The abortion issue is completely confused on both sides. Christian theology never got straight on the issue of the soul, and modern secular humanists deny the reality of ‘soul’ altogether. That’s not a good stance for humanism, and it echoes the scientism of false science. And it creates endless antagonism. But the Christian obsession with conception and soul is surely incorrect. The problem is that the ‘soul’ factor is never affected by conception, fetus’ and the implication of some kind of murder. The soul question is complex and the major religions have not really clarified the issues, save the Buddhist (and Hindu) conceptions, up to a point.
A Buddhist view of reincarnation would seem closer to the truth: sentient entities are anchored beyond space-time and their entry into birth cycles has no effect on that one way or the other. Abortion would then merely terminate a transient connection with a rebirth cycle. The issue of the soul is complex indeed but pertains in part to the efforts made by an individual in his life to realize actions of value by a determination not always clear to us. And in another legacy still present in sufism, but I think not Islam there is a concrete path to soul creation in a different sense via the injection of a soul seed plexus ‘stuff’. The spiritual path of the person in question helps to grow this ‘soul’ factor in this sense. Note that the ‘soul’ complex in our ‘buddhist’ take is not the reincarntion of the psychological person, as such, but of the overall complex of the man/woman.
This tradition of soul in the second sense probably existed in early Christianity and then died out. It seems inaccessible to public knowledge next to the disinformation of religion and the esoteric deceptions of spiritual mafias. But there is no need for a Rolls Royce, a chevrolet version of the soul is enough and carries all that is really needed. This second legacy apparently entered early monotheism from the legacy of Egyptian religion which shows its obsession with souls and the after life, a mystery mostly lost to us.
The reincarnating self is another version then of the soul, the basic operating space-time spooky physics mystery of the human self in nature. The best path for this case is the realization of consciousness given various names, such as the now much-confused term ‘enlightenment’. Then the self complex is released from space-time and the recurrent soul.
Thus we must suspect that abortion is not truly relevant to the overall picture one way or the other. Abortion would be like canceling a journey into space-time and staying home in the mysterious realm of potential selves prior to incarnations. The attempt to outlaw abortion in rightist groups is thus misinformed from the start, in part because the Christian legacy is now so incoherent that it has no real connection with reality, and that includes the rigidly invariant Catholic brands.
Social existence is complex and can’t support unlimited birthrates and the mother must consider the context in which a child can thrive, so the issue of abortion as saving lives from medical murder is a phatasm of confusion, and a rightist ideology so steeped in capitalism, murder, imperialism wreaks of the decayed theology of Christianity, their concern over abortion is hypocritical. In the end the mother must have the key say on the question. The view of the secular humanism is itself far from reality. We should note that all these issues are metaphysical and suffer the cautions of Kant. The risk of delusion is great. But the centuries of meditating persons have slowly but surely established, it seems, the reality of the self beyond birth cycles.