Scott Klusendorf posted a public reply to a critic of his debate on the Unbelievable show, which I blogged about yesterday.
The full reply is here, but I wanted to highlight’s Scott’s scientific defense that the embryo is a human being.
First, your claim that because biological life is continuous (an “unbroken tree” as you put it), we can’t say when the embryo’s life begins, is demonstrably false. Just because life is continuous between generations does not mean we can’t tell when an individual human begins to exist. The science of embryology points to a clear, non-arbitrary divide between sperm/egg on one hand, and a newly conceived embryo on the other. That is to say, from the earliest stages of development, embryos are distinct human beings. True, they have yet to grow and mature, but they are human nonetheless. Leading embryology textbooks affirm this.
For example, in “The Developing Human: Clinically Oriented Embryology” (Saunders/Elsevier, 2008), Keith L. Moore & T.V.N. Persaud write: “A zygote is the beginning of a new human being. Human development begins at fertilization, the process during which a male gamete or sperm…unites with a female gamete or oocyte…to form a single cell called a zygote. This highly specialized, totipotent cell marks the beginning of each of us as a unique individual.”
T.W. Sadler’s “Langman’s Embryology” (Saunders, 1993) states: “The development of a human begins with fertilization, a process by which the spermatozoon from the male and the oocyte from the female unite to give rise to a new organism, the zygote.”
Embryologists Ronan O’Rahilly and Fabiola Müller write, “Although life is a continuous process, fertilization is a critical landmark because, under ordinary circumstances, a new, genetically distinct human organism is thereby formed” (Human Embryology & Teratology. 2nd edition. New York: Wiley-Liss, 1996).
And then he quotes some pro-choice scholars, including Peter Singer and David Boonin, to make the point:
Contemporary defenders of abortion also reject your claim that we can’t tell when individual life begins. For example, in his book “Practical Ethics” (Cambridge, 1993) Peter Singer—a bioethicist at Princeton University and supporter of both abortion and infanticide —denies your claim the beginning of human life is can’t be known. He writes: “Whether a being is a member of given species is something that can be determined scientifically, by an examination of the nature of the chromosomes in the cells of living organisms. In this sense, there is no doubt that from the first moments of its existence an embryo conceived from human sperm and eggs is a human being.”
Philosopher David Boonin, author of “A Defense of Abortion” (Cambridge, 2002), writes: “A human fetus, after all, is simply a human being at a very early stage in his or her development.”
I tried to space it out a bit to make it more readable. I think what his sources are saying is that when an egg and sperm meet, they create something with a completely different DNA signature than either the sperm or the egg. I think if you have an organism that has human DNA, distinct from the mother and father, and it is developing in a self-directed way (unlike your finger nails, or hair, say), then you have a distinct human life. And I don’t think “because I’m bigger than she is” is an adequate reason to kill that other human being.
I have a rule in my life. Don’t do anything that is likely to get an innocent person killed. Why can’t everyone have this rule? Is recreational pre-marital sex REALLY that important? I don’t think any of the reasons that people give for having sex (self-esteem, pleasure, etc.) are more important than not killing an innocent human being. When little lives are at stake, we grown-ups should all try to control ourselves, so that we don’t harm people who are smaller and weaker than we are. It just isn’t right.
You can read the whole dialog between CoD and Scott on the Unbelievable page.