Assume Bad Faith

I agree that self-deception is common. But there are at least three reasons why assuming good faith is still a useful strategy:

1. You shouldn't just think of the assumption of good faith as a reaction to other people's lack of self-deception; you should also think of it as a way of mitigating your own self-deception. If you assume bad faith, then it's very easy to talk yourself into doing all sorts of uncharitable or uncooperative rhetorical moves, like lying to them, or yelling at them, or telling them that they only have their position because they're a bad person. You can tell yourself that you need to work around the self-deceptive parts of them, by pushing the right buttons to make the interaction productive. Yet a lot of these rhetorical moves will in fact be driven by your own hidden motivations, like your desire to avoid backing down, or your desire to punish the outgroup. So assuming good faith gives those motivations less cover.
2. Discussions are an iterated game, and it's easy for one person to accidentally do something which is interpreted by the other as a sign of bad faith, which causes the second person to respond in kind, and so on. Assuming good faith is like adding (limited) amounts of forgiveness to this tit for tat interaction.
3. While everyone has hidden motives, it's hard to know which hidden motives are at play in any given discussion. So when Zack says "This is difficult to pull off, which is why most people most of the time should stick to the object level", this can be seen as another way of saying "actually, as a strong heuristic, assume good faith".

Having said all this: some people should assume more good faith than they currently do; others less; and it's hard to know where the line is.

I fully agree with the initial premise that bias is common.  I don't see how this supports your conclusions; especially:

(1) You say that the difference between bias and deception is uninteresting, because the main case where you might care is that bias is more likely to fold against strong counter-argument.  But isn't this case exactly what people are using it for?

If I'm having a disagreement with you, and I think I could make a strong argument (at some cost in time/effort), then the question of whether you will fold to a strong argument seems like the central question in the decision to either make that argument or simply walk away.

But I thought the central point of this post was to argue that we should stop using "bad faith" as a reason for walking away?

(2) In your final example (where I point out that you've contradicted yourself and you say "look, a distraction!"), I don't see how either of your proposed responses would prevent you from continuing with "look, another distraction!"

You suggest we could stick to the object level and then the process emitting the outputs would be irrelevant.  But whether we're caught in an infinite loop seems pretty important to me, and that depends crucially on whether the distraction was strategic (in which case you'll repeat it as often as you find it helpful) or inadvertent (in which case I can probably get you back on topic).

If you are committed to giving serious consideration to everything your interlocutor says, then a bad actor can tie you up indefinitely just by continuing to say new things.  If you don't want to be tied up indefinitely, your strategy needs to include some way of ending the conversation even when the other guy doesn't cooperate.

(3) In your example of a pseudo-disagreement (about expanding a factory into wetlands), you say it's inefficient that the conflict is disguised as a disagreement.  But your example seems perfectly tailored to show that the participants should use that disguise anyway, because the parties aren't engaged in a negotiation (where the goal is to reach a compromise) they are engaged in a contest before a judge (the regulatory commission) who has predetermined to decide the issue based on how it affects the avian life.  If either side admits that the other side is correct about the question of fact then the judge will decide against them.

Complaining that this is inefficient seems a bit like complaining that it is inefficient for the destruction of factories to reduce a country's capacity for war, and war would be more efficient if there were no incentives to destroy factories.  The participants in a war cannot just decide that factories shouldn't affect war capacity; that was decided by the laws of physics.

from the standpoint of modeling information transmission [LW · GW], the difference between bias and deception is uninteresting—usually not relevant to what probability updates should be made.

I think this sentence is assuming a one-way conversation?

Yes, if you give a talk, and I watch it later on YouTube, then I agree that I shouldn’t care too much whether you are sincerely motivated to speak the truth but you have been led astray by self-serving rationalizations, versus you explicitly don’t care about the truth and are just mouthing whatever words will make you look good.

But if we’re in a room together, having a back-and-forth conversation, then those are two very different situations. For example, deception-versus-bias is relevant to my prospects for changing your mind via object-level discussion.

Hmm, actually, even in the one-way-conversation case, deception-vs-bias has nonzero relevance. For example, if I know that you are biased but not deceptive, and you make a very unambiguous claim that I know you know, but that I can’t check for myself (e.g. if you say “I have eaten calamari before”), then I should put more credence on that claim, if I know you’re biased but not deceptive, compared to the other way around.

Here’s another perspective: I find the terms “good faith” / “bad faith” to be incredibly useful in everyday life, and I’m not sure how you would explain that fact. Do you think I’m insufficiently cynical or something?

