Abortion is Murder

I don't take issue with any part of your rebuttal. Defining any moment in a phase of life is inherently imprecise and fraught with uncertainty. There are countless ways we could define the moment of viability, and whatever definition we come up with will certainly change over time as our level of technology increases. Ultimately the definition of the moment is somewhat arbitrary, as it is nothing more than the term we humans outside of the womb have chosen to give it, backed by whatever data we have available to us. But this "obstacle" applies to any moment in the phases of life, not just the moment of viability: we cannot currently detect the precise millisecond fertilization occurs, or when the embryo officially becomes a fetus, and even if we could it would still just be our definition of the state of an organism that will grow regardless of what we choose to call it. But it is worth arriving at a definition for something as important as the concept of human life, even if that definition will be refined over time and be defined differently by our governments. We currently do perform viability tests for babies, and in many places an abortion is not permitted after the baby is deemed viable, so some attempt at this is being made. Some governments choose an arbitrary number of weeks and consider the baby viable based on the statistics of survival rates. If it is a moment that needs to be defined precisely, accordingly precise standards that depend on our current level of medical technology can be established to detect it. Theoretically a mechanism could be devised that would monitor a fetus continuously and pinpoint the exact moment the vital signs indicate an established threshold has been reached, and a light would flip from red to green to mark the precise moment the baby was deemed viable and can be classified as a human life form. But no dramatic physiological change would have taken place at this moment, as these physiological changes are continuous at some level -- it is merely a dramatic change in what we've chosen to call the fetus: human life. Defining the moment accurately is important because the consequence of getting it wrong is that a viable baby is miscategorized as a human fetus. Over time as the methods of detecting the moment are improved, abortions that were previously not classified as murder might become reclassified as such, and we would need to work out the ramifications of such a circumstance. An equivalent test could be devised to detect the exact moment of fertilization or implantation, and its output would be equally arbitrary, as the involved organism(s) were unarguably "alive" before the defined moment. The state transition into human life carries enormous implications. Once the fetus makes the transition to something we call human life, we start calling it murder to if it is intentionally terminated. But the implications cannot be the motivation for the definition of life, they are the consequences of the definition we choose. So we have to examine what makes the moment of viability a good definition for the beginning of human life. After the moment of viability the baby has the potential to live independently of the mother (although certainly not independent of a caregiver, as Pro pointed out), which is a characteristic of all human life, but a shared characteristic is not enough to make the argument that they should be classified the same. The significance is that after this point the baby is an individual, with a fate separate from the mother's. Before this moment their fates are tied; if the mother dies, so does the fetus. Therefore it makes sense to say this the beginning of the individual (or in the case of conjoint twins, the individuals). It makes more sense to define human life as beginning at the moment of viability than to define it at the moment of fertilization. The moment the chromosomes and the DNA sequence have been determined is just another moment in the process -- it is the moment the potential identity of the eventual individual is established so it is not at all insignificant, but there were moments preceding it involving the same organisms, with the difference being that the preceding chromosomes were separated by some distance in time and space. Theoretically if we could determine identity before fertilization, would it be considered murder to abort the organisms before fertilization, perhaps because it would result in a deficient identity? The moment of viability is also just a moment in the process, but it signifies the moment the identity becomes an individual. And since before you are an individual, you have an identity but no independent fate, and by extension no individual rights, because you are not yet your own individual person. An implication of my position is that it would not be considered murder to abort an identity that is not yet an individual, which has controversial ramifications when considering an abortion that is performed because the identity is genetically defective.