Does human life begin at conception, at 4 month fetal life,  independent viability, presence of a heartbeat, etc.?

How crucial is brain function in deciding on aborting a fetus? Who decides?

Does death occur when the brain is declared ‘dead’, when the heart stops beating, etc. Who has the right to decide? (Ourselves with an advance directive, our families, doctors?)

Needless to say, it was a thought provoking discussion…..