Abstract
There appear to be two major areas of uncertainty in the abortion dispute, namely the status of the fetus with respect to personhood and the validity of the doctrine of the double effect, or which of several moral principles takes priority in cases of conflict. This paper attempts to show that one can accept the uncertainty on these issues and yet reach a plausible view on the morality of abortion. This is done by consideration of the various possible combinations of controversial factors and which combinations indicate abortion to be right and which wrong. Probabilities of rightness and wrongness are then generated for several kinds of cases where abortion is usually desired. The conclusion of the paper is that in the absence of certainty in the basic issues, we can make a decision on the strength of the probabilities, in which case abortion is justified in those cases where it has usually been requested.