Leading article: An obscurantist and absurd judgment

No one should doubt the gravity of the ruling by one of the eight advocates general to the European Union's Court of Justice on the issue of stem cells. It looks set to kill off a fledgling bioscience discipline that could revolutionise medicine in the 21st century.

The ruling grew from an objection by Greenpeace in Germany to a patent application from a German scientist who has developed the first clinical applications of stem-cell technology for patients suffering from Parkinson's disease. The cells used were derived from human embryos, and the French advocate general, Yves Bot, has ruled that such cells could develop into a human being and therefore cannot be patented. His judgment would put an end to studies to use stem cells to repair diseased hearts and damaged spines, and to cure blindness.

This view is at odds with the premiss on which British biosciences have proceeded since the Warnock report decided more than 30 years ago that the use of human embryos was permissible so long as the cells used had been fertilised for less than 14 days. If the 13 Grand Chamber judges of the European Court of Justice now endorse Mr Bot's opinion, decades of British research in this field will be jettisoned. The advocate general has ruled that even the blastocyst stage of development, reached around five days after fertilisation, must also be classified as an embryo. His ruling even covers an unfertilised ova whose division has been stimulated by parthenogenesis. Such a ruling is obscurantist.

Mr Bot claims his view has taken account of the philosophical, moral, human and economic issues at stake. It is hard to see how. What he has done is elevate a philosophical precautionary principle to absurd limits which take no account of the harm that will be done to hundreds of thousands of people whose health could benefit from these technologies – nor of the fact that stem cell scientists will shift in their entirety to the United States, depriving Europe of a multimillion-pound industry.

An advocate general's opinion is not binding on the Court of Justice, though judges endorse them in 80 per cent of cases. This is one case in which they must rethink.