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Summary Notes

These are summary notes so that you can really listen in class and not spend the entire time copying notes. These notes will not substitute for reading the chapters in the text, nor can they replace the text as there are many subtleties we will discuss in class that are also presented in the text. Use these as a supplement.

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Section 3.1| Section 3.2 | Section 3.3 | Section 3.4

Smartboard notes

Chapter 3: Section 3.1

Fallacies in General

fallacy = "defect in an argument that consists in something other than merely false premises."

2 Types of Fallacies

  1. formal fallacy = form or structure of the argument is defective; only applies to deductive arguments that have identifiable forms
  2. informal fallacies = 'can be detected only through analysis of the content of the argument"



3.2 Fallacies of Relevance

Premises are logically irrelevant to the conclusion, yet they may seem to be relevant psychologically.


  1. APPEAL TO FORCE: "always involves a threat by the arguer to the physical or psychological well-being of the listener or reader who may be a single person or a group of persons"
  2. APPEAL TO PITY: evokes pity from the reader/listener
  1. ACCIDENT: misapplication of a general rule that the particular case does not fit
  2. STRAW MAN: "distorts an argument .to more easily attack it"
  1. MISSING THE POINT: conclusion misses the point entirely; arguer does not understand the proper way to argue
  2. RED HERRING: changing the subject/central point entirely without the reader/listener noticing
  • Note distinction between straw man and red herring
  • Missing the point should not be used except as a last resort, "catch-all" fallacy.



3.3 Fallacies of Weak Induction


"connection between the premises and conclusion is not strong enough to support the conclusion"

  1. APPEAL TO UNQUALIFIED AUTHORITY: "cited witness or authority is not trustworthy"
  • Reasons why an authority might not be qualified:
    • lack of expertise
    • bias or prejudice
    • motive to lie or provide misinformation
    • might not perceive/recall an event accurately.
  • 2 points to consider:
  1. People may specialize in more than one field, and therefore, act as a qualified authority.
  2. In certain areas of debate there are no absolute answers (e.g., religion, politics, values), and no one can claim to be the absolute authority.
  • 2 Qualities
  1. Premises freely admit that nothing has been proven one way or the other.
  2. Conclusion makes a definite assertion/claim that such-and-such is the case.
  • 2 Exceptions
  1. Qualified researchers fail to turn up any evidence of certain phenomena after a search.
  2. Courtroom procedure: reasonable doubt.
  1. HASTY GENERALIZATION: inductive generalization drawn from a sample that is not necessarily representative of the entire population to which it is being applied.
  • Sample may be too small, or
    not randomly selected.
  • Hurley also notes that a small sample is not necessarily atypical in every case. See the examples that follow You have to look at the context to evaluate the quality of the sample.
  1. FALSE CAUSE: imagined causal connection that does not exist.
  • temporal succession & causal connection; common in the realm of superstition
  • oversimplified cause: arguer selects one of many causes and ignores systemic effects of multiple causes
  • "usually motivated by self-serving interests"
    • e.g. companies that try to deny culpability when their products or environmental practices cause illness/death; tobacco wars
  • It may be difficult to determine when two events are causally related (e.g. Ebola).
  • Cause and effect are often not easily distinguished from one another.
  • "Statistical correlations by themselves often reveal little about what is actually going on..."
  • Data used for group projects may present this problem
  1. SLIPPERY SLOPE: arguer predicts a chain reaction of undesirable events when there is little likelihood that these events will come to pass
  • Note that this is a popular political tactic to get people to vote for radical legislation
  • "rests on emotional conviction"
  1. WEAK ANALOGY: "analogy is not strong enough to support the conclusion that is drawn"
  • What is an analogy? See Chapter 9.1
  • How can we tell if two things are similar/alike in some way?



3.4 Fallacies of Presumption and Ambiguity

Fallacies of Presupposition: "premises presume what they purport to prove"

  1. Begging the question: "requesting the source"
  • arguer conceals the key premise by using complex terminology
  • arguer lacks good evidence to support claim
  • often occurs in arguments for the existence of God (remind class of Descartes)
  • Many forms:
  1. assume what you are trying to prove
  2. "premise of an argument merely restates the conclusion in slightly different language"
  3. "circular reasoning in a chain of inferences"
  • arguments are usually valid but unsound
  • concealed premise is usually unsound or untrue
  1. Complex question: two or more questions are being asked and a single answer is prompted by the questioner
  • correct response: "resolve complex question into its component questions answer each separately"
  • Leading questions are different as they suggest the answer within the question that is being asked.
  • tricks respondent into admitting something that he/she did not want to
  1. False Dichotomy: presents two alternatives as if they were jointly exhaustive and the only two possible alternatives in existence
  • Again, the argument is valid, but unsound.
  • Review disjunctive syllogism:

p v q

  • You may have to supply a missing premise to fill out the syllogism.
  1. Suppressed Evidence: ignoring an important piece of evidence that would entail acceptance of a different conclusion.
  • Quoting passages out of context from religious, political, legal documents that "support a conclusion the passage was not intended to support."
  • Note the difference between begging the question and suppressed evidence.
  1. Equivocation: "word or phrase is used either explicitly or implicitly in two different sense in the argument."
  • Techniques to confuse the listener:
  • use "equivocal word in ways that are subtly related."
  • "spread the shift in meaning over the course of an argument." This is a popular political favorite for rhetoric/propaganda.
  • Use the word two different ways to two different audiences.
  1. Amphiboly: sentence is syntactically ambiguous and is interpreted in the wrong way.
  • There are two meanings for the sentence and the listener usually misinterprets.
  • Note difference between amphiboly and equivocation.
  1. Composition: attributes are transferred from the parts to the whole and the transfer is inappropriate.
  • Note that some transfers are appropriate and these are legitimate non-fallacies.
  • You must have "general knowledge of a situation" in order to recognize some fallacies of composition.
  • Since everything here is judged in context, you have to be familiar with the context to be a competent judge. (Mill’s utilitarianism)
  • Introduce the idea of distributed properties and collective properties
    • Distributed = every member of the group has that property
    • Collective = must consider the group as a whole to talk about the attribute in question.
  • Note method to distinguish composition from hasty generalization.
  1. Division: transferring an attribute from the whole to the parts erroneously.
  • Note the confusion with the "accident" fallacy, and
    the method to avoid this confusion.




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