In-depth Notes on Logical Fallacies

Fallacies Based on Irrelevant Premises

  • Definition: Premises that do not support the conclusion;
    • They have no bearing on the truth of the conclusion.

Fallacies Based on Unacceptable Premises

  • Definition: Relevant to the conclusion but dubious, defective, or unacceptable.

Begging the Question

  • Definition: Arguing in a circle by using the conclusion as a premise.
  • Examples:
    • Example 1:
      • Statement: God exists.
      • Justification: The Bible says so.
      • Further Justification: The Bible is true because God wrote it.
      • Conclusion: Therefore, God exists.
    • General Form: If P is true, then P is true (i.e., P therefore P).

Ethical Implications of Lies

  • Case 1: Assertion that lying is immoral under all circumstances.
  • Case 2: Arguments on free speech and its advantages to the state.

False Dilemma

  • Definition: Asserting only two alternatives when there are more.
  • Examples:
    • Either you support government arts funding or you're an uncultured thug.
    • Either I saw you at the party, or I was too drunk to see straight.

Conditional Form of False Dilemma

  • Example:
    • If you're not in favor of government arts funding, then you're an uncultured thug. You’re not in favor, so you're an uncultured thug.

Common False Dilemma Scenarios

  • Canada’s Oil Sands: Economic boon or environmental disaster?
  • Apple: Innovator or evil giant?
  • Questions regarding the government's competence or morality.

Asking for More Options

  • Example:
    • Can't be only about the rights of the accused versus victims; both can be important.

Slippery Slope

  • Definition: Arguing that a small first step will lead to significant and undesirable chain reactions.
  • Examples:
    • Support for firearms registration leads to prohibition on hunting and personal weapon ownership.
    • Banning pornography will lead to an increase in rape and sex crimes.

Hasty Generalization

  • Definition: Making conclusions about a group based on insufficient evidence.
  • Examples:
    • Only experiencing one sexist male professor does not imply all male professors are sexist.
    • Anecdotal evidence from one satisfactory Dell computer leads to a general endorsement.

Faulty Analogy

  • Definition: A defective argument by analogy.
  • Example:
    • Dogs and humans being similar leads to the false conclusion that humans give birth to puppies.

Unacceptable Premises

  • Examples of Faulty Reasoning:
    • If professional athletes can't use steroids, why allow them cold medication?
    • A robbery scenario justifying the leader's actions based on the amount of money received.
  • Summary: Arguments can be misled if based on superficial comparisons or flawed reasoning.

Identifying Fallacies

  • Common Examples:
    • Having black friends does not negate systemic racism.
    • Assumptions made based on a book’s readership.
    • Judges enforcing maximum sentences leads to exaggerated consequences for lighter sentences.