Definitions of fallacy

Definitions of ‘fallacy’ in common usage:

  1. Wikipedia definition of ‘fallacy’:  “incorrect reasoning in argumentation resulting in a misconception” – so an argument that follows a incorrect reasoning but arrives a correct misconception is not a fallacy (i.e. ‘I dreamed last night that it is hot in Ouagadougou, Burkina Faso today; therefore, it is hot in Ouagadougou today.’  The reasoning is fallacious, but my conclusion may be accurate.)
  2. Internet Encyclopedia of Philosophy: “A fallacy is a kind of error of reasoning.”  – the definition is accurate, but as it gives us no idea what ‘kind’ of error fallacies are, it is also so vague as to be wholly unhelpful.
  3. The Fallacy Files: “A ‘fallacy’ is a mistake, and a ‘logical’ fallacy is a mistake in reasoning.” – ‘mistake’ often implies failing to achieve an intended goal, i.e. earthquakes are not ‘mistakes.’ Fallacious reasoning is often used intentionally by experts who specialize in persuasion, and hence it is hard to see how it can be a ‘mistake.’ If we restrict the notion of ‘mistake’ to those believing the reasoning rather than producing it, we could rescue the definition from this worry, but it is possible to conceive of self-delusion as a kind of intentional, successful, internal deception of reason, which again, seems difficult to label as a ‘mistake.’
  4. Logical Fallacies: “A logical fallacy is, roughly speaking, an error of reasoning” – definition well qualified by ‘roughly speaking.’


Fake Expert

Fake Expert: A fallacious appeal to authority in which the 'expert' is not an expert at all.

Expert in the wrong domain

Expert in the wrong domain: a fallacious version of an appeal to authority - i.e. appealing to a doctor...

Slippery Slope

Slippery slope: If we take one step, we’ll have to take all the rest of them because there’s no...

Post Hoc Ergo Propter Hoc

Post hoc ergo propter hoc: “After this, therefore because of this”, a fallacy in reasoning about causes. (I took...

Poisoning The Well

Poisoning the well: Telling the audience what to think of a speaker when you’re introducing the speaker (My next...