When the Supreme Court legalized abortion in the landmark 1973 Roe v Wade Decision in 1973, they did so conditionally, stating that they had no certain knowledge as to when the fetus becomes a person and that they approved abortion only on the condition that the fetus is not a person. They said that if it ever became known that the fetus is really a person, then abortion would no longer be legal.
One of the drivers of legalized abortion was the rise in the out-of-wedlock birth rate, on the increase as a result of the Sexual Revolution of the 1960s.
The Supreme Court Justices were lawyers, not philosophers or biologists. They reasoned that if the fetus was merely a “human being in the making” and not yet a human person, then abortion would be legal; if the fetus was not a person, it did not enjoy the legal rights of a human person. At that stage, they reasoned, it was attached to the body in the same manner as an appendix and could therefore be removed. Nevertheless, the Supreme Court stated in its decision that if it ever became known that the fetus was indeed a person then abortion would be illegal.
So, the debate over abortion comes down to whether or not a fetus is a human person.
Human beings have a rationally intelligent nature that gives them the potential for rational thought which identifies them as persons. That is true even of a sleeping person who still retains his or her identity as a human person even though they cannot exercise their rational potential while physically asleep. The same is true of an unborn baby whose rational human nature identifies him or her as a human being from the moment they became a human being – at the moment of their conception even though they are too immature to exercise the rational potential their human nature gives them. This explains how a fetus – an unborn baby – is really a human being from the moment of conception. That potential is ALWAYS present (from the moment of conception) unlike an appendix or other bodily organs. Also, medical science has made considerable advances since 1973 and babies can now survive outside of the womb as early as 20 weeks. This could be pushed back even further as medical science progresses. The argument that the unborn baby is not a human is being progressively demolished by science and the philosophical argument for potentiality has totally destroyed it.
Abortion is the deliberate killing of an unborn child and it comes with a serious legal contradiction: Why is it (at least) Manslaughter for someone other than a physician to kill an unborn baby? If someone kills a pregnant woman he will be charged with Murder for taking the woman’s life, and Manslaughter for killing the unborn child. Does the personhood of the unborn child depend on who does the killing?
It stands to reason that human nature is infused in the unborn child at the moment of conception. Following is a syllogism that puts this concept into perspective:
The word “Person” refers to a being with a rationally intelligent nature.
Human nature is a rationally intelligent nature.
Therefore, a human being becomes a person when it becomes a new human being (with a rational human nature) at the moment of conception in the mother’s womb.