In the scientific debates of our day, it’s important to distinguish debates about scientific facts from debates about the ethical or metaphysical consequences of scientific facts.

That human life begins at conception is a scientific fact, and has been recognized as such since the early 19th century when fertilization of the ovum by the sperm was first observed in the laboratory. That life begins at conception is as much a scientific fact as heliocentrism, and the fact that the earth is round, and that water is H₂O.

A new human being comes into existence at the fusion of the egg and the sperm. The new human being develops through stages, and at each stage of human development — zygote, embryo, fetus, neonate, infant, child, adolescent, adult — the individual is a human being. There is no scientific debate about this.

There is, regrettably, a lot of denial of this scientific fact, most of it from those who find it necessary to deny the humanity of the human being whose life is ended by abortion. Biologist and blogger P.Z. Myers is such a denier. He writes:

This seems to be the core pseudo-scientific premise of the anti-choicers, and it rests on a fundamental flaw in their reasoning. Yes, it’s true that a human zygote is alive and cannot become a cat or a donkey, but “human” here is being used in the broadest possible sense.

The word human is used here as a noun, and it means a human being. A human being begins to exist at conception, and ceases to exist at death. There is no scientific debate about these facts.

We do not offer full rights and protections to everything that is “human”, or bleeding, spitting, and masturbation and menstruation would be illegal. Those acts also destroy living, human cells that cannot become donkey or cat cells.

“Human” here is used as an adjective, and human blood, or human saliva, or human semen, or human menstrual blood are not human beings. Human zygotes and human embryos and human fetuses and human neonates and human infants and human children and human adolescents and human adults are human beings. They are not the same as saliva or semen or menstrual blood.

Human beings are not the same thing as parts of human beings. A fetus is not a part of a human being. A fetus is a human being. We do not offer protection to semen and menstrual blood because semen and menstrual blood are not human beings.

We only offer legal rights to reasonably well-organized collections of human cells.

The legal protections offered to human beings at various stages of life are a matter of ethics, not a matter of science. From the perspective of science, human life begins at conception and ends at death.

Teratomas do not have a right to exist, nor do warts or severely damaged limbs — we will amputate badly injured, irreparable limbs even though they contain living human cells, because their retention puts the conscious part of the organism at risk.

Teratomas are cancers, and human beings during intrauterine life are not cancers. Killing a human being in the fetal stage of life is not the same thing as amputation. Amputation removes a diseased limb of a human being. Abortion kills a human being.

An amputation is a failure if it kills a human being. Abortion is a failure unless it kills a human being.

I think the reason for this flawed argument (besides motivated reasoning) is that the public has a serious misconception: they know about genes and a little bit about inheritance, and unfortunately what they infer from that tiny bit of knowledge is a kind of genetic determinism. People, they think, are defined by the genes present in their nuclei. They aren’t.

Myers’s reasoning is motivated reasoning. He supports abortion, so he denies the scientific fact that life begins at conception and ends at death.

Acknowledging the scientific fact that life begins at conception is not “genetic determinism.” The fact that life begins at conception was established as a scientific fact a century before the concept of gene was developed. Genetic determinism is irrelevant to the basic biological fact that human beings begin to exist at conception.

I wish there were a way to get this across, but I’m aware that it’s a difficult argument that requires a deeper understanding of biology than most people have.

Myers uses his understanding of biology to obfuscate the straightforward science of human embryology, in order to serve his ideological purposes. Acknowledging the scientific fact that human life begins at conception makes it more difficult to make the case for abortion. Rather than accept that and rethink his ideology, Myers misrepresents the science to fit his ideology. The similarity to his misrepresentation of evolution in order to serve his ideology is worth noting.

As Myers himself illustrates, scientists are not above misrepresenting even established basic science in order to advance their ideological agendas. We have seen it in the scientific racism of the late 19th and early 20th century, and we see it again in the egregious distortion of embryology by abortion supporters today.

Human beings are fully human regardless of race and regardless of age. Misrepresentation of biology to excuse abortion is the moral equivalent of scientific racism of a century ago.

Photo: Ultrasound image of fetus at 12 weeks, by Wolfgang Moroder. (Own work) [CC BY-SA 3.0 or GFDL], via Wikimedia Commons.