It contains two types of cells, but only one of those is destined to become part of the fetus -- the other will form the placenta. So at the blastocyst stage, all the cells which develop into the fetus are undifferentiated.
"Moreover, because therapeutic cloning requires the creation and disaggregation ex utero of blastocyst stage embryos, this technique raises complex ethical questions.""CRNT [cell replacement through nuclear transfer, aka therapeutic cloning] requires the deliberate creation and disaggregation of a human embryo."Robert P. Lanza, Arthur L. Caplan, Lee M. Silver, Jose B. Cibelli, Michael D. West, Ronald M. Green; "The ethical validity of using nuclear transfer in human transplantation"; The Journal of the American Medical Association284, 3175-3179; Dec 27, 2000.
Testimony of Edmund Pellegrino
My name is Edmund D. Pellegrino. I serve currently as professor of medicine and medical ethics at Georgetown University. In my 55 years in medicine, I have worked as a practicing clinician, research scientist, teacher, scholar in ethics and administrator. On the basis of all these experiences, I wish to oppose any relaxation of the current congressional ban on the production and use of living human embryos as the source of embryonic stem cells.
My objection is not directed against research involving multi-potential stem cells per se. The possibilities such cells offer for the replacement or repair of dead or dying cells in a variety of diseased organs is very great. Such research should be vigorously pursued and generously supported by federal and private funds.
My objection is grounded in the ethical impropriety of the deliberate production and destruction of living human embryos for the purpose of harvesting embryonic stem cells from the inner cell mass at the blastocyst stage of their early development. This extraction of the inner cell mass invariably results in the death of the embryo.
Effectively, this method ends the life of a new human being at its most vulnerable stage of existence. The human embryo is a member of the human species, the living result of the fusion of two living human cells. It is imprinted genetically as a unique member of the human species from the moment of conception. At that moment, it is set on its way to becoming a fully developed human adult. To interrupt this process is to violate the moral claim of a human being for protection at its most vulnerable stage. It is laudable to seek better ways to treat human disease and suffering.
But we are not free to use any means we choose. Even the good of others cannot justify the use of human embryos as mere means. The embryo's moral worth is not determined by its instrumental value for others. This would be to absolutize utility and to devalue the lives of all other classes of vulnerable human beings. The societal consequences are grave indeed.
These ethical objections cannot be over-ridden by the claim that the embryo is entitled to a "special respect" but that this respect can be violated if there is sufficient benefit for others. Respect is inherent in the moral status of what the human embryo is in fact. Respect is neither conferred nor removed by arbitrary social convention or convenience.
Nor can the ethical issues be side-stepped by calling the blastocyst a "pre-embryo." This is a euphemism of convenience with no ethical or biological justification. There is no arbitrary point at which we can logically confer or withdraw the moral claim of the embryo for protection of its life.
Moreover, there is genuine and increasing likelihood that the destruction of embryos is not necessary to obtain plutipotential stem cells. Recent work from very respectable scientific laboratories demonstrates the value of plutipotential stem cells from such sources as adult bone marrow (Johns Hopkins); adult human brain (University of Tennessee); neural stem cells (Harvard); muscle, thymus, T-cells, Epithelium stem cells (Tokyo); and autologous bone marrow cells. Use of cells from those sources would be morally defensible, since no living embryos are sacrificed. The effectiveness of these cells appears to equal that of cells obtained by destruction of living human embryos.
Pluripotential stem cells have enormous potential for human benefit, but, like all scientific research, research with these cells must be governed by ethical constraint. Lifting the Congressional ban is not justified logically; it is scientifically premature and unnecessary, and it is morally indefensible. If ethical constraint has any meaning, experiments involving production and destruction of living human embryos must not be done. Indeed, to be ethically sound the Congressional ban should be extended permanently to include privately supported as well as federally supported research involving the production and destruction of living human embryos. Edmund D. Pellegrino, M.D.
The newly conceived individual human being is the director of all the form and function which hallmarks the lifetime of that individual. You've chosen to ignore the actual start of the individual continuum of this individual human life, in favor of characterizing the start of individuality as the point of cell differentiation for the embryonic body, yet the scientific facts proclaim that the differentiation begins at an earlier stage.