Pope Leo XIII (Aeterni Patris, 1879) proclaimed Thomas Aquinas 'Teacher of the Church' to be always closely followed. Aquinas said that abortion of an embryo is not murder but the abortion of a foetus is. He thus approves use of embryo stem cells. Why does Pope Benedict reject Pope Leo and Aquinas?

Gerard Mulholland, Paris, France

Identify an argument with a derided organization and you can successfully chill all discussion. It worked when immigration was identified with the BNP. Now Ms Jardine wants us to equate her own opponents with the hated papists. Be very careful. Her predecessor was 'duty-to-die' Warnock.

S. Harvey, Lausanne, Switzerland

We must either admit that human life starts at conception (as the Catholic Church holds), and protect it, or descend further into the scientific lunacy we now find ourselves in. After all, 20 years ago, no-one would have believed that human embryos would be allowed. How much further are we going

RB, Aberdeen,

If you leave a human baby untended for a couple of days it can't survive either. Does this mean we should abort it? How many 10 year olds can get by without their mums? Are they abortable? Here in Spain, grown thirtysomethings don't fly the nest. Should we abort them?

Penelope, Barcelona, Spain

Catholics form a certain strong percentage of those with grave reservations about the morality of human fertilisation proposals. It is unwise to see the opposition as just coming from Catholics. There's an ingrained moral sense in us all. We need to allow it to breathe.

Father Bryan Storey, Tintagel, UK

God draws good from disasters. This life is only a small part of living. Condoms undermine human love by making birth control cosmetic.

Father Bryan Storey, Tintagel, UK

Look, any MP should be free to vote his or her own conscience. And their constituents should make note and decide whether or not to re-elect him or her. Unless I am very mistaken the number of MPs opposing embryonic research is but a small fraction of the total number of MPs in Westminster.

Robert Sieger, London, UK

How does Iain Rae know cows don't worship supernatural gods? Can he speak 'cow'?

Frances, Lee,

we have much to learn from our cow cousins, they are peaceful animals and don't worship supernatural gods.

iain rae, tunbridge wells, U.K.

We kill animals, we destroy life, on the basis that this life is not intellegent, surely a human embro, in the first few weeks, is equelly low in intellegence. Why should we treat our own species with any more kindness, after all, are we not all gods cretures?

Andrew Curran, Manchester, UK

Research throughout the years has always come under scrutiny and the church always opposes advancement in medicine. This research is essential and anyone who has known someone with these dreadful diseases welcomes stem cell research. As always the Catholic Church wants to bury its head in the sand

Gil, Bristol, England

MPs should represent their constituents, not their religion. Is it now legitimate to decide not to vote for an MP because they are catholic?

Andrew, Cambrudge,

I don't even know where to begin. Those arguing against the position taken by Catholic members offer empty positions and name calling as alternates to level-headed, human-centric, self-respecting positions held by the Catholic & other Christian or simply well-founded, conscientious members.

David, St. Louis, Missouri, USA

The RC church have proved so out of touch that their views must surely be ignored. Having seen at first hand the havoc wreaked upon a country still dominated by them and it's ignorance (my wife is a filipino) we need to treat them as outcasts in the same way we do any fundamentalists.

David N House, Wisbech, UK

I really wonder, how do devout catholics like Ruth Kelly reconcile their belief in a 'loving god' with natural disasters like the cyclone in Burma? Is there a logical answer?! Similarly, religious views on the ethics of stem cell research.

Derek, Lewes, UK

It is far from just the Catholic Church that have a problem with this bill- I am writing a piece about it and the same reaction has been given by the Church of England and numerous Christian churches (Evangelical included). The Catholic Church are just the ones shouting loud enough to be heard.

Nicola, Cumbria,

Stem sell research is essential for sufferers of Parkinson's and Motor Neurone disease. It gives hope even if the results will not benefit themselves.
Th Catholic resistance to condoms is a major problem when fighting the spread of Aids. A malignant religion, among others.

jane, Whittlesey, Cambs

Organised religions rely on doctrine but it is questionable whether that doctrine has any historical provenance or has high standards of morality and ethics and indeed some of the practise of organised religions is against the law. We cannot run the nation, or make law, on the basis of the unproven.

Keith, Rayleigh, Essex

I do not understand the Roman Catholic Church's opposition to stem cell research. Around a quarter of embryos abort naturally in the mother's womb, and the law requires that the microscopic stem cells created be destroyed within a short specified period. We should not deny ill people treatment.

Des, Edinburgh,

The Catholic Church is right: there is great moral repugnance to this bill. If people could vote in a referendum it would be defeated. But their Bishops let Catholics down by choosing Tony Blair who promoted this bill, as a main speaker in Westminster Cathedral and supporting left-wing causes.

George , Bolton, England

I'm very disappointed that the Catholic Church has to be given ears about this issue. This kind of research has so much potential to help people, and still, dogmatic ignorants like the Church are allowed a say in Government matters.

Flavio Zanchi, London,

The opposition is to the use of humans as an experimental model organism. There is no inherent scientific interest in human embryos specifically. The reasons for the proposed research are wholly pragmatic, and in fact by lessening respect for human life it will not contribute to human welfare.

Malcolm McLean, Bradford, UK