So I had an idea for a one-shot or small novella, depending on how the plot developed, about an argument between Twilight and Celestia. Twilight finds out she's immortal now that she's an alicorn, and Twilight then decides that, given the standard anti-death concepts that immortality is good, death is bad, and so on, they should turn everyone who wants to be an alicorn into one.

The problem is, I'm having a very difficult time coming up with actual arguments for Celestia.

- Celestia herself is immortal, she's lived for well over a thousand years, and she isn't horrifically depressed, so clearly, immortal life is worth living and there's enough stuff to do with an extended lifespan.

- For the purposes of this fic, it's possible to turn anypony into an alicorn. I'm likely going to go with the idea that the spell can only be used a few times a year, but that's still enough to turn anyone who wants it into an alicorn within a couple of decades via exponentiation: The first targets can all be gifted unicorns who can be easily trained to use the magic.

- In most of the "Immortality sucks" fics I've read, the only real argument that immortality sucks is that you have to watch everyone else grow up and die. If a large majority of the population were turned alicorn, this wouldn't be a problem anymore.

- Nothing in canon suggests that there's any sort of religion in Equestria. Even in fanfics I've read, I've only read one fanfic where someone made up an afterlife that some ponies believed in, and in many more that I've read, Celestia's name is actually used in place of God in various sentences, like "Oh for Celestia's sake!" Thus, it's unlikely they'd believe in an afterlife: Both in canon and the majority of fanon, the closest thing to a God appears to be Celestia herself.

I've come up with arguments for Celestia by roleplaying the argument out by myself, but I haven't come up with anything that Twilight can't just shoot down, and I'd prefer if the argument wasn't just Celestia getting steamrolled, and I'd like to do this by strengthening Celestia's side, not weakening Twilight's.

Is the argument for deathism really that weak? I've read over the Harry vs. Dumbledore deathism argument in HPMOR several times looking for ideas, and IIRC Eliezer actually claimed he steel-manned Dumbledore's position, but I don't find anything Dumbledore says convincing in the slightest, and ended that chapter feeling that Harry was the clear winner in that debate, and that's with Dumbledore having access to arguments that Celestia doesn't, given that in the Potterverse, nobody actually knows what it's like to be immortal, and Dumbledore believes in an afterlife.

Some other arguments I've come up with for Celestia:

Argument: We can't just have a massive ruling class.

Response: There's no need for alicorns to be royalty. "Princess = Alicorn, Alicorn = Princess" is only something that law and tradition dictate: They can be changed. After all, Blueblood is a prince and not an alicorn, and it's certainly possible for an alicorn to NOT be royalty, if the princesses wanted.

Argument: Harder to keep the populace in line, if everyone has more power.

Response: Celestia's not exactly going around fighting criminals herself with her alicorn powers, so Celestia being much more powerful than others isn't necessary to keep the peace. If anything, an alicornified populace is MORE likely to be able to govern itself: Atm, a pegasus criminal can only be pursued effectively by about one-third of police officers, for example.

Argument: Overpopulation.

Response: One response to this is the idea that, starting a year or so from a royal edict, ponies who wish to be changed into alicorns aren't permitted to give birth more than once or twice. A broader response is that "overpopulation" isn't actually a reason to oppose alicornification, it's just a problem that has to be solved in order to do it. Saying "There'd be overpopulation" and then forgetting about the entire idea would be like Twilight saying that they didn't know how she was supposed to save the Crystal Empire from being banished again when she got given the task, and responding to this by saying "Oh well, guess that's it, we may as well pack up and go home." rather than trying to actually solve the problem. That said, this is the only truly legitimate argument I've come up with, an argument that requires real thought to fully defeat, rather than an argument that has an easy response leap to my mind.

Argument: Mortals wouldn't understand the consequence of their decision.

Response: Again, several arguments for this. Firstly, there's no reason to believe the alicorn transformation is irreversible, even if it's not currently known how to transform it back. Secondly, Celestia can already predict the consequences, and since she thinks HER life is worth living, clearly there's a solid chance that other ponies will have their lives worth living as well.

So, the questions to ask:

Are there good arguments for Celestia I haven't thought of?

Are the arguments I've already posited sufficient to not straw-man the lifeism position, and to allow for a reasonable argument?

