chapter 12 informal fallacies ii: assumptions and induction invitation to critical thinking first...

Chapter 12Chapter 12Informal Fallacies II: Informal Fallacies II:

Assumptions and InductionAssumptions and Induction

www.criticalthinking1ce.nelson.comwww.criticalthinking1ce.nelson.com

Invitation to Critical ThinkingInvitation to Critical ThinkingFirst Canadian EditionFirst Canadian Edition

Joel RudinowJoel RudinowVincent E. BarryVincent E. Barry

Mark LetteriMark Letteri

© 2008 by Nelson, a division of Thomson Canada Limited© 2008 by Nelson, a division of Thomson Canada Limited 12-12-22

OverviewOverview

Fallacious AssumptionsFallacious Assumptions Fallacies of InductionsFallacies of Inductions


Fallacious AssumptionsFallacious Assumptions

• Informal fallacy of false dilemmaInformal fallacy of false dilemma• Loaded questions Loaded questions • Informal fallacy of innuendo Informal fallacy of innuendo • Informal fallacy of begging the Informal fallacy of begging the

question or circular reasoningquestion or circular reasoning



False dilemma fallacy:False dilemma fallacy: a a fallacy of fallacy of underestimating or underrepresenting the underestimating or underrepresenting the number of possible alternatives for a given number of possible alternatives for a given issue.issue.



Loaded Questions:Loaded Questions: a question is so a question is so worded that you can’t answer it without worded that you can’t answer it without also granting a particular answer to some also granting a particular answer to some otherother question. question.



Innuendo:Innuendo: a fallacy in which a fallacy in which a judgment, a judgment, usually derogatory, is implied by hinting. usually derogatory, is implied by hinting.



Begging the question or circular Begging the question or circular reasoning:reasoning: a fallacy of assuming or a fallacy of assuming or presupposing one's conclusion as a presupposing one's conclusion as a premise.premise.


Fallacies of InductionFallacies of Induction

GeneralizationsGeneralizations Small sampleSmall sample Unrepresentative Unrepresentative

samplesample Suppressed evidenceSuppressed evidence Bad baselineBad baselineAnalogiesAnalogies False analogiesFalse analogies Arguing Arguing ad ignorantiamad ignorantiam Invincible ignoranceInvincible ignorance

Hypothetical and causal Hypothetical and causal reasoningreasoning

Only game in townOnly game in town Jumping from correlation Jumping from correlation

to causeto cause Post hoc ergo propter hocPost hoc ergo propter hoc Overlooking a common Overlooking a common

causecause OversimplificationOversimplification Slippery slopeSlippery slope Gambler’s fallacyGambler’s fallacy


Fallacies of Induction: Fallacies of Induction: GeneralizationsGeneralizations

Small sampleSmall sample: a : a fallacy of statistical fallacy of statistical inference consisting of overestimating inference consisting of overestimating the statistical significance of evidence the statistical significance of evidence drawn from a small number of cases.drawn from a small number of cases.



Unrepresentative sampleUnrepresentative sample: a : a fallacy of fallacy of statistical inference involving statistical inference involving overestimating the statistical overestimating the statistical significance of evidence drawn from a significance of evidence drawn from a sample of a particular kind.sample of a particular kind.



Suppressed evidence:Suppressed evidence: persuasive strategy persuasive strategy consisting of covering up available consisting of covering up available evidence that conflicts with an intended evidence that conflicts with an intended conclusion.conclusion.



Bad baselineBad baseline: a : a fallacy of statistical fallacy of statistical inference based on an inappropriate inference based on an inappropriate basis of comparison.basis of comparison.


Fallacies of Induction: AnalogiesFallacies of Induction: Analogies

Faulty analogy: Faulty analogy: An An argument based on argument based on similarities that are similarities that are irrelevantirrelevant to the to the conclusion.conclusion.

An argument that glosses over relevant An argument that glosses over relevant differencesdifferences..



Arguing Arguing ad ignorantiamad ignorantiam:: a a fallacy of fallacy of inferring a statement from the absence of inferring a statement from the absence of evidence or lack of proof of its opposite.evidence or lack of proof of its opposite.



Invincible ignorance:Invincible ignorance: fallacy of refusing to fallacy of refusing to give due consideration to evidence that give due consideration to evidence that conflicts with what one is already conflicts with what one is already committed to believing.committed to believing.


Fallacies of Induction: Fallacies of Induction: Hypothetical and Hypothetical and Causal ReasoningCausal Reasoning

Only game in town:Only game in town: concluding hastily that concluding hastily that some explanation or solution holds true some explanation or solution holds true simply because one cannot think of a simply because one cannot think of a better one.better one.



Jumping from correlation to cause:Jumping from correlation to cause: causal fallacy in which causal fallacy in which an observed an observed statistical correlation is interpreted as statistical correlation is interpreted as showing a causal connection without first showing a causal connection without first having made a reasonable attempt to having made a reasonable attempt to isolate the cause by controlling the isolate the cause by controlling the relevant variables experimentally.relevant variables experimentally.



Post hoc ergo propter hocPost hoc ergo propter hoc:: aa variety of variety of causal fallacy in which order of events in causal fallacy in which order of events in time is taken to establish a cause and time is taken to establish a cause and effect relationship.effect relationship.



Overlooking a common cause:Overlooking a common cause: causal causal fallacy in which one of two effects of some fallacy in which one of two effects of some common cause is taken to cause the common cause is taken to cause the otherother..



Causal oversimplification:Causal oversimplification: a a variety of variety of causal fallacy in which significant causal causal fallacy in which significant causal factors or variables are overlooked.factors or variables are overlooked.



Gambler’s fallacy:Gambler’s fallacy: any of a variety of fallacies of any of a variety of fallacies of inductive reasoning concerning estimating or inductive reasoning concerning estimating or beating the odds, often based on the use of past beating the odds, often based on the use of past outcomes to predict the future outcome of outcomes to predict the future outcome of chance events.chance events.



Slippery slope:Slippery slope: a fallacy consisting of a fallacy consisting of objecting to something on the grounds that objecting to something on the grounds that it will lead, by dubious causal reasoning, to it will lead, by dubious causal reasoning, to some unacceptable set of consequences.some unacceptable set of consequences.

chapter 12 informal fallacies ii: assumptions and induction invitation to critical thinking first...

Documents

fallacy of underestimating

variety of causal fallacy

informal fallacies

causal reasoningjumping

causal reasoningpost

causal connection

causal reasoningonly

available evidence