I recently had a conversation with someone in which they used an example to illustrate a point:

"For example, if you tell me something [which isn't scientifically proven to be effective] works and I try it five times and don't notice a difference, but you've been doing it for 15 years... [maybe it not working after 5 times doesn't mean it doesn't work]."

I agreed that the experience in doing that thing could contribute to it working or not, and that just because it hasn't worked after 5 times of practice doesn't mean it's ineffective.

However, I then said:

"and at the same time if that thing has not been scientifically shown to work I have to make a judgement call on whether it is worth continuing to invest time and effort in that thing knowing that it could take some uncertain amount of time, like up to 15 years, to maybe see the benefit"

My conversation partner said that I was misinterpreting his example, and that assuming it would take up to 15 years is inaccurate and that I was somehow skewing the point - eg what if the person had a community of thousands of people for whom it worked in two weeks? He said I made assumptions about the time frame when I should have asked for more information.

To me it seemed like this was changing the example under my feet after he'd used the original example to prove his own point. Then when I tried to use the same example, he claimed I shouldn't assume that this is all the information we have, and that I should have asked/clarified before using the example. I did not think we were even disagreeing with each other about the original points, but at that point it turned into a debate about my usage of his example.

With the information I had in the example I could only say that it might take anywhere between 5 times and 15 years - maybe it would be a few days, maybe it would be a few months, maybe it would be years, etc...so aside from changing the example it seems like that doesn't negate my point anyway, which was that with something unproven one would have to make a judgement call with whatever information they had to see if it's worth the time investment for something that may or may not work. It feels like we went off on some peripheral tangent arguing about an example when the original point still stands anyway. However, being told that I misinterpreted the example when I only used the same example he did to make his point bothered me, and that's what this question is mostly about.

My questions:

  • Is my conversation partner right that I made assumptions that I shouldn't have in using his example as it was presented without asking for more information?
  • Am I right in that providing an example and then claiming that the other person should have asked for more information when they use the same example, is not really a fair expectation?
  • Is one of these viewpoints (or both?!) some kind of logical fallacy that I could read more about?

Things I've tried:

Based on the above I thought maybe I was making a Strawman fallacy, but I don't think I was skewing or changing his original example - I used the information given, but the claim is that I should've asked him for more information before making any point with the original example.

For a second I thought maybe he made the No True Scotsman fallacy, above it states "the speaker amends the terms of the claim" (in this case the example), but the example given on the page above makes me doubt its relevance.

The fact that the debate about my usage of the example doesn't really seem to negate the thing I was trying to say also makes me believe that he may have made a 'Red Herring' fallacy: "We were talking about trying something that hasn't been scientifically proven to work, but you bring up the idea that I used your example wrongly even though it does nothing to negate my point". However, I now actually care about whether I did use the example wrongly, so that is where I am looking for a fallacy or point of failure in either of our arguments.

Thanks for your input!

3 Answers 3


Just so it's said, Most of the things people refer to as (informal) fallacies — No True Scotsman and Strawman fallacies included — are not actually fallacies, but are simply mistakes in language. A fallacies is an error in the structure of the logic involved; a language mistake is derived from semantic content. Apples and oranges...

But that caveat aside, there are two mistakes in language here that are worth considering. First, you should note that the 'time' element in this discussion was not meant to be an interval level measurement, but instead it was a categorical distinction between casual experimentation and committed practice. Reducing it to a simple time measure — as though there were some definitive point (measured in nanoseconds) between five trials and fifteen years at which the [whatever] starts working — misconstrues his point. He was trying to offer something between a personal testimonial and an exhortation: that if one does this sufficiently long (as he has) then results will be achieved (as he has seen). For example, we can think about meditation (which the medical community acknowledges has clinical benefits). Meditating five times won't do anything for anyone. Some people might see results after two weeks, others after two months, others after two years, depending on their commitment to practice and their natural aptitude. Trying to reduce that to a linear time-model makes no sense whatsoever.

Second, there's the peculiar phrase "that thing has not been scientifically shown to work [...]". It's a mistake in language to treat 'science' as an 'object' in this broadly under-specified way. The most that we are going to get from 'science', generally speaking, is

  • The success or failure of the 'thing' to achieve some specific outcome, which may or may not be transferrable to other outcomes
  • The potential of the 'thing' to produce unwanted or dangerous secondary results

Science can tell us whether something is safe or if it produces specific measurable outcomes, but it cannot tell us whether something 'works' or 'has an effect' in the broader sense. We can't really say that something "has not been scientifically shown to work" without specifying exactly what work it has been shown not to do. Otherwise we end up making category errors. I mean, I think it's safe to say it is scientifically provable that Bill Gates cannot bench-press 300 lbs, but that would not be scientific proof that Bill Gates cannot do anything, right?

