MEPX
Chapter 6 of 10All chapters
  1. 1What an argument is
  2. 2Validity and soundness
  3. 3If, then
  4. 4All, some, none
  5. 5Necessary and sufficient
  6. 6Deduction against induction
  7. 7Formal fallacies
  8. 8Informal fallacies
  9. 9Logic puzzles
  10. 10Using it in real arguments

Chapter 6 of 10

Deduction against induction

Guaranteed against likely.

Two kinds of support

Deduction guarantees its conclusion if the premises hold. Induction generalises from cases and can only make a conclusion probable, however many cases there are.

  • A thousand white swans do not prove all swans are white.
  • One black swan disproves it, which is why falsification is powerful.

Abduction

Inference to the best explanation sits alongside both: given the evidence, which account makes it least surprising? It is how diagnosis and debugging actually work.