I do sometimes run into good faith disagreements, they feel very different from typical disagreements.

Example 1: someone says something on the phone about "Simon building a computer science model of his father's situation". I think it's referring to Simon A and a friend thinks it's Simon B. We bet and call the person back and I was wrong and feel silly.

Example 2: Someone says that standard financial prudence calls for minimizing market beta. I think this is wrong and it calls for increasing it in most cases. Then I look it up and realize it's because you can lever up a low market beta to a high one.

It feels really different from a normal non-trivial disagreement. In both cases it felt at the time like I was very probably correct and it was confusing that the other person disagreed. There is usually some mix of bad faith and good faith in typical cases, and that makes the resolution a lot slower.

If I meet a friend at a café to talk, then there's nothing hidden about a key motivation being the social interaction with the friend. If the friend would say "You are talking in bad faith because I thought you just care about learning information from me but then you are actually here to enjoy the social interaction with me" that would feel very weird to me. 

Partial notes so far:

So, things I explicitly agree with:

• "You're acting in bad faith" is pretty non-specific and much less useful.
• The spectrum between "object level" and "full-contact psychoanalysis" is a useful frame for considering how to deal with problems of bias/deception/motivated-cognition/etc. (I don't know that it's the only frame, but seems like a nice default if you haven't thought of a better one).
• I think the "generally stick to object level, bring out the psychoanalysis when it seems particularly important" is a pretty good BATNA.

Thing I agree with although I'm not sure it has quite the same implication you argue:

• "Most people are doing some flavor/degree of bias/duplicitousness/motivation/deception most of the time." 
  
  It seems true, although it feels Fallacy of Gray [LW · GW]-ish? The question is how often this comes up to a degree that really gets in the way.  It seems right that one should at least consider "hmm, this is a spectrum that is almost never on the "zero" degree, so maybe I should hypothesize that its 'significant' more often." But it feels like this post is implying a higher degree of "assume things are at a 'significant' end of the spectrum."

I'm not sure how much of a direct response this post is to Assuming Positive Intent, but I want to revisit So8res' stated definition there:

First, a few words on what I mean by “good faith”.  Imagine you’re having a conversation with someone. 

Sometimes, your conversation partner is acting with virtuous conversational motives: maybe they’re curious, maybe they’re trying really hard to understand your arguments, maybe they think you’re wrong about something important and they’re struggling to get you to understand what they’re saying. 

Other times, your conversation partner may be acting with malicious conversational motives: they might be explicitly focused on embarrassing you in front of people whose favor they are trying to win, or they might be trying explicitly to cause other listeners to associate you with something distasteful (a la the worst argument in the world), or they might be explicitly attempting to manipulate your actions. We can characterize your conversation partner along this axis, which ranges roughly from “well-intentioned” to “ill-intentioned”.

This feels somewhat different from what you're talking about here. Whether you intended this post as part-of-that-conversation or not, I think tendency to conflate the thing-you're-talking-about-AFAICT and This Thing feels important to notice.

Most disagreements of note—most disagreements people care about—don't behave like the concert date or physics problem examples: people are very attached to "their own" answers. Sometimes, with extended argument, it's possible to get someone to change their mind or admit that the other party might be right, but with nowhere near the ease of agreeing on (probabilities of) the date of an event or the result of a calculation—from which we can infer that, in most disagreements people care about, there is "something else" going on besides both parties just wanting to get the right answer.

There is a big difference between the apple colours and concert dates and most typical disagreements: namely that for apples and concerts, there is ridiculously strong, unambiguous evidence that one side is correct. 

Looking at QM interpretations, for example, if a pilot wave theory advocate sits down with a Many-worlds person, I wouldn't expect them to reach an agreement in an afternoon, because the problem is too bloody complicated, and there is too much evidence to sift through. In addition, each person will have different reactions to each piece of evidence, as they start off with different beliefs and intuitions about the world. I don't think it's "bad faith" that people are not identical bayesian clones of each other. 

Of course, I do agree that oftentimes the reasons for interpreting evidence differently are influenced by bias, values, and self-interest. It's fair to assume that, say, a flat-earther will not be won over by rational debate. But most disagreements are in the murky middle, where the more correct sides is unlikely to win outright, but can shift the other person a little bit over to the correct side. 

