• An attempt to justify a conclusion by rational means
  • Set of statements consisting of:
    • One or more premises (supporting statements)
    • A conclusion (statement in need of support)
  • A bad argument can have a true conclusion
  • "Is this a good argument?" !== "Do you agree with the conclusion?"

Forms of Arguments

  • Deductive arguments
  • Non-deductive arguments
    • Tries to provide probable support for its conclusion
      • A conclusion should seem more likely to be true
      • Not definitive truth
    • A non-deductive argument providing probable support is strong
      • Strength comes in degrees
    • A strong argument with true premises is cogent
      • Cogency runs parallel to soundness
      • Cogent arguments can have false conclusions
    • Types
  • Ontological arguments

Reconstructing Arguments

  • Piece together an argument from a passage of text
  • There may be missing pieces
    • Hidden premises or conclusions
    • Can happen due to various reasons:
      • Lazy author
      • Think premise(s) are obvious
  • Look for a conclusion indicator (eg. so)
  • How to find missing premises
    • Search for credible premise that would make argument valid (or as strong as possible)
    • Choose premise that is:
      • Most plausible
      • Fits best with author's intent
      • Principle of Clarity
        • Always attribute the strongest possible interpretation of an author's position consistent with the text

Evaluating Arguments

  • Think about two questions:
    • Are the premises of this argument true?
    • Assuming the premises are true, to what extend do they support the conclusion?
  • Look out for faulty reasoning
    • A fallacy
    • Error in reasoning that commonly persuades people