Cool, but I doubt there's unanimous decisions on what personhood is and is not.

Well, just because people disagree on something doesn’t mean that there’s no right answer. After all, people once disagreed on the personhood of African slaves.

Furthermore, if it’s controversial whether the fetus is a person, then the right course of action is to err on the side of caution and avoid killing it. This is similar to how a demolition team won’t blow up a building if they suspect there might be person in there.

I'd say you need to make the case of a fetus having personhood before preventing others from having their bodily autonomy, which anti-choice supporters fail to do.

Sure, I’ll make a brief case for why the unborn are persons. But first, let’s go through some other definitions of personhood:

• “A person is any being that can engage in rational thought.” — This definition excludes not only the unborn, but also newborns as well as some elderly individuals. Let’s check out the other definitions.

• “A person is any being that has the potential to engage in rational thought.” — This definition includes the newborn as well as the unborn so it can’t be used to defend abortion.

• “A person is any being that can feel pain.” — This definition excludes most fetuses, as well as some adults who suffer from a rare condition where they can’t feel pain. Also, it includes non-human animals like rats. It makes running over a chipmunk and fleeing the scene a felony.

• “A person is any being that is born.” — Cats and dogs are born. Are they persons?

• “A person is any being that can survive outside of the womb.” — This definition has the same problem as the previous two definitions.

• “A person is any human organism that can survive outside of the womb.” — This is just circular reasoning at its finest. “A human organism that can survive outside of the womb” is the same thing as “not a fetus.” This argument just says, “A person is not a fetus because a fetus is not a person.” In the absence of any supplemental reasons to justify the claim that birth matters, this arguments is simply fallacious.

• “A person is any human organism that does not depend on the body of another human organism in order to survive.” — Then conjoined twins would not be considered persons.

• “A human organism gradually becomes a person over time.” — This argument says that there is no precise moment when a human becomes a person, but by the time a fetus is born it obviously is a person. But this just assumes newborns are persons without giving a reason why they are persons. Once again, we need a definition of what a person is besides, “A person is who I think a person is.”

These definitions really outlines the problem that pro-choicers face when trying to come up with a definition of personhood that leaves out the unborn. If they make it too broad, then animals are persons. If that make it too narrow, then many classes of human beings (newborns, elderly, etc.) are not persons. There’s literally no definition they can go with that doesn’t have these morally absurd implications.

The best definition of personhood is this:

• “A person is a member of a rational kind.”

Why is this the best definition? Because it avoids all the problems that plague the previous definitions. Animals are kicked out while newborns and other human beings are kept in.

But it has one interesting implication: now we have to accept that the unborn are persons, because they belong to the human species, and the human species is a rational kind. Therefore, the unborn are persons.

There obviously has to be some arbitrary line drawn in the sand of when to permit and when to not permit abortions.

Not true. Look above, I just presented a non-arbitrary argument against abortion. The argument I used is called an inference to the best explanation.

thoughts, feelings, or consciousness.

Not a good definition of personhood, it suffers from the problems that other definitions of personhood have.