abortion can be ethically justified

We can approach the ethics of abortion from three different perspectives. First, we must decide what exactly a fetus is and if it is morally significant. Second, we must determine if a woman is obligated to carry the fetus to term if we grant it full moral significance. Third, we must look at the consequences of the pro-life position. 1. I submit that it is a prima facie logical fallacy to treat an entity like what it will becomes instead of like what it is presently. We do not treat peach seeds like peach trees and accordingly we should not treat a fetus like a fully-gown human being. In usual moral deliberations, we tend to reason that if an entity cannot feel pain, it has no moral significance. This is why we do not have moral obligations to rocks. Since, according to the best medial science, the fetus cannot experience pain until 20 weeks, it must be justifiable to abort before that period. After that period, it seems to me that as the fetus gains fully human facilities, it should gain increasing moral significance. Of course, I do not offer a clear bright line here, but it justifies some abortions. 2. Let us suppose that I grant that a fetus has the same moral status as a fully-gown person. Philosopher Judith Thomson offers this scenario as an argument for abortion even under these circumstances: "You wake up in the morning and find yourself back to back in bed with an unconscious violinist. A famous unconscious violinist. He has been found to have a fatal kidney ailment, and the Society of Music Lovers has canvassed all the available medical records and found that you alone have the right blood type to help. They have therefore kidnapped you, and last night the violinist's circulatory system was plugged into yours, so that your kidneys can be used to extract poisons from his blood as well as your own. The director of the hospital now tells you "Look, we're sorry the Society of Music Lovers did this to you – we would never have permitted it if we had known. But still, they did it, and the violinist is now plugged into you. To unplug him would be to kill him. But, never mind, it's only for nine months. By then he will have recovered from his ailment, and can safely be unplugged from you." It is morally incumbent on you to accede to this situation?" She thinks that answer is clearly ‘no', and since the scenario is analogous to abortion, you are likewise not morally required to allow the fetus to use your kidneys and other vital organs and are morally allowed to remove the entity. 3. I have argued elsewhere that if ‘life begins at conception', it follows that all fertilized eggs are morally important. Here's the problem, when one attempt to have children through normal sexual reproduction it is estimated that "Only 50 to 60 percent of all conceptions advance beyond 20 weeks of gestation. Of the pregnancies that are lost, 75 percent represent a failure of implantation and are therefore not clinically recognized as pregnancies." (Norwitz, E.R. . "Implantation and the survival of early pregnancy." The New England Journal of Medicine vol. 34508 Nov. 2001 1400-1408) This indicates that the decision to attempt to have children leads to the death of many fertilized eggs, which, according to the pro-life position, are fully significant individuals. The death of these eggs is not justifiable especially when the only motivation is to have children. That should be enough to get us started