A number of philosophers maintain that the destruction of an embryo in the first 2 weeks after fertilization is not morally problematic as it is metaphysically impossible for any human organism to then have existed. We contend that the typical adult human organism was once a zygote so there is no metaphysical shortcut to justify early abortion. We show that five arguments against human organisms ever having been zygotes fail. All of the arguments have to do with one variant or (...) another of the zygote or early embryo dividing. They do not provide any reason to believe that since some adult organisms are not identical to zygotes due to earlier divisions, none could have been. (shrink)

In this essay, I attempt to provide answers to the following four queries concerning the metaphysics of early human embryogenesis. (1) Following its first cellular fission, is it coherent to claim that one and only one of two “blastomeric” twins of a human zygote is identical with that zygote? (2) Following the fusion of two human pre-embryos, is it coherent to claim that one and only one pre-fusion pre-embryo is identical with that postfusion pre-embryo? (3) Does a live human being (...) come into existence only when its brain comes into existence? (4) At implantation, does a pre-embryo become a mere part of its mother? I argue that either if things have quidditative properties or if criterialism is false, then queries (1) and (2) can be answered in the affirmative; that in light of recent developments in theories of human death and in light of a more “functional” theory of brains, query (3) can be answered in the negative; and that plausible mereological principles require a negative answer to query (4). (shrink)

This paper analyzes the transformation from the human zygote to the implanted embryo under the prism of substantial change. After a brief introduction, it vindicates the Aristotelian ideas of substance and accident, and those of substantial and accidental change. It then claims that the transformation from the multicelled zygote to the implanted embryo amounts to a substantial change. Pushing further, it contends that this substantial change cannot be explained following patterns of genetic reductionism, emergence, and self-organization, and proposes Gustavo Bueno’s (...) idea of anamorphosis as a means to encapsulate criticism against such positions. (shrink)

”Merely fact-minded sciences make merely factminded people.”“ …the positivistic concept of science in our time is, historically speaking, a residual concept. It has dropped all the questions which had been considered under the now narrower, now broader concepts of metaphysics….all these ‘metaphysical’ questions, taken broadly – commonly called specifically philosophical questions – surpass the world understood as the universe of mere facts. They surpass it precisely as being questions with the idea of reason in mind. And they all claim a (...) higher dignity than questions of fact, which are subordinated to them even in the order of inquiry. Positivism, in a manner of speaking, decapitates philosophy.”Edmund HusserlIn ethical literature associated with controversies at the beginning and end of human life, there is often a two-part structure: first, basic facts about the topic are presented in a more or less descriptive format, then there is the ethics or policy. (shrink)

The fundamental question I consider is the following: What is it that makes one thing a person and another thing not? I do not provide a complete answer; rather I begin to develop a framework for answering the question. In this essay I do the following: (1) distinguish between the powers possessed by persons and the constitutions of persons, and propose some metaphysical conjectures concerning the relationship between persons' powers and their constitutions; (2) propose for Christians, as well as for (...) others, an hylomorphic soul-body alternative to Cartesianism; (3) highlight some prominent differences between the nature of human persons and the natures of brute animals; and (4) apply this framework for understanding human persons to problems in biomedical ethics concerning the ontological and moral status of human embryos and of the comatose. (shrink)

In some quarters, it is held that Anscombe proved that a zygote is not a human being on the basis of an argument involving the possibility of identical twins, but there is surprisingly little agreement on what her argument is supposed to be. I criticize several extant interpretations, both as interpretations of Anscombe and as self-standing arguments, and offer a different understanding of her conclusion on which the non-specificity of creation processes and their goals is at issue.

Michael Lockwood has recently concluded that it can be morally permissible to perform potentially damaging non-therapeutic experiments on live human (pre)embryos. The reasons he provides in support of this conclusion commit him inter alia to the following controversial theses: (i) an organism's potential for twinning bears critically on the identity conditions for that organism; and (ii) functionally intact mentality-mediating neurological structures play a critical role in establishing the identity conditions for human organisms. I argue that Lockwood has given us no (...) good reason to endorse either of these theses and, hence, that he has given us no good reason to believe that it can be morally permissible to perform potentially damaging non-therapeutic experiments on live human (pre)embryos. (shrink)