The point is that when someone "hears voices" - which do not respond to the will in the same way in which internal monologues do, there's no demons, there's no new brain added. It is existing brain regions involved in the internal monologue failing to integrate properly with the rest. Less dramatically, when people claim they e.g. want to get on a diet but are mysteriously unable to - their actions do not respond to what they think is their will but instead respond to what they think is not their will - it's the regions which make decisions about food intake not integrating with the regions that do the talking (Proper integration either results in the diet or absence of the belief that one wants to be on a diet). The bottom line is, brain is not a single CPU of some kind. It is a distributed system parts of which are capable of being in conflict, to the detriment of the well being of the whole.

Well, if you insist, here goes:

(A non-bizarre delusion would be believing that your guru was raised from the dead, the exception for "culturally accepted response pattern" isn't for tulpa hallucinations, it is so that someone who feels the presence of god in the church, hopefully without actually seeing a god hallucination, isn't diagnosed.)

Here's the criteria for e.g. 295.40 Schizophreniform Disorder:

• One of the following criteria, if delusions are judged to be bizarre, or hallucinations consist of hearing one voice participating in a running commentary of the patient's actions or of hearing two or more voices conversing with each other: Delusions, Hallucinations, (...)

• Rule out of Schizoaffective or Mood Disorders

• Disturbance not due to drugs, medication, or a general medical condition (e.g. delirium tremens)

• Duration of an episode of the disorder (hallucinations) one to six months

Criteria for 298.80: Brief Psychotic Disorder

• Presence of one (or more) of the following symptoms: hallucinations (...)

• Duration between one day and one month

• Hallucination not better accounted for by Schizoaffective Disorder, Mood Disorder With Psychotic Features, Schizophrenia

Criteria for 298.90: Psychotic Disorder NOS (Not Otherwise Specified):

• Psychotic symptomatology (e.g. hallucinations) that do not meet the criteria for any specific Psychotic Disorder, Examples include persistent auditory hallucinations in the absence of any other features.

• Where are the additional criteria for that? Wait, there are none!

In summary: You tell a professional about that "friend" you're seeing and hearing, you either get 295.40 Schizophreniform Disorder or 298.80: Brief Psychotic Disorder depending on the time frame, or 298.90: Psychotic Disorder NOS (Not Otherwise Specified) in any case. Congratulations!

That's specifically the religion exemption, yes.

I think implicit in that question was, 'and how does it differ?'

A friend of mine has a joke in which he describes any arbitrary magic card (and later, things that weren't magic cards) by explaining how it differed from an Ornithopter (Suq'Ata Lancer is just like an Ornithopter except it's red instead of an artifact, and it has haste and flanking instead of flying, and it costs 2 and a red instead of 0, and it has 2 power instead of 0. Yup, just like an Ornithopter). The humor lay in the anti-compression - the descriptions were technically accurate, but rather harder to follow than they needed to be.

Eradicating the humor, you could alternately describe a Suq'Ata Lancer as a Gray Ogre with haste and flanking. The class of 'cards better than Gray Ogre' is a reference class that many magic players would be familiar with.

Trying to get a handle on the idea of the tulpa, it's reasonable to ask where to start before you try comparing it to an ornithopter.

Why would "which reference class is x most like" be a "failure mode"? Don't just word-match to the closest post including the phrase "reference class" which you remember.

When you're in a dark alley, and someone pulls a gun and approaches you, would it be a "failure mode" to ask yourself what reference class most closely matches the situation, then conclude you're probably getting mugged?

Saying "uFAI is like Terminator!" - "No, it's like Matrix!" would be reference class tennis, "which reference class is uFAI most like?" wouldn't be.

I think the term is "reference class tennis".

(There often is no need for an actual causal model to strongly believe in an effect, correlation is sufficient. Some of the most commonly used pharmaceutical substances had/still have an unknown causal mechanism for their effect. Still, I do have one in this case:)

You are teaching your brain to create false sensory inputs, and to assign agency to those false inputs where non is there.

Once you've broken down those barriers and overcome your brain's inside-outside classifier - training which may be in part innate and in part established in your earliest infancy ("If I feel this, then there is something touching my left hand") - there is no reason the "advice" / interaction cannot turn harmful or malicious, that the voices cannot become threatening.

I find it plausible that the sort of people who can train themselves to actually see imaginary people (probably a minority even in the tulpa community) already had a predisposition towards schizophrenia, and have the bad fortune to trigger it themselves. Or that late-onset schizophrenia individuals mislabel themselves and enter the tulpa community. What's the harm:

Even if beneficial at first, there is no easy treatment or "reprogramming" to reestablish the mapping of what's "inside", part of yourself, and "outside", part of an external world. Many schizophrenics know the voices "aren't real". Doesn't help them in re-raising the walls. Indeed, there often is a progression with schizophrenics, of hearing one voice, to hearing more voices, to e.g. "others can read my thoughts".

As a tulpa-ist, you've already dissociated part of yourself and assigned it to the environment. Let me iterate I am not concerned with you having an "inner Kawoomba" you model, but with actually seeing / hearing such a person. Will you suddenly find yourself with more than one hallucinated person walking around with you? Maybe someone you start to argue with? You can't turn off?

Slippery slope arguments (even for short slopes) aren't perfectly convincing, but I just see the potential harm weighed against the potential benefit (in my estimation low, you can teach yourself to analytically shift your perspective without hacking your sensory input) as very one sided. If tulpas conferred a doubled life-span, my conclusion would be different ...

If you're familiar with the Sorceror's Apprentice:

Wrong I was in calling

Spirits, I avow,

For I find them galling,

Cannot rule them now.