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May 2015 Policy Study, Number 15-4


Embryonic Stem Cell Research Is Morally Wrong


Section IV



To be fair, consider Werner’s potential response to the foundation of my criticisms. Werner may argue against the substance view of persons, against the empirical verifiability of my description, and against the potential these beings have to give them actual rights. If these arguments work, then they seem to undermine the basis for some of the objections against Werner’s analogical argument.


Werner’s argument may be given from the fact that in the early stages of an embryo’s existence it can be twinned and recombined. Thus, how can one claim that an embryo is a person if it can divide itself and occasionally recombine? The substance view of persons says that a person must be a unique individual. But this claim may be disputed on empirical grounds given that early embryos can divide and may recombine. If an individual divides, it is no longer the same individual. If two individuals recombine, they are no longer two individuals, but one.  Werner quotes M. A. Warren:


It is not clear that the zygote is the same organism or proto-organism as the embryo that may later develop from it. During the first few days of its existence, the conceptus subdivides into a set of virtually identical cells, each of which is “totipotent” — capable of giving rise to an embryo. Spontaneous division of the conceptus during this period can lead to the birth of genetically identical twins or triplets. Moreover, it is thought that two originally distinct zygotes sometimes merge, giving rise to a single and otherwise normal embryo. These facts lead some bioethicists to conclude that there is no individuated human organism prior to about fourteen days after fertilization, when the “primitive streak” that will become the spinal cord of the embryo begins to form.[25]


One can see the conclusion Warren draws from her analysis is that “there is no individuated human organism prior to about fourteen days after fertilization.”[26]


Thus, the argument runs as follows. A person may be an individual substance with a rational nature. However, an embryo in the first fourteen days of its existence is not an individual substance, because it can be divided and recombined. If the embryo were an individual substance with a rational nature it could not be divided or recombined. Patrick Lee explains that the argument says an embryo is not an individual after fertilization, but simply a mass of cells.[27] Wolter and Shannon explain:


Because of the possibility of twinning, recombination, and the potency of any cell up to gastrulation to become a complete entity, this particular zygote cannot necessarily be said to be the beginning of a specific, genetically unique individual human being. While the zygote is the beginning of genetically distinct life, it is neither an ontological individual nor necessarily the immediate precursor of one.[28]


Wolter and Shannon’s explanation avoids the problem that arises from saying that one human person can form two persons, which can then recombine back into one person. Thus, postulating a later time for personhood avoids the problems associated with the division and recombination of embryos.  However, another consequence of using a later time for personhood is it causes the embryo’s moral status to change in its earliest period since it is no longer a person. If this argument is successful, the embryo may no longer have the same rights as an adult human person.


Additionally, Werner may point out that positing a human nature as the basis for rights is not empirically verifiable. This argument resonates with many scientists because they feel if something cannot be measured in a laboratory or test tube empirically, then it cannot be true. Thus, the metaphysical speculation that posits a human nature is unfounded empirically.


Werner may also say that basing the embryo’s right to life on its potential to become rational is fallacious. He points out, “Why should it be accorded fully fledged rights, including a right to life? At age 8, I was a potential motorist, a potential property owner, and potentially morally autonomous. But, at age 8, my potential for these did not accord me the right to them…. Those potential rights did not grant me the actual rights in question.”[29] Thus, the potential person should not have the rights of an actual person.




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