As a Catholic and a biologist, I respect the value of life. As an American, and a human being, I cherish the rights of life and liberty. Abortion is an extremely difficult issue for most of us. Fortunately, the facts of life do not yield to political pressure; by seeking the truth, we can find peace.
"When does human life begin?" Disagreements inevitably arise because that fundamental question is inherently vague.
Every cell that composes a human body -- from a fertilized egg to the cell at the tip of your nose -- is alive, capable of carrying on the processes of life. And each living cell arises only from the division of another living cell: At least since the days of Genesis or the Primeval Soup (a different debate), "spontaneous generation" has been a myth. Except for the evolution or extinction of a species, human or any other life never truly begins or ends; it just goes on and on.
That's all well and good for the human species, but individual human beings are born and do die. The question is not so much "when does human life begin?" but rather "when does one human life begin...or end?"
Over recent decades, as "right to life" laws have been continually debated, "right to die" laws have been generally decided: In most states, the end of a life -- a truly human life -- is defined by the irreversible cessation of higher brain functions.
A body may have a heart that beats and lungs that breathe, at least with the aid of machines; a body may exhibit reflex reactions, from a jerking knee to a "silent scream"; but if the brain no longer demonstrates truly human thought, feeling, and awareness, the person who inhabited that body is legally -- and most would agree actually -- dead.
If that is when a truly human life ends, then when does a truly human life begin?
According to the very best science, the neurological connections required for truly human thought, feeling, and awareness do not form within the brain of the human fetus until approximately the 28th week of development -- depending upon the experiment and individual involved, that figure may vary somewhat; but by every account, it is within the third trimester.
It is no more murder to abort a human fetus in the first two trimesters than it is to withhold life-support from a terminally ill patient in a permanently vegetative state. Unpleasant as they may be, those are the facts of life.
So when I am asked, "Are you 'pro-choice' or 'pro-life'?" I have to answer in good conscience "Both": I am pro-choice for the first two trimesters and pro-life for the third.
Although that position typically evokes disdain from both sides of the debate, I believe it is entirely consistent with Roe v. Wade: that monumental decision allows few restrictions on abortions during the first two trimesters but many during the third. In its reasoning, the Court focused on the "survivability" of the fetus; although viability out of the womb is more a matter of technology, it seems the Justices arrived at a decision consistent with biology.
Abortion, however, is more than biology. It is indeed, as the pro-life forces insist, a matter of morality.
But how can one say that a being -- not yet born or no longer living -- possesses a soul if he or she does not possess truly human thought, feeling, and awareness -- the very essence of a soul, according to virtually every faith on Earth?
Those who favor "right to life" laws are generally the same as those who opposed "right to die" laws. I hold them in respect for erring on the side of life, as much as I hold in contempt those who sent millions to their deaths in the concentration camps.
However, there are other lives at stake -- not only the women who are pregnant but also, today, the victims of Parkinson's Disease, spinal cord injuries, and other disorders who may benefit from research on "stem cells", harvested from early human embryos.