There was a fascinating exchange on the BBC Radio 4 Today Progrmme last week between Colin Blakemore, former head honcho at the Medical Research Council, and Clifford Longley, billed as a ‘Catholic writer’. It followed immediately after ‘Thought for the Day’, delivered by journalist and broadcaster Indarjit Singh, and dealt with the same topic: changes to the UK’s Human Fertilisation and Embryology Bill. These proposed changes will allow the fusion of human nuclei derived from adult cells with enucleated animal eggs for research purposes. The resulting cell will contain both human nuclear DNA and proteins, and animal cytoplasmic protein together with a small amount of mitochondrial DNA from the original animal egg cell. The amendment has been rather predictably denounced by religious leaders on the grounds that it undermines the ‘sanctity of human life’. Indarjit Singh, in fact, brought up the Nazis in his segment. I can see no particular reason to mention Nazis in this context; they certainly have had no idea of modern genetics or embryology and indeed, demonstrated a rather shaky grasp of science in general. The passing mention seems to serve the function of stirring vague notions that scientists are a bit like Nazis, especially when they do anything with embryos. But I will let that pass for now.

Longley and Blakemore were both more measured. This is possibly because they were debating with another human being rather than having an opportunity to say whatever they liked with no requirement to defend it. It could also be because Blakemore is no embryology expert, and Longley did not want to find himself defending statements made by others for which he can have no responsibility, such as that of the Bishop of Edinburgh, who compared such experiments to Frankenstein’s.

The good Bishop went on to say, “I think most reasonable people would say when you combine an animal embryo and a human embryo that is by definition monstrous.” Really? That is certainly no definition of monstrous that would be recognised by any dictionary. But it is an attempt to tap into deep-seated, if ill-defined, feelings shared by much of the public about purity and, yes, sanctity (of which more below). Now, if we see this in terms of a human/animal hybrid, then that immediately produces images of monsters: the minotaur, say, or the Island of Dr Moreau. It is worth noting that all these horror stories are just that. Stories. As described above, nothing of the sort is happening here and allowing the embryos produced in this research to be implanted, much less carried to term, will remain against the law.

But here’s another story, maybe more in the way of a thought experiment. Imagine if bringing an animal/human hybrid to term were permitted by law. And imagine if a healthy child resulted. How would the church and the other assorted legions of faith treat that child? Presumably as less than human, because he or she would be tainted with mitochondrial DNA of non-human origin. The child in question could have all the attributes we recognise as human, and yet not qualify as such. I think this is the real problem that we’re struggling with here. Much of religion rests on the notion that humans are different from animals – it explains some of the persistent resistance to Darwin’s ideas in the face of a mountain of evidence in their favour. Many people feel very uneasy with the idea that we are animals. But such questions do not, in my view, undermine the sanctity of human life; instead, they force us to think about what we see as human. And indeed, what we mean by the word ‘sanctity’.

Why the use of the word ‘sanctity’? What does it mean? It is not an easily defined word in any truly rigorous way, requiring us to reach for words like ‘sacred’ or ‘holy’, which in turn beg the question of holy according to which authority? But from the way in which it is commonly used we can recognise that it is different from other rather fuzzy words like ‘meaning’ or ‘quality’. One potential synonym is ‘inviolable’; and yet it is interesting that balls of cells lacking nervous systems, experience or the capacity for independent existence are considered worthy of more concern in this regard than the suffering millions of the earth: those living with HIV or other incurable illnesses, or fleeing in the face of genocide, all of whom are hideously capable of experiencing fear, pain and despair.

The question of where the feelings the Bishop is trying to stir up come from is a good one. Some recent research suggests a link between certain moral standpoints associated with conservatism and the emotion of disgust, in particular where purity is concerned. I should at this point declare that I am not easily disgusted, and maybe this has some relevance to my opinion. But what I think is more important is that I understand what the mooted experiments actually involve, and so I see the religious response as being at best ignorant, and at worst mendacious.

Back on the Today programme, Longley put his finger on something. He seemed to be trying to find some common ground between those like him, who see a blastocyst (and, presumably, sperm and ova) as human beings, and those who hold the view I have adumbrated above. He couldn’t see any. And I think he is right. What we do need to do, however, is find a way in which the views of some, unsupported by evidence, are not forced on others. If people do not wish to, there is no requirement for them to have anything to do with these experiments, nor indeed to use any life-saving therapies which could result. But this is not what the cardinals want.

I do not wish to argue with the right of adherents of any faith to believe in their particular beliefs. What I object to is the tendency to take those stories and derive from them universal statements which will limit the rights of others.