EDIT: In order to ideally clear up some misconceptions, this is my order of priority for this fanfiction.

Priority 1: There must be a story.

I don't want anything where one side simply cannot win. Examples: "If everypony isn't turned alicorn, the land of Equestria will run out of magic." "Only ten alicorns can exist at a time, then the spell stops working." These arguments destroy all possible counter-arguments, and render the basic premise of the story impossible.

Priority 2: Unless it would ruin the story (1), I must not leave out an argument.

Unless an argument would completely ruin the story, it stays. I'm not going to ignore an argument in order to strengthen or weaken a side unless it's completely irrefutable. Fortunately, I have yet to find one of these arguments. If I had, I likely would never have tried to write this.

Priority 3: Unless it would ruin the story (1) or misrepresent the sides (2), the fight between ideologies must be an honest, relatively evenly-matched battle.

Unless one side is actually blatantly superior and the only way to ensure an even fight is to weaken the superior side, both sides must be shown to have merit within the fanfiction, and be argued to my full ability.

Priority 4: If it can be done while adhering to Priority 1, 2, and 3, Alicornism wins.

If, after the honest, relatively evenly-matched battle between properly represented sides, alicornism hasn't been shown to be inferior, alicornism will win in my fanfiction. In the event that alicornism winning requires the sides to be dishonestly shown, or for deathism to be weakened or strawmanned, alicornism won't win, but if it could go either way, I choose alicornism. Fact is, I'm a transhumanist. It's the viewpoint I support. I'm not going to give my side Plot Immunity. I expect alicornism to win, but that's the thing: I am honestly not certain that it will. I plan for it to win, but in the event that the arguments against it turn out too strong, I am perfectly willing to change the ending. But I am going to allow it to win if possible. I don't think that's an unfair stance to take.

I would have to say that the biggest reason I would have against immortality would be

1) over-population is the first problem. You've covered the solution, but it requires absolute agreement from all strata of society.

2) the civilisation of Equestria itself depends on ponies doing special jobs. You've covered this with "not every pony can be royalty" but it's more than that. They handle weather, crops, building, newspapers, rubbish collection and so on. If every pony is suddenly a member of the ruling class, what happens to civilisation if they don't want to do it any more, en masse? Again, this isn't a binding reason, but it is a complete evolution of pony society.

The biggest problem I have is this:

3) assuming you have to become an alicorn to be an immortal, then what other baggage comes with that elevation? Are alicorns naturally more powerful than any other unicorn? What happens when immature and/or unstable folk gain godlike powers? It's an easy cop-out to say most mortals "aren't ready" for immortality, but with Celestia it appears to be a truer form of not only immortality/invulnerability, but a whole super-charged boost to magical ability.

I had one other, I think, and I think it was much better, but I can't think of it.

The main problem I see that this is not just a "Immortality Vs Normal lifespan" discussion; there is also the matter of power.

There can be a lot of sensible arguments stating why ponies shouldn't have generalized access to Celestia-grade powers, so I feel that this would muddle the main discussion you want to develop.

I'd recommend for the power part of the discussion to be removed from the equation, stating that the alicornization doesn't improve ponies' magical power too much.

Midnightshadow:

Point one: Good point. Attempts at curbing birth rate would evoke a LOT of opposition. This is an excellent conflict to drive the story. I don't think it's enough to make the idea untenable, but it's enough to make the idea difficult and make arguing against it a lot less stupid.

Point two: The point is, if everyone is an alicorn, alicorns are no longer the ruling class. Royalty is the ruling class because they are royalty, not because they are alicorns. It would be like ponydom would be if there were no alicorns at all: There would be no master race, period. And no pony would be more or less suited to a job based on race.

That said, you would still have a point with this second one, I believe, if it were human society, not pony. In pony society, cutie marks tend to determine most jobs anyway.

Point three: They would be more powerful, yes. But again, if every pony is an alicorn, there's more than enough alicorns to keep the unstable ones in check. It's not like Celestia going postal, where there's no pony powerful enough to stop her. It'd be like a regular unicorn going postal now, though admittedly with a lot more potential for property damage.

If you think of the other point, I'd love to hear it. I already have some very good ones now :) Point three is fairly easily answered imo, but points one and likely two raise objections that could certainly drive a good argument.