I think this is the clearest articulation of this problem I've seen. I think it helps me understand what was going on with Bad intent is a disposition, not a feeling [LW · GW] and Assuming Positive Intent. (I think "Assuming Positive Intent" wasn't quite talking about the same thing this post is talking about, but was heavily overlapping. I feel better able to think about the differences now)

I think I basically agree with everything written here as-stated, but will think for a bit and try to check/flesh-out my updated model.

I generally like the move of "talk about cost-benefit analyses" rather than arguing 'shoulds'.

I think that this post relies too heavily on a false binary. Specifically, the description of all arguments as "good faith" or "bad faith" completely ignores the (to my intuition, far likelier) possibility that most arguments begin primarily (my guess is 90% or so, but maybe I just tend not to hold arguments with people below 70%) good faith, then people adjust according to their perception of their interlocutor(s), audience (if applicable), and the importance of the issue being argued. Common signals of arguments in particularly bad faith advanced by otherwise intelligent people include persistent reliance on most listed logical fallacies (dismissing that criticism and keeping a given point after its fallacious nature is clearly explained; sealioning and whataboutism are prototypical exemplars), moving the goalposts, and ignoring all contradictory evidence.

Another false binary: this also ignores the possibility of both sides in an argument being correct (or founded on correct factual data). For example, today I spent perhaps 10 minutes arguing over whether a cheese was labeled as Gouda or not, because I'd read the manufacturer's label which did not contain that word but did say "Goat cheese of Holland" and my interlocutor read the price label from Costco which called it "goat Gouda." I'm marginally more correct because I recognized the contradiction in terms (in the EU gouda can only be made from milk produced by Dutch cows), but neither of us was lying or arguing in bad faith, and yet I briefly struggled to believe that we were inhabiting the same reality and remembering it correctly. They were a very entertaining 10 minutes, but I wouldn't want to have that kind of groundless argument more than once or twice a week, and that limit assumes a discussion of trivial topics as opposed to an ostensibly sincere debate on something which I hold dear.

“You can’t tell what someone is doing by watching what they’re doing.”

Bad faith and merely occluded thought processes are distinguished not by passive observation of what comes out of one’s interlocutor’s mouth, but by what happens when you push in various ways.

I think that I largely agree with this post. I think that it's also a fairly non-trivial problem. 

The strategy that makes the most sense to me now is that one should argue with people as if they meant what they said, even if you don't currently believe that they do. 

But not always - especially if you want to engage with them on the point of whether they are indeed acting in bad faith, and there comes a time when that becomes necessary. 

I think pushing back against the norm that it's wrong to ever assume bad faith is a good idea. I don't think that people who do argue in bad faith do so completely independently - for two reasons - the first is simply that I've noticed it clusters into a few contexts, the second is that acting deceptively is inherently more risky than being honest, and so, it makes more sense to tread more well-trodden paths. More people aiding the same deception gives it the necessary weight.

It seems to cluster among things like morality (judgements about people's behaviors), dating preferences (which are kind of similar), and reputation. There is kind of a paradox I've noticed in the way that people who tend to be kind of preachy about what constitutes good or bad behavior will also be the ones who argue that everyone is always acting in good faith (and thus chastise or scold people who want to assume bad faith sometimes). 

People do behave altruistically, and they also have reasons to behave non-altruistically too, at times (whether or not it is actually a good idea for them personally). The whole range of possible intentions is native to the human psyche. 

I'm not fully clear on the concrete difference between "assume good faith" and "stick to the object level", as instrumental strategies. I'll use one of Zach's examples, written as a dialog. Alice is sticking to the object level. I'm imagining that she is a Vulcan and her opinions of Zach's intentions are inscrutable except for the occasional raised eyebrow.

• Alice: "Your latest reply seems to contradict something you said earlier."
• Zach: "Look over there, a distraction!"
• Alice: "I don't understand how the distraction is relevant to resolving the inconsistency in your statements that I raised."

Here is my attempt at the same conversation with Bob, who aggressively assumes good faith.

• Bob: "Is there a contradiction between your latest reply and this thing you said earlier?"
• Zach: "Look over there, a distraction!"
• Bob: "I'd love to talk about that later, but right now I'm still confused about what you were saying earlier, can you help me?"

Is that the type of thing? Bob is talking as if Zach has a heart of gold and the purest of intentions, whereas Alice is talking as if Zach is a non-sentient text generator. In both cases admitting that you're doing that isn't part of the game. Both of them are modeling Zach's intentions, at least subconsciously. Both are strategically choosing not to leak their model of Zach to Zach at this stage of the conversation. Both are capable of switching to a different strategy as needed. What are the reasons to prefer Alice's approach to Bob's?

