Is there a name, preferably an “ad Latin” name, for this fallacy:
The anarchist Peter Kropotkin differed with many anarchists over World War I, arguing that German militarism posed such a grave threat that anarchists should not oppose the war. Jump to 2020. Imagine a more general discussion on anarchism, where Kropotkin is quoted favourably on an entirely different topic, say, the division of labour. “Ha!” shouts someone, “Kropotkin was in favour of World War I, therefore we should disregard everything he says about anarchism.”
In practice it’s usually more subtle, but the intent is the same: X said Y, which is then used to discredit other ideas that X may have held, or the entire body of ideas that X was associated with. Hasty generalization or fallacy of composition or ad hominem don’t seem to quite apply. Help?
I don’t see why argument ad hominem wouldn’t apply. A person’s other viewpoints on a subject should not discredit their viewpoint on a different subject, even when the subjects are somewhat associated. Richard Nixon may have made valid arguments about the balance of power between the different branches of US government, and the fact that he also said “It’s not illegal if the President does it” isn’t really grounds for not considering his statements about balance of power on their own merits.
To claim otherwise is to say “Argument X is wrong because the person who made it once took Position Y which is bad therefore the person making Argument X is bad therefore Argument X must be bad”.
The case posited relies too much on argument from authority, that is: Here is Kropotkin’s argument about X, with the underlying assumption that the argument’s merits are at least enhanced because of who they came from. I don’t like those kinds of arguments, and not only because they are vulnerable to the kind of tactic you are trying to name. If the argument is a good argument, what difference does it make who made it before? It shouldn’t even come up in the discussion, and if it didn’t come up, the counter-argument about the authority’s feet of clay in other areas would not come up either. Both sides of this kind of argument are a form of ad hominem – the validity of the argument is based on who made it.
It seems to me the problem is relying on a single case. Person X said Y once therefore you cannot consider anything else that person said on the subject.
Context matters. You need to take a lot in and not just one sentence. See what they said and how that comports with their actions/utterances over time.
Also, the person may have changed opinions over their lifetime. I do not think they can completely shed their past and can should be held accountable to it but they also can say they have changed. Whether you believe them or not is up to you.
But if Alice or Bob on the internet thinks Kropotkin just perfectly expressed the correct view about the division of labor, they may reasonably want to quote from and cite Kropotkin’s essay “On the Implications of the Division of Labor in a Capitalist Society” (which I totally just made up). To not mention where these ideas are coming from might very well be intellectually dishonest; and perhaps Kropotkin had a sentence or paragraph which (in the opinion of Alice or Bob) just perfectly expresses the situation; and if you quote from someone else verbatim without mentioning who wrote it, you would definitely be intellectually dishonest.
But none of that means Alice or Bob should be obligated to defend every other position Kropotkin ever took on every subject imaginable.
I don’t think there’s anything wrong with referring to the thinkers who came before you. We all “stand on the shoulders of giants”*. But it is dishonest not to give proper credit where credit is due.
*Most often attributed to Isaac Newton, although various other people expressed the idea before he did, and Newton had various nutty ideas about alchemy which of course I am in no way endorsing.
If I argued in January that Covid is not going be a big deal, and will fizzle out without anyone dying in the US. That is a perfectly valid thing to bring up to counter another argument I’m making now, even in an unrelated area.
It doesn’t disprove my statement about say, who is going to win the Best Actor Oscar next year, but its not completely irrelevant either. Its perfectly logical to be a little less trusting of a source that has been spectacularly wrong in the past.
I think you are correct that both sides of this - ad hominem and appeal to authority - are informal fallacies rather than strict fallacies. That they hinge on relevance, which is somewhat subjective.
If someone has a conviction for domestic violence, deplorable as it is, it’s probably irrelevant to the validity of the paper he published in experimental physics. So raising the issue of his past crime would be an ad hominem. If he has a conviction for cheating on his taxes, that’s an intermediate case - we might argue that perhaps it raises the relevant issue of honesty, and whether we should trust his results without independent verification. If he has had a past paper retracted for falsifying experimental results, then obviously it’s entirely relevant, and it would certainly not be an ad hominem to be suspicious.
