A better example comes from your own post:
,that is the fetus does have a right to live, does it have a right to the use of the woman's body.
— Rank Amateur
Where do you get the idea the fetus has any rights? In Roe v. Wade it's argued that such have potential rights coincident with the rights they would actually have if and when born alive, but not until. That's the US Supreme Court, referring to practice "from time immemorial." — tim wood
here is the argument:
The Violinist in the coma
An argument and rebuttals on the fetus right to the use of the woman’s body – heavily borrowed from Dr. Judith Thomson
P1
Even granting, only for the sake of this argument, that the fetus is such a thing that it has a right to exist, this right does not mean that the woman, with rights of her own, has any obligation to supply the fetus with the use of her body.
In defense of this proposition Dr. Thompson proposes the following though experiment.
On the way home from the symphony last night, I was attacked. Hit over the head, had a bag placed over my head, dragged into a van an given a shot that rendered me un-conscience. I wake up some time later on a gurney, with a tube in my arm, taking my blood - putting it through some machine and then pumping it into another person on another gurney to my left. I look over and at once recognize him as the greatest violinist in the world.
My captors, apologize, identify themselves and tell me they are the family and friends of the violinist. It seems he has a fatal condition, that they all thought was incurable. But found out through a fit of luck that there was an antibody only existent in my blood, that if he was given continually for a period of 9 months would completely cure him. Knowing that I was an aficionado, they assume I would be more than willing to stay here and allow the violinist the use of my blood for 9 month. Although there will be some discomfort, they will do all they can to make me as comfortable during the process as possible. They also state, that do to the unique nature of the situation , and me being the only person in the world who can save him, I have a moral obligation to stay connected to the violinist and save his life.
I say while I do agree that the violinist is great, and while understanding the uniqueness of the situation. Me being in this situation was not an act of my free will. I made no judgment or made no act that says I should be in this condition - rip out the tube and leave.
P1 – amended - Even granting, only for the sake of this argument, that the fetus is such a thing that it has a right to exist, this right does not mean that the woman, with rights of her own, has any obligation to supply the fetus with the use of her body when through no act of her own is placed in the situation where the fetus needs the use of her body
Abortion in cases of rape is not immoral, and I agree
P2 Even granting, only for the sake of this argument, that the fetus is such a thing that it has a right to exist, this right does not mean that the woman, with rights of her own, has any obligation to supply the fetus with the use of her body, even if she is at least in part agreed to the situation if it can cause her serious harm.
Same though experiment as above – only. I wasn’t abducted. The family comes to me, tell the situation. I am an aficionado, I agree. We get attached to each other all is going well. Until at month 3 I start feeling bad. I am feeling weaker and weaker. Having trouble breathing. I ask the family what is going on, they apologize, say they didn’t know this could happen - but it turns out taking out your antibodies is hurting you. The doctors are unsure to what degree – maybe even will kill you, but it will definitely cause you some amount of harm, and that harm will be permanent.
I rip out the tube and limp out of there to my doctor
P2 is agreed - in the case of some degree permanent or prolonged harm to the mother abortion is morally permissible . It impossible to identify exactly for every instance what that is, so there is some element of judgment or reasonableness here.
P3. Even granting, only for the sake of this argument, that the fetus is such a thing that it has a right to exist, this right does not mean that the woman, with rights of her own, has any obligation to supply the fetus with the use of her body. Even if freely entering into the situation – simply because she so desires.
Same violinist, same situation. Except this time I promised the family I would see this through. I freely get connected to the violinist. It is going along just as described all is going well. Then at month 1, my best friend comes to visit. Great guy. And we both love the now Los Angeles Rams. He is holding 2 tickets to the super bowl, 50 yard line, 10 rows up. Passes to 3 parties super bowl week as well, Maxim, ESPN and Playboy. 2 suites for the week in Atlanta and first class, no make that a private jet, to and from. I told you he was a good friend.
I rip out the tube and follow my friend out the door
P3 is not agreed.
My counter argument.
P1.
Adult human beings who knowingly and freely undertake some action, are responsible for the results of that action.
P2.
Entering into some action, with a known possible result, is an implied acceptance of the possibility of that result.
P3
Becoming pregnant is a known possible outcome of having sex. Properly using an effective method of birth control, can greatly and nearly eliminate this possibility - but it is a known possibility none the less.
P4.
As given for the sake of this argument, the fetus is such a thing as to have right to life. Pregnancy entails the dependency on the use of the mothers body to support such a thing with a right to life, and as above is a known possible outcome.
Conclusion: Freely entered into, sex is an implied agreement to possible known outcomes of this action. A know possible outcome of sex is the dependence on another human beings life on the use of ones body. Since we are responsible for the known outcomes of our actions. There is implied consent for the use of the mothers body, and unless in the situations already agreed, abortion is immoral.