Epistemological status: Moderately confident that this is a more useful way to use a concept that has been expanded upon by others. 

Previous building blocks: See Logical Rudeness and All Another Brick in the Motte and  for the foundations, as well as Against Accusing People of Motte and Bailey for the direct predecessor.

If you haven’t read the previous building blocks, the core idea is called the Motte and Bailey. A Motte and Bailey argument is what you call it when someone makes a clearly supported and uncontested claim, then makes an outrageous but advantageous claim, then swaps between these two claims whenever it's useful to them. It draws from the medieval tactic of having an easily farmable bailey right next to a heavily fortified motte, then moving your peasants and troops back and forth between them whenever raiders come or leave.

I

Amy and Bob would like to have a civil discussion about a philosophical difference they have. Their conversation goes something like this:

Amy: I don't understand why you think tautologies are important. I mean, you can't get any extra information out of them, right?
Bob: There are actually a number of different kinds of tautologies. For example, a logical tautology might say "either X equals Y or X does not equal Y" and while you might be correct that no new information is gained from this, I find it helps me organize my thoughts.
A: Ah, I didn't know that. I've mostly seen them used as rhetorical devices.
B: They can be used that way, but it's far from the most interesting thing about them for me.
A: As long as people are going to keep using tautologies to win arguments though, how do we help those who don’t understand them well enough to defend against tautology based arguments?
B: Oh go soak your head.  I think if you learned more about them you’d be able to actually counter them when people did use them in arguments.
A: Even if I studied tautologies enough to do so, I worry that making a general rule of needing to study all potential rhetorical devices to be able to defend against them might be prohibitively difficult.
B: As much as I love tautologies, I do think tautology proponents should be more careful in their usage.
B: At least as long as we have to deal with idiots who try to ban anything they don’t understand.

This conversation disintegrated quickly. Bob seems to be moving between the position that tautologies are one way to organize information, and the position that if you don’t understand them there’s something wrong with you. This looks like a straightforward example of Motte and Bailey.

II

Imagine Bob is the vice-president of the Tautologies club at a well respected college, and he has just been invited into a very nice conference room by some campus authority.

Authority: We've had some complaints about the behavior of your club. Apparently proponents of tautologies are disruptive, disrespectful, and frankly prone to outrageous acts.
Bob: What? That catches me completely by surprise: one of our members, Carol, has a perfect behavioral record- no infractions at all in the entire four years of her time here at the university.
Authority: Yes but-
Bob: Also, our secretary Dean just got a commendation last semester for Showing Proper Decorum. Isn't he going to the Competitive Decorum Displays next fall? Surely you aren't saying that he's disrespectful!
Authority: No but-
Bob: In addition, I happen to know that our treasurer Evan is on the boards of several charities with you. Really, I think the Tautology Club is full of wonderful people!
Authority: Then what do you have to say about your club president screaming "B is B, motherf**kers!" in the middle of a class before running up to the front of the room to spray paint your club slogan onto the professor's chest?!
Bob: I recognize that Bella may have made a few poor choices, but I do hope you'll consider leniency. After all, Tautology club members are really good people.

An organization is not a person, but it contains people. Membership in an organization usually suggests things about a person, and there are correlations to be found between members of a group, but very few groups can be treated as a singular entity. This is a best case scenario where the Tautology club is a defined organization with memberships and presidents! If this was something larger and more diffuse like a political party or a fandom, Bob might not even know who Bella is.

III

Let's try that first conversation again.

Amy: I don't understand why you think tautologies are important. I mean, you can't get any extra information out of them, right?
Bob: There are actually a number of different kinds of tautologies. For example, a logical tautology might say "either X equals Y or X does not equal Y" and while you might be correct that no new information is gained from this, I find it helps me organize my thoughts.
Amy: Ah, I didn't know that. I've mostly seen them used as rhetorical devices.
Bob: They can be used that way, but it's far from the most interesting thing about them for me.
Amy: As long as people are going to keep using tautologies to win arguments though, how do we help those who don’t understand them well enough to defend against tautology based arguments?
Bella: Oh go soak your head.  I think if you learned more about them you’d be able to actually counter them when people did use them in arguments.
Amy: Even if I studied tautologies enough to do so, I worry that making a general rule of needing to study all potential rhetorical devices to be able to defend against them might be prohibitively difficult.
Bob: As much as I love tautologies, I do think tautology proponents should be more careful in their usage.
Bella: At least as long as we have to deal with idiots who try to ban anything they don’t understand.

