Tantalus Prime is a graduate student in neuroscience. He’s been following my debate about abortion with Joshua Rosenau of the NCSE. He asks some questions about my views on the right to life that are worth answering.
Tantulus:

Egnor asserts that humanity is a discrete, not a continuous variable. If so, then would he kindly point to the exact point at which the human begins? After all, fertilization itself is a multi-step process. So, where is it? When the sperm breaches the oocyte membrane? Formation of the pro-nuclei? Initial DNA replication? Degeneration of the pro-nuclei membrane? Formation of the mitotic spindle? Fusion of the chromosomes? Division of the chromosomes and formation of the first daughter cells? This really should be an easy answer for Egnor. Since biological science affirms that there is a discrete distinction between human and gametes, pointing to that magic point should be trivial.

Good question. I’m not omniscient, and fortunately omniscience is not a prerequisite to hold a moral opinion. I don’t know the exact moment during the process of fertilization that a human being begins. Fusion of the chromosomes seems right to me, but I’m not sure. That said, it is a matter of biological fact that prior to fertilization no human being is present, and after fertilization has occurred (e.g. at the first mitosis) a human being- a member of the species homo sapiens– is present. That’s basic biology, not opinion. Whether that human being has the right to life is a matter of opinion and is the crux of our discussion. The exact moment at which a fertilizing egg becomes human is a good scientific question. That a fertilized egg is a member of the species homo sapiens– a human being– is a biological fact. When that human being (whenever it becomes human) has a right to life is a good moral question.
Tantalus:

Using his regental powers, Egnor again claims something by fiat. At least in this case, he isn’t claiming that biological science affirms he is right. Of course this raises some interesting questions too. Why isn’t Egnor equally outraged about the growth of in vitro fertilization, which necessitates the production of far more fertilized eggs than are necessary, resulting in the destruction of many human lives?

I have no regental powers. I note a biological fact (human life begins at conception) and a widely held moral viewpoint (all human beings have a right to life). Regarding in vitro fertilization, I believe that it is immoral. I sympathise with couples (and singles) who want children, but artificial production of human beings is immoral, and destruction of the human beings so created is immoral.

Or the fact that about half of all pregnancies end in spontaneous abortion?

I regret natural death, but it is not a moral issue. A point of idiom: natural death of an unborn child is a ‘miscarriage’. “Spontaneous abortion” is an oxymoron. We don’t refer to natural death of an adult as ‘spontaneous homicide’. It’s an attempt to elide the distinction between intentional killing and unintended death. Furtive. Back to Tantalus’ point; natural death of zygotes/embryos/fetuses in no way mitigates the moral evil of abortion. Intentional killing is not rendered moral by the existence of unintentional death.

Or the dying who are prevented from exerting their right to life by seeking assitance in ending it?

I oppose assisted suicide with every fiber of my being. It is homicide. People who are suffering and want to die should be given love and care and help to ease their suffering, which is always available. Homicide– killing another or oneself– is never a moral response to suffering.

Or the use of the death penalty?

I oppose the death penalty.

Or war?

I support Just War Doctrine, in which war is immoral unless it is purely defensive (i.e. acting to oppose agression) and a series of conditions are together met:
1) The damage inflicted by the aggressor on the nation or community of nations must be lasting, grave, and certain.
2) All other means of putting an end to it must have been shown to be impractical or ineffective.
3) There must be serious prospects of success.
4) The use of arms must not produce evils and disorders graver than the evil to be eliminated.

Really, holding true to this belief means that you don’t even have a right to lethal self-defense, since an attacking individual’s right to life trumps your own right to not be hurt, or robbed, or intimidated.

We each have the right to protect ourselves. The force we use must be only that necessary for protection, and no more. If we must use lethal force to protect our life, it is moral to do so if our direct intention is self-protection and the unavoidable consequence of our self-protection is the death of the attacker. This is a venerable moral principle expressed most formally by Aquinas’ theory of double-effect, and it is the basis for all Western legal statutes on killing in self-defense. I presume that Tantalus is acquainted with it. The principle of double effect (PDE) is a way of sorting out moral actions when an act has both good and bad consequences (as most acts do). In applying the principle of double-effect, it is generally agreed that four principles must together be met:
1) The act must be good in itself. (PDE doesn’t justify an intrinsically evil act that would have good consequences– e.g. killing Hitler in his crib).
2) The agent must intend the good effect and not intend the evil effect (PDE doesn’t justify kissing your mother-in-law if you have a cold and you intend to give it to her).
3) The first effect must be good or at least the good and evil must be commensurate. The good effect must not be the result of the evil one (PDE does not justify waterboarding, because the good effect– disclosure of terrorist plans– is the result of the evil effect– torture).
4) There must be proportionately grave reason to justify the act (PDE does not justify killing someone who is merely insulting you.)

Or if you are a pregnant woman who is diagnosed with cancer and must go through with chemotherapy to live, it is not allowed because that would necessitate an abortion.

Double-effect theory applies (Tantalus needs to bone up on Aquinas!). It is moral for the woman to have chemotherapy if it is necessary to save her life, because the intention is to save her life, and the death of the unborn child is an unavoidable and unintended consequence of that life-saving intention. Apply PDE:
1) The act must be good in itself. (Chemotherapy to treat cancer is good.)
2) The agent must intend the good effect and not intend the evil effect (You intend to treat your cancer. You don’t want to kill your child.)
3) The first effect must be good or at least the good and evil must be commensurate. The good effect must not be the result of the evil one (Treating your cancer is not the result of killing your child. Killing your child is the unavoidable and unintended consequence of treating your cancer.)
4) There must be proportionately grave reason to justify the act (You have cancer.)
Chemotherapy to treat cancer in this circumstance meets all four criteria for a moral act by the principle of double effect.

That’s what it is really about in Egnor’s mind. It’s not just that zygotes have a right to life; they have more of a right to life than any one else.

All human beings have the same right to life.
It’s worth noting that my viewpoints are mundane moral opinions derived from several millenia of Judeo-Christian morality and until a century and a half ago these moral principles were held by the vast majority of people in the West.
That educated people like Tantalus are surprised and confused by mere affirmation of the moral framework of Western Civilization is a commentary on the times in which we live.