Farsan:

I agree, at least to an extent. The idea would be that alicorns would be stronger than unicorns, but not Celestia-grade powerful, and have a spectrum similar to unicorns. Alicorns who didn't bother to study magic beyond the basic stuff that natural experimentation would provide (Like a pegasus learning to fly, but not working on speed, agility, or tricks) would probably be as strong as an amateur magic enthusiast now, alicorns reasonably talented in magic could reach high-level-unicorn levels of power, and alicorns like Twilight would have powers that could actually hold their own against Celestia or Luna for a while, but not actually win a magic duel against them. But...there's no reason that the average pony on the street would know this, which would certainly lead to interesting reactions from the populace.

Additionally, we don't know how powerful Celestia really is. We know that Celestia lost to Chrysalis, and that wasn't a battle that took out half of Canterlot or anything. They can raise and lower the sun and moon, sure, but that also happens to be their special talents. Rarity has the ability to find gems, but she's singularly unimpressive with other magic.

That said, it's another objection that could be raised. I don't know if Celestia herself would be likely to raise it, but Luna might, and if none of the alicorns raised it, it would still likely be a societal issue.

So, all in all, I already have a lot to drive the story. Excellent :)

746391 First question: do you want Celestia to have good points, or not?

Celestia should probably argue that ponies are adapted to the cycle of death and rebirth; the trouble with immortality for everyone is that now ponies still have the drives to procreate, conquer, and replace their elders. Luna was Celestia's first student that she elevated to immortality; things were fine for a hundred years, and then Luna grew tired of being perpetually number 2 and rebelled. Twilight was elevated only because she understands social dynamics enough to be okay with being perpetually second-tier and because she genuinely likes Celestia much more than Luna did. If Twilight spreads immortality to everyone, the result won't be a complete reduction in deaths, but a transfer of deaths from age-related disease to murders, and Celestia is pretty sure that will lead to less harmony and happiness.
(Note: Faust has commented that she always planned for Twilight to be Celestia's successor. If Celestia is immortal, she hardly needs a successor, but that's how deeply ingrained that pattern is in the human psyche.)
She can also call on the destructive impact of family on civic society; Celestia banned cousin marriage, with the result that ponies couldn't depend solely on their families, and had to have wider social networks. With immortality, families can grow much stronger than possible with no cousin marriage and old age, leading to clannishness, vendettas, and a collapse of social trust.

You can also put in technical constraints easily enough; if there's a finite amount of life-extension magic to go around, then the conversation becomes a very short "why don't we give everyone mansions?" "Because we can't." "Oh." (That's what I will eventually do with my fic: Princess Twilight is just as mortal as her friends, brother, and sister-in-law, and is encouraged to research longevity if she wants to stick around.)

A better steel-man for Celestia would be arguing an extinction event such as John B. Calhoun's work.. There are many ways forward and many ways to improve us, but there is a difference between being more and being better.

Use this chance to apply Fun Theory to Equestria. What haven't ponies explored or unlocked that their new mastery over death might allow them to pursue?

If Celestia doesn't have enough arguments, then give her some examples.

I don't know how far you're willing to stretch canon, but let's say that Luna was one of Celestia's previous students. Presumably, when Luna threw her tantrum and rebelled, many ponies were hurt or killed. Most ponies are not responsible and emotionally stable enough to be alicorns. (Lesson Zero? Twilight got better.)

The counterargument is of course that a population of alicorns would not be damaged as badly. Perhaps they are glass cannons — ageless and powerful in some aspects but ultimately fragile? (See Celestia v. Chrysalis) Or maybe the land cannot heal itself following an alicorn-tier battle? (See the Everfree)

You could bring interspecies politics into play.

Per the Mountain Accords, the dragons and griffons had agreed to launch an all-out offensive against Equestria should the number of alicorns created exceed the agreed limit of five. They claimed that alicorns were simply too powerful, and in the wake of Luna's banishment and the associated destruction, what else could Celestia do but agree?

