give Up inquiry easily

Intellectual Conscientiousness

Attentive & Careful

Intellectual Autonomy

Thinking for Yourself

Proper Skepticism

Doubt insofar as Lacking Evidence

Intellectual Empathy

Seeing from Others' Perspectives

Open-mindedness

Willing to Consider Other Views

Intellectual Humility

Admit when you Don't Know

Intellectual Honesty

Truthfulness in matters of truth

Curiosity

Motivation to Ask Questions & Seek Truth

ARGUMENT

a group of statements where one statement (the conclusion) is affirmed on the basis of the other statement(s) (the premises).

LOGIC

the study of the methods and principles involved in reasoning which allow us to distinguish good arguments from bad arguments.

Statement

Sentence that is either true or false

Premise

Statement intended to support conclusion

Conclusion

Statement of position being argued for

Conclusion Indicators

Words that indicate a conclusion such as therefore, thus, so, hence, consequently, it follows that.

Premise Indicators

Words that indicate premises such as since, because, for, as, given that, on the grounds that.

Standardizing Arguments

Identify the Conclusion & Premises, exclude anything that does not support the conclusion, number the statements, and write each as 1 statement.

Strength of Arguments

The degree of support that its premises provide for its conclusion.

Sound Argument

The argument is valid & all its premises are true.

Argument Evaluation

The goal of an argument is to provide reasons that show the conclusion to be credible or at least more credible than it would otherwise be.

Credibility of Premises

How credible are the premises?

Support for Conclusion

How much would the premises support the conclusion, if they were true?

Deductively Valid

If the argument's premises were true, this would guarantee its conclusion.

Decisive

The argument is strong enough to overcome any known objections & opposing arguments, and thus to apparently decide the debate in favor of its conclusion.

Cogent

If the argument's premises were true, this would show its conclusion to be probable, + all its premises actually are true.

Strong

The premises provide enough support to show the conclusion to be significantly more probable than it otherwise would be.

Plausible

The premises appear relevant enough to the conclusion that the argument is worth further consideration.

Weak

The premises provide little support for the conclusion.

Irrelevant

The premises provide no support for the conclusion.

Argument by Example

Infers from particular or statistical claims.

Analogical Argument

Claims that since 2 things are similar in certain ways, we should conclude that they are similar in another way.

Argument from Authority

Appeals to experts in a field.

Causal Argument

Provides a plausible causal explanation, then shows that other explanations are less likely.

Deductive Argument

Aims to entail conclusion w/certainty.

Reductio Argument

Aims to refute opposing view by showing that it has absurd implication.

Weston: Rules for Argument

1. Resolve premises and conclusion. 2. Unfold your ideas in a natural order. 3. Start from reliable premises. 4. Be concrete and concise. 5. Build on substance, not overtone. 6. Use consistent terms.

Principle of Charity

Interpret opposing arguments in the strongest way of the possible options.

Fallacy

An argument form that is logically weak yet often disproportionately persuasive.

Cognitive Bias

Irrational psychological tendency in judgment.

Strawman

Misrepresenting someone's argument in order to refute it more easily.

Improper Appeal to Emotion

Persuading by evoking emotion that is inappropriate for the situation, out of proportion, or irrelevant to the conclusion.

Equivocation

The meaning of a word shifts over the course of an argument.

Belief Bias

Tendency to interpret & evaluate argument more charitably if we agree with its conclusion, and unfairly if we disagree with it.

Framing Effect

Tendency to be persuaded partly by the presentation & wording of an idea, not just its substance.

True

Corresponds to Reality.

Credible

A rational person would believe it.

Acceptable

Plausible enough to be willing to accept.

Govier: When Premises Are Acceptable

Supported by a Strong Subargument, Supported Elsewhere, Known a priori (by the meaning of the terms) to Be True, Common Knowledge, Supported by Appropriate Testimony, Supported by Proper Authority, Accepted Provisionally for the sake of argument.

Govier: When Premises Are Unacceptable

Vagueness or Ambiguity, Known a priori (by the meaning of the terms) to Be False, Inconsistency between Premises, Easily Refutable, Missing Needed Support, Fallacy of Begging the Question.

Law of Noncontradiction

Contradictory statements cannot both be true! (in same sense at same time).

Consistent Statements

A set of statements is consistent when it is logically possible for all of them to be true (no contradiction between them).