To be clear, I completely agree that assuming good faith is a disaster as an epistemic strategy. As well as the reasons mentioned above, brains are evolutionarily adapted to detect hidden motives and generate emotions accordingly. Trying to fight that is unwise.

A clarification:

Consider the premises (with scare quotes indicating technical jargon):

1. "Acting in Bad Faith" is Baysean evidence that a person is "Evil"
2. "Evil" people should be shunned

The original poster here is questioning statement 1, presenting evidence that "good" people act in bad faith too often for it to be evidence of "evil."

However, I belive the original poster is using a more broad definition of "Acting in Bad Faith" than the people who support premise 1.

That definition, concisely, would be "engaging in behavior that is recognized in context as moving towards a particular goal, without having that goal." Contrast this with the OP quote: bad faith is when someone's apparent reasons for doing something aren't the same as the real reasons. The persons apparent reasons don't matter, what matters is the socially determined values associated with specific behaviors, as in the Wikipedia examples. While some behavior (eg, a conversation) can have multiple goals, some special things (waving a white flag, arguing in court, and now in the 21st century that includes arguing outside of court) have specific expected goals (respectively: allowing a person to withdraw from a fight without dying, to present factual evidence that favors one side of a conflict, and to persuade others of your viewpoint). When an actor fails to hold those generally understood goals, that disrupts the social contract and "we" call it "Acting in Bad Faith"

The LessWrong Review [? · GW] runs every year to select the posts that have most stood the test of time. This post is not yet eligible for review, but will be at the end of 2024. The top fifty or so posts are featured prominently on the site throughout the year.

Hopefully, the review is better than karma at judging enduring value. If we have accurate prediction markets on the review results, maybe we can have better incentives on LessWrong today. Will this post make the top fifty?

There is something slippery about the ways you write your posts, I've read several of them and that's the impression I'm constantly being left with. You make a couple of generally true statements then apparently jump to a conclusion which doesn't actually follow from them but feels somewhat relevant. 

Here, as a demonstration, I try to hold the general fabula of your argument but replace bad faith with not having human values:

People get touchy about accusation of being inhumane. They think that you shouldn't dehumanize, but that if you've determined something doesn't have human values, you shouldn't even be talking to them, that you need to exile them.

However, being inhumane doesn't actually mean having malicious intent. It can also mean neutrality. Also human values are extremely rare. Most of the objects in the universe do not have them. And the term human values isn't even well defined.

And that's why we shouldn't try to optimize for human values.

I think it's clear that the last sentence doesn't actually follow from the previous two paragraphs. The fact that most of the reality doesn't have human values doesn't mean that we shouldn't create norms promoting them and clever plans that would actually make the reality more aligned with human values. There is a self-fulfiling component here. Our agency and coordination can make human values more widespread only if we actually try to do it.

Likewise, the fact that there are reasons why people generally do have hidden motives, and most conversations are not honest attempts to find truth between two unbiasly disagreeing parties doesn't mean that we shouldn't try to uphold good faith promoting norms: demand good faith and do our best to engage with as much good faith as we can muster, while talking to other people who do the same. After all, if no one does it then there won't be any good faith engagement at all. 

It's an obvious case of iterated prisoners dilemma. Cooperation means doing your best to engage with the point of discussion in an honestly truth seeking way. Defection - propagating your own view point by any means necessary. Clearly, cooperating with a defector isn't helpful. So It's useful to have norms to disincentivise defection, exiling them from the conversation.

In practise, there is a whole spectrum between being perfectly good faith and pushing your own agenda by every dirty trick in the book. Some people just do not know how to do better, some people are too much under control of their biases, some people can be just having fun by trolling. There can be different reasons why people are not engaging in the best possible faith, and maliciousness of intent is irrelevant. Whatever your reasons if you can't uphold the required level - there is nothing to talk about. Please do better and come again.

And of course it makes sense to have some compassion here and forgive occasional slips when it seems that the person is honestly trying to engage in good faith. Just as in general with iterated prisonners dilemma with small error probability.

I think this elucidates the "everyone has motives" issue nicely. Regarding the responses, I feel uneasy about the second one. Sticking to the object level makes sense to me. I'm confused how psychoanalysis is supposed to work without devolving. 

