Abstract

Harvesting human embryonic stem (hES) cells is a highly controversial field of research because it rests on the destruction of human embryos. Altering the procedure of nuclear transfer (NT) is suggested to generate hES cell lines without ethical obstacles by claiming that no embryo would be involved. While discussing the nature of an embryo and related central questions concerning their moral status and the respect they deserve, this paper argues that the entity created by somatic cell nuclear transfer (SCNT) or altered nuclear transfer (ANT) is an embryo and has the same moral status as a natural embryo. Respect for the embryo is expressed by the ethical principles of proportionality, probability and subsidiarity. This paper argues that the human embryo should only be taken for research with high ranking goals, which are proven in animal experimentation and for which there are no alternatives. This makes ANT obsolete and shows that SCNT to produce hES cells is premature at the present time