are any of you honest enough to simply answer the question asked?

[GUBU]

you can't be forced to donate a part of your body for the benefit of another person. 

See, both sides agree on that point. That is pretty fundamental.

Where the disagreement comes is in how they define what a person is, and who has the right not to have his or her body interfered with. Anti-abortion people think of the fetus as a person with a body, and abortion forces that person to "donate"-- or completely give up -- that body for the benefit of another person (the mother). 

Naturally pro-choice people don't agree with that, based on their definition of what a person is -- when the personhood of the thing in the womb begins. 

I guess the law usually defines personhood as viability. Catholics base the idea of personhood on good old Aristotelian potential. They say that the only real ontological change happens at conception, and from there it's only a question of the fulfillment of that thingy's potential -- a change that happens all through the person's life. 

(For the record, I know that there were times in my life when, if the birth control had failed, I would have preferred my partner to get an abortion, so I don't oppose it for others either. But I understand both sides of the argument.)

Up until the 1860s the rcc based their ideology on abortion on what they considered to be actual personhood*. Hence why abortion was deemed legal by the church up to 13 weeks.

*A very subjective and unscientific approach was used, mainly dealing with the idea of ensoulment and when that happened.