When someone cannot function in their society, conduct their affairs within thei society's reasonable expectations; or is a danger to themselves or others. I think that's a practical standard.
In the USA, not only do some extreme religious practices come under this heading (like polygamous child marriage) but so do some ideologies (like Sovereign Citizens).
In the USA, not only do some extreme religious practices come under this heading (like polygamous child marriage) but so do some ideologies (like Sovereign Citizens).
I'm not anti-Christian. I'm anti-stupid.