I think I might refine the definition of the argumentum ad imperfectionem somewhat today.  As I alleged the other day, ad imperfectionem fallacy occurs when one asserts that the minor errors in someone's argument may be justifiably exaggerated by opponents of that argument.  So, for instance, minor errors in a legal filing undermine one's entire case, not just those particular claims relevant to those errors.  For, after all, if there are a couple of typos, who knows what other kinds of serious errors there could be.  This, of course, is the response of a crazy person.  But not all crazy is the same, so it's worth it to take a closer look at the crazy.   

On this description, the imperfectionem is a variation of the ignoratio elenchi (IE).  The ignoratio elenchi, sometimes called "missing the point" or–get this–"non sequitur", is a kind of a catch-all category of fallacy: any other basic failure of informal entailment gets thrown in here.  Here, for instance, is the way Patrick Hurley puts it in A Concise Introduction to Logic:

Missing the point illustrates a special form of irrelevance.  This fallacy occurs when the premises of an argument support one particular conclusion, but then a different conclusion, often vaguely related to the correct conclusion, is drawn.


but in some ways it serves as a catchall for arguments that are not clear instances of one or more of the other fallacies.

Textbooks will often use examples of IEs with outrageous conclusions where more moderate ones are available.  So, for instance, given the inevitable shortcomings in weather forecasts, one ought not to listen to them at all.  That's dumb, as weather forecasts are predictions, and predictions can be wrong.  Again, the conclusion of a crazy person.  This conclusion, in that particular example, is driven by the idea that any imperfection, however minor, in the assertions of one party are sufficient to create doubt about that party's entire case. 

I think the argumentum ad imperfectionem is focused on the inference from the relatively minor shortcomings of one side to either (a) the truth of the opposite side (in which case it looks like a false dichotomy) or (b) to the conclusion that no one can really claim to know one's conclusion is true (in which case it looks like an appeal to ignorance) or finally (c) to the conclusion that the opposite side is relatively more justified. 

I can think of examples of all three of these.  But for today, here's an example of (a):

(a) in the minds of many, the various quibbles and revisions involved in the science of global warming justify skepticism of the entire thesis.  Here's an example of that from the Washington Post:

"What's happened here is that there's an industry of climate-change denialists who are trying to make it seem as though you can't trust anything that is between the covers" of the panel's report, said Jeffrey Kargel, a professor at the University of Arizona who studies glaciers. "It's really heartbreaking to see this happen, and to see that the IPCC left themselves open" to being attacked.

That's not an example of an actual argument, as it is a report of someone else's argument.  But people really do make that allegation, unfortunately.

Maybe if I'm motivated I'll find examples of the others later.

9 thoughts on “Refinements”

  1. You're trying to invent a fallacy? 
    The only circumstances in which this would be of benefit to anyone would be a) there is something – logically or dialectically- wrong with the arguments thus presented, b) such arguments occur in the context of a critical discussion, c) they haven't been pinpointed, coined or baptized by anyone before, d) the "fallaciousness" of these arguments does not make them fall under any other category, e) there is something "illicit" or "deceiving" which makes this type of fallacy distinguishable from a 'simple' weak argument. 
    Now, one can understand such ambition, Mr. Hurley’s obscure definition of fallacy being given. Enigmatic as it is (“a fallacy is a defect in an argument that consists in something other than false statements”) it is unlikely that it will serve as a starting point. He says “the term non sequitur (“it does not follow”) is another name for fallacy”. Another name given by who? How is many questions or petitio principii, Aristotle’s surviving fallacies, a non sequitur? How is ad baculum a non sequitur, for that matter?

    Anyway, I see no practical way in which your new fallacy ad imperfectionem could meet at least some of the conditions from a) to e). Plus, the starting is so … old school: “ad imperfectionem fallacy occurs when one asserts that the minor errors in someone's argument may be … ”. How are you supposed to tell the errors appart? Maybe it is a small (“minor”) error with great consequences: like a zero on a document, or the letter “s” at the end of a noun. But, even if you could, it would be a weak argument, not a fallacy. Weak arguments are not the same thing as fallacies, at leas for some others than Mr. Hurley. 


  2. Hello Argumentics,

    Though I think I could probably satisfy your conditions a-d (which you don't even bother to consider by the way), I think it's obvious you and I have different notions of "fallacy."  Perhaps at this point you might offer reasons why your basic conditions are more clear, enlightening, helpful, or correct.  I'm all ears.   

  3. I had a long, witty response to Argumentics, but your site blocks my responses.
    Anyway, I was also confused as to what Argumentics considers a fallacy. The distinction between run of the mill "weak arguments" and clear cut fallacious ones seems specious. A fallacy, I have always taken it, is when the conclusion does not follow from the premises. And there are a variety of ways in which this might occur, hence the taxonomy of fallacies.
    But I might just think that because you were my logic teacher.

  4. I assume you already know your invitation is not doable in a blog comment. You're asking me to delineate old school informal logic (that is, "informalized logic") from more recent pragmatic and dialectical approaches. I cannot do that here.  
    All the same, I know we have different conceptions of the word "fallacy", but I do not consider them incompatible. What you're doing (and I mean this in a slight general manner, about this blog) is you take arguments and try to evaluate them by means of (formal or informal, chiefly informal) logic. Hence, a logical analysis. 
    The point you are missing is that an argument utterly involves two people (or parties, or instances). You cannot dismiss arguments here and there without taking notice of their dialectical context. Let me summarize, and you tell me if I am wrong:
    You think a fallacy is: in one way or another, (intentionally) disguised (more or less) faulty argumentation. 
    Well I think fallacy is a specific type of move in a (covert or overt) dialogue. And dialogues have rules (not from Heaven) but from the very fact that participants engaged, bearing in mind some sort of goal(s). In order to achieve those goals, both of them must follow the rules. When they don't, fallacies occur.And when they do, they do not occur in the realm of logic, but in the realm of dialectic (of presumptive reasoning).  
    But since you won't even bother to consider some of the circumstances mentioned above, you will probably won't even bother to consider some of the things mentioned here. Please do but make me aware of the reasons behind your disregard.


  5. Hey Argumentics,

    You have made certain solomonic pronouncements about the nature of this and the nature of that.  That's nice, but you'll need an argument that your approach is more enlightening in the present case. 

    I think the claim that I "won't even bother" is silly–in our dialogue–because you have no reason to assert that.  I think I said that I can satisfy your conditions, and I also said that it hadn't occurred to you that I might be able to.  That I "won't even bother" clearly implies purposeful disregard, when I haven't–to my knoweldge–disregarded anything–it's a blog post, after all, so please note the context.

    Yes, I also get it that arguments have contexts and interlocutors and rules.  I don't think anything I do here contradicts that fairly obvious notion.    

  6. Isn't the ad imperfectionem fallacy explicitly about the unreasonable response to someone else's position?

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