Madam, - As I spent some time early in my scientific career working in the Department of the Physiology of Reproduction at the Rockefeller Institute, New York, I believe I have something to contribute to the debate on the use and disposal of human embryos, as requested in a recent issue of The Irish Times (July 21st) by Dr Diarmuid Martin, Catholic Archbishop of Dublin.
It seems to me that the wrong question is being asked in the debate. The question is not "When does life begin?" since life in some form is already present in both eggs and sperm.
The question should be: "When does the life of the human individual begin?" And this cannot be earlier than the division of a monozygote which might produce twins.
The question has already been discussed in great detail in the American journal, Science, as early as July 1981 and the most reasonable approach to the question that I could find was to link it with the time of death of an individual, which is usually accepted as the time when the brain ceases to function.
There is no functioning brain in embryos. Like the eggs and sperm cells which are obviously dispensable they have the potential for life - that is all. They have not the individuality of the foetus with a functional brain.
Therefore it is my view that the life of the individual human being begins at this stage of gestation. - Yours, etc,
Prof RODERICK P. KERNAN, Templeogue, Dublin 6W.