Abstract
The ethical issues integral to embryo research and brain death are intertwined with comprehensive views of life that are not explicitly discussed in most policy debate. I consider three representative views – a naturalist, romantic, and theist – and show how these might inform the way practical ethical issues are addressed. I then consider in detail one influential argument in embryo research that attempts to bypass deep values. I show that this twinning argument is deeply flawed. It presupposes naturalist commitments that are at issue in the embryo research debate, and exhibits a blindness to alternative philosophical viewpoints. By considering the work of Hans Driesch, the discoverer of the facts of embryology integral to the twinning argument, I show how the twinning facts are compatible with romantic and theistic accounts that affirm full moral status for the early embryo. While these alternative interpretations might have a tenuous status in current scientific debate, they should be respected in ethical and policy debate