Thank you for your reply!

Some people might ,while mentally capable, give general consent to being committed if suicidal, but later withdraw it , while incapable ,at least in a professionals judgement.

If they consent to intervention while competent and withdraw when incompetent, it is quite straightforward that the desires they stated while competent should override their later desires while incompetent. There is precedent; DNRs and DNIs are both documents recording the desires of competent patients for when they are incapacitated or incompetent.

That's not well defined in the case above.

I apologize if I was unclear; an individuals current preferences ought to be respected while they are mentally competent and not when they are mentally incompetent. If a competent individual states their preferences for how they are treated when they are incompetent, these ought to be respected as well.

But you're not calling for less involuntary commitment.

The amount of involuntary commitment is irrelevant so as long as it is not forced upon mentally competent individuals. 

A quick reminder not to allow perfect to be the enemy of good; just because a proposal does not completely resolve a problem does not mean it will not improve the situation. It is better to do something right rather than endlessly quibble about doing nothing wrong. We must strive to do our best, even when it is not enough, rather than becoming paralyzed by the sheer scale of the world's problems. Be kind to the people around you, practice self-care, and be willing to forgive yourself while correcting your errors. 

Have a wonderful Saturday night!

Thank you for your comment! You raise some good points, particularly regarding competence.

people who might want intervention

By definition, if you want to be committed, you have not been involuntarily committed. Involuntary prevention is what I take issue with; I apologize if I have been unclear. If an individual indicates that they would like others to prevent them from committing suicide or they would like to seek assistance for suicidal ideation, they ought to receive the help they require. 

it's your own belief ...you haven't shown it is a principle that transcends merely subjective preferences

My argument is that we all have subjective preferences, and since none of these preferences are inherently superior, we therefore ought to allow each mentally competent individual to decide and act upon their own preferences. I will attempt to demonstrate that it is a principle when my karma recovers or I am able to make another post. (Whichever comes first.)

Is there a completely reliable way of determining that?

Given that nobody here is omniscient, there is no perfect way to determine anything; however, perfect ought not to be the enemy of good. Any adult is mentally competent by default, and may only be considered mentally incompetent if they are currently impaired (severe dementia, psychosis, severe hallucinations, etc). In general, it is safe to assume that those who do not have and do not have a history of mental impairment are mentally competent, and those who have or have a history of mental impairment are not mentally competent.

Thank you for your thoughtful comment! You make many good points.

Says who? 

The notion that one's moral philosophy, personal values, and religion do not give one the right to infringe upon the freedoms of others is cruxy; if you disagree, than my conclusion does not apply to you. However, I will note that a society in which everyone can impose their values upon eachother (or, worse, a society in which one group imposes their values upon everyone else) would quickly devolve into chaos or tyranny. I would also like to avoid isolated demands for rigor; do you continue to believe people ought to be able to impose their values upon others in other contexts, such as conversion therapy (borne of the values condemning homosexuality and potentially protecting homosexuals from eternal torment) or restrictions upon women's education (borne of the values denoting women as inferior to men)?

Obviously, that's a continuum.

You are correct. I apologize for any confusion my writing has caused; by "suicidal individuals are not incompetent nor beyond reason", I intended to say that suicide ideation does not inherently render one mentally incompetent. If an individual is mentally incompetent, they ought to be prevented from committing suicide; if an individual is mentally competent, they ought to be allowed to exercise their autonomy. 

That doesn't imply "never intervene"... [t]here are people regret their suicide attempts...

Using force on a mentally competent individual cannot be justified by your belief that they will regret their actions later. Allow me to restate a sentence from the post: 

At the time of the attempt, the [mentally competent] suicidal individual is fully understanding and accepting of the consequences of their actions, and preventing a process they have consented to infringes upon their personal freedoms.

Of course, this is irrelevant to you if you believe that personal/religious values justify the use of force.

My apologies if I was unclear; I am opposed to using force on mentally competent individuals. I would not consider those experiencing psychosis, delusions, and other severely impaired perceptions of reality as fully mentally competent. Yes, in these instances it is acceptable to treat others by force.

Again, it depends on whether or not the individual is mentally competent. If the deeply erroneous world model is borne out of hallucinations of bugs coming out of the walls to eat you, then no, it is not unethical to prevent this individual's suicide and correct the model with the appropriate therapy and anti-psychotics. If the deeply erroneous world model is held by a mentally competent individual who believes something false (such as a false diagnosis of dementia, for instance), then it is not unethical to correct this model by convincing the individual that the distressing belief is false, though it is unethical to use force to do so.

Thank you for the recommendation. I will read it this week.

Thank you for your comment! Yes, I am aware that there are treatments for suicide ideation, I simply disagree with applying them by force. I am also aware that suicide prevention, involuntary commitment, and treatment for suicide ideation differ from place to place; in that particular section, I was referring to one treatment. I apologize if I appeared to be generalizing.

I apologize for the lack of understanding on my part, but when you refer to "a deeply flawed world model", do you mean that the world in which the individual lives is deeply flawed, that the individual perceives the world as deeply flawed, or that the individual has a deeply flawed perception of the world?

If the individual's environment is deeply flawed, and this motivates them to end their life, it is absolutely not unethical to correct the flaws in their environment. If the individual's outlook on the world motivates them to end their life, it is absolutely not unethical to convince them that the world is not a bad place or that suicide is not the optimal solution. However, it is unethical to use force in your attempts to do so. 

If an individual has a deeply flawed perception of reality (as in, "psychosis, late-stage dementia", not "outlook on the world is disagreeable or more depressing than average"), they are not mentally competent and should therefore be prevented from committing suicide.

Good point! Yes, the ideal path that maximizes health outcomes would definitely involve testing for a disorder before treating it. However, given there are no externalities (such as a shortage of a particular treatment), a person should have the right to do whatever they wish to their body, including harming it. Requesting treatment before official diagnosis is beneficial in cases where the ailment is difficult to diagnose, stigmatized, and/or has a poor prognosis without rapid treatment. An instance where informed consent has been shown to be successful is the treatment of gender dysphoria; a gender dysphoria diagnosis carries social stigma, requires approximately a year of therapy to diagnose, and those with gender dysphoria face worse outcomes (suicide, prejudice-motivated crimes while presenting as their neurological gender) when treatment is delayed.