"Millennia-old established traditions define life as beginning with the first independent breath of the newborn infant"
First independent breath? Give a fuck what in your opinion, "millennia old traditions" define. This is neither a tradition nor a fact. If this is critical thinking then like everything else you disturbed people touch, redefine or deem, it all falls right apart when rational scrutiny is applied.
Following your distorted logic our numerical system starts at 2. Everything starts somewhere and to proffer the argument that when a sperm enters an egg and fertilizes that egg, is not the beginning of life is analogous to the Roman Numeral system starting at 2. It's illogical and frankly, fucking stupid.
Take your version of "critical thinking" back to reddit or facebutt and appy it over there. It doesn't work here or in reality. Perhaps your mother should have aborted you before you took your " millennia old, established, traditionally defined, first breath of life".
Subvert.