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An argument for the personhood of the unborn (Part II)

(Continued from Part I)
The SLED Test
Having scientifically established the humanity of embryos, we next use logic to consider the philosophical differences between unborn human beings and those human beings we unequivocally consider “people.” The unborn differs from the newborn in four ways: size, level of development, environment, and degree of dependency. One can use the acronym SLED to easily remember these four categories.9
We first think about size (the “S” in SLED). Embryos are smaller than newborns, but we know size is not relevant for determining personhood. I am over six feet tall and weigh nearly two hundred pounds, which makes me far larger than most of my female colleagues, but no one can credibly claim that I am therefore more of a person than they are. We intuitively understand that size is irrelevant when determining if a human is a person.
Next, we consider differences in level of development (the “L” in SLED). A newborn is less developed than a toddler, who is less developed than an adolescent, who is less developed than an adult. All are properly accorded equal status as people under the law, even though they look different. Prepubescent children have not yet developed sexually, but we consider them people. Retarded children with severely underdeveloped brains also count as people. So what should we logically conclude when we observe that embryos are less developed than newborns? We realize that we cannot define people based upon how developed they happen to be. We must define people based on what they are. A person has the innate capacity to perform personal acts, even if that person cannot do so at the moment. A human being’s level of development is irrelevant when assessing personhood.
What of differences in environment (the “E” in SLED)? The human embryo inside the mother is in a different environment than the newborn baby, and the human embryo frozen in a bottle of liquid nitrogen is in a very different environment than either of the other two human beings. Environment, however, has no relevance when it comes to deciding which human beings are people. I did not become less of a person by getting out of my car earlier today, nor did I become more of a person by sitting down in front of my computer. My status as a person does not change depending upon which side of my bed I choose to sleep on tonight. Nor does it matter if I put on scuba gear and descend sixty feet underwater. Clearly, where one is has no bearing on who one is.10 Likewise, a newborn girl’s short trip down the birth canal cannot logically make her more of a person than her identical twin about to follow her. By the same token a frozen human embryo is no less entitled to our protection, even though it sits suspended in a bottle rather than growing in a womb.
Last, we think about differences in degree of dependency (the “D” in SLED), which lawyers and politicians call “viability.” Those who argue that viability makes all the difference are wrong. If they were right, many born human beings would have to be considered “non-people.” For example, everyone dependent on pacemakers, dialysis machines, insulin, respirators, or wheelchairs would forfeit their status as people. After all, each relies on external help to survive and none are viable in the true sense of the word. In fact, newborn children cannot honestly be considered viable either, because without the care and feeding they receive from their parents, they quickly die. If we refuse to strip diabetics and newborns of their personhood on viability grounds, by what logic can we do so to embryos? As one former abortionist points out, there is no moral difference between a unborn child ‘plugged into’ and dependent upon a mother and a kidney patient plugged into and “dependent” upon a dialysis machine.11 Degree of dependency has no bearing on a human being’s status as a person.
That covers the “SLED Test.” We can see, then, that the unborn child differs from a newborn child in only four ways: size, level of development, environment, and degree of dependency. Individually, none of these criteria have anything important to say about whether a human being is a person, and no combination of these criteria carries any additional moral weight.

Continued in Part III

8) Id., p. 22; See also “Biogenesis and Abiogenesis”, New Advent (stating “all visible organisms arise only from germs of the same kind”), originally at
9) Scott Klusendorf, Fetal Tissue and Embryo Stem Cell Research: The March of Dimes, NIH, and Alleged Moral Neutrality, p. 32 (2000); Stephen D. Schwarz, The Moral Question of Abortion, p. 15-18 (1990) (coining the acronym SLED … widely popularized by Klusendorf).
10) Beckwith, Politically Correct Death, p. 114.
11) Bernard N. Nathanson & Richard N. Ostling, Aborting America, p. 213 (1979).