On the other hand, if you look around at the real world it's also pretty obvious that most people frequently do make choices not in their own best interests, or even in line with their own stated goals.
I find it interesting that you make a distinction between people making choices that are not in their own best interests and choices not in line with their own stated goals. The implication is that some people's stated goals are not in line with their own 'best interests'. While that may be true, presuming that you (or anyone else) are qualified to make that call and override their stated goals in favour of what you judge to be their best interest is a tendency that I consider extremely pernicious.
Forcing people to not do stupid things is indeed an easy road to very questionable practices, but a stance that supports leaving people to make objectively bad choices for confused or irrational reasons doesn't really seem much better. "Sure, he may not be aware of the cliff he's about to walk off of, but he chose to walk that way and we shouldn't force him not to against his will." Yeah, that's not evil at all.
There's a world of difference between informing someone of a perceived danger that you suspect they are unaware of (a cliff they're about to walk off) and forcibly preventing them from taking some action once they have been made aware of your concerns. There is also a world of difference between offering assistance and forcing something on someone to 'help' them against their will.
Incidentally I don't believe there is a general moral obligation to warn someone away from taking an action that you believe may harm them. It may be morally praiseworthy to go out of your way to warn them but it is not 'evil' to refrain from doing so in my opinion.
Not to mention that, in reality, a lot of stupid decisions negatively impact people other than just the person making them. I'm willing to grant letting people make their own mistakes but I have to draw the line when they start screwing things up for me.
In general this is in a different category from the kinds of issues we've been talking about (forcing 'help' on someone who doesn't want it). I have no problem with not allowing people to drive while intoxicated for example to prevent them causing harm to other road users. In most such cases you are not really imposing your will on them, rather you are withholding their access to some resource (public roads in this case) based on certain criteria designed to reduce negative externalities imposed on others.
Where this issue does get a little complicated is when the negative externalities you are trying to prevent cannot be eliminated without forcing something upon others. The current vaccination debate is an example - there should be no problem allowing people to refuse vaccines if they only harmed themselves but they may pose risks to the very old and the very young (who cannot be vaccinated for medical reasons) through their choices. In theory you could resolve this dilemma by denying access to public spaces for people who refused to be vaccinated but there are obvious practical implementation difficulties with that approach.
I find it interesting that you make a distinction between people making choices that are not in their own best interests and choices not in line with their own stated goals.
Generally what I had in mind there is selecting concrete goals without regard for likely consequences, or with incorrect weighting due to, e.g. extreme hyperbolic discounting, or being cognitively impaired. In other words, when someone's expectations about a stated goal are wrong and the actual outcome will be something they personally consider undesirable.
If they really do know wha...
In this video, Julian Savulescu from the Uehiro centre for Practical Ethics argues that human beings are "Unfit for the future" - that radical technological advance, liberal democracy and human nature will combine to make the 21st century the century of global catastropes, perpetrated by terrorists and psychopaths, with tools such as engineered viruses. He goes on to argue that enhanced intelligence and a reduced urge to violence and defection in large commons problems could be achieved using science, and may be a way out for humanity.
Skip to 1:30 to avoid the tedious introduction
Genetically enhance humanity or face extinction - PART 1 from Ethics of the New Biosciences on Vimeo.
Genetically enhance humanity or face extinction - PART 2 from Ethics of the New Biosciences on Vimeo.
Well, I have already said something rather like this. Perhaps this really is a good idea, more important, even, than coding a friendly AI? AI timelines where super-smart AI doesn't get invented until 2060+ would leave enough room for human intelligence enhancement to happen and have an effect. When I collected some SIAI volunteers' opinions on this, most thought that there was a very significant chance that super-smart AI will arrive sooner than that, though.
A large portion of the video consists of pointing out the very strong scientific case that our behavior is a result of the way our brains are structured, and that this means that changes in our behavior are the result of changes in the way our brains are wired.