Throughout my life I have heard many arguments in defense of abortion. Most of them are terrible. One that is popularly given is as follows:
Abortion should be allowed until the baby is viable outside of the womb. Until that point, it is either not a person or it is a part of the mother. Either way, we should be allowed to kill it.
This notion of viability is woefully vague and ultimately incoherent when applied in this way. First, it seems that viability outside of the womb is arbitrary. Obviously, a baby outside of the womb is still not viable of itself. It must still be cared for by another and it must depend upon another for its continued existence. Dependency remains, the only thing that changes is location. Second, viability outside of the womb is arbitrary but for a different reason. No human being is viable outside the atmosphere of the earth or underwater. Do we cease to be human beings in either of these conditions? Of course not. Viability, then, seems to be a useless standard for determining whether or not someone is a human being.
The other argument is that before viability outside of the womb, the baby is a part of the mother and not its own person. If this were true, all pregnant women would have two hearts, four legs, and women with male children would have penises. This is obviously not the case, so viability again proves to be a useless standard.
Ultimately, though, none of the arguments in favor of abortion are really attempts to justify the practice. For the most part, abortion was made widespread by feminists who want to be men, women who want to be whores, and men who want to have sex with women without committing to them. Abortion is a symptom of the disease of modern sexual relations and family structure. This is why political activism against abortion is so fruitless on a nation-wide scale. It is like thinking that a cold can be cured if you can prevent yourself from sneezing.