ution" and forbid all abortions except to save the mother's life "or something equally serious." This argument assumes that there are no negatives operating on the other side of the question. But there are hundreds of possible cases in which, if we assume that this is not a human being but only has the potential to be one, there are strong potential negative outcomes attached to carrying the fetus to the point where it becomes a human being: a mother who is emotionally incapable of caring for a child; parents who are financially unable to care for a child; a mother who is a drug addict; a mother who has other children who do not receive proper care; or parents who simply do not want another child. Unwanted children are a real problem but the harmful consequences of their being unwanted are consequences that happen to the children -- not to the adults involved.
The argument as it is presented merely assumes that the allowing a fetus to mature and be born is something that operates entirely in favor of the fetus. The position is that the fetus must be defended against those who would harm it. But there is absolutely no doubt that the child, once it is born, is a human being. Therefore we know that by forbidding abortions in every case (except danger to the life of the mother) we are ensuring that the fetus (which we do not know for certain to be a human being) will become a human being. The harm that may be done to that potential human being should be given some weight as well.
This returns us to the argument about the humanity of the fetus. In order to protect the possible humanity of the fetus, the argument goes, we must "err on the side of caution." But since we are quite certain that the child who is born is human, is there not something to be said for erring on the side of a certain human being which every fetus that matures will certainly become? The argument is based on the fact that there can be no guarantee that...