So, do you agree that the two concepts (parinibbana and materialist brain death) are essentially synonyms for the same "non-state", the only difference being the respective world system (samsara versus a 'one physical life then done') one lives under?The problem with this is that, regardless of your belief, if there is indeed "rebirth", then parinibbana will not be reached by inducing brain death in an unawakened one.
The Buddha did not teach suicide for a reason, specifically because according to his teachings, there is "rebirth".
I am having great difficulty understanding what nibbana actually is. To my (western influenced) mind, I cannot see how parinibbana can be anything other than 'what it was like before someone in a physicalist world system was born'. It just seems like double-speak gobbledegook to assert parinibbana as being anything other than the permanent cessation of consciousness. There is no self that exists in this life, that is either annihilated or carried on to another state. It's just the process by which consciousness is sustained comes to an end. Basically, the very same thing as what every western materialist believes happens to them when they die!
Why devote your life, or even some part of your life to the Dhamma, when what we have here in the west is a coherent world view (scientific materialism) that accounts for far more phenomena, and has far more predictive value than essentially the mythical world view of an Indian man that lived ~2500 years ago. What is the basis for going with the latter? Blind faith?
It seems to me that people don't actually really believe in samsara. If samsara were actually the case, a human life and it's sufferings would be totally insignificant compared to the ceaseless rebirths into the brutal and visceral animal, ghost, and hell realms. I'd drop everything and ordain tomorrow.