I was arguing with a friend (we were at loggerheads with respect to our views) and in the middle of the argument he refuted my claims by saying that even he used to have the same views (as I do now) a couple of years ago implying that the views he holds now are more advanced or that his current position is more informed.

The implication is obviously untrue, because not all people get wiser with time and the views/beliefs that follow existing ones may not necessarily be "better". (Eg. Otherwise normal people becoming bigots with time).

So, I was wondering if there is a name to the fallacy that a person (A) commits by implying that someone's (B's) argument is invalid because A used to hold the same views in the past and now A's views are changed. Thanks.

  • The answer to this question rightfully depends on a missing information, whether my friend justified his current position. He actually did not supply me the reasons that made him change his mind all those years ago. Instead he was just presenting his opinions as facts and trying to argue on the basis of that. Jun 27, 2016 at 5:07

3 Answers 3


This is essentially a variation on appeal to authority. The person claims to have expertise that exceeds yours, because he supposedly understands both your position, and a superior one.

The key here is that this itself is not an argument. If he really once held your exact position, and changed his mind for good, cogent reasons, then he should provide those reasons instead of merely implying they exist. In other words, if he was convinced by an argument that successfully defeats yours, then why isn't he just using that argument instead?

Like all informal fallacies, this gains strength from its plausibility. It is common for a person's views to evolve from a less correct position to a more correct one. But there's a difference between claiming something and demonstrating it.

  • From the rhetorical viewpoint, there may be a dollop of ad hominem in here as well. "I used to believe that" carries the implication, "but now I'm not so foolish/uninformed/flawed in some other way."
    – EvilSnack
    Nov 25, 2023 at 15:07

Not every discussion about important topics is a structured logical argument in which you can point out fallacies. Instead (imho) it is better to analyze these types of situations in terms of the rhetorical/persuasive technique(s) being applied.

From Aristotle's Rhetoric

Of the modes of persuasion furnished by the spoken word there are three kinds. The first kind depends on the personal character of the speaker; the second on putting the audience into a certain frame of mind; the third on the proof, or apparent proof, provided by the words of the speech itself.

If Alice says "I used to think X, like you do, but now I think Y" to Bob, this by itself addresses the first two modes of persuasion. By acknowledging that Bob's position at least seems reasonable sometimes, Alice is generating goodwill between herself and her audience. Said in a slightly different way, since everybody thinks they're reasonable, Alice is saying "look I'm reasonable too -- I shared this belief with you (a belief that you current think is still reasonable)." Carried along with this is an implicit idea that Alice is knowledgeable about the reasons why you might come to believe X; another boost to Alice's character and a facet of similarity on which to base goodwill. Finally, by calling out the idea that people can, and do, change their minds about X you've introduced this idea into the audience's frame of mind.

The third mode, apparent proof, isn't directly manifest in your short description, but if Alice were to walk Bob through where she used to stand, and why/how she's changed her mind can provide a compelling case (in the very least it was compelling to Alice herself). Thus arguing from "I used to stand where you do" and explaining how and why you've changed is an effective rhetorical technique that addresses all of the modes of persuasion.

Often, this is a form of, or relies on, the ganfalloon technique of persuasion.

If all that your friend said "I used to think like you do" and left it at that, then you can see why it falls down -- it doesn't address the third mode of persuasion at all.


First off, it's not super important to name fallacies (please see Sample/ Guide: What is the name of fallacy: A implies B. Therefore C?). Especially in the case of informal fallacies like this one, people may not always be convinced.

This sounds like a variation on the appeal to progress or appeal to novelty. The basic form is:

  1. X is new.
  2. Ergo is correct.

Here, the variation is :

  1. I used to believe not X.
  2. I then started to believe X (i.e., it was the new thing for me).
  3. Ergo, X is correct.

In all likelihood, there's more going on that just this obvious fallacy, and that will point out the rub in playing "name the fallacy." If it is just as above, it's an appeal to novelty. If there's more to it, then the question is whether the explanation for the change is (a) compelling as to why that person changed their view and then (b) the sort of explanation that would apply not just to the individual in question.

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