Sir

It is regrettable that ethics has been split from science and renamed bioethics. Ethics is an integral part of science. Like science, it requires us to be consistent and empirically justified in our interpretations of the actions of scientists. The ethics of science and science itself share the goal of comprehending in human terms scientists' actions in manipulating the physical world.

The division of science and ethics has been driven by an increasing interest in the actions of scientists by non-scientists. An unfortunate result of this has been a shift away from the consistent and justifiable methodology of science to an approach based on an often ill-defined 'personal philosophy' and 'gut feeling', for instance as described in Correspondence by D. P. Leader: “Reproductive cloning: an attack on human dignity” (Nature 424, 14; 200310.1038/424014c).

Such 'gut feelings' undoubtedly play a part in science but are useless for proper understanding. The reactions of non-specialist observers to complex ethical problems raised by cutting-edge science such as embryonic stem-cell research are no more justified or useful than their opinions about the technical difficulties yet to be overcome. The central issue in the ethical debate surrounding the embryo is not whether it is wrong to kill innocent human beings, but what the embryo and its disaggregation constitutes. The specialist scientific community's familiarity with the facts places it in a privileged position in determining the interpretation or interpretations best supported by the facts.

The rise of bioethics as an independent discipline has resulted in a confrontation between ethics and science that has obscured the similar aims of both. Of considerable concern is the increasingly political and religious nature of bioethics and the power it wields over the direction and progress of science. Science and the ethics of science are two sides of the same coin, dealing with the same empirical data and actions of the same scientists.

As well as thinking of their actions in terms of future experimental design, scientists must explain the significance of their actions in the wider scientific and human contexts. Scientists must take the lead in ensuring that the progress of science is both ethical and as free from political intervention as possible, if for no other reason than that only they can do so.