Abortion is a very difficult issue to address, both because it is highly emotionally charged and because the morality involved, even without religious belief, is unclear.
When I attempted to address it years ago, it seemed to me that the fundamental question that had to be answered was this: What sorts of entities have what sorts of rights, to what degree, against whom, under what circumstances, and why?
I do not have a comprehensive answer, but I do have part of an answer: Thinking, feeling beings--the sorts of beings who care about how they are treated--are to be treated as morally relevant. Even a cat is morally relevant: it matters to the cat that you pet it instead of sticking a knife in it (even if it cannot formulate the thought). You don't get to do whatever you want to to a cat, as a moral matter. Even less do you have the moral freedom to do as you choose to a thinking, feeling being--like an adult human being or even a young child.
Is an embryo a thinking, feeling being? Does it care how it is treated? Could it care? I think the answer is clearly no. It has no more conscious awareness than a rock has. Unless one uses a potentiality argument having to do with the embryo's potentially becoming a thinking, feeling being, the embryo has no moral rights, and abortion of an embryo is morally permissible.
Is a fetus a thinking, feeling being? Does it care how it is treated? Could it care? Well, at some point in its development nerves develop and, presumably, the capacity to feel pain develops. At that point, it matters how the fetus is treated. It might be morally permissible to kill it painlessly, but not to kill it with the infliction of pain. So, abortion might then be morally permissible, but only if it is done in a way that does not cause the fetus to feel pain.
Carl Sagan noted that the capacity for rational thought requires a cerebral cortex (at least, it does in humans), and that that capacity did not develop until after the twentieth week. Reasoning that it is the capacity for rational thought that is supposed to separate human beings from the lower animals, and noting that we do not seem to think that it is morally wrong to kill chickens or cattle, Sagan concluded that we should not think of the fetus as having human rights until after the twentieth week, and should permit abortion before then.
I think that the fetus certainly is not a thinking, feeling being before then. It is not even a thinking, feeling being until well after birth. But it has the capacity to feel pain at some point--and it certainly does by twenty weeks--and at that point, it is like a cat: it matters how we treat it, even if we think that "having it put down" is OK.
So, because it is not yet a thinking, feeling being--because it is a mental blank slate, but one which can experience pain--my view is that abortion before twenty weeks is morally permissible but that the infliction of pain upon the fetus is not. This has implications for how abortion should be performed.
Of course, I have not here dealt with the potentiality argument.
Who will explain me that icon?
when dealing with atheists (open discussion forum) there is a problem. Atheists do not accept the word of God (for them does not exist), they argue that the law of the Lord is irrational. okay. here is an example that shows that atheists do not use them properly rationality. the Christian point of view: the precepts of the Lord are saints. the precepts of the Lord been revealed for the good of humanity. my opinion. the precepts of the Lord are rational. In fact, we can understand them. natural rights are written by the creator of the universe: God
here's proof: atheists irrational ideas.
[the natural rights. who decides that a woman can have an abortion? the woman alone? her husband ? the boyfriend? those who commit sexual assault ? society? the state? all viable options . a person is excluded from the decision : the child to be born . of course the child does not hold any rights. a rational reason ? the child can not speak. okay . the mute people do not have rights ? the child is not a citizen. okay . stateless persons have no rights ? the child is not aware . okay . people with severe brain damage have no rights ? the child is a part of the woman's body. the unborn child is not a human being. Really? because his heart beating? because it moves his arms and legs? the unborn child is a living being. this is a fact. at this stage the child can not live without a woman . okay . How many people survive with the help of medical devices ? the dialysis have no rights ? the unborn child is a living being that has no natural rights. incredible ! respond "rationally"to these questions.]