@komododragon8 A fetus developed into a person just like how an egg hatches into a bird. If I went into a bird's nest and smashed the eggs, people will react as though I have killed the birds. Which I did. Do you ask a pregnant woman "how's their body" if you want to know the state of their fetus? You would most likely ask "how's their baby", hence implying that you acknowledge the fetus as a separate entity like a person.
@komododragon8 Mos animals have a bias to their own species. A lion would likely prefer killing a gazelle than killing another lion, similarly, a human would prefer killing an ant than killing another human (even if said human was not fully developed).
Uther: Eggs are in a different state than a mature bird just as a fetus is in a different state than a mature human. We treat things how they are, not based on what they will become. It doesn't matter how terminally ill someone is, they are treated as a person, not a corpse. A person isn't treated as a criminal until they have been convicted of a crime.
@kmododragon8 The fetus is still living, and we indirectly acknowledge them as human. If I wanted to differentiate different eggs I would call one egg an "ostrich egg" even if it's not an ostrich yet. Hence, if you wan to differentiate different fetuses you would call one fetus a human fetus even if it weren't a fetus yet. An ant can never become a person because it is fully grown, however, a fetus can become a person even if it weren't one yet.
Uther: That still doesn't change the fact that the fetus is in a different state than an adult and lacks many traits that a mature human would possess. Traits such as conscienceless and emotional complexity which many consider to be needed for personhood. The potential argument holds no water as every decision you make has the potential to create something, yet we ultimately do not punish people for using a condom or pulling out.
778: Again the fetus does no possess many traits which are considered important for personhood. Also as I have said before the potential argument does not have any value here as every decision you make (such as wearing a condom or an IUD) can prevent a potential life from forming.
The only thing here is that a fetus has more POTENTIAL to change the world. At the current stages of life, an ant is more valuable, as it is capable of doing more than a fetus. However at later stages... The ant is STILL more valuable, as the fetus will just turn into another in the way person, polluting the Earth and killing plants and creatures.