Similarly, appeal to authority can be valid, most especially in highly technical areas. It’s obviously quite reasonable to defer to experts who have relevant skills if we aren’t ourselves technically qualified to interpret the scientific evidence directly. Deferring to CDC advice on COVID-19 for example. But (a recent thread comes to mind) there’s no reason to think that we should expect Einstein’s views on moral issues to be vastly superior to any reasonably intelligent person just because of his vastly superior genius in physics.
I don’t think this is at issue. Nobody is suggesting that we should not give credit for good ideas. The question is when/whether an appeal to authority is justified in our assessment of whether the ideas are good.
If you didn’t think up the argument yourself, I think you do have some duty to say “as the Russian anarchist Peter Kropotkin argued…” or “I find Kropotkin’s arguments on the subject in The Conquest of Bread most convincing; to try and summarize them…” Which in turn leads to the possibility that someone will retort “But Kropotkin thought the First World War was justified, so what does he know about anything?!?” I agree that’s fallacious (or at least probably so–an authority’s ideas on one subject might conceivably be relevant to impeaching that authority’s ideas on a different but arguably related subject), but I don’t think just not mentioning where you got your ideas from is the proper counter to that fallacy.
My point was that whatever you say about who first came up with an argument, it’s entirely irrelevant to the validity of the argument. By all means give credit, but briefly, and then move on to supporting or defending the argument itself (and not just summarizing it, but telling why you find it convincing). It’s up to you, as the presenter of the argument, to make it clear that your argument does not depend on who first came up with it.
If, after that, someone comes back to discredit your source, then it’s clear that the attack is ad hominem and that it does not bear on your arguments.
Also it seems to me that maybe the main logical fallacy here is in the OP.
Sure with hindsight, given all we know about the terrible things that followed, its is reasonable* to call being pro-war at the outbreak of WW1 a terrible mistake. But at the time, as anarchist (or anyone on the left side of the political spectrum) was siding with the western powers (for all their faults) against the militarist German regime such a terrible call? If someone had made a similar call in 1939 they would have been lauded as foresighted, with the advantage of hindsight we can say the Hitlers regime was far worse than the Kaisers, but at the time the decision was not so cut and dried.
Not sure if that has a name, maybe hindsight fallacy?
Keep in mind this is almost the exact argument many on the right are using to discredit a lot of medical experts (ie Fauci). They predicted X back in March and it was wrong, therefore they shouldn’t be listened to about anything, ever.
How many times are you hearing people suggest that Fauci is lying because in March he said we shouldn’t wear masks and therefore nothing he can say could ever possibly be true or even spoken in good faith?
not super relevant to OP but from a purely Anarchist pointer of it should also be pointed out that the nearest they ever got to power, before or since AFAIK was in the aftermath of the Russian revolution, prior to being ruthlessly wiped out by the Bolsheviks once they were secure in power. And that was the direct result of WW1, so was it a bad call for an Anarchist to make, even in hindsight?
In the example you give here, the attack and attempt to discredit the speaker’s previous idea (X) is based upon a new idea or statement the speaker made (Y) rather than the speaker’s previous ideas in and of themselves.
The most relevant example I can think of would be Linus Pauling touting Vitamin C as a cure-all does not immediately invalidate his previous accomplishments.
Although, as others have noted (@Riemann) what’s not clear, but does matter, is how closely related X & Y are. The closer X & Y are in subject, the more the new bad idea Y may cast a shadow over the previous good ideas X.
I think the argument from authority would be the opposite direction of the example you give: “Because they had great X ideas in the past and are an authority on X, Y must therefore also be a great idea”,
But its really not Ad Hominen, or any logical fallacy. Ad Hominen would be to say that A is wrong about X because A was mean to kittens in the past, that speaks to A’s character but says nothing about the correctness of his opinion on X.
Its not illogical to say that because A was wrong about X in the past there is a greater chance he is wrong about Y now. Even if X and Y are unrelated its still a valid data point, and (in the absence of any other evidence) a reasonable reason to doubt Y.