Inconsistent Statements

A set of statements is inconsistent when it is logically impossible (contradictory) for all of them to be true.

Fallacy: Begging the Question

Assuming that which needs to be proven; the conclusion is a premise reworded, circular reasoning; rely on A to prove B & vice versa.

Arguments by Example

Inductive Generalization; Start from particular or statistical claims, make inference beyond.

Example Arguments by Example

1. I've met several players on the basketball team and they are all over 6 feet tall. 2. Therefore, most of the players on the basketball team are probably at least 6 feet tall.

Rules for Arguments by Example

1. Use more than one example (or enough examples). 2. Use representative examples. 3. Background rates are often crucial. 4. Statistics need a critical eye. 5. Reckon with counterexamples.

Sampling

Population: The entire set of items that an argument pertains to.

Sample

Set of examples from population that inference is based on.

Sampling Bias

Factors that tend to make sample unrepresentative.

Self-Selection Bias

If individuals must choose to participate, and those who would choose to do so are not representative of the population.

Non-Response Bias

When the group not responding to a survey would have different responses on average.

Unbiased Sampling

Methods that tend to make sample representative.

Random Sampling

Method of selecting examples where each member of the population is equally likely to be chosen.

Stratified Sampling

Method of sampling where each relevant subgroup is represented in proportion to its share of the population.

Understanding Polls

Suppose election poll says 52% of likely voters support candidate Smith, with 95% Confidence Interval & 3% Margin of Error.

Confidence Interval

There is a 95% probability that the actual percentage of the voting population supporting Lee is within 3% (above or below) 52%.

Hasty Generalization (or Anecdotal Evidence) Fallacy

Making an inference based on a sample that is too small or unrepresentative

Availability

Basing judgments of frequency on ease with which examples can be recalled

Vividness Effect

Tendency to overestimate the significance of vivid information

Representativeness

Judging the probability of something being a member of a category by how closely it resembles a prototype of that category

Base Rate Neglect

Neglecting background probabilities when making inferences

Gambler's Fallacy

Judging probability of independent events as if they were not independent

Base Rate Neglect - Example

Mike is tall, muscular, and in excellent physical condition. He has an aggressive and competitive personality.

Anecdotes

When it's OK to use a smaller number of examples: The population that you infer a conclusion about is very small.

Anecdotes

Your conclusion is modest (E.g., "Some x are y ...").

Anecdotes

Statistics aren't available about the topic, so best we can do is infer from experience.

Anecdotes

The example is a representative illustration of a claim backed by statistics.

Counterexample

Example that counts against a generalization.

Arguments by Analogy

Claims that since 2 things are similar in some way, then they are also similar in another way.

Analogy

Comparison between two things.

Analogues

Items being compared in an analogy.

Disanalogy

Difference between two things.

Causal Analogy

X causes Z. Y is like X. Therefore, Y will also cause Z.

Historical Analogy

Causal analogy where X is a historical event.

Legal Analogy

Case Y is like precedent case X in the legally relevant ways. Therefore, the ruling on Y should be the same as the ruling on X.

Moral Analogy

Act X is right (or wrong). Act Y is like act X in the morally relevant ways. Therefore, act Y is also right (or wrong).

Deductive Analogy

The premises of argument X guarantee conclusion Z1. The logical relation between the premises of argument Y and Z2 is the same as that between those of X and Z1. Therefore, argument Y guarantees Z2.

Reductio Analogies

Opponent's argument X is logically equivalent to arg. Y for absurd conclusion Z. So if we accept X then we must accept Z. Therefore, reject X.

Evaluating Analogical Arguments

Be open-minded to analogical reasoning - don't dismiss.

Evaluating Analogical Arguments

Are the analogues really similar in the way that is claimed?

Evaluating Analogical Arguments

How relevant are the similarities to the conclusion drawn?

Faulty Analogy

Analogical argument where the analogues are not really similar in ways relevant to the conclusion.

Teleological Argument

An argument for the existence of God based on the design and order in the universe.

Turing Test

A test of a machine's ability to exhibit intelligent behavior equivalent to, or indistinguishable from, that of a human.

Chinese Room Argument

A thought experiment that argues against the notion that a program can have a mind or understanding.

Drowning Child Analogy

An analogy used by Peter Singer in 'Famine, Affluence, & Morality' to illustrate moral obligations.

Speciesism Analogy

An analogy used in 'Animal Liberation' by Peter Singer to critique discrimination against non-human animals.