It takes her several seconds to come up with something that doesn't give too much away about herself.  "Suppose a woman likes a man to dress up in a particular erotic style in the bedroom.  She may not want that information revealed to the world, and she may also not want it revealed to a man who definitely doesn't like to dress up that particular way."

"Okay, I think we're probably way more open about kinks than you guys are but there is a gap there. I'm just not sure why you'd trust a matchmaker with that information."

"Higher levels of secrecy promise than three."

"...I mean, sure, but anyone could say that, and also it would be fairly nervewracking to tell a stranger about your embarrassing kinks even if you did have perfect confidence it would travel no farther."

"Traditions that build up momentum behind a logical algorithm's output, enforcement mechanisms that I doubt could exist here, ongoing monitoring, statistics showing that it works well enough.  There's a professional guild of mate matchmakers and so far as secrecy oaths go they're considered level five Confessors.  I wouldn't trust the secrecy oath of a level five Confessor with the fate of dath ilan, nonspecific stats say there have been violations at that level, but I'd feel cheerful about staking my mother's true life on it if there was a moderately good reason."

"Oh, like priests. - priests are not as important as this comparison may make them sound and would be hard to explain."

"Yeah, that didn't translate.  In theory, you shouldn't be able to trust anyone without logical decision theory to explain how their decision and your decision can fit into your respective concepts of yourselves as sane people.  But it's pretty clear from the emotions human beings have that they've been solving this problem over an evolutionary timescale that must far predate coherence theorems, and I wouldn't be surprised if that's enough for 'priests' to function.  Though if I was just arriving on Earth for the first time I'd probably say something about the huge role that trust plays in a lot of economic flows and how weird it is that priests aren't more important."

"Priests are more specific than you're imagining. Uh, how do you fancy the idea of my having my brother over on the weekend so he can be another perspective on Earth for you?"

"Two data points instead of one!  Hooray!"  'Hooray' is such a weird translated term but Thellim likes it actually.

Isabella snorts. Opens her packet of almond cookies from the restaurant and eats one and offers Thellim the other. "He's not a sub either, if you were specifically hoping for more on those, but I suppose if you don't want to take up correspondence with Jackson I could introduce you to my dad."

The words 'sub' and 'dad' in such proximity produce a queasy feeling in her, it is possible to avoid imagining that happening to her family but it takes effort and the prethoughts of the suppressed thought are still there.  "I should probably avoid talking to subs until I've had more time to -" get used to the idea is not something she ever wants to do "- adapt to that fact being the case."

"Okay. - Alex says I can tell you he's nondynamic at, uh, secrecy level three."

"Nondynamic.  I'm so glad that's an option.  That significantly decreases my wild-guess probability that the next lunar eclipse turns me into a dom or sub and oh right I need to talk with you about setting up suicide arrangements if that turns me into a sub.  Preferably by knocking me out beforehand, having a psion detect it, and killing me before I can wake up if that happened.  I don't want there to be a new version of me who's aware before she dies, she might start saying that she's okay being a submissive and then you'd have an ethical dilemma."

"...uh, I'm not comfortable with arranging to kill you, among other things that's illegal. Also people are usually fine at discerning their own roles and don't need a psion to detect it so the skill has not likely been developed."

"You've got - what was the number, a hundred thousand psions?  Small as a fraction of the population but it sounds quite large in absolute terms to me.  There is a nontrivial chance that somebody has developed the skill and it beats committing suicide beforehand just to be sure.  I realize the next place I wake up may be even less pleasant than this or that I might not wake up at all, but I'd take that over, say, a 40% chance of a 40% chance of being turned into a sub.  Unless it looks like my existence is too important to your world to ethically die which... is a really upsetting thought I'd rather not think about right now though I acknowledge it is probable before tabling it."

('Tabling, why is the word for that tabling?' Thellim distracts herself.)

"I mean, sure, maybe there's somebody in another country who's picked it up, but I have no way to find them because this isn't a service people routinely use and if I looked for it some of the people advertising it would not even be psions. People do not suddenly become subs on their eclipses, anyway, there's no sudden discontinuity in kids figuring themselves out around them, many are stably confident earlier or uncertain later and then there's people like Alex."

"I'll need to research that further but... thank you, that sounds somewhat reassuring if it is true.  Let me also guess, you think I'm not reacting correctly to the concept of what a submissive really is because I do not understand what that is like from the inside or how it really works in people."

"I'd hate to have role-altering magic applied to me too, but not more than I hated the entire concept of puberty and I was never suicidal about it."

"Yeah, it's not about role-altering, it's specifically about becoming a sub.  Becoming a dom is morally horrifying if it makes me want to do that to subs, but that is a manageable fear.  One where, unlike the sub thing, I can think about tradeoffs without that causing huge internal stresses and a core fallback which unfortunately also says 'Don't be a sub'.  Oh, point of honor, I agree to be bound by Alex's secrecy level three, but on future occasions you need to check that and wait for my clear formal response before telling me the thing, or the Algorithm does not include me thereby."  The thought that this wasn't obvious to Isabella is very strange, but so's Earth.

"I mean, usually when he clears me to mention it it's just assumed that this is moderately personal information that people shouldn't bandy about, but you could not be understood to know that and we were just both tickled by the concept of regularly deployed secrecy levels. He presents as a dom if anyone asks."

"What happens to publicly known nondynamics here?  I'm suddenly worried that you've overestimated secrecy level three, though I'm willing to go higher of course."

"Oh, nothing happens particularly, he just doesn't want to field questions and various ignorance and confusion about it."

"I shall note for the record - because I do sometimes feel that my world is probably being misunderstood, in much the same way that I might be misunderstanding, oh, say, your own - that we actually make a big deal about not being a monoculture which is why I'm sensitive about it, we know that's a risk and steer around it.  I mention this now because if there was a non-defecting property of people that they felt socially pressured to hide, even if just to avoid puzzled questions, our monoculture alarms would be blaring loud warnings.  Alex could say 'I'm nondynamic', add the syllables farsheth, and nobody would bug him about it even if they had no idea at all what he meant.  This is one of the many ways that we are very very protective of individual and subcultural diversity."

"You avoid being a monoculture by affecting incuriosity about how people are being weird, at least except if they might be being weird enough that someone needs to disappear them?"

"We avoid being a monoculture by recognizing that 'weird people' can get asked too many questions in a way that annoys them, and creating a standard protocol that they can very quickly use to avoid that situation, so as to decrease the social pressure against being non-defectingly diverse.  The only circumstance under which I can imagine somebody being disappeared is if knowing that they existed posed a potential threat huge enough to make up for the damage to Civilizational structures that rely on public knowledge and collective monitoring of enforcement processes.  Our first visitor ever from some unknown other world is the only plausible Exception coming to mind large enough to merit that, because of the sheer uncertainty surrounding everything about them, and previously I wouldn't have called that plausible."