746954

I second the interspecies politics argument. Celestia can't just start alicornifying all the ponies she wants, or the other species will unite and wipe out pony kind to prevent world domination by a race of immortal alicorn overlords. A small handful of alicorns can, with difficulty, be countered (see A Canterlot Wedding), but an entire nation would be unstoppable, and she knows that all their neighbors know this. Perhaps the only reason that the races of the world allowed ponykind to uplift Celestia and her sister at all was the greater threat of Discord - and after the god of chaos was sealed, it took some epic political, diplomatic, and PR maneuvering for the sisters to escape the traditional fate of alicorns who fulfilled the purposes of their creation (execution to prevent them from merely replacing whatever threat they initially dealt with).

Alternatively, maybe Celestia is planning on making all ponies into alicorns, but the level of magical infrastructure and social engineering needed to make sure society can handle the transition without collapsing into an eternal hell of misery and murder will take millennia. Twilight's education and ascension is the first step in a long, long road to reach this end.

746391
Another possibly good point would be "absolute power corrupts absolutely": what if Starswirl had been a genius with average levels of magical power but an incredible drive? What if Celestia had gifted him with great power, which he used to found the Crystal Empire, then he slowly grew callous until Celestia and Luna had to entomb him? Then, considering that Luna may have also been gifted by Celestia, wouldn't that be two-for-two, with Celestia now hoping against it, but preparing until Twilight falls, too?

Another possible argument would be the opposite of fertility: sterility. Are alicorns even fertile? How many people would pass on personal immortality if it comes from the cost of losing the regular form of immortality (reproduction)?

Another possibility could be that there is a finite magnitude of divine energies, so if everyone became alicorns, then every alicorn would be no more powerful than they had been as ponies. This conjecture could be further developed into a form of worship theory, where all ponies passively leak racial magic, which alicorns passively soak and use. Alicorns, however, can also actively absorb unicorn magic (thus explaining how Celestia disrupted Twilight's magic surge during her entrance exam, how she ended the want-it-need-it spell in Lesson Zero, and why she has a School for Gifted Unicorns) or absorb the energies of willing worshipers (giving an even better reason why Luna became Nightmare Moon). These all boil down to Equestria being incapable of supporting more than a very low number of alicorns, which has only risen recently due to Cadance suddenly getting her own kingdom.
Another possibility for 'finite divine energies' could be 'need for purpose': alicorns need to connect to mana sources. Celestia has the Sun, Luna has the Moon, Cadance has the intangible concept of Love, and Twi will likely have something like Friendship. So, other than the other Elements latching onto their Elements, there would be very few 'purposes' (energy sources) to go around.

In addition to this thread, I've got some excellent arguments over at LessWrong itself. Together, these ought to ensure that it's a very good fight between the two ideologies, and not one where one side is simply stomped on. I was originally intending for Twilight to win Celestia over, followed by the larger pony society being the main obstacle to the mass alicornification, but now it seems I have enough ammunition to make this a real, story-length battle between the two sides.

746571

Yes, I want Celestia to have some good points. I'd like things to be difficult, but not impossible, for the protagonists. The plan I have for this particular fanfiction is for the arguments for alicornification to be JUST good enough to win, not one where deathism just gets stomped on repeatedly. I'd rather have an interesting story than anti-death propaganda.

Your argument is a pretty good one, too, though it tends to be a bit weaker in Equestria: Most ponies genuinely are just GOOD. A great deal of them actually believe in and practice the ideals of friendship and harmony, and their world tends to be a lot more idyllic than ours. The Luna angle definitely gives it a lot of bite though.

746954

Possible, but I'd rather not add that level of original content if I can avoid it. A more vague argument that the other nations would feel threatened would be a lot better than a solid political treaty that's never been mentioned or alluded to before.

747996

As much as I like the thought experiment, I'm looking for good arguments against it, not ironclad reasons why the very concept is impossible to execute that aren't canonical. This is meant to be a transhumanist-themed fic after all, I just don't want it to be one where deathism gets stomped on! I want it to be a good fight, which means neither side can have an overwhelmingly dominant argument, and your argument is actually more dominant than "Celestia gets completely obliterated by Twilight's logic and rhetoric" as it doesn't even allow for the possibility of one side even trying to fight back.

I won't repeat the ideas that others have already posited above, but I'll add that it might be an interesting internal conflict for Celestia to realize and overcome the unconscious jealousy bias that would naturally result when someone who's part of a 'special' privileged group is faced with the possibility of everyone else getting the same status - especially when said status has led people to worship you for millennium.

