Destroying a fertilised egg is not the murder of a person any more than destroying a skin cell is

MANY letters to your paper assert that the fertilised egg is a human being

(ie a person) and, as killing people is wrong, so all interventions from the day after pill to late foetal abortion should remain a crime.

The premise of this argument is faulty. A fertilised egg is no more a human person than a flake of dandruff: both types of cell have all the information (DNA) to produce complete human beings, but they are not themselves human beings yet; they only have the potential to become human beings.

Every skin cell can be used to create a clone of the original animal. This has been done for sheep (Dolly), some dogs and, most recently, monkeys and, in principle, could be done for humans.

So, my dandruff cell could be used to produce my identical twin, separated in time from me, but able to develop into a complete human person distinct from me.

So, is destroying my dandruff equivalent to murdering my identical twin? Of course not.

So, then, destroying a fertilised egg is not murder of a person, any more than destroying a skin cell is.

When does the foetus become a person by reason of its developing complexity? The medieval Church argued it was not until the quickening” — several weeks after conception. Others argue for 21 weeks.

The choice is somewhat arbitrary and subject to debate, but it cannot be from the moment of conception as a single cell, for then skin cells would also have to be granted separate personhood as well.