For example, let's say someone thinks my motivation for writing this comment is [negative-valence trait or behavior]. How exactly am I supposed to verify my intentions?

In the simple case, I know what my intentions are and they either trust me when I tell them or they don't. 

It's the cases when people can't explain themselves that are tricky. Not everyone has the introspective skill, or verbal fluency, to explain their reasoning. I'm not really sure what to do in those cases other than asking the person I'm psychoanalyzing if that's what's happening. 

I fully disagree that "bad faith" is a useless distinction, though you're right that it's not the only reason for disagreement or miscommunication.  

Your examples show that "bad faith" comprises BOTH malign intent AND deception in the intent of a communication or negotiation.  It's saying one thing ("I surrender" or "I'll negotiate these terms") while maliciously meaning another ("I'm going to keep fighting" or "I am just wasting your time").  It's more specific than EITHER "deception" or "antagonism", because it's a mix of the two.

Honest conflicts can be resolved (or at least explored and then fought), and non-malign confusion or miscommunication can be identified and recovered from or isolated to cooperation-without-agreement or an actual conflict.  But "bad faith" combines these in a way that makes identification difficult, presumably because at least one party isn't interested in identifying and resolving the crux.

Good post, I largely agree with your point. This part in particular is relevant:

If I'm doing full-contact psychoanalysis, the problem with "I don't think you're here in good faith" is that it's insufficiently specific. Rather than accusing someone of generic "bad faith", the way to move the discussion forward is by positing that one's interlocutor has some specific motive that hasn't yet been made explicit---and the way to defend oneself against such an accusation is by making the case that one's real agenda isn't the one being proposed, rather than protesting one's "good faith" and implausibly claiming not to have an agenda.

I get accused of bad faith regularly (whether the accusation is earnest and made in "good faith" is another question) and I agree completely that a naked denial doesn't accomplish anything. Like you, I usually can see what the accusation is based on and so what I do is acknowledge that the suspicion is reasonable (it often is!) and then explain why it's wrong. If I can't see what it's based on, then I ask something along "what could convince you otherwise?" Sometimes there's nothing that could dislodge the truck stuck in the mud, and it's good to know that.

I find that this is a useful approach in everyday personal disagreements too because a lot of them are spawned out of suspicions. If someone shirks on a household chore, maybe it's because they genuinely forgot OR MAYBE it's because they are driven by animus and hatred towards their roommates. If the shirking continues as part of a regular pattern, it's perfectly reasonable for the roommates to become drawn to the latter hypothesis.

To your broader point, accusing someone of bad faith doesn't really accomplish much, and your proposed solutions (just stick to the object level or, in the alternative and if the circumstances warrant it, full-contact psychoanalysis) seem perfectly appropriate.

I liked the length, readability, and importance; happy to spend my reading budget on this.

Here are some thoughts I had:

• You said, "the belief that persistent good faith disagreements are common would seem to be in bad faith!" and this tripped my alarm for gratuitous meta-leveling. Is that point essential to your thesis? Unless I read too quickly, it seems like you gave a bunch of reasons why that belief is wrong, then pointed out that it would seem to be in bad faith, but then didn't really flesh out what the agenda/angle was. Was that intentional? Am I just stumbling over a joke I don't understand?
• I would be interested to read a whole post about how full-contact psychoanalysis can go well or poorly. I've seen it go well, but usually in ways that are noticeably bounded, so I think I'll challenge the word "full" here. You meant this as an idealization/limiting case, right?
• I feel like there is an implicit call to action here, which may not be right for everyone. I anticipate early adopters of Assuming Bad Faith to pay noticeable extra costs, and possibly also late adopters. I don't have anything in particular in mind, just Chesterton's Fence and hidden order type heuristics, plus some experience seeing intentional norm-setting go awry. 

Hm. Interesting topic.

It sounds like in this post, you're mostly taking a sort of God's Eye perspective on the problem. Like, if you could look down and set group norms with respect to bad faith, what norms would you set?

This is a different question from the question of what to do in everyday life. I think in everyday life, accusing people of acting in bad faith is almost always going to be a bad idea. For starters, I think most people believe "bad faith" means "with ill intent" (I did before reading this post). So you'd have to start by clarifying that you are talking about something different. But still, after doing so, I think the result is likely to be a) the conversation devolves and b) you stir up animosity with the other person. Something more How To Win Friends And Influence People style seems wiser.