Of course, since Celestia seems to genuinely care for and value the growth and improvement of everyone, she will likely be ashamed and corrective of this bias when she becomes cognizant of it, but as any apprentice rationalist knows, this first step can be pretty damn difficult.

Good point. And if I go with something like that, I could actually make the four alicorns represent a spectrum of opinion on the matter, if I so chose.

Twilight: Of course we should do it! We should start right now! Why haven't we ALREADY STARTED?
Cadence: Definitely, we should do it. But...let's be cautious, really. I mean, things could easily go wrong. It could take decades, even centuries for things to go smoothly.
Celestia: No...no, I don't think it should be done. You have some good points, really, but it's just too dangerous.
Luna: Are you bucking kidding me? Have all of you forgotten Nightmare Moon that quickly? It's too dangerous to even consider it!

Possibility:
Twilight: We need to alicorn everypony!
Celesita: What do you think I've been trying to do?
Basically, Celestia wants to- but can't. Maybe Twilight can solve it!

Perhaps there are stringent requirements to alicorning? Maybe it only works on unicorns- what do you do with earth ponies and pegasi? Does it require sufficient power, or friendship, or love, or some combination of the above? Perhaps there are several "Elements" in the world- Light(Celestia), Dark(Luna), Love(Cadence), Friendship, Magic(Twilight was one of the last two)- and you need sufficient amounts of them?

Perhaps being an Alicorn exposes you to dangers- psychological ones. Alicorns who don't have very strong personal ties to other ponies tend to go very insane- after all, they've got a lot more time to go unstable in.

I prefer arguments that arise naturally out of the logic inherent in the setting, rather than arguments that arise from adding new things to canon. I'd be willing to do that potentially if there were no good arguments without adding an artificial factor into it, but there are plenty of arguments that don't require throwing new stuff into the mix. The "Alicornification has a very strict requirement" thing would make a lot of sense canonically, but then it ruins the entire story.

As someone from LW pointed out:

If there's a finite amount of life-extension magic to go around, then the conversation becomes a very short "why don't we give everyone mansions?" "Because we can't." "Oh."

A short fic about Twilight's hope that everyone can be immortal, followed by dealing with the crushing of that hope is a fine idea for a story, but it simply isn't the kind of story I'm interested in writing.

EDIT: In order to ideally clear up some misconceptions, this is my order of priority for this fanfiction.

Priority 1: There must be a story.

I don't want anything where one side simply cannot win. Examples: "If everypony isn't turned alicorn, the land of Equestria will run out of magic." "Only ten alicorns can exist at a time, then the spell stops working." These arguments destroy all possible counter-arguments, and render the basic premise of the story impossible.

Priority 2: Unless it would ruin the story (1), I must not leave out an argument.

Unless an argument would completely ruin the story, it stays. I'm not going to ignore an argument in order to strengthen or weaken a side unless it's completely irrefutable. Fortunately, I have yet to find one of these arguments. If I had, I likely would never have tried to write this.

Priority 3: Unless it would ruin the story (1) or misrepresent the sides (2), the fight between ideologies must be an honest, relatively evenly-matched battle.

Unless one side is actually blatantly superior and the only way to ensure an even fight is to weaken the superior side, both sides must be shown to have merit within the fanfiction, and be argued to my full ability.

Priority 4: If it can be done while adhering to Priority 1, 2, and 3, Alicornism wins.

If, after the honest, relatively evenly-matched battle between properly represented sides, alicornism hasn't been shown to be inferior, alicornism will win in my fanfiction. In the event that alicornism winning requires the sides to be dishonestly shown, or for deathism to be weakened or strawmanned, alicornism won't win, but if it could go either way, I choose alicornism. Fact is, I'm a transhumanist. It's the viewpoint I support. I'm not going to give my side Plot Immunity. I expect alicornism to win, but that's the thing: I am honestly not certain that it will. I plan for it to win, but in the event that the arguments against it turn out too strong, I am perfectly willing to change the ending. But I am going to allow it to win if possible. I don't think that's an unfair stance to take.

