A name is not an intrinsic trait of a person, it's a legal abstraction. Your name has no meaning outside of it's designation as a name and you can change it at any time. 'Mike', 'Michael', and 'Michelangelo' all mean the same thing- it's just an arbitrary word used to identify a person. 'Him' and 'Her' on the other hand are not arbitrary and do not mean the same thing, they refer to directly observable biological traits that cannot be changed.

How do you tell if someone is a 'him' or 'her'? What are the criteria you use to make that decision, and why are they immutable?

(Please don't say XY chromosomes, you don't do a genetic test on everyone you meet.)

We can tell instinctively based on a whole slew of traits, within a split second of looking at a person your brain identifies their sex whether you want to or not. Skeletal structure alone is a dead giveaway.

So if your brain instinctive recognizes someone as a "her", they're a "her"?

Human brains seem really good at these things, just like they're good at for example recognizing faces. Perhaps it has something to do with evolutionary pressure for our survival?

These ability also differ (or can be influenced) by culture so ... I wouldn't make any universalist claims based on human perception.

Yes.

We use our best judgement. In my experience it's most often confused in babies because it can be difficult to tell at times. I do not get upset when they say my son is adorable even though I don't have a son. I accept the spirit of their comment and try to politely correct them with something like: Thank you, she loves to flash a good smile. Then I go on my way.

A him is someone who was born with a penis.

A her is someone who was born with a vagina.

The very, very few people who don't fit clearly into either of these categories (intersex) are exceptions and can be handled on a case-by-case basis.

They are immutable because their reproductive role is immutable. A her can never impregnate. A him can never gestate.

(Either can choose not to perform their particular ability, or lose the ability to do so, but that doesn't change the meaning of these words.)

Some hers can never gestate, specifically barren ones, does that make them not hers?

I answered that for you already in my OP. But try this:

If a car is broken down, is it no longer a car?

Does it become an airplane?

Nope, but it is sad when such a person wishes to have a child

Her can impregnate at our current tech level. Without any gene editing the resulting baby will be always female though.

As for him gestating I encourage you to read more Sci-Fi.

We actually recently hit this very issue - a bad account migration resulted in everyone having flastname accounts - but that first initial and last name were based on legal names not common names - as a result a number of employees were upset at being forced to revert to birth names, especially those who had immigrated at a young age and adopted a new name.

I have a friend who was named at birth after their absentee parent and really dislikes ever being called by that name. It is important and polite to use names that people personally prefer within reason.

Are you going to lose your shit, call my boss and try to get me fired when I call you Michael because it's what's written down for everyone to see?

I think it's pretty clear that other people's preference for nicknames (or gender pronouns) are not a burden on you and your insistance to call people by the wrong name (or gender) is for some other reason. That was my point. This isn't about trans people causing undue burden on you.

You don't have to pretend. Nobody thinks my name is actually "Mike" but if I ask you to call me that instead of "Michael" then what is it to you?

And if you really feel that your gender is being intruded upon by trans people then i encourage you to find something more meaningful and unique to attach your identity to, because your manhood feeling threatened is not a respectable reason to deny trans people their identity.

> why do I need to care again?

I was going to ask you the same!

You describe one possible situation, let me imagine a different one. I say that I like going by Mike, and you keep making a point of always referring to me as Michael even when it doesn't really make sense to go full formal. After multiple months of it, I kinda get tired of this and decide to accept offer from another company and tell our boss that. When they ask me why I want to leave I'll be sure to mention that, and maybe they'll evaluate our productivity and decide it's better for business to just fire you instead. See how different those two situations are even thought the premise is the same?