Having critically looked at the various viewpoints of authors, we can arrive at a broad conclusion. While there is no universal consensus as to permit abortion or not, general moral guidelines can be perused for arriving at decisions. Under these guidelines, preserving the life and prospects of a developing fetus is the default position from which the decision to abort is a matter of exception rather than the rule. Authors arguing from moderate and conservative stances have laid a series of moral and legal criteria for a case of abortion to satisfy. It is obvious that most cases would not qualify under these sound criteria. Further weakening the liberal stance is the ‘burden of proof’ criteria. A fetus’ development to full maturity and birth is a natural course of action. So it is upon pro-choice advocates to present convincing arguments for stalling this natural phenomenon. In other words, continuation of pregnancy happens by default, unless persuasive reasons to the contrary are offered. Such rationale have not yet been presented by those supporting abortion. Hence, on balance, abortion is morally acceptable only under rare and peculiar circumstances that are an exception rather than the rule.
Dan Marquis, Why Abortion is Immoral (400)
Thomson, A Defense of Abortion (391)
Mary Anne Warren, On the Moral and Legal Status of Abortion (384)
L.W. Sumner, A Moderate View (405)