Content warning: Frank discussion of trans issues.
A motte-and-bailey castle is one where productive land, the bailey, surrounds a defensive structure, the motte. People can spend most of their time in the bailey, but quickly retreat into the motte when attacked.
A motte-and-bailey argument is one where someone makes a proposition that can be interpreted in two ways. One interpretation, the motte, is trivially true, or at least difficult to dispute. The other interpretation, the bailey, is bold, radical, and much harder to defend. Someone advancing a motte-and-bailey argument will talk up their radical, profound bailey – until challenged, when they will retreat and only defend the trivial, defensible motte.
Proposition: Vampires are real.
Motte: Vampires are beings that feed off the life-force of others. Some people, like bosses and landlords, drain the energy (i.e. life-force) of others by being excessively demanding. Therefore, such a person is a sort of “vampire.”
Bailey: There exists undead beings who feed off the blood of humans, can turn into bats or wolves, are warded off by garlic and crucifixes, and can only be killed by a stake through the heart.
Suppose somebody tells you that vampires are real and tries to sell you stakes and garlic to protect yourself from them. You challenge them to demonstrate that vampires are real. They then say that “vampires,” include such people as bosses and landlords, so of course they’re real. This is a motte-and-bailey argument, because selling garlic and crucifixes presupposes the bailey interpretation, but the argument defending the behavior is applicable only to the motte.
Sometimes, a person making a motte-and-bailey argument actually believes both the motte and the bailey, but when pressed chooses only to defend the motte – simply because it’s easier to do so. However, there’s a curious variation where the bailey is a position that its advocate does not really hold, but for whatever reason wishes to express. I’m going to call this a motte-and-pretend-bailey1. As an example, people will occasionally say stuff like:
Proposition: Trans women are 100% biologically female.
Motte: Trans women are psychologically female because of some aspect of their biology. This makes them “female” in a biological way, i.e. biologically female. This is true, and because of the law of the excluded middle, must be 100% true. Therefore, trans women are 100% biologically female.
Bailey: Trans women have all the biological attributes used to classify things as female – for instance, they produce eggs rather than sperm.
No one who’s remotely informed actually believes the bailey here. Trans women are keenly, painfully aware of the biological differences between us and cis females. It’s true that we’re female with respect to our psychology, and – to varying degrees – parts of our biology. Some trans women are full of estrogen and have breasts and vulvae. With respect to those things, they are female. However, pretty much all of us also have prostates, seminal glands and y-chromosomes. With respect to those things, we are male. However, it’s extremely uncomfortable to say that – and also fraught socially/politically.
If you concede that there is some context in which trans women can be called male, then people will feel justified calling us male in other contexts. For instance, if you go to a right-wing news site, you’ll see a bunch of headlines like “Feminists divided over biological males in women’s spaces,” which makes it sound like they’re talking about males in general, and not women who can be considered male in one particular sense that isn’t actually relevant to the situation. So to shut that down, some people insist that trans women are 100% biologically female, and, if pressed, just rules-lawyer every single word in the sentence. And to be honest, I think that’s a pretty reasonable thing to do, even if it’s epistemically frustrating.
Another example of a motte-and-pretend-bailey would be:
Proposition: Everyone has their own reality.
Motte: What each person calls “reality” is really their own perception of the world. Since this differs for everyone, everyone has their own reality.
Bailey: Everyone lives in their own universe, and things can be literally true in one person’s universe and literally false in another’s. Universes can overlap such that people from different universes can encounter each other, but the things that are true in each person’s universe remain true for them, without contradiction. For instance. If Alice believe that vampires exist, and Bob disagrees, then that’s because Alice lives in a universe where vampires exist, and Bob lives in one where they don’t. If Alice spreads garlic all over her house and carries a stake and cross in her purse, that’s a reasonable precaution against the very real chance that she could be attacked by vampire in her universe.
Effectively no one really believes this bailey either2. However, saying “everyone has their own reality,” is an effective way to diffuse disputes, and also positions you against people imposing their worldview on others, which is a good thing. This idea is also helpful if you want to practice magic or religion or otherwise obtain psychological benefits that come from inhabiting an imaginary world.
People who point them out tend to be pretty cynical about these types of argument patterns, but I can definitely see why they exist. Overall, I’d say they’re neither good nor bad, but it’s advisable to be aware of what’s going on when someone makes such an argument.
Maybe a better name would be “Motte and Gaily” (??)↩︎
I’ll concede that I think it’s possible that there are other universes, and for all I know, there might theoretically be a way for people from different universes to talk to each other. However, this is not what’s going on when people disagree about things. Alice believes in vampires not because she lives in a universe where they actually exist, but because she’s mistaken.↩︎