WHEN experiments involving human embryos began all those years ago, scientists pretended restraint and moderation.

There would, they assured us, be limits on what would be allowed and mere experiment for experiment's sake would not be permitted to run ahead of moral considerations.

So much for restraint. We are now, less than a generation later, in a position where anything goes. What response could there be except disgust to the news that babies are to be created using aborted foetuses? What greater revulsion could anyone feel upon hearing that it will soon be possible to implant an embryo into a male of the species and, by hormonal treatments, cause him to give birth to a child? And, as if these were not horrors enough, last week we learnt that an American scientist has artificially created an embryo hermaphrodite - a monstrous creature which is part male, part female.

"O world unnatural! How monstrous and unnatural!"

The research scientists, along with the bishops who by their silence give them tacit approval, say that this is "progress" and all to the good because it offers hope of parenthood to those who otherwise would not have that hope. Or that it offers cures for those suffering from otherwise incurable diseases.

That argument misses the point. Because we can do something does not mean we ought to do it. There are some things worse than disease and worse even than death. After all, disease may be borne stoically and death faced courageously. But how can we live with the knowledge that by our depraved and selfish actions we ourselves are no longer fit to be called human beings?

The idea that the end justifies the means is a species of philosophy known as Utilitarianism. It has also been called "Pig Philosophy". According to Utilitarianism, if I believe my aims and purpose are right, there is nothing I cannot do to attain them - including torture and murder. And that can't be right by any moral standard.

The ends do not always justify the means. And in one case in particular, they never justify the means. And that, as the great philosophers and Christ himself taught us, is in our dealings with one another. Classical philosophy and the Jewish and Christian traditions have always told us that we must never treat our fellow human beings as means to an end but as ends in themselves. If we use or kill embryos in the interests of medical therapy or fertilisation treatment, then we are treating the embryos - who are our fellow human beings - as less than human. Bluntly, we are engaging in mutilation and murder for our own self-obsessed purposes and to satisfy the lust for power which goes by the name of "scientific research".

I fear that the more we get ahead of ourselves and discard what is natural and decent and moral and human, and turn to horrific experimentation on our own kind out of a corrupt self-interest, the fiercer in the end will be nature's own judgement on us. And, as a priest, I fear even more terribly the judgement of God.

* Peter Mullen is Rector of St Michael's, Cornhill, in the City of London, and Chaplain to the Stock Exchange.