In the UK--correct me if I'm wrong--there is a legal definition of “not being in possession of yourself“ aka “not being a person.”
That's the fun thing--someone such as a lawyer needs to define, using some empirical signal, something supposedly transcendental like person, something lawyers argue and argue about regarding say chimps in zoos.
The following says so much about how we still regard being a (human) person as (paradoxically) the property of a subject (at the very least, this is an infinite regress and of course, it's absolutely ecological violence enshrined in law); and s a mind in a body with some kind of unmentionable interface between them whose operation remains obscure.
Check it out: if you have taken more than 5 hits of acid, you are not in possession of yourself and cannot testify in court.
(I think it's five, possibly three: someone help me out please.)
The really funny thing is, there is an implicit acceptance here that vague bundles of things can exist: otherwise the Sorites logic would apply. One hit--still a person? Yes. Two hits? Yes. Three hits? Yes. You can keep adding hits to the person and the same logic will apply.