So yes, you did use his example incorrectly. Or perhaps better put (per Wittgenstein), you used his example within a completely different language game than he used it, and that caused confusion and hurt feelings. It's as though you said to me "Hey, I'm going to run to the store" and I responded with "But won't that make you sweaty?". You used 'run' figuratively where I used 'run' literally, and in such a simple case it comes across as a joke. But between you and this other guy the mismatch in language context is subtle and confusing, and you have to take the effort to piece out the problem clearly, or you'll never get it solved.

  • Thank you; I suppose I didn't communicate that my using 'up to 15 years' was not so relevant to my point, and I used '15 years' simply as it was in the existing example. In my mind if all we know is that 5 times wasn't enough and the expert has been doing it for 15 years of committed practice as per example,all we have going into the practice is that it could take some amount of time between 5 times and 15 (or n) years to work, if at all. And maybe that uncertain possibility isn't worth even starting all that investment. In my mind that evaluation would be needed for any potential timespan Commented Aug 9, 2019 at 19:51

Rather than looking for fallacies to determine who was more rational in an argument, one might attempt to analyze the speech acts of the dialogue in terms of what Douglas Walton describes as "formal dialogue systems for argumentation" (page 2). This may help pinpoint more accurately where the argument succeeded or not for the participants.

Walton notes that such systems go back to Aristotle: (page 2)

Throughout the Topics and On Sophistical Refutations, Aristotle outlined a dialectical game in which there are two participants called the Questioner and the Answerer where the Questioner tries to trap the Answerer into a contradiction by putting a series of yes-no questions to him that he must answer, one way or the other.

Although this is more formal than the dialogue presented by the OP since it has locution rules, structural rules, and commitment rules. It also has rules for winning or losing which may be able to substitute for the search for a fallacy to determine who was more rational in the argument.

To try constructing a dialogue table let Q be the OP and the opponent A. They are arguing whether a practice is effective.

  1. A accepts the thesis that "the practice is effective" and this becomes a commitment for A.
  2. A commits to the claim that someone A knows has been using the practice for 15 years.
  3. A commits to the claim that Q tried the practice five times without success.
  4. A commits to the claim that no scientific study has yet been done on the practice.

Rather than trying to get A to make more commitments, Q attempts to draw a conflict from 2 and 4.

  1. Q: "if that thing has not been scientifically shown to work I have to make a judgement call on whether it is worth continuing to invest time and effort in that thing knowing that it could take some uncertain amount of time, like up to 15 years, to maybe see the benefit"

At this stage the argument breaks down. A does not commit to 5.

For Q to win, Q has to lead A into a "conflict" forcing A to commit to a contradiction. Since 5 does not appear to be a deductively valid conclusion from 2 and 4, A does not have to commit to it. The only way A can lose is by being driven to a conflict; Q loses by running out of time or exceeding a question-limit for the game.

If this were a cross-examination in a trial, and not a game, something similar would happen, but there would also be a judge (and perhaps even a jury) who must be persuaded. According to Walton, Q would have two goals when questioning A: (page 8)

One is to obtain information and the other is to test the reliability of the information.

Q has a limited time in either the game or the trial to question A. The questions need to be relevant.

In summary Q did not ask enough of the right questions to draw the conclusion made in 5 above. If one were looking for a fallacy to describe why Q did not win, because the game ended without A being driven to a conflict, it might be "jumping to conclusions".

Walton, D. Conflict Diagrams for Cross-examination Dialogues. 2018. Retrieved on August 5, 2019 from Douglas Walton's site at /https://www.dougwalton.ca/papers%20in%20pdf/18Cross1.pdf


I'm not sure there are (named) fallacies in either of your arguments, but you're both making a similar mistake: trying to extrapolate personal success or failure with some treatment or practice into an overall conclusion about its actual (objective) effectiveness.

It does sound like you're already familiar with this idea: that double-blinded, rigorous, scientific studies are the best way to truly determine whether the (perceived) benefit someone might report is truly due to the treatment, or if it is due to other factors (like the placebo effect).

Your friend is correct that your (short-term) failure doesn't necessarily mean that whatever we're talking about is proved false, but you are correct that your friend's long-term satisfaction isn't proof of its effectiveness either.

It is hard to say more without delving into the actual details of whatever treatment or practice we are talking about.

For example: many people insist that they feel better after acupuncture treatment; but rigorous scientific studies have shown that they feel better at the same rate as people who simply lay in a darkened room with relaxing music and nice-smelling oils (placebo group).

What should we conclude, then? That those people are lying when they say that acupuncture helps them? No; we should conclude that the part of acupuncture that makes people feel better is not the needles (and in fact, the needles can be dangerous).

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