On the other hand, in talking to people whom you're very close to, I could see it being fruitful sometimes. But even then, I suspect it'd be best to not bring it up in the midst of the current conversation, and instead bring it up eg. the next day as a separate conversation. Like, "Hey, remember that conversation we had yesterday? I was a little unhappy with something. Mind if we talk about it?"

As for the God's Eye perspective, one thing is that I think it depends on the group. For example, I don't think "psychoanalyze as you wish" would work very well in a group of middle school aged girls. For a group of experienced rationalists, I'd be more optimistic.

For groups like rationalists where it's more plausible to work, I'm having trouble thinking about guidelines for when it is and when it isn't ok to psychoanalyze. Maybe "use your judgement" would be fine?

I do really like the idea though of it being a norm eg. in rationalist circles to not get touchy about bad faith accusations. But in other circles I could see touchiness being a useful norm, although I'm not sure. Chesterton's Fence [? · GW] and Memetic Immune Systems [? · GW] seem like things to keep in mind there.

there is "something else" going on besides both parties just wanting to get the right answer

There are also different priors [LW · GW]. While in general you might very well be right (or at least this post makes a lot of sense to me), I often have conversations where I'm pretty sure both my interlocutor and I am discussing things in good faith, but where we still can't agree on pretty basic things (usually about religion).

What's missing in this discussion is why one is talking to the "bad faith" actor in the first place.

If you're trying to get some information and the "bad faith" actor is trying to deceive you, you walk away. That is, unless you're sure that you're much smarter or have some other information advantage that allows you to get new useful information regardless. The latter case is extremely rare.

If you're trying to convince the "bad faith" actor, you either walk away or transform the discussion into a negotiation (it arguably was a negotiation in the first place). The post is relevant for this case. In such situations, people often pretend to be having an object level discussion although all parties know it's a negotiation. This is interesting.

Even more interesting, Politics: you're trying to convince an amateur audience that you're right and someone else is wrong. The other party will almost always act "in bad faith" because otherwise the discussion would be taking place without an audience. You can walk away while accusing the other party of bad faith but the audience can't really tell if you were "just about to loose the argument" or if you were arguing "less in bad faith than the other party", perhaps because the other party is losing the argument. Crucially, given that both parties are compelled to argue in bad faith, the audience is to some extent justified in not being moved by any object level arguments since they mostly cannot check if they're valid. They keep to the opinions they have been holding and the opinions of people they trust.

In this case, it might be worth it to move from the above situation, where the object level being discussed isn't the real object-level issue, as in the bird example, to one where a negotiation is taking place that is transparent to the audience. However, this is only possible if there is a competent fourth party arbitrating, as the competing parties really cannot give up the advantage of "bad faith". That's quite rare.

An upside: If the audience is actually interested in the truth, however, and if it can overcome the tribal drive to flock to "their side", they can maybe force the arguing parties to focus on the real issue and make object-level arguments in such a way that the audience can become competent enough to judge the arguments.Doing this is a huge investment of time and resources. It may be helped by all parties acknowledging the "bad faith" aspect of the situation and enforcing social norms that address it. This is what "debate culture" is supposed to do but as far as I know never really has.

My takeaway: don't be too proud of your debate culture where everyone is "arguing in good faith", if it's just about learning about the word. This is great, of course, but doesn't really solve the important problems.

Instead, try to come up with a debate culture (debate systems?) that can actually transform a besides-the-point bad-faith apparent disagreement into a negotiation where the parties involved can afford to make their true positions explicitly known. This is very hard but we shouldn't give up. For example, some of the software used to modernize democracy in Taiwan seems like an interesting direction to explore.

Isn't this self-defeating?

Take for example the comments here, if all of them are assumed to have been made not in 'good faith', why would you ever substantially engage with them?

And vice versa, if they all start not assuming 'good faith' with future posts by 'Zack_M_Davis', doesn't that imply a negation of any built up credibility?

And if so, why would they care at all about what is written by this account?

Oh that’s fun, Wikipedia caused me to believe for so many years that “bad faith” means something different from what it means and I’m only learning that now.

the most persuasive lie is the one you believe yourself

If someone really believes it, then I don't think they're operating in "bad faith". If the hidden motive is hidden to the speaker, that hiding doesn't come with intent.

It doesn't matter whether you said it was red because you were consciously lying or because you're wearing rose-colored glasses

It definitely matters. It completely changes how you should be trying to convince that person or behave around them.

It's different to believe a dumb argument than to intentionally lie, and honestly, humans are pretty social and honest. We mostly operate in good faith.