A certain form of ethical thinking would like to draw absolute limits to human activity. The limits are often said to be natural: nature is replacing God as ultimate moral authority.
Nature is what we believe we still can believe in, when we no longer believe in God.
God thus moves into the human embryo. As its nature, as its potential to develop into a complete human being, he continues to lay down new holy commandments.
The irony is that this attempt to formulate nature’s commandments relies on the same forms of human activity that one wants to delimit. Without human embryo research, no one would know of the existence of the embryo: no one could speculate about its “moral status” and derive moral commandments from it.
This dependence on modern research activities threatens the attempt to discover absolute moral authority in nature. Modern research has disassociated itself from the old speculative ambition to stabilize scientific knowledge as a system. Our present notion of “the embryo” will be outdated tomorrow.
Anyone attempting to speculate about the nature of the embryo – inevitably relying on the existence of embryo research – will have to acknowledge the possibility that these speculations already are obsolete.
The changeability of the modern world thus haunts and destabilizes the tendency to find absolute moral authority in nature.