Earlier quoted context omitted.
Science didn't fail and actually helps a lot here. We know the brain development level of fetus at different stages. As a society we're generally ok with killing fish, reptiles and most of the society is ok with killing mammals. That places abortion cut-off anywhere between 3 and 6 months for the current state of the society moral development. And that is what most of the states have when they aren't dominated by ant…
Science has failed to define what a human life is (really what any life is). It has not enumerated the qualities that make us human nor has it established a plausible theory and effective model that allows us to assess the attributes of a developing fetus and declare, "this one is human, this one is still a pile of cells". (And that's not to say it hasn't been helpful in sussing out practical guidelines so far.) I re…
Those questions you pose is not really of scientific domain - they are actually equivalent reformulation of the religious question when/where "soul" is created (equivalence of the "soul" and "human" questions is established by the religious dogma that only humans have "soul"). Science has Cro-Magnons, Neanderthals, Australopithecus, etc... It is the question of religion domain whether Neanderthals or our common ancestors all the way to ancient apes were "humans"/"had soul". If notion of "soul" exists where did it appear between us and those cells $2B years ago to which each of us is connected through the continuous chain of bodies?