748056
Well, here are a few non-ironclad arguments:
1) Celestia did not transform Twilight: it was Twilight who became supercharged with the life energies of two pegassai and two Earth ponies on top of her own and an additional unicorn's; Celestia didn't do a thing but wait until the correct moment to cast an anesthesia spell, so Twilight wouldn't feel the utter agony of growing two wings, having her four existing hooves remodeled and having her horn grow an extra inch.

2) Celestia did not transform Twilight: she and Luna became Alicorns by experimenting with the Elements after their first defeat of Discord. Non-Bearers cannot become immortal alicorns, and Cadence is a mortal alicorn, descendant from either Celestia and Luna. There are a few tangents that can develop from this one:
2.1) Each transformation was weaker than the next. Of the six original Elements, only Celestia and Luna became true immortals, with the other four being progressively longer-lived mortal alicorns. Will Twilight have the fortitude to choose which of her friends becomes a true immortal, and which only gets an additional century?
2.2) Of the original bearers, only the two unicorns had horns to center the transformation around.
2.3) The transformation is based on absorbing nonrecoverable life energy. The princess can live with herself after preserving her favourite pony at the cost of stealing a decade from the already short lives of five mortals, but will Twilight be able to do the same in turn?

3) The alicorn transformation has the prerequisite of a horn to absorb the spell into the body. Will Twilight start a classicist society, where Earth ponies and pegassai live surrounded by immortal demigods? And how many centuries, or even decades, will the fabric of society hold before 'surrounded' becomes 'dominated', or even 'enslaved'?
And, of course, Celestia and Luna wouldn't be able to do anything about it, having been demoted from "The Two Alicorn Sisters" to "two faces in a crowd".

4) Same as last, but centered around some obscure factor (likely a recessive gene) rather than horns. Now the three races become servants of the alicorns.

5) Alicorns experience power surges. Celestia trusts Twilight to be able to control her power surges, especially considering that Twilight already has experience with at least one of them (her entrance exam) and with handling really powerful spells. Will the average unicorn not fry themselves with their first alicorn power surge, especially if the average unicorn never possesses enough power to ever experience a single power surge? And what about ponies who had never even used telekinesis goring themselves by trying to levitate teaspoons?
At that, I expect that Twi will not have a smooth passage: she will find ways to put herself and others in danger, just through not knowing her new physical strength.

6) The 'Nanny Pinkie Pie' problem, godling version. Celestia may have been able to afford Cadance as an alicorn by keeping a very close watch on her as a foal, thus keeping Cadance from killing herself until her instinctual limiters kicked in.

EDIT: I really can't think about weak arguments, can I?

The first four arguments simply are not within the style I'm looking for. I'm looking for arguments that work within the established logic of the setting. There is absolutely no need to invent arguments. We have plenty of arguments without doing that.

A weakened argument 5 (I doubt alicorns would fry themselves, but they could certainly have the potential to inadvertently cause property damage) and argument 6 are quite solid, and I hadn't thought about Argument 6.

These aren't new arguments, but a few twists that you might find useful for the purposes of making this more of a story.

First, in the interests of making it make more sense for this to come up now, you could suggest that Celestia never studied the process of becoming an alicorn or considered attempting to replicate it, while Twilight has figured out how to duplicate the effect. Make Twilight's alicornism a happy accident, with Twilight's reaction being "whoa, we have to figure out how to help everyone with this as quickly as possible!".

Second, if you're writing Twilight as the typical pro-immortality rationalist, you're going to need some very strong and fast arguments from Celestia to quickly give Twilight a reason to not treat "ponies are dying as we speak" as an emergency demanding immediate action. Twilight can be willing to listen to Celestia's first argument or two on the basis of respect for her position, but motivating a substantial discussion while ponies continue to die will require Celestia to lead with her strongest arguments in favor of caution.

And third, as an alternative point to consider in the "irrevocable decision" argument, in addition to the counterargument that "someone could probably find a way to un-alicorn a pony, if they really wanted": you might consider making alicorns immortal and very hard to seriously injure but not completely invulnerable, meaning that anyone who doesn't want to be immortal can easily enough choose to abruptly stop being so at any time they choose.

I really like the suggestion earlier in the thread to use other ponies to provide other points of view, especially Luna.

I'd also suggest completely decoupling the notion of magic power level from alicornism. Becoming an alicorn should not inherently mean having powers sufficient to manipulate the sun and moon, unless you were already as powerful as Twilight.