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May 2015 Policy Study, Number 15-4


Embryonic Stem Cell Research Is Morally Wrong


Section V



There are problems with Werner’s probable counter-arguments.  Consider the following reasons offered that twinning, recombination, empirical verifiability, and the potentiality argument does not affect the reasons given in support of the personhood of the early embryo.


First, the fact that the embryo may divide in its earliest stages does not mean it is not an individual substance before it divides. Consider, for example, what happens to a tapeworm when you cut it in half.[30]  The tapeworm is an individual substance before you cut it in half, and it is two individual substances after you cut it. Thus, just because you cut the tapeworm in half, it does not make it less of a substance before or after it is cut in half. In the same way, in the earliest stages of an embryo’s existence, it is an individual substance with a rational nature, and can become two individual substances, each with a rational nature. This is exactly what happens in the case of identical twins. The twins have the exact same DNA, but each has its own rational nature.


Further, Patrick Lee points out that this objection is based on a confusion of the word individual.[31] He writes,


When a person is defined as a certain type of individual, the word means logically undivided, as opposed to a universal or class, where the property or nature is divided among many. The division of the embryo shows only that he or she is physically divisible. Before splitting, the zygote or the two-, four-, or eight-celled embryo is an individual, not a universal. From the fact that A can split into B and C, it simply does not follow, nor does the fact at all suggest, that A was not an individual before the division.[32]


Thus, Lee makes it clear that an individual exists before the division, and from one individual, two individuals may arise.


Secondly, what happens to the early embryo that has divided but recombines? The fact that an embryo in the earliest stage of its existence may recombine does not pose a problem for the substance view of persons. The early embryo that has recombined is an individual substance. Prior to its recombination it was many individual substances. For example, prior to conception, the sperm cell and the ova were individual substances. After conception, the sperm cell and ova are no longer individual substances, but have become one substance, namely, an embryo. Thus, the combination of each substance undergoes a substantial change and becomes a third thing, a new substance.[33]


Werner may object to attributing the personhood of a human to her rational nature because it is not empirically verifiable. He may hold that if science cannot empirically verify the human nature that I am ascribing to all mankind, then such a nature does not exist. However, this assumption is unwarranted because the principle of verifiability, which says all things must be empirically verifiable to be true, is not empirically verifiable and therefore cannot be true. The principle of empirical verifiability is self-stultifying and cannot be used as an objection to positing a human nature.


Last, Werner commits two mistakes in the argument that speaks of the potential future actions of a human. The first is he begs the question regarding the personhood of the embryo. It is only by assuming an embryo is not already a person that allows one to raise this objection. The second mistake is that Werner assumes all rights are equal. The right to life is a fundamental right, whereas the right to drive a car, to drink, and to vote are not. One can recognize this easily by considering the following questions: Does the age of a person affect their right to vote or drink? Does the age of a person affect their right to live? One can see the clear difference between these rights. One is a foundational right that ought to be accorded to all human beings regardless of age. Patrick Lee points out, “The basic right to life is the same as having moral status at all, that is, being the sort of entity that can have rights or entitlements to begin with.”[34] Comparing the right to vote or drive with the right to life is a category mistake. These rights are fundamentally different.




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