"It is wrong to kill an innocent human being, a fetus is an innocent human being, therefore abortion is wrong." The debate focuses on two distinct issues: (1) whether the human fetus has a right to life and (2) whether these rights equal or override the rights of the mother. A person's stance on this debate may depend greatly on their definition of a human being as opposed to a human life form. If the fetus is considered to be a human being from the moment of conception, then yes termination would be the wrongful ending of a life, but if being human is defined through having a certain level of self awareness and acknowledgment of your person, then the fetus is not yet a human being so aborting it would be as immoral as terminating a cluster of cancer cells, for example. However, to qualify as a fetus, cells require a separate criteria - fetuses are potential human beings from the moment of conception. Their future contains potential value, in the same way a fully grown human being's does, which leads us on to the definition of killing.
Killing could be defined as the cessation of potential to continue life. From conception, the fetus has the potential to continue life, therefore an abortion could be defined as killing. The child who is born and later grows into an adult is the very same being who before birth was in its mother's womb. It is a person earlier as well as later and this is the continuum of human life. Why would something gradually 'turns into' a person? It might also be argued that shortly after conception, a unique DNA code is formed which will remain unchanged throughout the life of the fetus and throughout the potential later life after birth. This view bases its argument on science, yet still rejects termination of the zygote as it values the fetus as highly as a born human, in physical terms, because the zygote has the code to develop physically even though this has not yet occurred.
Others might then question when a physical being acquires a human soul. Before this point, surely the fetus does not come any higher up on the scale than an animal, whom we do not generally value as highly as humans. The majority of us do not see it as wrong to terminate an animal's life for our own gain, because an animal does not have a human 'soul'. Therefore a 'pro-life' view must ascertain that a fetus acquires a soul or spiritual dimension, and therefore a 'persona' from conception.
However, physically, even at the age of one month a fetus can not be distinguished from the embryo of a cat or dog and although the fetus is undoubtedly 'life', it does not have fully 'human status'. So the question I would pose to this point would be, do we require a recognizably human form to acquire a human soul? Even if you do not believe in a soul, should any significance be placed on intelligence and awareness when interpreting what a human being is? A fetus is not a form of intelligent life because it has not yet had any experience, so therefore probably hasn't had thoughts. A fetus is unaware as to its status (i. e. alive), so does it matter if its life is terminated? However, if this was the argument, it could be claimed that small babies have no concept of their being alive until, maybe the age of one or even two, yet most abortionists would not condone infanticide. It could be said that a person should have an interest in their own future before they earn the right to it.
Even if a fetus is defined as a human being because it has a potential life, if the fetus does not yet aspire to live, its rights are irrelevant, because it demands and expects none. It is impossible to argue that the fetus values its future yet, so why should it have a right to it? It could be argued that as the child could not possibly survive independently of the mother- at least before approximately four months into the pregnancy, - it is not yet an independent human being, but an attachment of the mother, therefore she should be allowed to terminate it, if this is what she wants to do to herself, as opposed to when the child is physically independent of the mother, when any potentially life ending action against it would be inflicted upon the child directly, not its mother. Based on the view that the fetus is already a small baby, some extreme anti-abortionists would maintain that abortion is impermissible even to save the mothers life. The rationale behind this view would be that the child is innocent, and killing the child would be active, on the other hand, letting the mother die would be passive. This introduces two new concepts, the first being the mother's rights in competition to those of the fetus and the second being the question of innocence and how we would define this. The majority of abortions, however, are not performed in the interests of saving the mothers life, but to deter inconvenience and difficulty on either her part, or the child's.
For example, the mother may feel she is unable to raise a child in her current social situation or the child may be born severely disabled. It may be acceptable to some to sacrifice the fetus in order save the mother, but not to abort the fetus in order to please the mother. If a fetus is aborted because the mother does not view it as the potential child she had hoped for (e. g. the fetus is deformed or disabled in some way), this is effectively grading human life. Some may say that this is what is wrong.
Even though the fetus is partly a product of the mother, does this give her the right to decide whether it should life, because in truth the fetus is a separate life form from the mother- whereas a different type of cell cluster (like skin cells) are part of her. Many people claim that the mother should have a right to choose what happens to her own body, but this does not take into account that she is also choosing what happens to another [potential] person's body, even if it is not yet fully formed. On the other hand, the fetus is within her body and she produced it, she should have the right to terminate it as she does to remove any other part of her body. My final response to the above statement would be to question the phrase 'innocent human being.' How do we have an absolute definition of 'innocent' when we do not all share the same values? To use the argument that the fetus is innocent is to say that humans who have 'done wrong' (by the perception of other humans) have less of a right to life.
How are we as humans, supposed to grade other humans and their right to life, without some kind of guiding external force? To judge another being as innocent is to presume yourself as correct, but how do we know what is correct when we can only rely upon our own thoughts (and the opinions of others) to tell us this? : If we do not all see the same things as wrong (for example, some people see abortion as wrong and others do not) how can we say who has done wrong and who is innocent of doing wrong? The statement above implies it is more wrong to kill a being who is 'innocent' than one who is flawed. Some might claim that whether or not the fetus is 'innocent' has no relevance, as our ideas of who is innocent come from within ourselves- flawed human beings. We see it as wrong to kill other humans because this is what society, and possibly our own instincts tell us, but if this is only a value the world has created, why should we believe it without the guidance of an external force? I think if the fetus is viewed as a human being (by the definitions I have discussed above) terminating it is the murder of a person, but whether or not this is wrong relies on our perception of the value life has.