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View Diary: A Series On Logic: Informal Fallacies, Part 1 — Ambiguity (Updated!) (22 comments)

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  •  Request for clarification (2+ / 0-)
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    Brown Thrasher, linkage

    I'd like to share my reactions to this diary and the proposed series in order to understand the goal. My confusion is this: I feel like you're conflating two topics that aren't as closely connected as most people think.

    The first of these topics is actual mathematical logic. That's where you seemed headed with your definition of "proposition". We'd continue with truth functions, syllogisms, and the rest of propositional logic, then leap to predicate calculus, and onward. It would be interesting to see how far you could go while targeting a lay audience. (Full disclosure: My own field is computational logic, unlikely to be interesting here.)

    The second topic is what we might call "rhetoric" or "argumentation" or even just "debate": Being aware of fallacies and flaws in arguments or information presented to you, how people manipulate your emotions rather than your reason, the nature of "proof" in nonmathematical reasoning (and the unacceptable substitutions for proof frequently encountered) and so forth. You start to tackle this in your treatment of ambiguity.

    This second topic is IMHO more important in political settings, and certainly seems to be what people are eager for, based on the comments. I myself think that studying "real" logic isn't all that relevant. The syllogism "Some men are Greeks, Aristotle is a man, therefore Aristotle is a Greek" is invalid, but understanding exactly why and learning about implication and quantification and Venn diagrams doesn't help much in understanding political discourse, because this isn't typically the sort of invalidity we need to learn to cope with and be on guard against (though the terminology can be helpful). And yet I always run across the sentiment that somehow studying formal logic will improve our debating skills. The skills we really need are much harder.

    I'd be interested to hear your reaction to my point of view and your intent for the series. Possibly you disagree with me entirely, or possibly you just mean to use the word "logic" in a more informal sense, as when you distinguish between formal and informal fallacy.

    If you do intend to cover formal logic, then certainly I'm in 100%, and I'll try not to be overly pedantic in commenting on the material. But as long as I'm writing: Your definition of "proposition" makes me uneasy. I don't think a proposition needs to be "falsifiable" or "factual" and certainly not "about reality". I'd say it like this: a proposition is a sequence of words to which we can assign a truth value, either "true" or "false". This is purely a grammatical concept and has nothing to do with the real world, which might or might not be the determiner of whether "true" or "false" is the correct truth value. "Snow is white" is a proposition, as are "I journeyed hither a Boeotian road" and "There is no God but Allah" and "A scout is reverent" and "x equals 3". Non-propositions include "love" and "running quickly" and "Where are you?" and "Damn it!", because these don't admit of being designated "true" or "false". "Thoughts fly far", to take your example, is certainly a proposition, since it has the correct grammatical form---it can be labelled either true or false, though we might disagree on which is correct.

    I suppose that there's no longer any question about the falsehood of the proposition "Ends With Space is not going to be pedantic".

    Anyway, I look forward to the series.

    •  Thanks for your input. (0+ / 0-)

      I was certainly hoping to get some critical comments to help my presentation (& yes, some degree of pedantry is called for here).

      Since I'm planning on referring to previous diaries as the series develops, I will definitely update (or completely revise & re-diary?) the inaugural "lesson" to correct any hastily-written inaccuracies such as those you mention. (& yes, upon reflection, my definition indeed sounded more like an attempt to describe a scientific hypothesis than the much simpler concept of a proposition).

      As for the overall purpose of the series, political applications definitely constitute one of the driving points — though one can certainly take the raw basics of this subject many different directions, & in that sense I think I'd err if I confined the import of the early definitions too quickly.

      Tell Congress: DON'T BREAK THE INTERNET! Learn about the OPEN Act.

      by Brown Thrasher on Wed Apr 04, 2012 at 09:35:09 PM PDT

      [ Parent ]

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