14: Logical Fallacies, Part Deux
Hi guys! Here's part two of our series on the logical fallacies. The art is "Hercules Delivering Prometheus," by Nicolas Bertin. You'll find the rest of the logical fallacies below the episode.
Fallacies of Ambiguity
18. Equivocation (“Definitional Ambiguity”) - a fallacy of ambiguity that sneakily changes a definition or sense of a key word during a discussion.
19. Amphiboly (“Syntactical Ambiguity”) - a fallacy of ambiguity in which an entire sentence or passage can be taken in two or more ways.
20. Distinction Without a Difference (“Connotation Dodging”) - a fallacy of ambiguity that uses a synonym or restatement to exempt itself from an opponent's charge.
21. Composition (“Part-to-whole Fallacy”, “Mad-Addling”) - a fallacy of ambiguity that assumes something true of the parts must be true of the whole.
22. Division (“Whole-to-part Fallacy”, “Add-Maddling”) - a fallacy of ambiguity that assumes something true of the whole must be true of the parts.
23. Accent (“Emphasis”) - a fallacy of ambiguity that sneakily changes the sense of a sentence by means of where the emphasis is placed.
24. Repetition (“Early & Often”) - a fallacy of ambiguity that uses repetition to bypass a discussion of the truth or falsity of a proposition.
25. Loaded Question (“Complex Question”) - a fallacy of ambiguity that veils unproven (presupposed) assertions under seemingly innocent questions.
26. Selective Arrangement (“Shadow Shifting”, “Shell Gaming”) - a fallacy of ambiguity that leaves out or disguises the facts that do not fit with the presupposed conclusion.
27. Exigency (“Advertisers' Fallacy”) - a fallacy of ambiguity that attempts to persuade solely or primarily on the basis of a limited time frame.
28. No True Scotsman (“Ad Hoc Rescue”) - a fallacy of ambiguity that eliminates an exception to a presupposed generalization by dismissing the exception without justification.
Fallacies of Form
29. Petitio Principii (“Circular Reasoning”, “Begging the Question”) - a fallacy of form that assumes what needs to be proven.
30. Post Hoc Ergo Propter Hoc (“False Cause”) - a fallacy of form that assumes causation based on temporal precedence alone.
31. Cum Hoc Ergo Propter Hoc (“Correlation vs Causation Fallacy”) - a fallacy of form that assumes causation based on correlation alone.
32. Affirming the consequent (“AffCon”) - a fallacy of form that has the general structure “If P, then Q. Q. Therefore P.”
33. Denying the Antecedent (“DenAnt”) - a fallacy of form that has the general structure “If P, then Q. Not P. Therefore, not Q.”
34. Bifurcation (“Either-Or”, “False Dilemma”, “False Dichotomy”) - a fallacy of form that illegitimately limits choices.
35. Fallacy of Compromise (“Argument to Moderation”, “Middle Ground”) - a fallacy of form that assumes truth is always to be found perfectly in between two opposing propositions.
36. Naturalistic Fallacy (“Is-Ought Fallacy”) - a fallacy of form that makes claims about how something ought to be based on its existence or on its pleasantness.
37. Slippery Slope (“Thin Edge of the Wedge”, “Slipfishing”) - a fallacy of form that asserts but does not demonstrate a connection between a proposed idea and a resulting series of bad consequences. Also, the bald denial that some clearly treacherous and dangerous step will lead to any negative consequences at all.
38. False Analogy (“Broken Metaphor”) - a fallacy of form that, ignoring pertinent differences, compares on situation to another to draw the desired conclusion.
39. Hasty Generalization (“Apriorism”, “Converse Accident”) - a fallacy of form that draws a board conclusion based on a too-small sample size.
40. Sweeping Generalization (“Painting with a broad brush”) - a fallacy of form that applies a general rule absolutely, regardless of reasonable exceptions.
These fallacies are compiled partially from The Amazing Dr. Ransom's Bestiary of Adorable Fallacies, by Doublas Wilson & N.D. Wilson, an excellent book on logic. The rest come from A Logic Book: Fundamentals of Reasoning, by Robert M. Johnson.