Oh. Oops. This isn’t a conversation between a reasonable person and someone committing Motte and Bailey; this is a conversation between one reasonable person and two separate people. Bob and Bella are both being consistent, and while Bella is kind of rude Amy would still have a much more productive discussion if she can talk to either of these people one-on-one rather than trying to address both of them at once.

IV

Amy, Bob, and Bella’s conversation is somewhat contrived, but less than you might think. I have had conversations where two people had the same user icon in a system where you had to pick from a short list of icons and I had to keep double-checking which of them said something. I’ve been in fast moving IRC conversations where there weren’t user icons, just handles, and mistakenly skimmed over the handle. There were mass texts where everyone was a string of numbers instead of a name. Mixups happen.

Then there are conversations where you know, intellectually, that you’re talking to different people, but it doesn’t feel like it. Twitter and Facebook seem to create these conversations a lot but you can get the same impression when talking to a crowd. If every inch of concession you make to Bob is immediately leapt upon by a dozen Bellas who demand a mile, then Bob starts to look like a Trojan horse and you stop wanting to concede anything. 

I call this pattern the Mob and Bailey. It’s not a fallacy or doctrine, and it’s not committed by any individual: it can happen with people who are perfectly consistent and arguing in good faith. Even if Bella wasn’t abrasive the basic problem remains; she and Bob are on the same side for different reasons, and will be convinced by different things. Neither Bob nor Bella need to be trying to mess things up for this to create a problem, the argument will get mired quite naturally through the process of Amy trying to argue with both of them at the same time.

I still don’t have a solution to the Motte and Bailey problem, but the solution to the Mob and Bailey is straightforward once you realize what you’re dealing with. Pick one person, ask what specific thing they believe, and talk about that. Ignore everyone else. Once that one conversation concludes, pause, clear your head, and if you want to go again then sit down to pick another person.

V

You cannot argue with a group. You cannot convince a group of things or change a group’s mind.

I’m not saying that doing so is hard. I am saying that The Tautology Club is not a single thing. It does not have ears to hear or a mouth to speak. The idea of arguing with The Tautology Club is ill-formed in the way that performing knee surgery on The Tautology Club is ill-formed. You can argue with the people in the group. That’s not impossible, it’s only as difficult as arguing with someone usually is. Most of the time, distinctions like the one between arguing with The Tautology Club and arguing with the members of The Tautology Club is pedantry. In this case, I think it’s useful to make that distinction deliberately in your mind.

You cannot argue with The Tautology Club. 

You can argue with Bob and Bella, who are in The Tautology Club. I claim that the process of doing this will be more successful if you argue with one of them at a time instead of trying to argue with both at once. I also claim that the process of arguing with a chimeric combination of both of them which you treat as one entity will be less successful than either one at a time or both at once. If you ever find yourself going “Aha! You say tautologies are for organizing your thoughts, but your ally just said anyone who doesn’t understand tautology is an idiot” you are having a bad problem and you are unlikely to have a productive discussion today. This gets more and more true the larger and less coordinated the group is. 

If you argue with the Pope, you are not actually arguing with Catholicism. I predict if you are not a religious scholar of some kind that you will be surprised at the breadth of opinion and diversity in the Catholic Church. If you argue with the U.S. Secretary of Defense, you are not actually arguing with the U.S. Military. I predict if you are not in or adjacent to the military somehow that you will be surprised at the breadth of opinion and diversity in the U.S. Military. If you argue with the U.S. President, you are not actually arguing with the United States of America. Those are the easy ones where there is a structure and you’re talking to the acknowledged head of it! 

If you argue with a random anarchist, you can’t conclude that all anarchists hold the same beliefs! Of course anarchists disagree with each other and have different ideas of what their philosophy is, that could practically be the definition of anarchism except obviously there’s lots of different definitions of anarchism! If you try to argue with “liberals” or “conservatives” by talking to whoever is most vocal about their political beliefs at the thanksgiving dinner table, you are actually arguing with that specific person. Don’t argue with The Tautology Club, argue with Bob or Bella.

You cannot argue with The Tautology Club, but you can debate things with individuals. It isn’t Motte and Bailey if two different people genuinely hold different views, even if they’re in some sense on the same side as each other. If you find yourself arguing with a group that seems to hold different views where some of their claims are unobjectionable and others are outrageous, you may be dealing with Mob and Bailey. Try keeping track of which person holds which positions, or just talking to one person at a time.